Last data update: Jul 08, 2025. (Total: 49524 publications since 2009)
Records 1-30 (of 31 Records) |
Query Trace: O'Reilly CE[original query] |
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Pathogens associated with linear growth faltering in children with diarrhea and impact of antibiotic treatment: The global enteric multicenter study
Nasrin D , Blackwelder WC , Sommerfelt H , Wu Y , Farag TH , Panchalingam S , Biswas K , Saha D , Jahangir Hossain M , Sow SO , Reiman RFB , Sur D , Faruque ASG , Zaidi AKM , Sanogo D , Tamboura B , Onwuchekwa U , Manna B , Ramamurthy T , Kanungo S , Omore R , Ochieng JB , Oundo JO , Das SK , Ahmed S , Qureshi S , Quadri F , Adegbola RA , Antonio M , Mandomando I , Nhampossa T , Bassat Q , Roose A , O'Reilly CE , Mintz ED , Ramakrishnan U , Powell H , Liang Y , Nataro JP , Levine MM , Kotloff KL . J Infect Dis 2021 224 S848-s855 BACKGROUND: The association between childhood diarrheal disease and linear growth faltering in developing countries is well described. However, the impact attributed to specific pathogens has not been elucidated, nor has the impact of recommended antibiotic treatment. METHODS: The Global Enteric Multicenter Study enrolled children with moderate to severe diarrhea (MSD) seeking healthcare at 7 sites in sub-Saharan Africa and South Asia. At enrollment, we collected stool samples to identify enteropathogens. Length/height was measured at enrollment and follow-up, approximately 60 days later, to calculate change in height-for-age z scores (ΔHAZ). The association of pathogens with ΔHAZ was tested using linear mixed effects regression models. RESULTS: Among 8077 MSD cases analyzed, the proportion with stunting (HAZ below -1) increased from 59% at enrollment to 65% at follow-up (P < .0001). Pathogens significantly associated with linear growth decline included Cryptosporidium (P < .001), typical enteropathogenic Escherichia coli (P = .01), and untreated Shigella (P = .009) among infants (aged 0-11 months) and enterotoxigenic E. coli encoding heat-stable toxin (P < .001) and Cryptosporidium (P = .03) among toddlers (aged 12-23 months). Shigella-infected toddlers given antibiotics had improved linear growth (P = .02). CONCLUSIONS: Linear growth faltering among children aged 0-23 months with MSD is associated with specific pathogens and can be mitigated with targeted treatment strategies, as demonstrated for Shigella. |
Characteristics of Salmonella recovered from stools of children enrolled in the Global Enteric Multicenter Study.
Kasumba IN , Pulford CV , Perez-Sepulveda BM , Sen S , Sayed N , Permala-Booth J , Livio S , Heavens D , Low R , Hall N , Roose A , Powell H , Farag T , Panchalingham S , Berkeley L , Nasrin D , Blackwelder WC , Wu Y , Tamboura B , Sanogo D , Onwuchekwa U , Sow SO , Ochieng JB , Omore R , Oundo JO , Breiman RF , Mintz ED , O'Reilly CE , Antonio M , Saha D , Hossain MJ , Mandomando I , Bassat Q , Alonso PL , Ramamurthy T , Sur D , Qureshi S , Zaidi AKM , Hossain A , Faruque ASG , Nataro JP , Kotloff KL , Levine MM , Hinton JCD , Tennant SM . Clin Infect Dis 2021 73 (4) 631-641 ![]() ![]() BACKGROUND: The Global Enteric Multicenter Study (GEMS) determined the etiologic agents of moderate-to-severe diarrhea (MSD) in children under 5 years old in Africa and Asia. Here, we describe the prevalence and antimicrobial susceptibility of non-typhoidal Salmonella (NTS) serovars in GEMS and examine the phylogenetics of Salmonella Typhimurium ST313 isolates. METHODS: Salmonella isolated from children with MSD or diarrhea-free controls were identified by classical clinical microbiology and serotyped using antisera and/or whole genome sequence data. We evaluated antimicrobial susceptibility using the Kirby-Bauer disk diffusion method. Salmonella Typhimurium sequence types were determined using multi-locus sequence typing and whole genome sequencing was performed to assess the phylogeny of ST313. RESULTS: Out of 370 Salmonella-positive individuals, 190 (51.4%) were MSD cases and 180 (48.6%) were diarrhea-free controls. The most frequent Salmonella serovars identified were Salmonella Typhimurium, serogroup O:8 (C2-C3), serogroup O:6,7 (C1), Salmonella Paratyphi B Java and serogroup O:4 (B). The prevalence of NTS was low but similar across sites, regardless of age, and was similar amongst both cases and controls except in Kenya, where Salmonella Typhimurium was more commonly associated with cases than controls. Phylogenetic analysis showed that these Salmonella Typhimurium isolates, all ST313, were highly genetically related to isolates from controls. Generally, Salmonella isolates from Asia were resistant to ciprofloxacin and ceftriaxone but African isolates were susceptible to these antibiotics. CONCLUSION: Our data confirms that NTS is prevalent, albeit at low levels, in Africa and South Asia. Our findings provide further evidence that multi-drug resistant Salmonella Typhimurium ST313 can be carried asymptomatically by humans in sub-Saharan Africa. |
Impact of safe water programs on water treatment practices of people living with human immunodeficiency virus, Ethiopia, 2008
Kim S , O'Reilly CE , Abayneh SA , Bhattarai A , Ahmed J , Mekonnen A , Salah Z , Quick R . Water (Switzerland) 2020 12 (11) Household water chlorination has been shown to reduce diarrhea incidence among people living with Human Immunodeficiency Virus (PLHIV). Some HIV programs in Ethiopia previously provided a socially marketed chlorination product (brand name WuhaAgar) to prevent diarrhea. To evaluate the program, we compared WuhaAgar use and water treatment practices between 795 clients from 20 antiretroviral therapy (ART) clinics and 795 community members matched by age, sex, and neighborhood. Overall, 19% of study participants reported water treatment with WuhaAgar. Being an ART clinic client was associated with reported treatment of drinking water (matched odds ratios (mOR): 3.8, 95% confidence interval (CI): 2.9-5.0), reported current water treatment with WuhaAgar (mOR: 5.5, 95% CI 3.9-7.7), and bottles of WuhaAgar observed in the home (mOR: 8.8, 95% CI 5.4-14.3). Being an ART clinic client was also associated with reported diarrhea among respondents (mOR: 4.8, 95% CI 2.9-7.9) and household members (mOR:2.8, 95% CI: 1.9-4.2) in the two weeks preceding the survey. Results suggest that promoting and distributing water chlorination products in ART clinics was effective in increasing access to and use of water treatment products among PLHIV. The positive association between ART clinic attendees and diarrhea likely resulted from the immunocompromised status of ART clinic clients. |
Factors associated with typical enteropathogenic Escherichia coli infection among children <5 years old with moderate-to-severe diarrhoea in rural western Kenya, 2008-2012.
Fagerli K , Omore R , Kim S , Ochieng JB , Ayers TL , Juma J , Farag TH , Nasrin D , Panchalingam S , Robins-Browne RM , Nataro JP , Kotloff KL , Levine MM , Oundo J , Parsons MB , Laserson KF , Mintz ED , Breiman RF , O'Reilly CE . Epidemiol Infect 2020 148 1-37 ![]() Typical enteropathogenic Escherichia coli (tEPEC) infection is a major cause of diarrhoea and contributor to mortality in children <5 years old in developing countries. Data were analysed from the Global Enteric Multicenter Study examining children <5 years old seeking care for moderate-to-severe diarrhoea (MSD) in Kenya. Stool specimens were tested for enteric pathogens, including by multiplex polymerase chain reaction for gene targets of tEPEC. Demographic, clinical and anthropometric data were collected at enrolment and ~60-days later; multivariable logistic regressions were constructed. Of 1778 MSD cases enrolled from 2008 to 2012, 135 (7.6%) children tested positive for tEPEC. In a case-to-case comparison among MSD cases, tEPEC was independently associated with presentation at enrolment with a loss of skin turgor (adjusted odds ratio (aOR) 2.08, 95% confidence interval (CI) 1.37-3.17), and convulsions (aOR 2.83, 95% CI 1.12-7.14). At follow-up, infants with tEPEC compared to those without were associated with being underweight (OR 2.2, 95% CI 1.3-3.6) and wasted (OR 2.5, 95% CI 1.3-4.6). Among MSD cases, tEPEC was associated with mortality (aOR 2.85, 95% CI 1.47-5.55). This study suggests that tEPEC contributes to morbidity and mortality in children. Interventions aimed at defining and reducing the burden of tEPEC and its sequelae should be urgently investigated, prioritised and implemented. |
Diarrhoeal disease and subsequent risk of death in infants and children residing in low-income and middle-income countries: analysis of the GEMS case-control study and 12-month GEMS-1A follow-on study
Levine MM , Nasrin D , Acacio S , Bassat Q , Powell H , Tennant SM , Sow SO , Sur D , Zaidi AKM , Faruque ASG , Hossain MJ , Alonso PL , Breiman RF , O'Reilly CE , Mintz ED , Omore R , Ochieng JB , Oundo JO , Tamboura B , Sanogo D , Onwuchekwa U , Manna B , Ramamurthy T , Kanungo S , Ahmed S , Qureshi S , Quadri F , Hossain A , Das SK , Antonio M , Saha D , Mandomando I , Blackwelder WC , Farag T , Wu Y , Houpt ER , Verweiij JJ , Sommerfelt H , Nataro JP , Robins-Browne RM , Kotloff KL . Lancet Glob Health 2019 8 (2) e204-e214 BACKGROUND: The Global Enteric Multicenter Study (GEMS) was a 3-year case-control study that measured the burden, aetiology, and consequences of moderate-to-severe diarrhoea (MSD) in children aged 0-59 months. GEMS-1A, a 12-month follow-on study, comprised two parallel case-control studies, one assessing MSD and the other less-severe diarrhoea (LSD). In this report, we analyse the risk of death with each diarrhoea type and the specific pathogens associated with fatal outcomes. METHODS: GEMS was a prospective, age-stratified, matched case-control study done at seven sites in Africa and Asia. Children aged 0-59 months with MSD seeking care at sentinel health centres were recruited along with one to three randomly selected matched community control children without diarrhoea. In the 12-month GEMS-1A follow-on study, children with LSD and matched controls, in addition to children with MSD and matched controls, were recruited at six of the seven sites; only cases of MSD and controls were enrolled at the seventh site. We compared risk of death during the period between enrolment and one follow-up household visit done about 60 days later (range 50-90 days) in children with MSD and LSD and in their respective controls. Approximately 50 pathogens were detected using, as appropriate, classic bacteriology, immunoassays, gel-based PCR and reverse transcriptase PCR, and quantitative real-time PCR (qPCR). Specimens from a subset of GEMS cases and controls were also tested by a TaqMan Array Card that compartmentalised probe-based qPCR for 32 enteropathogens. FINDINGS: 223 (2.0%) of 11 108 children with MSD and 43 (0.3%) of 16 369 matched controls died between study enrolment and the follow-up visit at about 60 days (hazard ratio [HR] 8.16, 95% CI 5.69-11.68, p<0.0001). 12 (0.4%) of 2962 children with LSD and seven (0.2%) of 4074 matched controls died during the follow-up period (HR 2.78, 95% CI 0.95-8.11, p=0.061). Risk of death was lower in children with dysenteric MSD than in children with non-dysenteric MSD (HR 0.20, 95% CI 0.05-0.87, p=0.032), and lower in children with LSD than in those with non-dysenteric MSD (HR 0.29, 0.14-0.59, p=0.0006). In children younger than 24 months with MSD, infection with typical enteropathogenic Escherichia coli, enterotoxigenic E coli encoding heat-stable toxin, enteroaggregative E coli, Shigella spp (non-dysentery cases), Aeromonas spp, Cryptosporidium spp, and Entamoeba histolytica increased risk of death. Of 61 deaths in children aged 12-59 months with non-dysenteric MSD, 31 occurred among 942 children qPCR-positive for Shigella spp and 30 deaths occurred in 1384 qPCR-negative children (HR 2.2, 95% CI 1.2-3.9, p=0.0090), showing that Shigella was strongly associated with increased risk of death. INTERPRETATION: Risk of death is increased following MSD and, to a lesser extent, LSD. Considering there are approximately three times more cases of LSD than MSD in the population, more deaths are expected among children with LSD than in those with MSD. Because the major attributable LSD-associated and MSD-associated pathogens are the same, implementing vaccines and rapid diagnosis and treatment interventions against these major pathogens are rational investments. FUNDING: Bill & Melinda Gates Foundation. |
Water, sanitation, and hygiene characteristics among HIV-positive households participating in the Global Enteric Multicenter Study in Rural Western Kenya, 2008-2012
Schilling KA , Awuor AO , Rajasingham A , Moke F , Omore R , Amollo M , Farag TH , Nasrin D , Nataro JP , Kotloff KL , Levine MM , Ayers T , Laserson K , Blackstock A , Rothenberg R , Stauber CE , Mintz ED , Breiman RF , O'Reilly CE . Am J Trop Med Hyg 2018 99 (4) 905-915 Diarrheal illness, a common occurrence among people living with human immunodeficiency virus (PLHIV), is largely preventable through access to safe drinking water quality, sanitation, and hygiene (WASH) facilities. We examined WASH characteristics among households with and without HIV-positive residents enrolled in the Global Enteric Multicenter Study (GEMS) in rural Western Kenya. Using univariable logistic regression, we examined differences between HIV-positive and HIV-negative households in regard to WASH practices. Among HIV-positive households, we explored the relationship between the length of time knowing their HIV status and GEMS enrollment. No statistically significant differences were apparent in the WASH characteristics among HIV-positive and HIV-negative households. However, we found differences in the WASH characteristics among HIV-positive households who were aware of their HIV status >/= 30 days before enrollment compared with HIV-positive households who found out their status < 30 days before enrollment or thereafter. Significantly more households aware of their HIV-positive status before enrollment reported treating their drinking water (odds ratio [OR] confidence interval [CI]: 2.34 [1.12, 4.86]) and using effective water treatment methods (OR [CI]: 9.6 [3.09, 29.86]), and had better drinking water storage practices. This suggests that within this region of Kenya, HIV programs are effective in promoting the importance of practicing positive WASH-related behaviors among PLHIV. |
Efficacy of a solar concentrator to Inactivate E. coli and C. perfringens spores in latrine waste in Kenya
Murphy JL , Ayers T , Foote A , Woods E , Wamola N , Fagerli K , Waiboci L , Mugoh R , Mintz ED , Zhao K , Marano N , O'Reilly CE , Hill VR . Sci Total Environ 2019 691 401-406 Alternative sanitation options are needed for effective waste management in low-income countries where centralized, large-scale waste treatment is not easily achievable. A newly designed solar concentrator technology utilizes solar thermal energy to treat feces contained in drums. This pilot study assessed the efficacy of the new design to inactivate microbes in 13 treatment drums under field conditions in Kenya. Three-quarters of the drums contained <1000E. coli/g of total solids following 6h of solar thermal treatment and inactivation of thermotolerant C. perfringens spores ranged from <1.8 to >5.0log10. Nearly all (94%) samples collected from treatment drums achieved thermophilic temperatures (>50 degrees C) during the treatment period, however this alone did not ensure samples met the WHO E. coli guideline; higher, sustained thermophilic temperatures tended to be more effective in reaching this guideline. The newly designed solar concentrator was capable of inactivating thermotolerant, environmentally-stable microorganisms as, or possibly more, efficiently than a previous design. Additional data are needed to better characterize how temperature, time, and other parameters affect the ability of the solar concentrator to inactivate microbes in feces. |
Inappropriate use of antibiotics for childhood diarrhea case management - Kenya, 2009-2016
Rhee C , Aol G , Ouma A , Audi A , Muema S , Auko J , Omore R , Odongo G , Wiegand RE , Montgomery JM , Widdowson MA , O'Reilly CE , Bigogo G , Verani JR . BMC Public Health 2019 19 468 Background: Antibiotics are essential to treat for many childhood bacterial infections; however inappropriate antibiotic use contributes to antimicrobial resistance. For childhood diarrhea, empiric antibiotic use is recommended for dysentery (bloody diarrhea) for which first-line therapy is ciprofloxacin. We assessed inappropriate antibiotic prescription for childhood diarrhea in two primary healthcare facilities in Kenya. Methods: We analyzed data from the Kenya Population Based Infectious Disease Surveillance system in Asembo (rural, malaria-endemic) and Kibera (urban slum, non-malaria-endemic). We examined records of children aged 2-59 months with diarrhea (≥3 loose stools in 24 h) presenting for care from August 21, 2009 to May 3, 2016, excluding visits with non-diarrheal indications for antibiotics. We examined the frequency of antibiotic over-prescription (antibiotic prescription for non-dysentery), under-prescription (no antibiotic prescription for dysentery), and inappropriate antibiotic selection (non-recommended antibiotic). We examined factors associated with over-prescription and under-prescription using multivariate logistic regression with generalized estimating equations. Results: Of 2808 clinic visits with diarrhea in Asembo, 2685 (95.6%) were non-dysentery visits and antibiotic over-prescription occurred in 52.5%. Of 4697 clinic visits with diarrhea in Kibera, 4518 (96.2%) were non-dysentery and antibiotic over-prescription occurred in 20.0%. Antibiotic under-prescription was noted in 26.8 and 73.7% of dysentery cases in Asembo and Kibera, respectively. Ciprofloxacin was used for 11% of dysentery visits in Asembo and 0% in Kibera. Factors associated with over- and under-prescription varied by site. In Asembo a discharge diagnosis of gastroenteritis was associated with over-prescription (adjusted odds ratio [aOR]:8.23, 95% confidence interval [95%CI]: 3.68-18.4), while malaria diagnosis was negatively associated with antibiotic over-prescription (aOR 0.37, 95%CI: 0.25-0.54) but positively associated with antibiotic under-prescription (aOR: 1.82, 95%CI: 1.05-3.13). In Kibera, over-prescription was more common among visits with concurrent signs of respiratory infection (difficulty breathing; aOR: 3.97, 95%CI: 1.28-12.30, cough: aOR: 1.42, 95%CI: 1.06-1.90) and less common among children aged < 1 year (aOR: 0.82, 95%CI: 0.71-0.94). Conclusions: Inappropriate antibiotic prescription was common in childhood diarrhea management and efforts are needed to promote rational antibiotic use. Interventions to improve antibiotic use for diarrhea should consider the influence of malaria diagnosis on clinical decision-making and address both over-prescription, under-prescription, and inappropriate antibiotic selection. |
Colonization factors among enterotoxigenic Escherichia coli isolates from children with moderate-to-severe diarrhea and from matched controls in the Global Enteric Multicenter Study (GEMS).
Vidal RM , Muhsen K , Tennant SM , Svennerholm AM , Sow SO , Sur D , Zaidi AKM , Faruque ASG , Saha D , Adegbola R , Hossain MJ , Alonso PL , Breiman RF , Bassat Q , Tamboura B , Sanogo D , Onwuchekwa U , Manna B , Ramamurthy T , Kanungo S , Ahmed S , Qureshi S , Quadri F , Hossain A , Das SK , Antonio M , Mandomando I , Nhampossa T , Acacio S , Omore R , Ochieng JB , Oundo JO , Mintz ED , O'Reilly CE , Berkeley LY , Livio S , Panchalingam S , Nasrin D , Farag TH , Wu Y , Sommerfelt H , Robins-Browne RM , Del Canto F , Hazen TH , Rasko DA , Kotloff KL , Nataro JP , Levine MM . PLoS Negl Trop Dis 2019 13 (1) e0007037 ![]() BACKGROUND: Enterotoxigenic Escherichia coli (ETEC) encoding heat-stable enterotoxin (ST) alone or with heat-labile enterotoxin (LT) cause moderate-to-severe diarrhea (MSD) in developing country children. The Global Enteric Multicenter Study (GEMS) identified ETEC encoding ST among the top four enteropathogens. Since the GEMS objective was to provide evidence to guide development and implementation of enteric vaccines and other interventions to diminish diarrheal disease morbidity and mortality, we examined colonization factor (CF) prevalence among ETEC isolates from children age <5 years with MSD and from matched controls in four African and three Asian sites. We also assessed strength of association of specific CFs with MSD. METHODOLOGY/PRINCIPAL FINDINGS: MSD cases enrolled at healthcare facilities over three years and matched controls were tested in a standardized manner for many enteropathogens. To identify ETEC, three E. coli colonies per child were tested by polymerase chain reaction (PCR) to detect genes encoding LT, ST; confirmed ETEC were examined by PCR for major CFs (Colonization Factor Antigen I [CFA/I] or Coli Surface [CS] antigens CS1-CS6) and minor CFs (CS7, CS12, CS13, CS14, CS17, CS18, CS19, CS20, CS21, CS30). ETEC from 806 cases had a single toxin/CF profile in three tested strains per child. Major CFs, components of multiple ETEC vaccine candidates, were detected in 66.0% of LT/ST and ST-only cases and were associated with MSD versus matched controls by conditional logistic regression (p</=0.006); major CFs detected in only 25.0% of LT-only cases weren't associated with MSD. ETEC encoding exclusively CS14, identified among 19.9% of 291 ST-only and 1.5% of 259 LT/ST strains, were associated with MSD (p = 0.0011). No other minor CF exhibited prevalence >/=5% and significant association with MSD. CONCLUSIONS/SIGNIFICANCE: Major CF-based efficacious ETEC vaccines could potentially prevent up to 66% of pediatric MSD cases due to ST-encoding ETEC in developing countries; adding CS14 extends coverage to ~77%. |
Diarrhoea, enteric pathogen detection and nutritional indicators among controls in the Global Enteric Multicenter Study, Kenya site: an opportunity to understand reference populations in case-control studies of diarrhoea
Berendes DM , O'Reilly CE , Kim S , Omore R , Ochieng JB , Ayers T , Fagerli K , Farag TH , Nasrin D , Panchalingam S , Nataro JP , Kotloff KL , Levine MM , Oundo J , Laserson K , Breiman RF , Mintz ED . Epidemiol Infect 2018 147 1-9 Given the challenges in accurately identifying unexposed controls in case-control studies of diarrhoea, we examined diarrhoea incidence, subclinical enteric infections and growth stunting within a reference population in the Global Enteric Multicenter Study, Kenya site. Within 'control' children (0-59 months old without diarrhoea in the 7 days before enrolment, n = 2384), we examined surveys at enrolment and 60-day follow-up, stool at enrolment and a 14-day post-enrolment memory aid for diarrhoea incidence. At enrolment, 19% of controls had 1 enteric pathogen associated with moderate-to-severe diarrhoea ('MSD pathogens') in stool; following enrolment, many reported diarrhoea (27% in 7 days, 39% in 14 days). Controls with and without reported diarrhoea had similar carriage of MSD pathogens at enrolment; however, controls reporting diarrhoea were more likely to report visiting a health facility for diarrhoea (27% vs. 7%) or fever (23% vs. 16%) at follow-up than controls without diarrhoea. Odds of stunting differed by both MSD and 'any' (including non-MSD pathogens) enteric pathogen carriage, but not diarrhoea, suggesting control classification may warrant modification when assessing long-term outcomes. High diarrhoea incidence following enrolment and prevalent carriage of enteric pathogens have implications for sequelae associated with subclinical enteric infections and for design and interpretation of case-control studies examining diarrhoea. |
Clinical, environmental, and behavioral characteristics associated with Cryptosporidium infection among children with moderate-to-severe diarrhea in rural western Kenya, 2008-2012: The Global Enteric Multicenter Study (GEMS)
Delahoy MJ , Omore R , Ayers TL , Schilling KA , Blackstock AJ , Ochieng JB , Moke F , Jaron P , Awuor A , Okonji C , Juma J , Farag TH , Nasrin D , Panchalingam S , Nataro JP , Kotloff KL , Levine MM , Oundo J , Roellig DM , Xiao L , Parsons MB , Laserson K , Mintz ED , Breiman RF , O'Reilly CE . PLoS Negl Trop Dis 2018 12 (7) e0006640 BACKGROUND: Cryptosporidium is a leading cause of moderate-to-severe diarrhea (MSD) in young children in Africa. We examined factors associated with Cryptosporidium infection in MSD cases enrolled at the rural western Kenya Global Enteric Multicenter Study (GEMS) site from 2008-2012. METHODOLOGY/PRINCIPAL FINDINGS: At health facility enrollment, stool samples were tested for enteric pathogens and data on clinical, environmental, and behavioral characteristics collected. Each child's health status was recorded at 60-day follow-up. Data were analyzed using logistic regression. Of the 1,778 children with MSD enrolled as cases in the GEMS-Kenya case-control study, 11% had Cryptosporidium detected in stool by enzyme immunoassay; in a genotyped subset, 81% were C. hominis. Among MSD cases, being an infant, having mucus in stool, and having prolonged/persistent duration diarrhea were associated with being Cryptosporidium-positive. Both boiling drinking water and using rainwater as the main drinking water source were protective factors for being Cryptosporidium-positive. At follow-up, Cryptosporidium-positive cases had increased odds of being stunted (adjusted odds ratio [aOR] = 1.65, 95% CI: 1.06-2.57), underweight (aOR = 2.08, 95% CI: 1.34-3.22), or wasted (aOR = 2.04, 95% CI: 1.21-3.43), and had significantly larger negative changes in height- and weight-for-age z-scores from enrollment. CONCLUSIONS/SIGNIFICANCE: Cryptosporidium contributes significantly to diarrheal illness in young children in western Kenya. Advances in point of care detection, prevention/control approaches, effective water treatment technologies, and clinical management options for children with cryptosporidiosis are needed. |
A randomized controlled trial to assess the impact of ceramic water filters on prevention of diarrhea and cryptosporidiosis in infants and young children - Western Kenya, 2013
Morris JF , Murphy J , Fagerli K , Schneeberger C , Jaron P , Moke F , Juma J , Ochieng JB , Omore R , Roellig D , Xiao L , Priest JW , Narayanan J , Montgomery J , Hill V , Mintz E , Ayers TL , O'Reilly CE . Am J Trop Med Hyg 2018 98 (5) 1260-1268 Cryptosporidium is a leading cause of diarrhea among Kenyan infants. Ceramic water filters (CWFs) are used for household water treatment. We assessed the impact of CWFs on diarrhea, cryptosporidiosis prevention, and water quality in rural western Kenya. A randomized, controlled intervention trial was conducted in 240 households with infants 4-10 months old. Twenty-six weekly household surveys assessed infant diarrhea and health facility visits. Stool specimens from infants with diarrhea were examined for Cryptosporidium. Source water, filtered water, and filter retentate were tested for Cryptosporidium and/or microbial indicators. To estimate the effect of CWFs on health outcomes, logistic regression models using generalized estimating equations were performed; odds ratios (ORs) and 95% confidence intervals (CIs) are reported. Households reported using surface water (36%), public taps (29%), or rainwater (17%) as their primary drinking water sources, with no differences in treatment groups. Intervention households reported less diarrhea (7.6% versus 8.9%; OR: 0.86 [0.64-1.16]) and significantly fewer health facility visits for diarrhea (1.0% versus 1.9%; OR: 0.50 [0.30-0.83]). In total, 15% of intervention and 12% of control stools yielded Cryptosporidium (P = 0.26). Escherichia coli was detected in 93% of source water samples; 71% of filtered water samples met World Health Organization recommendations of < 1 E. coli/100 mL. Cryptosporidium was not detected in source water and was detected in just 2% of filter rinses following passage of large volumes of source water. Water quality was improved among CWF users; however, the short study duration and small sample size limited our ability to observe reductions in cryptosporidiosis. |
Correction: Sanitation practices and perceptions in Kakuma refugee camp, Kenya: Comparing the status quo with a novel service-based approach
Nyoka R , Foote AM , Woods E , Lokey H , O'Reilly CE , Magumba F , Okello P , Mintz ED , Marano N , Morris JF . PLoS One 2017 12 (12) e0190129 The second author’s name is spelled incorrectly. The correct name is: Andrew M. Foote. The correct citation is: Nyoka R, Foote AM, Woods E, Lokey H, O’Reilly CE, Magumba F, et al. (2017) Sanitation practices and perceptions in Kakuma refugee camp, Kenya: Comparing the status quo with a novel service-based approach. PLoS ONE 12(7): e0180864. |
Animal-related factors associated with moderate-to-severe diarrhea in children younger than five years in western Kenya: A matched case-control study
Conan A , O'Reilly CE , Ogola E , Ochieng JB , Blackstock AJ , Omore R , Ochieng L , Moke F , Parsons MB , Xiao L , Roellig D , Farag TH , Nataro JP , Kotloff KL , Levine MM , Mintz ED , Breiman RF , Cleaveland S , Knobel DL . PLoS Negl Trop Dis 2017 11 (8) e0005795 BACKGROUND: Diarrheal disease remains among the leading causes of global mortality in children younger than 5 years. Exposure to domestic animals may be a risk factor for diarrheal disease. The objectives of this study were to identify animal-related exposures associated with cases of moderate-to-severe diarrhea (MSD) in children in rural western Kenya, and to identify the major zoonotic enteric pathogens present in domestic animals residing in the homesteads of case and control children. METHODOLOGY/PRINCIPAL FINDINGS: We characterized animal-related exposures in a subset of case and control children (n = 73 pairs matched on age, sex and location) with reported animal presence at home enrolled in the Global Enteric Multicenter Study in western Kenya, and analysed these for an association with MSD. We identified potentially zoonotic enteric pathogens in pooled fecal specimens collected from domestic animals resident at children's homesteads. Variables that were associated with decreased risk of MSD were washing hands after animal contact (matched odds ratio [MOR] = 0.2; 95% CI 0.08-0.7), and presence of adult sheep that were not confined in a pen overnight (MOR = 0.1; 0.02-0.5). Variables that were associated with increased risk of MSD were increasing number of sheep owned (MOR = 1.2; 1.0-1.5), frequent observation of fresh rodent excreta (feces/urine) outside the house (MOR = 7.5; 1.5-37.2), and participation of the child in providing water to chickens (MOR = 3.8; 1.2-12.2). Of 691 pooled specimens collected from 2,174 domestic animals, 159 pools (23%) tested positive for one or more potentially zoonotic enteric pathogens (Campylobacter jejuni, C. coli, non-typhoidal Salmonella, diarrheagenic E. coli, Giardia, Cryptosporidium, or rotavirus). We did not find any association between the presence of particular pathogens in household animals, and MSD in children. CONCLUSIONS AND SIGNIFICANCE: Public health agencies should continue to promote frequent hand washing, including after animal contact, to reduce the risk of MSD. Future studies should address specific causal relations of MSD with sheep and chicken husbandry practices, and with the presence of rodents. |
Factors associated with the duration of moderate-to-severe diarrhea among children in rural western Kenya enrolled in the Global Enteric Multicenter Study, 2008-2012
Schilling KA , Omore R , Derado G , Ayers T , Ochieng JB , Farag TH , Nasrin D , Panchalingam S , Nataro JP , Kotloff KL , Levine MM , Oundo J , Parsons MB , Bopp C , Laserson K , Stauber CE , Rothenberg R , Breiman RF , O'Reilly CE , Mintz ED . Am J Trop Med Hyg 2017 97 (1) 248-258 Diarrheal disease is a leading cause of death among young children worldwide. As rates of acute diarrhea (AD; 1-6 days duration) have decreased, persistent diarrhea (PD; > 14 days duration) accounts for a greater proportion of the diarrheal disease burden. We describe factors associated with the duration of moderate-to-severe diarrhea in Kenyan children < 5 years old enrolled in the Global Enteric Multicenter Study. We found 587 (58%) children experienced AD, 360 (35%) had prolonged acute diarrhea (ProAD; 7-13 days duration), and 73 (7%) had PD. We constructed a Cox proportional hazards model to identify factors associated with diarrheal duration. Risk factors independently associated with longer diarrheal duration included infection with Cryptosporidium (hazard ratio [HR]: 0.868, P = 0.035), using an unimproved drinking water source (HR: 0.87, P = 0.035), and being stunted at enrollment (HR: 0.026, P < 0.0001). Diarrheal illness of extended duration appears to be multifactorial; given its association with adverse health and development outcomes, effective strategies should be implemented to reduce the duration and severity of diarrheal illness. Effective treatments for Cryptosporidium should be identified, interventions to improve drinking water are imperative, and nutrition should be improved through exclusive breastfeeding in infants ≤ 6 months and appropriate continued feeding practices for ill children. |
Sanitation practices and perceptions in Kakuma refugee camp, Kenya: Comparing the status quo with a novel service-based approach
Nyoka R , Foote AD , Woods E , Lokey H , O'Reilly CE , Magumba F , Okello P , Mintz ED , Marano N , Morris JF . PLoS One 2017 12 (7) e0180864 Globally, an estimated 2.5 billion people lack access to improved sanitation. Unimproved sanitation increases the risk of morbidity and mortality, especially in protracted refugee situations where sanitation is based on pit latrine use. Once the pit is full, waste remains in the pit, necessitating the construction of a new latrine, straining available land and funding resources. A viable, sustainable solution is needed. This study used qualitative and quantitative methods to design, implement, and pilot a novel sanitation system in Kakuma refugee camp, Kenya. An initial round of 12 pre-implementation focus group discussions (FGDs) were conducted with Dinka and Somali residents to understand sanitation practices, perceptions, and needs. FGDs and a supplementary pre-implementation survey informed the development of an innovative sanitation management system that incorporated the provision of urine and liquid-diverting toilets, which separate urine and fecal waste, and a service-based sanitation system that included weekly waste collection. The new system was implemented on a pilot scale for 6 weeks. During the implementation, bi-weekly surveys were administered in each study household to monitor user perceptions and challenges. At the end of the pilot, the sanitation system was assessed using a second round of four post-implementation FGDs. Those who piloted the new sanitation system reported high levels of user satisfaction. Reported benefits included odor reduction, insect/pest reduction, the sitting design, the appropriateness for special populations, and waste collection. However, urine and liquid diversion presented a challenge for users who perform anal washing and for women who had experienced female genital mutilation. Refugee populations are often culturally and ethnically diverse. Using residents' input to inform the development of sanitation solutions can increase user acceptability and provide opportunities to improve sanitation system designs based on specific needs. |
Epidemiology, seasonality and factors associated with rotavirus infection among children with moderate-to-severe diarrhea in rural western Kenya, 2008-2012: The Global Enteric Multicenter Study (GEMS)
Omore R , Tate JE , O'Reilly CE , Ayers T , Williamson J , Moke F , Schilling KA , Awuor AO , Jaron P , Ochieng JB , Oundo J , Parashar UD , Parsons MB , Bopp CC , Nasrin D , Farag TH , Kotloff KL , Nataro JP , Panchalingam S , Levine MM , Laserson KF , Nuorti JP , Mintz ED , Breiman RF . PLoS One 2016 11 (8) e0160060 OBJECTIVE: To evaluate factors associated with rotavirus diarrhea and to describe severity of illness among children <5 years old with non-dysenteric, moderate-to-severe diarrhea (MSD) in rural western Kenya. METHODS: We analyzed data from children <5 years old with non-dysenteric MSD enrolled as cases in the Global Enteric Multicenter Study (GEMS) in Kenya. A non-dysenteric MSD case was defined as a child with ≥3 loose stools in 24 hrs. and one or more of the following: sunken eyes, skin tenting, intravenous rehydration, or hospitalization, who sought care at a sentinel health center within 7 days of illness onset. Rotavirus antigens in stool samples were detected by ELISA. Demographic and clinical information was collected at enrollment and during a single follow-up home visit at approximately 60 days. We analyzed diarrhea severity using a GEMS 17 point numerical scoring system adapted from the Vesikari score. We used logistic regression to evaluate factors associated with rotavirus infection. RESULTS: From January 31, 2008 to September 30, 2012, among 1,637 (92%) non-dysenteric MSD cases, rotavirus was detected in stools of 245 (15.0%). Rotavirus-positive compared with negative cases were: younger (median age, 8 vs. 13 months; p<0.0001), had more severe illness (median severity score, 9 vs 8; p<0.0001) and had to be hospitalized more frequently (37/245 [15.1%] vs. 134/1,392 [9.6%]), p <0.013). Independent factors associated with rotavirus infection included age 0-11 months old (aOR = 5.29, 95% CI 3.14-8.89) and presenting with vomiting ≥3 times/24hrs (aOR = 2.58, 95% CI [1.91-3.48]). Rotavirus was detected more commonly in warm and dry months than in the cool and rainy months (142/691 [20%] vs 70/673 [10%]) p<0.0001). CONCLUSIONS: Diarrhea caused by rotavirus is associated with severe symptoms leading to hospitalization. Consistent with other settings, infants had the greatest burden of disease. |
The burden of cryptosporidium diarrheal disease among children < 24 months of age in moderate/high mortality regions of Sub-Saharan Africa and South Asia, utilizing data from the Global Enteric Multicenter Study (GEMS)
Sow SO , Muhsen K , Nasrin D , Blackwelder WC , Wu Y , Farag TH , Panchalingam S , Sur D , Zaidi AK , Faruque AS , Saha D , Adegbola R , Alonso PL , Breiman RF , Bassat Q , Tamboura B , Sanogo D , Onwuchekwa U , Manna B , Ramamurthy T , Kanungo S , Ahmed S , Qureshi S , Quadri F , Hossain A , Das SK , Antonio M , Hossain MJ , Mandomando I , Nhampossa T , Acacio S , Omore R , Oundo JO , Ochieng JB , Mintz ED , O'Reilly CE , Berkeley LY , Livio S , Tennant SM , Sommerfelt H , Nataro JP , Ziv-Baran T , Robins-Browne RM , Mishcherkin V , Zhang J , Liu J , Houpt ER , Kotloff KL , Levine MM . PLoS Negl Trop Dis 2016 10 (5) e0004729 BACKGROUND: The importance of Cryptosporidium as a pediatric enteropathogen in developing countries is recognized. METHODS: Data from the Global Enteric Multicenter Study (GEMS), a 3-year, 7-site, case-control study of moderate-to-severe diarrhea (MSD) and GEMS-1A (1-year study of MSD and less-severe diarrhea [LSD]) were analyzed. Stools from 12,110 MSD and 3,174 LSD cases among children aged <60 months and from 21,527 randomly-selected controls matched by age, sex and community were immunoassay-tested for Cryptosporidium. Species of a subset of Cryptosporidium-positive specimens were identified by PCR; GP60 sequencing identified anthroponotic C. parvum. Combined annual Cryptosporidium-attributable diarrhea incidences among children aged <24 months for African and Asian GEMS sites were extrapolated to sub-Saharan Africa and South Asian regions to estimate region-wide MSD and LSD burdens. Attributable and excess mortality due to Cryptosporidium diarrhea were estimated. FINDINGS: Cryptosporidium was significantly associated with MSD and LSD below age 24 months. Among Cryptosporidium-positive MSD cases, C. hominis was detected in 77.8% (95% CI, 73.0%-81.9%) and C. parvum in 9.9% (95% CI, 7.1%-13.6%); 92% of C. parvum tested were anthroponotic genotypes. Annual Cryptosporidium-attributable MSD incidence was 3.48 (95% CI, 2.27-4.67) and 3.18 (95% CI, 1.85-4.52) per 100 child-years in African and Asian infants, respectively, and 1.41 (95% CI, 0.73-2.08) and 1.36 (95% CI, 0.66-2.05) per 100 child-years in toddlers. Corresponding Cryptosporidium-attributable LSD incidences per 100 child-years were 2.52 (95% CI, 0.33-5.01) and 4.88 (95% CI, 0.82-8.92) in infants and 4.04 (95% CI, 0.56-7.51) and 4.71 (95% CI, 0.24-9.18) in toddlers. We estimate 2.9 and 4.7 million Cryptosporidium-attributable cases annually in children aged <24 months in the sub-Saharan Africa and India/Pakistan/Bangladesh/Nepal/Afghanistan regions, respectively, and ~202,000 Cryptosporidium-attributable deaths (regions combined). ~59,000 excess deaths occurred among Cryptosporidium-attributable diarrhea cases over expected if cases had been Cryptosporidium-negative. CONCLUSIONS: The enormous African/Asian Cryptosporidium disease burden warrants investments to develop vaccines, diagnostics and therapies. |
Sanitation and hygiene-specific risk factors for moderate-to-severe diarrhea in young children in the Global Enteric Multicenter Study, 2007-2011: case-control study
Baker KK , O'Reilly CE , Levine MM , Kotloff KL , Nataro JP , Ayers TL , Farag TH , Nasrin D , Blackwelder WC , Wu Y , Alonso PL , Breiman RF , Omore R , Faruque AS , Das SK , Ahmed S , Saha D , Sow SO , Sur D , Zaidi AK , Quadri F , Mintz ED . PLoS Med 2016 13 (5) e1002010 BACKGROUND: Diarrheal disease is the second leading cause of disease in children less than 5 y of age. Poor water, sanitation, and hygiene conditions are the primary routes of exposure and infection. Sanitation and hygiene interventions are estimated to generate a 36% and 48% reduction in diarrheal risk in young children, respectively. Little is known about whether the number of households sharing a sanitation facility affects a child's risk of diarrhea. The objective of this study was to describe sanitation and hygiene access across the Global Enteric Multicenter Study (GEMS) sites in Africa and South Asia and to assess sanitation and hygiene exposures, including shared sanitation access, as risk factors for moderate-to-severe diarrhea (MSD) in children less than 5 y of age. METHODS/FINDINGS: The GEMS matched case-control study was conducted between December 1, 2007, and March 3, 2011, at seven sites in Basse, The Gambia; Nyanza Province, Kenya; Bamako, Mali; Manhica, Mozambique; Mirzapur, Bangladesh; Kolkata, India; and Karachi, Pakistan. Data was collected for 8,592 case children aged <5 y old experiencing MSD and for 12,390 asymptomatic age, gender, and neighborhood-matched controls. An MSD case was defined as a child with a diarrheal illness <7 d duration comprising ≥3 loose stools in 24 h and ≥1 of the following: sunken eyes, skin tenting, dysentery, intravenous (IV) rehydration, or hospitalization. Site-specific conditional logistic regression models were used to explore the association between sanitation and hygiene exposures and MSD. Most households at six sites (>93%) had access to a sanitation facility, while 70% of households in rural Kenya had access to a facility. Practicing open defecation was a risk factor for MSD in children <5 y old in Kenya. Sharing sanitation facilities with 1-2 or ≥3 other households was a statistically significant risk factor for MSD in Kenya, Mali, Mozambique, and Pakistan. Among those with a designated handwashing area near the home, soap or ash were more frequently observed at control households and were significantly protective against MSD in Mozambique and India. CONCLUSIONS: This study suggests that sharing a sanitation facility with just one to two other households can increase the risk of MSD in young children, compared to using a private facility. Interventions aimed at increasing access to private household sanitation facilities may reduce the burden of MSD in children. These findings support the current World Health Organization/ United Nations Children's Emergency Fund (UNICEF) system that categorizes shared sanitation as unimproved. |
The relationship between distance to water source and moderate-to-severe diarrhea in the Global Enterics Multi-Center Study in Kenya, 2008-2011
Nygren BL , O'Reilly CE , Rajasingham A , Omore R , Ombok M , Awuor AO , Jaron P , Moke F , Vulule J , Laserson K , Farag TH , Nasrin D , Nataro JP , Kotloff KL , Levine MM , Derado G , Ayers TL , Lash RR , Breiman RF , Mintz ED . Am J Trop Med Hyg 2016 94 (5) 1143-9 In the developing world, fetching water for drinking and other household uses is a substantial burden that affects water quantity and quality in the household. We used logistic regression to examine whether reported household water fetching times were a risk factor for moderate-to-severe diarrhea (MSD) using case-control data of 3,359 households from the Global Enterics Multi-Center Study in Kenya in 2009-2011. We collected additional global positioning system (GPS) data for a subset of 254 randomly selected households and compared GPS-based straight line and actual travel path distances to fetching times reported by respondents. GPS-based data were highly correlated with respondent-provided times (Spearman correlation coefficient = 0.81, P < 0.0001). The median estimated one-way distance to water source was 200 m for cases and 171 for controls (Wilcoxon rank sums/Mann-Whitney P = 0.21). A round-trip fetching time of > 30 minutes was reported by 25% of cases versus 15% of controls and was significantly associated with MSD where rainwater was not used in the last 2 weeks (odds ratio = 1.97, 95% confidence interval = 1.56-2.49). These data support the United Nations definition of access to an improved water source being within 30 minutes total round-trip travel time. |
Notes from the field: Ongoing cholera outbreak - Kenya, 2014-2016
George G , Rotich J , Kigen H , Catherine K , Waweru B , Boru W , Galgalo T , Githuku J , Obonyo M , Curran K , Narra R , Crowe SJ , O'Reilly CE , Macharia D , Montgomery J , Neatherlin J , De Cock KM , Lowther S , Gura Z , Langat D , Njeru I , Kioko J , Muraguri N . MMWR Morb Mortal Wkly Rep 2016 65 (3) 68-69 On January 6, 2015, a man aged 40 years was admitted to Kenyatta National Hospital in Nairobi, Kenya, with acute watery diarrhea. The patient was found to be infected with toxigenic Vibrio cholerae serogroup O1, serotype Inaba. A subsequent review of surveillance reports identified four patients in Nairobi County during the preceding month who met either of the Kenya Ministry of Health suspected cholera case definitions: 1) severe dehydration or death from acute watery diarrhea (more than four episodes in 12 hours) in a patient aged ≥5 years, or 2) acute watery diarrhea in a patient aged ≥2 years in an area where there was an outbreak of cholera. An outbreak investigation was immediately initiated. A confirmed cholera case was defined as isolation of V. cholerae O1 or O139 from the stool of a patient with suspected cholera or a suspected cholera case that was epidemiologically linked to a confirmed case. By January 15, 2016, a total of 11,033 suspected or confirmed cases had been reported from 22 of Kenya's 47 counties. The outbreak is ongoing. |
Improved health among people living with HIV/AIDS who received packages of proven preventive health interventions, Amhara, Ethiopia
O'Reilly CE , Taylor EV , Ayers T , Fantu R , Abayneh SA , Marston B , Molla YB , Sewnet T , Abebe F , Hoekstra RM , Quick R . PLoS One 2014 9 (9) e107662 In 2009, basic care packages (BCP) containing health products were distributed to HIV-infected persons in Ethiopia who were clients of antiretroviral therapy clinics. To measure health impact, we enrolled clients from an intervention hospital and comparison hospital, and then conducted a baseline survey, and 7 bi-weekly home visits. We enrolled 405 intervention group clients and 344 comparison clients. Intervention clients were more likely than comparison clients to have detectable chlorine in stored water (40% vs. 1%, p<0.001), soap (51% vs. 36%, p<0.001), and a BCP water container (65% vs. 0%, p<0.001) at every home visit. Intervention clients were less likely than comparison clients to report illness (44% vs. 67%, p<0.001) or health facility visits for illness (74% vs. 95%, p<0.001), and had lower median illness scores (1.0 vs. 3.0, p<0.05). Participation in the BCP program appeared to improve reported health outcomes. |
Draft Genome Sequences of Nine Enteropathogenic Escherichia coli Strains from Kenya.
Hazen TH , Humphrys MS , Ochieng JB , Parsons M , Bopp CA , O'Reilly CE , Mintz E , Rasko DA . Genome Announc 2014 2 (3) ![]() We report here the draft genome sequences of nine enteropathogenic Escherichia coli (EPEC) strains isolated from children in Kenya who died during hospitalization with diarrhea. Each of the isolates possess the EPEC adherence factor (EAF) plasmid encoding the bundle-forming pilus, which is characteristic of EPEC. These isolates represent diverse serogroups and EPEC phylogenomic lineages. |
A national cholera epidemic with high case fatality rates--Kenya 2009
Loharikar A , Briere E , Ope M , Langat D , Njeru I , Gathigi L , Makayotto L , Ismail AM , Thuranira M , Abade A , Amwayi S , Omolo J , Oundo J , De Cock KM , Breiman RF , Ayers T , Mintz E , O'Reilly CE . J Infect Dis 2013 208 Suppl 1 S69-77 BACKGROUND: Cholera remains endemic in sub-Saharan Africa. We characterized the 2009 cholera outbreaks in Kenya and evaluated the response. METHODS: We analyzed surveillance data and estimated case fatality rates (CFRs). Households in 2 districts, East Pokot (224 cases; CFR = 11.7%) and Turkana South (1493 cases; CFR = 1.0%), were surveyed. We randomly selected 15 villages and 8 households per village in each district. Healthcare workers at 27 health facilities (HFs) were surveyed in both districts. RESULTS:. In 2009, cholera outbreaks caused a reported 11 425 cases and 264 deaths in Kenya. Data were available from 44 districts for 6893 (60%) cases. District CFRs ranged from 0% to 14.3%. Surveyed household respondents (n = 240) were aware of cholera (97.5%) and oral rehydration solution (ORS) (87.9%). Cholera deaths were reported more frequently from East Pokot (n = 120) than Turkana South (n = 120) households (20.7% vs. 12.3%). The average travel time to a HF was 31 hours in East Pokot compared with 2 hours in Turkana South. Fewer respondents in East Pokot (9.8%) than in Turkana South (33.9%) stated that ORS was available in their village. ORS or intravenous fluid shortages occurred in 20 (76.9%) surveyed HFs. CONCLUSIONS: High CFRs in Kenya are related to healthcare access disparities, including availability of rehydration supplies. |
Survey of culture, golden gate assay, universal biosensor assay, and 16S rRNA gene sequencing as alternative methods of bacterial pathogen detection
Lindsay B , Pop M , Antonio M , Walker AW , Mai V , Ahmed D , Oundo J , Tamboura B , Panchalingam S , Levine MM , Kotloff K , Li S , Magder LS , Paulson JN , Liu B , Ikumapayi U , Ebruke C , Dione M , Adeyemi M , Rance R , Stares MD , Ukhanova M , Barnes B , Lewis I , Ahmed F , Alam MT , Amin R , Siddiqui S , Ochieng JB , Ouma E , Juma J , Mailu E , Omore R , O'Reilly CE , Hannis J , Manalili S , Deleon J , Yasuda I , Blyn L , Ranken R , Li F , Housley R , Ecker DJ , Hossain MA , Breiman RF , Morris JG , McDaniel TK , Parkhill J , Saha D , Sampath R , Stine OC , Nataro JP . J Clin Microbiol 2013 51 (10) 3263-9 ![]() Cultivation-based assays combined with PCR or enzyme-linked immunosorbent assay (ELISA)-based methods for finding virulence factors are standard methods for detecting bacterial pathogens in stools; however, with emerging molecular technologies, new methods have become available. The aim of this study was to compare four distinct detection technologies for the identification of pathogens in stools from children under 5 years of age in The Gambia, Mali, Kenya, and Bangladesh. The children were identified, using currently accepted clinical protocols, as either controls or cases with moderate to severe diarrhea. A total of 3,610 stool samples were tested by established clinical culture techniques: 3,179 DNA samples by the Universal Biosensor assay (Ibis Biosciences, Inc.), 1,466 DNA samples by the GoldenGate assay (Illumina), and 1,006 DNA samples by sequencing of 16S rRNA genes. Each method detected different proportions of samples testing positive for each of seven enteric pathogens, enteroaggregative Escherichia coli (EAEC), enterotoxigenic E. coli (ETEC), enteropathogenic E. coli (EPEC), Shigella spp., Campylobacter jejuni, Salmonella enterica, and Aeromonas spp. The comparisons among detection methods included the frequency of positive stool samples and kappa values for making pairwise comparisons. Overall, the standard culture methods detected Shigella spp., EPEC, ETEC, and EAEC in smaller proportions of the samples than either of the methods based on detection of the virulence genes from DNA in whole stools. The GoldenGate method revealed the greatest agreement with the other methods. The agreement among methods was higher in cases than in controls. The new molecular technologies have a high potential for highly sensitive identification of bacterial diarrheal pathogens. |
Quality of piped and stored water in households with children under five years of age enrolled in the Mali site of the Global Enteric Multi-Center Study (GEMS)
Baker KK , Sow S , Kotloff KL , Nataro JP , Farag TH , Tamboura B , Doumbia M , Sanogo D , Diarra D , O'Reilly CE , Mintz E , Panchalingam S , Wu Y , Blackwelder WC , Levine MM . Am J Trop Med Hyg 2013 89 (2) 214-222 Water, sanitation, and hygiene information was collected during a matched case-control study of moderate and severe diarrhea (MSD) among 4,096 children < 5 years of age in Bamako, Mali. Primary use of piped water (conditional odds ratio [cOR] = 0.45; 0.34-0.62), continuous water access (cOR = 0.30; 0.20-0.43), fetching water daily (cOR = 0.77; 0.63-0.96), and breastfeeding (cOR = 0.65; 0.49-0.88) significantly reduced the likelihood of MSD. Fetching water in > 30 minutes (cOR = 2.56; 1.55-4.23) was associated with MSD. Piped tap water and courier-delivered water contained high (> 2 mg/L) concentrations of free residual chlorine and no detectable Escherichia coli. However, many households stored water overnight, resulting in inadequate free residual chlorine (< 0.2 mg/L) for preventing microbial contamination. Coliforms and E. coli were detected in 48% and 8% of stored household water samples, respectively. Although most of Bamako's population enjoys access to an improved water source, water quality is often compromised during household storage. |
Burden and aetiology of diarrhoeal disease in infants and young children in developing countries (the Global Enteric Multicenter Study, GEMS): a prospective, case-control study
Kotloff KL , Nataro JP , Blackwelder WC , Nasrin D , Farag TH , Panchalingam S , Wu Y , Sow SO , Sur D , Breiman RF , Faruque AS , Zaidi AK , Saha D , Alonso PL , Tamboura B , Sanogo D , Onwuchekwa U , Manna B , Ramamurthy T , Kanungo S , Ochieng JB , Omore R , Oundo JO , Hossain A , Das SK , Ahmed S , Qureshi S , Quadri F , Adegbola RA , Antonio M , Hossain MJ , Akinsola A , Mandomando I , Nhampossa T , Acacio S , Biswas K , O'Reilly CE , Mintz ED , Berkeley LY , Muhsen K , Sommerfelt H , Robins-Browne RM , Levine MM . Lancet 2013 382 (9888) 209-22 BACKGROUND: Diarrhoeal diseases cause illness and death among children younger than 5 years in low-income countries. We designed the Global Enteric Multicenter Study (GEMS) to identify the aetiology and population-based burden of paediatric diarrhoeal disease in sub-Saharan Africa and south Asia. METHODS: The GEMS is a 3-year, prospective, age-stratified, matched case-control study of moderate-to-severe diarrhoea in children aged 0-59 months residing in censused populations at four sites in Africa and three in Asia. We recruited children with moderate-to-severe diarrhoea seeking care at health centres along with one to three randomly selected matched community control children without diarrhoea. From patients with moderate-to-severe diarrhoea and controls, we obtained clinical and epidemiological data, anthropometric measurements, and a faecal sample to identify enteropathogens at enrolment; one follow-up home visit was made about 60 days later to ascertain vital status, clinical outcome, and interval growth. FINDINGS: We enrolled 9439 children with moderate-to-severe diarrhoea and 13,129 control children without diarrhoea. By analysing adjusted population attributable fractions, most attributable cases of moderate-to-severe diarrhoea were due to four pathogens: rotavirus, Cryptosporidium, enterotoxigenic Escherichia coli producing heat-stable toxin (ST-ETEC; with or without co-expression of heat-labile enterotoxin), and Shigella. Other pathogens were important in selected sites (eg, Aeromonas, Vibrio cholerae O1, Campylobacter jejuni). Odds of dying during follow-up were 8.5-fold higher in patients with moderate-to-severe diarrhoea than in controls (odd ratio 8.5, 95% CI 5.8-12.5, p<0.0001); most deaths (167 [87.9%]) occurred during the first 2 years of life. Pathogens associated with increased risk of case death were ST-ETEC (hazard ratio [HR] 1.9; 0.99-3.5) and typical enteropathogenic E coli (HR 2.6; 1.6-4.1) in infants aged 0-11 months, and Cryptosporidium (HR 2.3; 1.3-4.3) in toddlers aged 12-23 months. INTERPRETATION: Interventions targeting five pathogens (rotavirus, Shigella, ST-ETEC, Cryptosporidium, typical enteropathogenic E coli) can substantially reduce the burden of moderate-to-severe diarrhoea. New methods and accelerated implementation of existing interventions (rotavirus vaccine and zinc) are needed to prevent disease and improve outcomes. FUNDING: The Bill & Melinda Gates Foundation. |
Health-seeking behavior during childhood diarrheal illness: results of healthcare use and attitude surveys of caretakers in western Kenya, 2007-2010
Omore R , O'Reilly CE , Williamson J , Moke F , Were V , Farag TH , van Eijk AM , Kotloff KL , Levine MM , Obor D , Odhiambo F , Vulule J , Laserson KF , Mintz ED , Breiman RF . Am J Trop Med Hyg 2013 89 29-40 We interviewed caretakers of 1,043 children < 5 years old in a baseline cross-sectional survey (April to May 2007) and > 20,000 children on five separate subsequent occasions (May of 2009 to December 31, 2010) to assess healthcare seeking patterns for diarrhea. Diarrhea prevalence during the preceding 2 weeks ranged from 26% at baseline to 4-11% during 2009-2010. Caretakers were less likely to seek healthcare outside the home for infants (versus older children) with diarrhea (adjusted odds ratio [aOR] = 0.33, confidence interval [CI] = 0.12-0.87). Caretakers of children with reduced food intake (aOR = 3.42, CI = 1.37-8.53) and sunken eyes during their diarrheal episode were more likely to seek care outside home (aOR = 4.76, CI = 1.13-8.89). Caretakers with formal education were more likely to provide oral rehydration solution (aOR = 3.01, CI = 1.41-6.42) and visit a healthcare facility (aOR = 3.32, CI = 1.56-7.07). Studies calculating diarrheal incidence and healthcare seeking should account for seasonal trends. Improving caretakers' knowledge of home management could prevent severe diarrhea. |
Risk factors for death among children less than 5 years old hospitalized with diarrhea in rural western Kenya, 2005-2007: a cohort study
O'Reilly CE , Jaron P , Ochieng B , Nyaguara A , Tate JE , Parsons MB , Bopp CA , Williams KA , Vinje J , Blanton E , Wannemuehler KA , Vulule J , Laserson KF , Breiman RF , Feikin DR , Widdowson MA , Mintz E . PLoS Med 2012 9 (7) e1001256 BACKGROUND: Diarrhea is a leading cause of childhood morbidity and mortality in sub-Saharan Africa. Data on risk factors for mortality are limited. We conducted hospital-based surveillance to characterize the etiology of diarrhea and identify risk factors for death among children hospitalized with diarrhea in rural western Kenya. METHODS AND FINDINGS: We enrolled all children <5 years old, hospitalized with diarrhea (≥3 loose stools in 24 hours) at two district hospitals in Nyanza Province, western Kenya. Clinical and demographic information was collected. Stool specimens were tested for bacterial and viral pathogens. Bivariate and multivariable logistic regression analyses were carried out to identify risk factors for death. From May 23, 2005 to May 22, 2007, 1,146 children <5 years old were enrolled; 107 (9%) children died during hospitalization. Nontyphoidal Salmonella were identified in 10% (118), Campylobacter in 5% (57), and Shigella in 4% (42) of 1,137 stool samples; rotavirus was detected in 19% (196) of 1,021 stool samples. Among stools from children who died, nontyphoidal Salmonella were detected in 22%, Shigella in 11%, rotavirus in 9%, Campylobacter in 5%, and S. Typhi in <1%. In multivariable analysis, infants who died were more likely to have nontyphoidal Salmonella (adjusted odds ratio [aOR] = 6.8; 95% CI 3.1-14.9), and children <5 years to have Shigella (aOR = 5.5; 95% CI 2.2-14.0) identified than children who survived. Children who died were less likely to be infected with rotavirus (OR = 0.4; 95% CI 0.2-0.8). Further risk factors for death included being malnourished (aOR = 4.2; 95% CI 2.1-8.7); having oral thrush on physical exam (aOR = 2.3; 95% CI 1.4-3.8); having previously sought care at a hospital for the illness (aOR = 2.2; 95% CI 1.2-3.8); and being dehydrated as diagnosed at discharge/death (aOR = 2.5; 95% CI 1.5-4.1). A clinical diagnosis of malaria, and malaria parasites seen on blood smear, were not associated with increased risk of death. This study only captured in-hospital childhood deaths, and likely missed a substantial number of additional deaths that occurred at home. CONCLUSION: Nontyphoidal Salmonella and Shigella are associated with mortality among rural Kenyan children with diarrhea who access a hospital. Improved prevention and treatment of diarrheal disease is necessary. Enhanced surveillance and simplified laboratory diagnostics in Africa may assist clinicians in appropriately treating potentially fatal diarrheal illness. Please see later in the article for the Editors' Summary. |
The epidemiology of hospitalization with diarrhea in rural Kenya: the utility of existing health facility data in developing countries
Tornheim JA , Manya AS , Oyando N , Kabaka S , O'Reilly CE , Breiman RF , Feikin DR . Int J Infect Dis 2009 14 (6) e499-505 OBJECTIVES: In developing countries where prospective surveillance is resource-intensive, existing hospital data can define incidence, mortality, and risk factors that can help target interventions and track trends in disease burden. METHODS: We reviewed hospitalizations from 2001 to 2003 at all inpatient facilities in Bondo District, Kenya. RESULTS: Diarrhea was responsible for 11.2% (n=2158) of hospitalizations. The annual incidence was 550 and 216 per 100000 persons aged <5 and ≥5 years, respectively. The incidence was highest in infants (1138 per 100000 persons), decreased in older children, peaked again among 20-29-year-olds (341 per 100000), and declined among those ≥65 years (157 per 100000). Female adults had higher incidence than males (rate ratio=1.84, 95% CI 1.61-2.10). Incidence decreased with distance from the district referral hospital (4.5% per kilometer, p<0.0001) and from the nearest inpatient facility (6.6% per kilometer, p=0.012). Case-fatality was high (8.0%), and was higher among adults than young children. Co-diagnosis with malaria, pneumonia, HIV, and tuberculosis was common. Peak diarrhea incidence fell one to two months after heavy rains. CONCLUSIONS: The trends revealed here provide useful data for public health priority setting and planning, including preventative interventions. The utility of such data justifies renewed efforts to establish and strengthen health management information systems in developing countries. |
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