Last data update: Nov 04, 2024. (Total: 48056 publications since 2009)
Records 1-28 (of 28 Records) |
Query Trace: Sawatwong P[original query] |
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Demographic and clinical factors associated with bacterial or nonbacterial etiologies of acute undifferentiated febrile illness: Findings from a 3-year observational study in Thailand, 2017-2020
Wodniak NR , Bhengsri S , Skaggs B , Uttayamakul S , Sawatwong P , Sangwichian O , Gregory CJ , Chuenchom N , Peanumlom P , Khemla S , Lertwitayakumjorn T , Chaoprasert S , Piralam B , Simmali T , Chara C , Bloss E , MacArthur JR , Heffelfinger JD . Am J Trop Med Hyg 2024 111 (3) 650-660 Acute undifferentiated febrile illness (AUFI) is often undiagnosed in Thailand, resulting in delayed or ineffective treatment. We compared the demographic, exposure history, and clinical characteristics of AUFI patients with laboratory evidence of bacterial and nonbacterial pathogens. Patients aged 2-80 years presenting to 12 hospitals in Nakhon Phanom and Tak provinces were enrolled from April 2017 through May 2020. Interviews were conducted and blood, urine, and sputum were collected for culture as well as rapid diagnostic and molecular testing. A total of 1,263 patients tested positive for one or more bacterial, viral, or parasitic pathogens and were included in the analysis. Multivariable logistic regression was performed to compare factors associated with bacterial infections versus nonbacterial infections. Bacterial infections were more commonly identified in participants from Nakhon Phanom than Tak. Bacterial infections were independently associated with several factors including age ≥50 years (adjusted odds ratio [95% CI]): (4.18 [2.85-6.14]), contact with farm animals (1.82 [1.29-2.57]), antibiotic use within 72 hours of hospital presentation (2.37 [1.50-3.74]), jaundice (2.31 [1.15-4.63]), existing comorbidities (2.77 [1.93-3.96]), contact with febrile individuals (0.42 [0.31-0.57]), muscle pain (0.44 [0.31-0.64]), and rash (0.45 [0.29-0.70]). Bacterial infections were also associated with longer hospitalization (2.75 [2.08-3.64]) and lower odds of recovery at the time of discharge (0.14 [0.07-0.31]). Consideration of patient characteristics and signs/symptoms may help to inform targeted laboratory testing for suspected infectious etiologies. Understanding factors associated with bacterial and non-bacterial causes of AUFI may aid diagnosis and judicious use of antibiotics in resource-limited settings. |
Characteristics, risk factors, and outcomes related to Zika virus infection during pregnancy in Northeastern Thailand: A prospective pregnancy cohort study, 2018-2020
Wongsawat J , Thamthitiwat S , Hicks VJ , Uttayamakul S , Teepruksa P , Sawatwong P , Skaggs B , Mock PA , MacArthur JR , Suya I , Sapchookul P , Kitsutani P , Lo TQ , Vachiraphan A , Kovavisarach E , Rhee C , Darun P , Saepueng K , Waisaen C , Jampan D , Sriboonrat P , Palanuwong B , Sukbut P , Areechokchai D , Pittayawonganon C , Iamsirithaworn S , Bloss E , Rao CY . PLoS Negl Trop Dis 2024 18 (5) e0012176 BACKGROUND: In response to the 2015-2016 Zika virus (ZIKV) outbreak and the causal relationship established between maternal ZIKV infection and adverse infant outcomes, we conducted a cohort study to estimate the incidence of ZIKV infection in pregnancy and assess its impacts in women and infants. METHODOLOGY/PRINCIPAL FINDINGS: From May 2018-January 2020, we prospectively followed pregnant women recruited from 134 participating hospitals in two non-adjacent provinces in northeastern Thailand. We collected demographic, clinical, and epidemiologic data and blood and urine at routine antenatal care visits until delivery. ZIKV infections were confirmed by real-time reverse transcriptase polymerase chain reaction (rRT-PCR). Specimens with confirmed ZIKV underwent whole genome sequencing. Among 3,312 women enrolled, 12 (0.36%) had ZIKV infections, of which two (17%) were detected at enrollment. Ten (83%, 3 in 2nd and 7 in 3rd trimester) ZIKV infections were detected during study follow-up, resulting in an infection rate of 0.15 per 1,000 person-weeks (95% CI: 0.07-0.28). The majority (11/12, 91.7%) of infections occurred in one province. Persistent ZIKV viremia (42 days) was found in only one woman. Six women with confirmed ZIKV infections were asymptomatic until delivery. Sequencing of 8 ZIKV isolates revealed all were of Asian lineage. All 12 ZIKV infected women gave birth to live, full-term infants; the only observed adverse birth outcome was low birth weight in one (8%) infant. Pregnancies in 3,300 ZIKV-rRT-PCR-negative women were complicated by 101 (3%) fetal deaths, of which 67 (66%) had miscarriages and 34 (34%) had stillbirths. There were no differences between adverse fetal or birth outcomes of live infants born to ZIKV-rRT-PCR-positive mothers compared to live infants born to ZIKV-rRT-PCR-negative mothers. CONCLUSIONS/SIGNIFICANCE: Confirmed ZIKV infections occurred infrequently in this large pregnancy cohort and observed adverse maternal and birth outcomes did not differ between mothers with and without confirmed infections. |
Causes of severe pneumonia requiring hospital admission in children without HIV infection from Africa and Asia: the PERCH multi-country case-control study
Pneumonia Etiology Research for Child Health Study Group , O'Brien Katherine L , Levine Orin S , Knoll Maria Deloria , Feikin Daniel R , DeLuca Andrea N , Driscoll Amanda J , Fancourt Nicholas , Fu Wei , Haddix Meredith , Hammitt Laura L , Higdon Melissa M , Kagucia E Wangeci , Karron Ruth A , Li Mengying , Park Daniel E , Prosperi Christine , Shi Qiyuan , Wu Zhenke , Zeger Scott L , Watson Nora L , Crawley Jane , Murdoch David R , Brooks W Abdullah , Endtz Hubert P , Zaman Khalequ , Goswami Doli , Hossain Lokman , Jahan Yasmin , Chisti Mohammod Jobayer , Howie Stephen R C , Ebruke Bernard E , Antonio Martin , McLellan Jessica L , Machuka Eunice M , Shamsul Arifin , Zaman Syed M A , Mackenzie Grant , Scott J Anthony G , Awori Juliet O , Morpeth Susan C , Kamau Alice , Kazungu Sidi , Ominde Micah Silaba , Kotloff Karen L , Tapia Milagritos D , Sow Samba O , Sylla Mamadou , Tamboura Boubou , Onwuchekwa Uma , Kourouma Nana , Toure Aliou , Sissoko Seydou , Madhi Shabir A , Moore David P , Adrian Peter V , Baillie Vicky L , Kuwanda Locadiah , Mudau Azwifarwi , Groome Michelle J , Mahomed Nasreen , Simões Eric A F , Baggett Henry C , Thamthitiwat Somsak , Maloney Susan A , Bunthi Charatdao , Rhodes Julia , Sawatwong Pongpun , Akarasewi Pasakorn , Thea Donald M , Mwananyanda Lawrence , Chipeta James , Seidenberg Phil , Mwansa James , Somwe Somwe Wa , Kwenda Geoffrey , Anderson Trevor P , Mitchell Joanne L . Lancet 2019 394 (10200) 757-779 BACKGROUND: Pneumonia is the leading cause of death among children younger than 5 years. In this study, we estimated causes of pneumonia in young African and Asian children, using novel analytical methods applied to clinical and microbiological findings. METHODS: We did a multi-site, international case-control study in nine study sites in seven countries: Bangladesh, The Gambia, Kenya, Mali, South Africa, Thailand, and Zambia. All sites enrolled in the study for 24 months. Cases were children aged 1-59 months admitted to hospital with severe pneumonia. Controls were age-group-matched children randomly selected from communities surrounding study sites. Nasopharyngeal and oropharyngeal (NP-OP), urine, blood, induced sputum, lung aspirate, pleural fluid, and gastric aspirates were tested with cultures, multiplex PCR, or both. Primary analyses were restricted to cases without HIV infection and with abnormal chest x-rays and to controls without HIV infection. We applied a Bayesian, partial latent class analysis to estimate probabilities of aetiological agents at the individual and population level, incorporating case and control data. FINDINGS: Between Aug 15, 2011, and Jan 30, 2014, we enrolled 4232 cases and 5119 community controls. The primary analysis group was comprised of 1769 (41·8% of 4232) cases without HIV infection and with positive chest x-rays and 5102 (99·7% of 5119) community controls without HIV infection. Wheezing was present in 555 (31·7%) of 1752 cases (range by site 10·6-97·3%). 30-day case-fatality ratio was 6·4% (114 of 1769 cases). Blood cultures were positive in 56 (3·2%) of 1749 cases, and Streptococcus pneumoniae was the most common bacteria isolated (19 [33·9%] of 56). Almost all cases (98·9%) and controls (98·0%) had at least one pathogen detected by PCR in the NP-OP specimen. The detection of respiratory syncytial virus (RSV), parainfluenza virus, human metapneumovirus, influenza virus, S pneumoniae, Haemophilus influenzae type b (Hib), H influenzae non-type b, and Pneumocystis jirovecii in NP-OP specimens was associated with case status. The aetiology analysis estimated that viruses accounted for 61·4% (95% credible interval [CrI] 57·3-65·6) of causes, whereas bacteria accounted for 27·3% (23·3-31·6) and Mycobacterium tuberculosis for 5·9% (3·9-8·3). Viruses were less common (54·5%, 95% CrI 47·4-61·5 vs 68·0%, 62·7-72·7) and bacteria more common (33·7%, 27·2-40·8 vs 22·8%, 18·3-27·6) in very severe pneumonia cases than in severe cases. RSV had the greatest aetiological fraction (31·1%, 95% CrI 28·4-34·2) of all pathogens. Human rhinovirus, human metapneumovirus A or B, human parainfluenza virus, S pneumoniae, M tuberculosis, and H influenzae each accounted for 5% or more of the aetiological distribution. We observed differences in aetiological fraction by age for Bordetella pertussis, parainfluenza types 1 and 3, parechovirus-enterovirus, P jirovecii, RSV, rhinovirus, Staphylococcus aureus, and S pneumoniae, and differences by severity for RSV, S aureus, S pneumoniae, and parainfluenza type 3. The leading ten pathogens of each site accounted for 79% or more of the site's aetiological fraction. INTERPRETATION: In our study, a small set of pathogens accounted for most cases of pneumonia requiring hospital admission. Preventing and treating a subset of pathogens could substantially affect childhood pneumonia outcomes. FUNDING: Bill & Melinda Gates Foundation. |
Enhancing respiratory disease surveillance to detect COVID-19 in shelters for displaced persons, Thailand-Myanmar border, 2020-2021
Knust B , Wongjindanon N , Moe AA , Herath L , Kaloy W , Soe TT , Sataranon P , Oo HM , Myat KZ , Win Z , Htet M , Htike M , Sudhiprapha B , Pyone AA , Win TP , Win HZ , Sawatwong P , Watthanaworawit W , Ling C , Gunaratne S , Lynn SA , Bhandari L , Nosten F , Skaggs B . Emerg Infect Dis 2022 28 (13) S17-s25 We developed surveillance guidance for COVID-19 in 9 temporary camps for displaced persons along the Thailand-Myanmar border. Arrangements were made for testing of persons presenting with acute respiratory infection, influenza-like illness, or who met the Thailand national COVID-19 Person Under Investigation case definition. In addition, testing was performed for persons who had traveled outside of the camps in outbreak-affected areas or who departed Thailand as resettling refugees. During the first 18 months of surveillance, May 2020-October 2021, a total of 6,190 specimens were tested, and 15 outbreaks (i.e., >1 confirmed COVID-19 cases) were detected in 7 camps. Of those, 5 outbreaks were limited to a single case. Outbreaks during the Delta variant surge were particularly challenging to control. Adapting and implementing COVID-19 surveillance measures in the camp setting were successful in detecting COVID-19 outbreaks and preventing widespread disease during the initial phase of the pandemic in Thailand. |
Etiology and clinical characteristics of severe pneumonia among young children in Thailand: Pneumonia Etiology Research for Child Health (PERCH) case-control study findings, 2012-2013
Bunthi C , Rhodes J , Thamthitiwat S , Higdon MM , Chuananon S , Amorninthapichet T , Paveenkittiporn W , Chittaganpitch M , Sawatwong P , Hammitt LL , Feikin DR , Murdoch DR , Deloria-Knoll M , O'Brien KL , Prosperi C , Maloney SA , Baggett HC , Akarasewi P . Pediatr Infect Dis J 2021 40 S91-s100 BACKGROUND: Pneumonia remains the leading cause of death among children <5 years of age beyond the neonatal period in Thailand. Using data from the Pneumonia Etiology Research for Child Health (PERCH) Study, we provide a detailed description of pneumonia cases and etiology in Thailand to inform local treatment and prevention strategies in this age group. METHODS: PERCH, a multi-country case-control study, evaluated the etiology of hospitalized cases of severe and very severe pneumonia among children 1-59 months of age. The Thailand site enrolled children for 24 consecutive months during January 2012-February 2014 with staggered start dates in 2 provinces. Cases were children hospitalized with pre-2013 WHO-defined severe or very severe pneumonia. Community controls were randomly selected from health services registries in each province. Analyses were restricted to HIV-negative cases and controls. We calculated adjusted odds ratios (ORs) and 95% CIs comparing organism prevalence detected by nasopharyngeal/oropharyngeal (NP/OP) polymerase chain reaction between cases and controls. The PERCH Integrated Analysis (PIA) used Bayesian latent variable analysis to estimate pathogen-specific etiologic fractions and 95% credible intervals. RESULTS: Over 96% of both cases (n = 223) and controls (n = 659) had at least 1 organism detected; multiple organisms were detected in 86% of cases and 88% of controls. Among 98 chest Radiograph positive (CXR+) cases, respiratory syncytial virus (RSV) had the highest NP/OP prevalence (22.9%) and the strongest association with case status (OR 20.5; 95% CI: 10.2, 41.3) and accounted for 34.6% of the total etiologic fraction. Tuberculosis (TB) accounted for 10% (95% CrI: 1.6-26%) of the etiologic fraction among CXR+ cases. DISCUSSION: More than one-third of hospitalized cases of severe and very severe CXR+ pneumonia among children 1-59 months of age in Thailand were attributable to RSV. TB accounted for 10% of cases, supporting evaluation for TB among children hospitalized with pneumonia in high-burden settings. Similarities in pneumonia etiology in Thailand and other PERCH sites suggest that global control strategies based on PERCH study findings are relevant to Thailand and similar settings. |
Epidemiology of the Rhinovirus (RV) in African and Southeast Asian Children: A Case-Control Pneumonia Etiology Study
Baillie VL , Moore DP , Mathunjwa A , Baggett HC , Brooks A , Feikin DR , Hammitt LL , Howie SRC , Knoll MD , Kotloff KL , Levine OS , O'Brien KL , Scott AG , Thea DM , Antonio M , Awori JO , Driscoll AJ , Fancourt NSS , Higdon MM , Karron RA , Morpeth SC , Mulindwa JM , Murdoch DR , Park DE , Prosperi C , Rahman MZ , Rahman M , Salaudeen RA , Sawatwong P , Somwe SW , Sow SO , Tapia MD , Simões EAF , Madhi SA . Viruses 2021 13 (7) Rhinovirus (RV) is commonly detected in asymptomatic children; hence, its pathogenicity during childhood pneumonia remains controversial. We evaluated RV epidemiology in HIV-uninfected children hospitalized with clinical pneumonia and among community controls. PERCH was a case-control study that enrolled children (1-59 months) hospitalized with severe and very severe pneumonia per World Health Organization clinical criteria and age-frequency-matched community controls in seven countries. Nasopharyngeal/oropharyngeal swabs were collected for all participants, combined, and tested for RV and 18 other respiratory viruses using the Fast Track multiplex real-time PCR assay. RV detection was more common among cases (24%) than controls (21%) (aOR = 1.5, 95%CI:1.3-1.6). This association was driven by the children aged 12-59 months, where 28% of cases vs. 18% of controls were RV-positive (aOR = 2.1, 95%CI:1.8-2.5). Wheezing was 1.8-fold (aOR 95%CI:1.4-2.2) more prevalent among pneumonia cases who were RV-positive vs. RV-negative. Of the RV-positive cases, 13% had a higher probability (>75%) that RV was the cause of their pneumonia based on the PERCH integrated etiology analysis; 99% of these cases occurred in children over 12 months in Bangladesh. RV was commonly identified in both cases and controls and was significantly associated with severe pneumonia status among children over 12 months of age, particularly those in Bangladesh. RV-positive pneumonia was associated with wheezing. |
Global burden of acute lower respiratory infection associated with human parainfluenza virus in children younger than 5 years for 2018: a systematic review and meta-analysis
Wang X , Li Y , Deloria-Knoll M , Madhi SA , Cohen C , Arguelles VL , Basnet S , Bassat Q , Brooks WA , Echavarria M , Fasce RA , Gentile A , Goswami D , Homaira N , Howie SRC , Kotloff KL , Khuri-Bulos N , Krishnan A , Lucero MG , Lupisan S , Mathisen M , McLean KA , Mira-Iglesias A , Moraleda C , Okamoto M , Oshitani H , O'Brien KL , Owor BE , Rasmussen ZA , Rath BA , Salimi V , Sawatwong P , Scott JAG , Simões EAF , Sotomayor V , Thea DM , Treurnicht FK , Yoshida LM , Zar HJ , Campbell H , Nair H . Lancet Glob Health 2021 9 (8) e1077-e1087 BACKGROUND: Human parainfluenza virus (hPIV) is a common virus in childhood acute lower respiratory infections (ALRI). However, no estimates have been made to quantify the global burden of hPIV in childhood ALRI. We aimed to estimate the global and regional hPIV-associated and hPIV-attributable ALRI incidence, hospital admissions, and mortality for children younger than 5 years and stratified by 0-5 months, 6-11 months, and 12-59 months of age. METHODS: We did a systematic review of hPIV-associated ALRI burden studies published between Jan 1, 1995, and Dec 31, 2020, found in MEDLINE, Embase, Global Health, Cumulative Index to Nursing and Allied Health Literature, Web of Science, Global Health Library, three Chinese databases, and Google search, and also identified a further 41 high-quality unpublished studies through an international research network. We included studies reporting community incidence of ALRI with laboratory-confirmed hPIV; hospital admission rates of ALRI or ALRI with hypoxaemia in children with laboratory-confirmed hPIV; proportions of patients with ALRI admitted to hospital with laboratory-confirmed hPIV; or in-hospital case-fatality ratios (hCFRs) of ALRI with laboratory-confirmed hPIV. We used a modified Newcastle-Ottawa Scale to assess risk of bias. We analysed incidence, hospital admission rates, and hCFRs of hPIV-associated ALRI using a generalised linear mixed model. Adjustment was made to account for the non-detection of hPIV-4. We estimated hPIV-associated ALRI cases, hospital admissions, and in-hospital deaths using adjusted incidence, hospital admission rates, and hCFRs. We estimated the overall hPIV-associated ALRI mortality (both in-hospital and out-hospital mortality) on the basis of the number of in-hospital deaths and care-seeking for child pneumonia. We estimated hPIV-attributable ALRI burden by accounting for attributable fractions for hPIV in laboratory-confirmed hPIV cases and deaths. Sensitivity analyses were done to validate the estimates of overall hPIV-associated ALRI mortality and hPIV-attributable ALRI mortality. The systematic review protocol was registered on PROSPERO (CRD42019148570). FINDINGS: 203 studies were identified, including 162 hPIV-associated ALRI burden studies and a further 41 high-quality unpublished studies. Globally in 2018, an estimated 18·8 million (uncertainty range 12·8-28·9) ALRI cases, 725 000 (433 000-1 260 000) ALRI hospital admissions, and 34 400 (16 400-73 800) ALRI deaths were attributable to hPIVs among children younger than 5 years. The age-stratified and region-stratified analyses suggested that about 61% (35% for infants aged 0-5 months and 26% for 6-11 months) of the hospital admissions and 66% (42% for infants aged 0-5 months and 24% for 6-11 months) of the in-hospital deaths were in infants, and 70% of the in-hospital deaths were in low-income and lower-middle-income countries. Between 73% and 100% (varying by outcome) of the data had a low risk in study design; the proportion was 46-65% for the adjustment for health-care use, 59-77% for patient groups excluded, 54-93% for case definition, 42-93% for sampling strategy, and 67-77% for test methods. Heterogeneity in estimates was found between studies for each outcome. INTERPRETATION: We report the first global burden estimates of hPIV-associated and hPIV-attributable ALRI in young children. Globally, approximately 13% of ALRI cases, 4-14% of ALRI hospital admissions, and 4% of childhood ALRI mortality were attributable to hPIV. These numbers indicate a potentially notable burden of hPIV in ALRI morbidity and mortality in young children. These estimates should encourage and inform investment to accelerate the development of targeted interventions. FUNDING: Bill & Melinda Gates Foundation. |
Pneumococcal colonization prevalence and density among Thai children with severe pneumonia and community controls
Piralam B , Prosperi C , Thamthitiwat S , Bunthi C , Sawatwong P , Sangwichian O , Higdon MM , Watson NL , Deloria Knoll M , Paveenkittiporn W , Chara C , Hurst CP , Akarasewi P , Rhodes J , Maloney SA , O'Brien KL , Baggett HC . PLoS One 2020 15 (4) e0232151 BACKGROUND: Pneumococcal colonization prevalence and colonization density, which has been associated with invasive disease, can offer insight into local pneumococcal ecology and help inform vaccine policy discussions. METHODS: The Pneumonia Etiology Research for Child Health Project (PERCH), a multi-country case-control study, evaluated the etiology of hospitalized cases of severe and very severe pneumonia among children aged 1-59 months. The PERCH Thailand site enrolled children during January 2012-February 2014. We determined pneumococcal colonization prevalence and density, and serotype distribution of colonizing isolates. RESULTS: We enrolled 224 severe/very severe pneumonia cases and 659 community controls in Thailand. Compared to controls, cases had lower colonization prevalence (54.5% vs. 62.5%, p = 0.12) and lower median colonization density (42.1 vs. 210.2 x 103 copies/mL, p <0.0001); 42% of cases had documented antibiotic pretreatment vs. 0.8% of controls. In no sub-group of assessed cases did pneumococcal colonization density exceed the median for controls, including cases with no prior antibiotics (63.9x103 copies/mL), with consolidation on chest x-ray (76.5x103 copies/mL) or with pneumococcus detected in whole blood by PCR (9.3x103 copies/mL). Serotype distribution was similar among cases and controls, and a high percentage of colonizing isolates from cases and controls were serotypes included in PCV10 (70.0% and 61.8%, respectively) and PCV13 (76.7% and 67.9%, respectively). CONCLUSIONS: Pneumococcal colonization is common among children aged <5 years in Thailand. However, colonization density was not higher among children with severe pneumonia compared to controls. These results can inform discussions about PCV introduction and provide baseline data to monitor PCV impact after introduction in Thailand. |
Identification of Gram negative non-fermentative bacteria: How hard can it be?
Whistler T , Sangwichian O , Jorakate P , Sawatwong P , Surin U , Piralam B , Thamthitiwat S , Promkong C , Peruski L . PLoS Negl Trop Dis 2019 13 (9) e0007729 INTRODUCTION: The prevalence of bacteremia caused by Gram negative non-fermentative (GNNF) bacteria has been increasing globally over the past decade. Many studies have investigated their epidemiology but focus on the common GNNF including Pseudomonas aeruginosa and Acinetobacter baumannii. Knowledge of the uncommon GNNF bacteremias is very limited. This study explores invasive bloodstream infection GNNF isolates that were initially unidentified after testing with standard microbiological techniques. All isolations were made during laboratory-based surveillance activities in two rural provinces of Thailand between 2006 and 2014. METHODS: A subset of GNNF clinical isolates (204/947), not identified by standard manual biochemical methodologies were run on the BD Phoenix automated identification and susceptibility testing system. If an organism was not identified (12/204) DNA was extracted for whole genome sequencing (WGS) on a MiSeq platform and data analysis performed using 3 web-based platforms: Taxonomer, CGE KmerFinder and One Codex. RESULTS: The BD Phoenix automated identification system recognized 92% (187/204) of the GNNF isolates, and because of their taxonomic complexity and high phenotypic similarity 37% (69/187) were only identified to the genus level. Five isolates grew too slowly for identification. Antimicrobial sensitivity (AST) data was not obtained for 93/187 (50%) identified isolates either because of their slow growth or their taxa were not in the AST database associated with the instrument. WGS identified the 12 remaining unknowns, four to genus level only. CONCLUSION: The GNNF bacteria are of increasing concern in the clinical setting, and our inability to identify these organisms and determine their AST profiles will impede treatment. Databases for automated identification systems and sequencing annotation need to be improved so that opportunistic organisms are better covered. |
One hypervirulent clone, sequence type 283, accounts for a large proportion of invasive Streptococcus agalactiae isolated from humans and diseased tilapia in Southeast Asia.
Barkham T , Zadoks RN , Azmai MNA , Baker S , Bich VTN , Chalker V , Chau ML , Dance D , Deepak RN , van Doorn HR , Gutierrez RA , Holmes MA , Huong LNP , Koh TH , Martins E , Mehershahi K , Newton P , Ng LC , Phuoc NN , Sangwichian O , Sawatwong P , Surin U , Tan TY , Tang WY , Thuy NV , Turner P , Vongsouvath M , Zhang D , Whistler T , Chen SL . PLoS Negl Trop Dis 2019 13 (6) e0007421 BACKGROUND: In 2015, Singapore had the first and only reported foodborne outbreak of invasive disease caused by the group B Streptococcus (GBS; Streptococcus agalactiae). Disease, predominantly septic arthritis and meningitis, was associated with sequence type (ST)283, acquired from eating raw farmed freshwater fish. Although GBS sepsis is well-described in neonates and older adults with co-morbidities, this outbreak affected non-pregnant and younger adults with fewer co-morbidities, suggesting greater virulence. Before 2015 ST283 had only been reported from twenty humans in Hong Kong and two in France, and from one fish in Thailand. We hypothesised that ST283 was causing region-wide infection in Southeast Asia. METHODOLOGY/PRINCIPAL FINDINGS: We performed a literature review, whole genome sequencing on 145 GBS isolates collected from six Southeast Asian countries, and phylogenetic analysis on 7,468 GBS sequences including 227 variants of ST283 from humans and animals. Although almost absent outside Asia, ST283 was found in all invasive Asian collections analysed, from 1995 to 2017. It accounted for 29/38 (76%) human isolates in Lao PDR, 102/139 (73%) in Thailand, 4/13 (31%) in Vietnam, and 167/739 (23%) in Singapore. ST283 and its variants were found in 62/62 (100%) tilapia from 14 outbreak sites in Malaysia and Vietnam, in seven fish species in Singapore markets, and a diseased frog in China. CONCLUSIONS: GBS ST283 is widespread in Southeast Asia, where it accounts for a large proportion of bacteraemic GBS, and causes disease and economic loss in aquaculture. If human ST283 is fishborne, as in the Singapore outbreak, then GBS sepsis in Thailand and Lao PDR is predominantly a foodborne disease. However, whether transmission is from aquaculture to humans, or vice versa, or involves an unidentified reservoir remains unknown. Creation of cross-border collaborations in human and animal health are needed to complete the epidemiological picture. |
Pneumococcal pneumonia prevalence among adults with severe acute respiratory illness in Thailand - comparison of Bayesian latent class modeling and conventional analysis
Lu Y , Joseph L , Belisle P , Sawatwong P , Jatapai A , Whistler T , Thamthitiwat S , Paveenkittiporn W , Khemla S , Van Beneden CA , Baggett HC , Gregory CJ . BMC Infect Dis 2019 19 (1) 423 BACKGROUND: Determining the etiology of pneumonia is essential to guide public health interventions. Diagnostic test results, including from polymerase chain reaction (PCR) assays of upper respiratory tract specimens, have been used to estimate prevalence of pneumococcal pneumonia. However limitations in test sensitivity and specificity and the specimen types available make establishing a definitive diagnosis challenging. Prevalence estimates for pneumococcal pneumonia could be biased in the absence of a true gold standard reference test for detecting Streptococcus pneumoniae. METHODS: We conducted a case control study to identify etiologies of community acquired pneumonia (CAP) from April 2014 through August 2015 in Thailand. We estimated the prevalence of pneumococcal pneumonia among adults hospitalized for CAP using Bayesian latent class models (BLCMs) incorporating results of real-time polymerase chain reaction (qPCR) testing of upper respiratory tract specimens and a urine antigen test (UAT) from cases and controls. We compared the prevalence estimate to conventional analyses using only UAT as a reference test. RESULTS: The estimated prevalence of pneumococcal pneumonia was 8% (95% CI: 5-11%) by conventional analyses. By BLCM, we estimated the prevalence to be 10% (95% CrI: 7-16%) using binary qPCR and UAT results, and 11% (95% CrI: 7-17%) using binary UAT results and qPCR cycle threshold (Ct) values. CONCLUSIONS: BLCM suggests a > 25% higher prevalence of pneumococcal pneumonia than estimated by a conventional approach assuming UAT as a gold standard reference test. Higher quantities of pneumococcal DNA in the upper respiratory tract were associated with pneumococcal pneumonia in adults but the addition of a second specific pneumococcal test was required to accurately estimate disease status and prevalence. By incorporating the inherent uncertainty of diagnostic tests, BLCM can obtain more reliable estimates of disease status and improve understanding of underlying etiology. |
High burden of extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae bacteremia in older adults: A seven-year study in two rural Thai provinces
Sawatwong P , Sapchookul P , Whistler T , Gregory CJ , Sangwichian O , Makprasert S , Jorakate P , Srisaengchai P , Thamthitiwat S , Promkong C , Nanvatthanachod P , Vanaporn M , Rhodes J . Am J Trop Med Hyg 2019 100 (4) 943-951 Bloodstream infection surveillance conducted from 2008 to 2014 in all 20 hospitals in Sa Kaeo and Nakhon Phanom provinces, Thailand, allowed us to look at disease burden, antibiotic susceptibilities, and recurrent infections caused by extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae. Of 97,832 blood specimens, 3,338 were positive for E. coli and 1,086 for K. pneumoniae. The proportion of E. coli isolates producing ESBL significantly increased from 19% to 22% in 2008-2010 to approximately 30% from 2011 to 2014 (P-value for trend = 0.02), whereas ESBL production among K. pneumoniae cases was 27.4% with no significant trend over time. Incidence of community-onset ESBL-producing E. coli increased from 5.4 per 100,000 population in 2008 to 12.8 in 2014, with the highest rates among persons aged >/= 70 years at 79 cases per 100,000 persons in 2014. From 2008 to 2014, community-onset ESBL-producing K. pneumoniae incidence was 2.7 per 100,000, with a rate of 12.9 among those aged >/= 70 years. Although most (93.6% of E. coli and 87.6% of K. pneumoniae) infections were community-onset, hospital-onset infections were twice as likely to be ESBL. Population-based surveillance, as described, is vital to accurately monitor emergence and trends in antimicrobial resistance, and in guiding the development of rational antimicrobial therapy recommendations. |
Global, regional, and national disease burden estimates of acute lower respiratory infections due to respiratory syncytial virus in young children in 2015: a systematic review and modelling study
Shi T , McAllister DA , O'Brien KL , Simoes EAF , Madhi SA , Gessner BD , Polack FP , Balsells E , Acacio S , Aguayo C , Alassani I , Ali A , Antonio M , Awasthi S , Awori JO , Azziz-Baumgartner E , Baggett HC , Baillie VL , Balmaseda A , Barahona A , Basnet S , Bassat Q , Basualdo W , Bigogo G , Bont L , Breiman RF , Brooks WA , Broor S , Bruce N , Bruden D , Buchy P , Campbell S , Carosone-Link P , Chadha M , Chipeta J , Chou M , Clara W , Cohen C , de Cuellar E , Dang DA , Dash-Yandag B , Deloria-Knoll M , Dherani M , Eap T , Ebruke BE , Echavarria M , de Freitas Lazaro Emediato CC , Fasce RA , Feikin DR , Feng L , Gentile A , Gordon A , Goswami D , Goyet S , Groome M , Halasa N , Hirve S , Homaira N , Howie SRC , Jara J , Jroundi I , Kartasasmita CB , Khuri-Bulos N , Kotloff KL , Krishnan A , Libster R , Lopez O , Lucero MG , Lucion F , Lupisan SP , Marcone DN , McCracken JP , Mejia M , Moisi JC , Montgomery JM , Moore DP , Moraleda C , Moyes J , Munywoki P , Mutyara K , Nicol MP , Nokes DJ , Nymadawa P , da Costa Oliveira MT , Oshitani H , Pandey N , Paranhos-Baccala G , Phillips LN , Picot VS , Rahman M , Rakoto-Andrianarivelo M , Rasmussen ZA , Rath BA , Robinson A , Romero C , Russomando G , Salimi V , Sawatwong P , Scheltema N , Schweiger B , Scott JAG , Seidenberg P , Shen K , Singleton R , Sotomayor V , Strand TA , Sutanto A , Sylla M , Tapia MD , Thamthitiwat S , Thomas ED , Tokarz R , Turner C , Venter M , Waicharoen S , Wang J , Watthanaworawit W , Yoshida LM , Yu H , Zar HJ , Campbell H , Nair H . Lancet 2017 390 (10098) 946-958 BACKGROUND: We have previously estimated that respiratory syncytial virus (RSV) was associated with 22% of all episodes of (severe) acute lower respiratory infection (ALRI) resulting in 55 000 to 199 000 deaths in children younger than 5 years in 2005. In the past 5 years, major research activity on RSV has yielded substantial new data from developing countries. With a considerably expanded dataset from a large international collaboration, we aimed to estimate the global incidence, hospital admission rate, and mortality from RSV-ALRI episodes in young children in 2015. METHODS: We estimated the incidence and hospital admission rate of RSV-associated ALRI (RSV-ALRI) in children younger than 5 years stratified by age and World Bank income regions from a systematic review of studies published between Jan 1, 1995, and Dec 31, 2016, and unpublished data from 76 high quality population-based studies. We estimated the RSV-ALRI incidence for 132 developing countries using a risk factor-based model and 2015 population estimates. We estimated the in-hospital RSV-ALRI mortality by combining in-hospital case fatality ratios with hospital admission estimates from hospital-based (published and unpublished) studies. We also estimated overall RSV-ALRI mortality by identifying studies reporting monthly data for ALRI mortality in the community and RSV activity. FINDINGS: We estimated that globally in 2015, 33.1 million (uncertainty range [UR] 21.6-50.3) episodes of RSV-ALRI, resulted in about 3.2 million (2.7-3.8) hospital admissions, and 59 600 (48 000-74 500) in-hospital deaths in children younger than 5 years. In children younger than 6 months, 1.4 million (UR 1.2-1.7) hospital admissions, and 27 300 (UR 20 700-36 200) in-hospital deaths were due to RSV-ALRI. We also estimated that the overall RSV-ALRI mortality could be as high as 118 200 (UR 94 600-149 400). Incidence and mortality varied substantially from year to year in any given population. INTERPRETATION: Globally, RSV is a common cause of childhood ALRI and a major cause of hospital admissions in young children, resulting in a substantial burden on health-care services. About 45% of hospital admissions and in-hospital deaths due to RSV-ALRI occur in children younger than 6 months. An effective maternal RSV vaccine or monoclonal antibody could have a substantial effect on disease burden in this age group. FUNDING: The Bill & Melinda Gates Foundation. |
Is higher viral load in the upper respiratory tract associated with severe pneumonia? Findings From the PERCH Study
Feikin DR , Fu W , Park DE , Shi Q , Higdon MM , Baggett HC , Brooks WA , Deloria Knoll M , Hammitt LL , Howie SRC , Kotloff KL , Levine OS , Madhi SA , Scott JAG , Thea DM , Adrian PV , Antonio M , Awori JO , Baillie VL , DeLuca AN , Driscoll AJ , Ebruke BE , Goswami D , Karron RA , Li M , Morpeth SC , Mwaba J , Mwansa J , Prosperi C , Sawatwong P , Sow SO , Tapia MD , Whistler T , Zaman K , Zeger SL , O' Brien KL , Murdoch DR . Clin Infect Dis 2017 64 S337-s346 Background.: The etiologic inference of identifying a pathogen in the upper respiratory tract (URT) of children with pneumonia is unclear. To determine if viral load could provide evidence of causality of pneumonia, we compared viral load in the URT of children with World Health Organization-defined severe and very severe pneumonia and age-matched community controls. Methods.: In the 9 developing country sites, nasopharyngeal/oropharyngeal swabs from children with and without pneumonia were tested using quantitative real-time polymerase chain reaction for 17 viruses. The association of viral load with case status was evaluated using logistic regression. Receiver operating characteristic (ROC) curves were constructed to determine optimal discriminatory viral load cutoffs. Viral load density distributions were plotted. Results.: The mean viral load was higher in cases than controls for 7 viruses. However, there was substantial overlap in viral load distribution of cases and controls for all viruses. ROC curves to determine the optimal viral load cutoff produced an area under the curve of <0.80 for all viruses, suggesting poor to fair discrimination between cases and controls. Fatal and very severe pneumonia cases did not have higher viral load than less severe cases for most viruses. Conclusions.: Although we found higher viral loads among pneumonia cases than controls for some viruses, the utility in using viral load of URT specimens to define viral pneumonia was equivocal. Our analysis was limited by lack of a gold standard for viral pneumonia. |
Limited Utility of Polymerase Chain Reaction in Induced Sputum Specimens for Determining the Causes of Childhood Pneumonia in Resource-Poor Settings: Findings From the Pneumonia Etiology Research for Child Health (PERCH) Study.
Thea DM , Seidenberg P , Park DE , Mwananyanda L , Fu W , Shi Q , Baggett HC , Brooks WA , Feikin DR , Howie SRC , Knoll MD , Kotloff KL , Levine OS , Madhi SA , O'Brien KL , Scott JAG , Antonio M , Awori JO , Baillie VL , DeLuca AN , Driscoll AJ , Higdon MM , Hossain L , Jahan Y , Karron RA , Kazungu S , Li M , Moore DP , Morpeth SC , Ofordile O , Prosperi C , Sangwichian O , Sawatwong P , Sylla M , Tapia MD , Zeger SL , Murdoch DR , Hammitt LL . Clin Infect Dis 2017 64 S289-s300 Background.: Sputum examination can be useful in diagnosing the cause of pneumonia in adults but is less well established in children. We sought to assess the diagnostic utility of polymerase chain reaction (PCR) for detection of respiratory viruses and bacteria in induced sputum (IS) specimens from children hospitalized with severe or very severe pneumonia. Methods.: Among children aged 1-59 months, we compared organism detection by multiplex PCR in IS and nasopharyngeal/oropharyngeal (NP/OP) specimens. To assess whether organism presence or density in IS specimens was associated with chest radiographic evidence of pneumonia (radiographic pneumonia), we compared prevalence and density in IS specimens from children with radiographic pneumonia and children with suspected pneumonia but without chest radiographic changes or clinical or laboratory findings suggestive of pneumonia (nonpneumonia group). Results.: Among 4232 cases with World Health Organization-defined severe or very severe pneumonia, we identified 1935 (45.7%) with radiographic pneumonia and 573 (13.5%) with nonpneumonia. The organism detection yield was marginally improved with IS specimens (96.2% vs 92.4% for NP/OP specimens for all viruses combined [P = .41]; 96.9% vs 93.3% for all bacteria combined [P = .01]). After accounting for presence in NP/OP specimens, no organism was detected more frequently in the IS specimens from the radiographic pneumonia compared with the nonpneumonia cases. Among high-quality IS specimens, there were no statistically significant differences in organism density, except with cytomegalovirus, for which there was a higher quantity in the IS specimens from cases with radiographic pneumonia compared with the nonpneumonia cases (median cycle threshold value, 27.9 vs 28.5, respectively; P = .01). Conclusions.: Using advanced molecular methods with IS specimens provided little additional diagnostic information beyond that obtained with NP/OP swab specimens. |
Standardization of laboratory methods for the PERCH Study
Driscoll AJ , Karron RA , Morpeth SC , Bhat N , Levine OS , Baggett HC , Brooks WA , Feikin DR , Hammitt LL , Howie SRC , Knoll MD , Kotloff KL , Madhi SA , Scott JAG , Thea DM , Adrian PV , Ahmed D , Alam M , Anderson TP , Antonio M , Baillie VL , Dione M , Endtz HP , Gitahi C , Karani A , Kwenda G , Maiga AA , McClellan J , Mitchell JL , Morailane P , Mugo D , Mwaba J , Mwansa J , Mwarumba S , Nyongesa S , Panchalingam S , Rahman M , Sawatwong P , Tamboura B , Toure A , Whistler T , O'Brien KL , Murdoch DR . Clin Infect Dis 2017 64 S245-s252 The Pneumonia Etiology Research for Child Health study was conducted across 7 diverse research sites and relied on standardized clinical and laboratory methods for the accurate and meaningful interpretation of pneumonia etiology data. Blood, respiratory specimens, and urine were collected from children aged 1-59 months hospitalized with severe or very severe pneumonia and community controls of the same age without severe pneumonia and were tested with an extensive array of laboratory diagnostic tests. A standardized testing algorithm and standard operating procedures were applied across all study sites. Site laboratories received uniform training, equipment, and reagents for core testing methods. Standardization was further assured by routine teleconferences, in-person meetings, site monitoring visits, and internal and external quality assurance testing. Targeted confirmatory testing and testing by specialized assays were done at a central reference laboratory. |
Molecular characterization of Mycoplasma pneumoniae infections in two rural populations of Thailand from 2009-2012.
Whistler T , Sawatwong P , Diaz MH , Benitez AJ , Wolff BJ , Sapchookul P , Thamthitiwat S , Winchell JM . J Clin Microbiol 2017 55 (7) 2222-2233 Studies on Mycoplasma pneumoniae in Thailand have focused on urban centers and have not included the molecular characterization. In an attempt to provide a more comprehensive understanding of this organism, we conducted a systematic random sampling to identify 3000 nasopharyngeal swab specimens, collected from January 2009 through July 2012 during population-based surveillance for influenza-like illness in two rural provinces. M. pneumoniae was detected by real-time PCR in 175 (5.8%) specimens. Genotyping was performed using the major adhesion protein (P1) and multilocus variable-number tandem-repeat analysis (MLVA). Of the 157 specimens typed, 97 were P1 type 1 and 60 were P1 type 2. Six different MLVA profiles were identified in 149 specimens with 4/5/7/2 (40%) and 3/5/6/2 (26%) predominating. There was no discrete seasonality to M. pneumoniae infections. Examination of the 23S rRNA sequence for known polymorphisms conferring macrolide resistance revealed all 141 tested to possess the genotype associated with macrolide susceptibility. |
Incidence of pneumococcal pneumonia among adults in rural Thailand, 2006-2011: implications for pneumococcal vaccine considerations
Piralam B , Tomczyk SM , Rhodes JC , Thamthitiwat S , Gregory CJ , Olsen SJ , Praphasiri P , Sawatwong P , Naorat S , Chantra S , Areerat P , Hurst CP , Moore MR , Muangchana C , Baggett HC . Am J Trop Med Hyg 2015 93 (6) 1140-1147 The incidence of pneumococcal pneumonia among adults is a key driver for the cost-effectiveness of pneumococcal conjugate vaccine used among children. We sought to obtain more accurate incidence estimates among adults by including results of pneumococcal urine antigen testing (UAT) from population-based pneumonia surveillance in two Thai provinces. Active surveillance from 2006 to 2011 identified acute lower respiratory infection (ALRI)-related hospital admissions. Adult cases of pneumococcal pneumonia were defined as hospitalized ALRI patients aged ≥ 18 years with isolation of Streptococcus pneumoniae from blood or with positive UAT. Among 39,525 adult ALRI patients, we identified 481 pneumococcal pneumonia cases (105 by blood culture, 376 by UAT only). Estimated incidence of pneumococcal pneumonia hospitalizations was 30.5 cases per 100,000 person-years (2.2 and 28.3 cases per 100,000 person-years by blood culture and UAT, respectively). Incidence varied between 22.7 in 2007 and 43.5 in 2010, and increased with age to over 150 per 100,000 person-years among persons aged ≥ 70 years. Viral coinfections including influenza A/B, respiratory syncytial virus (RSV), and adenovirus occurred in 11% (44/405) of pneumococcal pneumonia cases tested. Use of UAT to identify cases of pneumococcal pneumonia among adults in rural Thailand substantially increases estimates of pneumococcal pneumonia burden, thereby informing cost-effectiveness analyses and vaccine policy decisions. |
Incidence and etiology of acute lower respiratory tract infections in hospitalized children younger than 5 years in rural Thailand
Hasan R , Rhodes J , Thamthitiwat S , Olsen SJ , Prapasiri P , Naorat S , Chittaganpitch M , Henchaichon S , Dejsirilert S , Srisaengchai P , Sawatwong P , Jorakate P , Kaewpwan A , Fry AM , Erdman D , Chuananon S , Amornintapichet T , Maloney SA , Baggett HC . Pediatr Infect Dis J 2014 33 (2) e45-52 BACKGROUND: Pneumonia remains a leading cause of under-five morbidity and mortality globally. Comprehensive incidence, epidemiologic and etiologic data are needed to update prevention and control strategies. METHODS: We conducted active, population-based surveillance for hospitalized cases of acute lower respiratory tract infections (ALRI) among children <5 years of age in rural Thailand. ALRI cases were systematically sampled for an etiology study that tested nasopharyngeal specimens by polymerase chain reaction; children without ALRI were enrolled as controls from outpatient clinics. RESULTS: We identified 28,543 hospitalized ALRI cases from 2005 to 2010. Among the 49% with chest radiographs, 76% had findings consistent with pneumonia as identified by 2 study radiologists. The hospitalized ALRI incidence rate was 5772 per 100,000 child-years (95% confidence interval: 5707, 5837) and was higher in boys versus girls (incidence rate ratio 1.38, 95% confidence interval: 1.35-1.41) and in children 6-23 months of age versus other age groups (incidence rate ratio 1.76, 95% confidence interval: 1.69-1.84). Viruses most commonly detected in ALRI cases were respiratory syncytial virus (19.5%), rhinoviruses (18.7%), bocavirus (12.8%) and influenza viruses (8%). Compared with controls, ALRI cases were more likely to test positive for respiratory syncytial virus, influenza, adenovirus, human metapneumovirus and parainfluenza viruses 1 and 3 (P ≤ 0.01 for all). Bloodstream infections, most commonly Streptococcus pneumoniae and nontyphoidal Salmonella, accounted for 1.8% of cases. CONCLUSIONS: Our findings underscore the high burden of hospitalization for ALRI and the importance of viral pathogens among children in Thailand. Interventions targeting viral pathogens coupled with improved diagnostic approaches, especially for bacteria, are critical for better understanding of ALRI etiology, prevention and control. |
Respiratory syncytial virus circulation in seven countries with global disease detection regional centers
Haynes AK , Manangan AP , Iwane MK , Sturm-Ramirez K , Homaira N , Brooks WA , Luby S , Rahman M , Klena JD , Zhang Y , Yu H , Zhan F , Dueger E , Mansour AM , Azazzy N , McCracken JP , Bryan JP , Lopez MR , Burton DC , Bigogo G , Breiman RF , Feikin DR , Njenga K , Montgomery J , Cohen AL , Moyes J , Pretorius M , Cohen C , Venter M , Chittaganpitch M , Thamthitiwat S , Sawatwong P , Baggett HC , Luber G , Gerber SI . J Infect Dis 2013 208 Suppl 3 S246-54 BACKGROUND: Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in young children globally, with the highest burden in low- and middle-income countries where the association between RSV activity and climate remains unclear. METHODS: Monthly laboratory-confirmed RSV cases and associations with climate data were assessed for respiratory surveillance sites in tropical and subtropical areas (Bangladesh, China, Egypt, Guatemala, Kenya, South Africa, and Thailand) during 2004-2012. Average monthly minimum and maximum temperatures, relative humidity, and precipitation were calculated using daily local weather data from the US National Climatic Data Center. RESULTS: RSV circulated with 1-2 epidemic periods each year in site areas. RSV seasonal timing and duration were generally consistent within country from year to year. Associations between RSV and weather varied across years and geographic locations. RSV usually peaked in climates with high annual precipitation (Bangladesh, Guatemala, and Thailand) during wet months, whereas RSV peaked during cooler months in moderately hot (China) and arid (Egypt) regions. In South Africa, RSV peaked in autumn, whereas no associations with seasonal weather trends were observed in Kenya. CONCLUSIONS: Further understanding of RSV seasonality in developing countries and various climate regions will be important to better understand the epidemiology of RSV and for timing the use of future RSV vaccines and immunoprophylaxis in low- and middle-income countries. |
Hospitalizations for acute lower respiratory tract infection due to respiratory syncytial virus in Thailand, 2008-2011
Naorat S , Chittaganpitch M , Thamthitiwat S , Henchaichon S , Sawatwong P , Srisaengchai P , Lu Y , Chuananon S , Amornintapichet T , Chantra S , Erdman DD , Maloney SA , Akarasewi P , Baggett HC . J Infect Dis 2013 208 Suppl 3 S238-45 BACKGROUND: Few population-based estimates of the incidence of respiratory syncytial virus (RSV) infection in low- or middle-income countries are available. We describe the incidence and epidemiology of hospitalizations for RSV-associated acute lower respiratory tract infection (ALRI) detected by active population-based surveillance in 2 rural Thailand provinces during 2008-2011. METHODS: Patients hospitalized with ALRI were systematically sampled. Consenting patients provided nasopharyngeal swab specimens for RSV testing by real-time reverse-transcription polymerase chain reaction. RESULTS: Of 13 982 enrolled patients hospitalized with ALRI, 1137 (8.1%) were RSV positive. After adjustment for sampling and nonenrollment, the incidence of RSV-associated ALRI hospitalization was 85 cases per 100 000 persons/year. The highest rates occurred among children aged <5 years (981 cases per 100 000 persons/year) and <1 year (1543 cases per 100 000 persons/year). Rates were low among older children and young adults but high among persons aged >65 years (130 cases per 100 000 persons/year). Eight (0.7%) RSV-infected study patients died during hospitalization. Annual RSV hospitalizations peaked during July-October with almost no documented RSV hospitalizations during January-June. CONCLUSIONS: Our findings demonstrate the substantial contribution of RSV to global ALRI burden, especially in children aged <5 years and the elderly, and underscore the urgent need for effective prevention measures. |
Incidence and epidemiology of hospitalized influenza cases in rural Thailand during the influenza A (H1N1)pdm09 pandemic, 2009-2010
Baggett HC , Chittaganpitch M , Thamthitiwat S , Prapasiri P , Naorat S , Sawatwong P , Ditsungnoen D , Olsen SJ , Simmerman JM , Srisaengchai P , Chantra S , Peruski LF , Sawanpanyalert P , Maloney SA , Akarasewi P . PLoS One 2012 7 (11) e48609 BACKGROUND: Data on the burden of the 2009 influenza pandemic in Asia are limited. Influenza A(H1N1)pdm09 was first reported in Thailand in May 2009. We assessed incidence and epidemiology of influenza-associated hospitalizations during 2009-2010. METHODS: We conducted active, population-based surveillance for hospitalized cases of acute lower respiratory infection (ALRI) in all 20 hospitals in two rural provinces. ALRI patients were sampled 1:2 for participation in an etiology study in which nasopharyngeal swabs were collected for influenza virus testing by PCR. RESULTS: Of 7,207 patients tested, 902 (12.5%) were influenza-positive, including 190 (7.8%) of 2,436 children aged <5 years; 86% were influenza A virus (46% A(H1N1)pdm09, 30% H3N2, 6.5% H1N1, 3.5% not subtyped) and 13% were influenza B virus. Cases of influenza A(H1N1)pdm09 first peaked in August 2009 when 17% of tested patients were positive. Subsequent peaks during 2009 and 2010 represented a mix of influenza A(H1N1)pdm09, H3N2, and influenza B viruses. The estimated annual incidence of hospitalized influenza cases was 136 per 100,000, highest in ages <5 years (477 per 100,000) and >75 years (407 per 100,000). The incidence of influenza A(H1N1)pdm09 was 62 per 100,000 (214 per 100,000 in children <5 years). Eleven influenza-infected patients required mechanical ventilation, and four patients died, all adults with influenza A(H1N1)pdm09 (1) or H3N2 (3). CONCLUSIONS: Influenza-associated hospitalization rates in Thailand during 2009-10 were substantial and exceeded rates described in western countries. Influenza A(H1N1)pdm09 predominated, but H3N2 also caused notable morbidity. Expanded influenza vaccination coverage could have considerable public health impact, especially in young children. |
Bartonella vinsonii subsp. arupensis in humans, Thailand.
Bai Y , Kosoy MY , Diaz MH , Winchell J , Baggett H , Maloney SA , Boonmar S , Bhengsri S , Sawatwong P , Peruski LF . Emerg Infect Dis 2012 18 (6) 989-91 We identified Bartonella vinsonii subsp. arupensis in pre-enriched blood of 4 patients from Thailand. Nucleotide sequences for transfer-messenger RNA gene, citrate synthase gene, and the 16S-23S rRNA internal transcribed spacer were identical or closely related to those for the strain that has been considered pathogenic since initially isolated from a human in Wyoming, USA. |
Serology as an adjunct to polymerase chain reaction assays for surveillance of acute respiratory virus infections.
Sawatwong P , Chittaganpitch M , Hall H , Peruski LF , Xu X , Baggett HC , Fry AM , Erdman DD , Olsen SJ . Clin Infect Dis 2011 54 (3) 445-6 Diagnostic testing for viral infections has evolved during the past decade. Documenting a seroconversion, or significant increase in antibody titer between paired acute-phase and convalescent-phase serum specimens, is a well-proven method for detecting acute viral infection but can be challenging, because blood sample collection is invasive, a second blood sample is required, and late collection of the acute-phase serum sample complicates interpretation. In contrast, polymerase chain reaction (PCR) assays are rapid and sensitive when performed on respiratory specimens collected early in the illness but can lack specificity because of amplicon contamination or presence of virus not etiologically linked to the illness. PCR assays have largely replaced serologic examination and culture for detecting viral pathogens in respiratory disease surveillance [1]. The added value of serologic examination in disease surveillance has not been fully assessed. | We compared serologic examination and PCR results among patients enrolled in a pneumonia etiology study in rural Thailand from September 2003 through August 2005 [2]. Patients who were hospitalized and met a broad case definition for respiratory disease were enrolled. We compared patients who had specimens (nasopharyngeal swab and serum) tested for adenovirus, human metapneumovirus (HMPV), influenza viruses A and B, parainfluenza viruses (PIVs) 1–3, and respiratory syncytial virus (RSV), as described elsewhere [2]. Conventional (first 18 months) and real-time (last 6 months) reverse-transcription PCR assays were used [3]. Influenza human serologic examination was conducted using hemagglutination inhibition test [4]. Adenovirus; PIVs 1, 2, and 3; HMPV; and RSV immunoglobulin G antibodies were tested using enzyme immunoassay [5–8]. A positive result was defined as a positive PCR test result and/or a ≥4-fold increase in antibody titer of the convalescent serum sample. We analyzed PIV 1 and 3 together, because the presence of cross-reactive epitopes on these related viruses complicates serologic discrimination. We compared proportions using McNemar’s χ2 statistic. |
Evaluation of a newly developed lateral flow immunoassay for the diagnosis of cryptococcosis
Lindsley MD , Mekha N , Baggett HC , Surinthong Y , Autthateinchai R , Sawatwong P , Harris JR , Park BJ , Chiller T , Balajee SA , Poonwan N . Clin Infect Dis 2011 53 (4) 321-5 BACKGROUND: Cryptococcosis is a common opportunistic infection of human immunodeficiency virus (HIV)-infected individuals mostly occurring in resource-limited countries. This study compares the performance of a recently developed lateral flow immunoassay (LFA) to blood culture and enzyme immunoassay (EIA) for the diagnosis of cryptococcosis. METHODS: Archived sera from 704 HIV-infected patients hospitalized for acute respiratory illness in Thailand were tested for cryptococcal antigenemia using EIA. All EIA-positive and a subset of EIA-negative sera were tested by LFA, with results recorded after 5 and 15 minutes incubation. Urine from patients with LFA- and EIA-positive sera was tested by LFA. Antigen results from patients with positive cryptococcal blood cultures were compared. RESULTS: Of 704 sera, 92 (13%) were positive by EIA; among the 91 EIA-positive sera tested by LFA, 82 (90%) and 87 (96%) were LFA positive when read after 5 and 15 minutes, respectively. Kappa agreement of EIA and LFA for sera was 0.923 after 5 minutes and 0.959 after 15 minutes, respectively. Two of 373 EIA-negative sera were LFA positive at both time points. Of 74 urine specimens from EIA-positive patients, 52 (70.3%) were LFA positive. EIA was positive in 16 of 17 sera from blood culture-positive patients (94% sensitivity), and all sera were positive by LFA (100% sensitivity). CONCLUSIONS: A high level of agreement was shown between LFA and EIA testing of serum. The LFA is a rapid, easy-to-perform assay that does not require refrigeration, demonstrating its potential usefulness as a point-of-care assay for diagnosis of cryptococcosis in resource-limited countries. |
Human rhinovirus infections in rural Thailand: epidemiological evidence for rhinovirus as both pathogen and bystander
Fry AM , Lu X , Olsen SJ , Chittaganpitch M , Sawatwong P , Chantra S , Baggett HC , Erdman D . PLoS One 2011 6 (3) e17780 BACKGROUND: We describe human rhinovirus (HRV) detections in SaKaeo province, Thailand. METHODS: From September 1, 2003-August 31, 2005, we tested hospitalized patients with acute lower respiratory illness and outpatient controls without fever or respiratory symptoms for HRVs with polymerase chain reaction and molecularly-typed select HRVs. We compared HRV detection among hospitalized patients and controls and estimated enrollment adjusted incidence. RESULTS: HRVs were detected in 315 (16%) of 1919 hospitalized patients and 27 (9.6%) of 280 controls. Children had the highest frequency of HRV detections (hospitalized: <1 year: 29%, 1-4 year: 29%, ≥65 years: 9%; controls: <1 year: 24%, 1-4 year: 14%, ≥65 years: 2.8%). Enrollment adjusted hospitalized HRV detection rates were highest among persons aged <1 year (1038/100,000 persons/year), 1-4 years (457), and ≥65 years (71). All three HRV species were identified, HRV-A was the most common species in most age groups including children aged <1 year (61%) and all adult age groups. HRV-C was the most common species in the 1-4 year (51%) and 5-19 year age groups (54%). Compared to controls, hospitalized adults (≥19 years) and children were more likely to have HRV detections (odds ratio [OR]: 4.8, 95% confidence interval [CI]: 1.5, 15.8; OR: 2.0, CI: 1.2, 3.3, respectively) and hospitalized children were more likely to have HRV-A (OR 1.7, CI: 0.8, 3.5) or HVR-C (OR 2.7, CI: 1.2, 5.9) detection. CONCLUSIONS: HRV rates were high among hospitalized children and the elderly but asymptomatic children also had substantial HRV detection. HRV (all species), and HRV-A and HRV-C detections were epidemiologically-associated with hospitalized illness. Treatment or prevention modalities effective against HRV could reduce hospitalizations due to HRV in Thailand. |
The burden of hospitalized lower respiratory tract Infection due to respiratory syncytial virus in rural Thailand
Fry AM , Chittaganpitch M , Baggett HC , Peret TC , Dare RK , Sawatwong P , Thamthitiwat S , Areerat P , Sanasuttipun W , Fischer J , Maloney SA , Erdman DD , Olsen SJ . PLoS One 2010 5 (11) e15098 BACKGROUND: We describe the epidemiology of hospitalized RSV infections for all age groups from population-based surveillance in two rural provinces in Thailand. METHODS: From September 1, 2003 through December 31, 2007, we enrolled hospitalized patients with acute lower respiratory tract illness, who had a chest radiograph ordered by the physician, from all hospitals in SaKaeo and Nakhom Phanom Provinces. We tested nasopharyngeal specimens for RSV with reverse transcriptase polymerase chain reaction (RT-PCR) assays and paired-sera from a subset of patients with IgG enzyme immunoassay. Rates were adjusted for enrollment. RESULTS: Among 11,097 enrolled patients, 987 (8.9%) had RSV infection. Rates of hospitalized RSV infection overall (and radiographically-confirmed pneumonia) were highest among children aged <1 year: 1,067/100,000 (534/100,000 radiographically-confirmed pneumonia) and 1-4 year: 403/100,000 (222/100,000), but low among enrolled adults aged ≥65 years: 42/100,000. Age <1 year (adjusted odds ratio [aOR] = 13.2, 95% confidence interval [CI] 7.7, 22.5) and 1-4 year (aOR = 8.3, 95% CI 5.0, 13.9) were independent predictors of hospitalized RSV infection. CONCLUSIONS: The incidence of hospitalized RSV lower respiratory tract illness among children <5 years was high in rural Thailand. Efforts to prevent RSV infection could substantially reduce the pneumonia burden in children aged <5 years. |
Enrichment culture and molecular identification of diverse Bartonella species in stray dogs
Bai Y , Kosoy MY , Boonmar S , Sawatwong P , Sangmaneedet S , Peruski LF . Vet Microbiol 2010 146 314-9 Using pre-enrichment culture in Bartonella alpha-Proteobacteria growth medium (BAPGM) followed by PCR amplification and DNA sequence identification that targeted a fragment of the citrate synthase gene (gltA), we provide evidence of common bartonella infections and diverse Bartonella species in the blood of stray dogs from Bangkok and Khon Kaen, Thailand. The overall prevalence of all Bartonella species was 31.3% (60/192), with 27.9% (31/111) and 35.8% (29/81) in the stray dogs from Bangkok and Khon Kaen, respectively. Phylogenetic analyzes of gltA identified eight species/genotypes of Bartonella in the blood of stray dogs, including B. vinsonii subsp. arupensis, B. elizabethae, B. grahamii, B. quintana, B. taylorii, and three novel genotypes (BK1, KK1 and KK2) possibly representing unique species with ≤90.2% similarities to any of the known Bartonella species B. vinsonii subsp. arupensis was the only species detected in dogs from both sites, B. quintana and BK1 were found in the dogs from Bangkok, B. elizabethae, B. taylorii, KK1 and KK2 were found in the dogs from Khon Kaen. We conclude that stray dogs in Thailand are frequently infected with Bartonella species that vary with geographic region. As some Bartonella species detected in the present study are considered pathogenic for humans, stray dogs in Thailand may serve as possible reservoirs for Bartonella causing human illnesses. Further work is needed to determine the role of those newly discovered Bartonella genotypes/species in human and veterinary medicine. |
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