Last data update: Dec 09, 2024. (Total: 48320 publications since 2009)
Records 1-30 (of 32 Records) |
Query Trace: Chitnis AS[original query] |
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Tuberculosis and chronic hepatitis B virus infection screening among non-US-born persons in an Integrated Health System in California
Wick JM , Ni Y , Halmer N , Wong RJ , Chitnis AS , Jaganath D , Krueger AL , Skarbinski J . Open Forum Infect Dis 2024 11 (9) ofae484 BACKGROUND: Tuberculosis infection (TBI) and chronic hepatitis B virus (HBV) infection disproportionately affect non-US-born persons. Early identification and treatment are critical to reduce transmission, morbidity, and mortality, but little is known about screening in the United States. METHODS: We conducted a cross-sectional study in a large integrated California health system in September 2022 assessing TBI and HBV screening among persons aged ≥18 years who were born in countries with high TB burden (TB disease incidence rates ≥20/100 000 population) and/or HBV burden (hepatitis B surface antigen seroprevalence >2%). RESULTS: Of 510 361 non-US-born persons born in countries with high TB burden, 322 027 (63.1%) were born in countries with high HBV burden and 188 334 (36.9%) in countries with only high TB burden. Among persons born in countries with high TB and HBV burden, 29.6% were screened for TBI, 64.5% for HBV, and 23.4% for TBI and HBV; 9.9% had TBI and 3.1% had HBV infection. Among persons born in countries with high TB burden only, 27.9% were screened for TBI and 7.5% had TBI. CONCLUSIONS: Among non-US-born persons from countries with high TB and HBV burden, we found low screening rates and elevated prevalence of TBI and chronic HBV infection. Cotesting for TBI and HBV infection in non-US-born persons from countries with high TB and HBV burden might improve outcomes by identifying persons who warrant TBI treatment, HBV treatment, or HBV vaccination. Increased screening is the first step in reducing health inequities and overall disease burden. |
Expected vs reported chronic hepatitis B infection cases in persons with active tuberculosis - California, 2016-2020
Bertumen JB , Pascopella L , Han E , Glenn-Finer R , Wong RJ , Chitnis A , Jaganath D , Jewell MP , Gounder P , McElroy S , Stockman L , Barry P . J Public Health Manag Pract 2024 Epidemiologic data regarding persons with active tuberculosis (TB) and chronic hepatitis B virus (cHBV) infection are limited because of lack of routine surveillance of cHBV in persons with TB. Potential underdiagnosis of cHBV in California among those with TB is concerning. We matched TB and cHBV registries to identify cHBV infections among persons diagnosed with TB during 2016-2020 and described their demographic characteristics. We calculated expected cHBV cases among persons with TB for each demographic characteristic using published cHBV prevalence estimates for the locations of birth for persons with TB. Estimates were from general or emigrant adult and teen populations. Reported cHBV infection among persons with TB were 23% lower than expected, particularly among Asian persons, persons living in the two healthiest Healthy Places Index quartiles, and residents of less populated jurisdictions in California. Results show the possibility exists for underdiagnosis of cHBV in persons with TB in California. |
Epidemiology and treatment outcomes of tuberculosis with chronic hepatitis B infection-California, 2016-2020
Bertumen JB , Pascopella L , Han E , Glenn-Finer R , Wong RJ , Chitnis A , Jaganath D , Jewell M , Gounder P , McElroy S , Stockman L , Barry P . Clin Infect Dis 2024 BACKGROUND: Improved epidemiologic and treatment data for active tuberculosis (TB) with chronic hepatitis B virus (cHBV) infection might inform and encourage screening and vaccination programs focused on persons at risk of having both conditions. METHODS: We matched the California Department of Public Health TB registry during 2016-2020 to the cHBV registry using probabilistic matching algorithms. We used chi-square analysis to compare the characteristics of persons with TB and cHBV with those with TB only. We compared TB treatment outcomes between these groups using modified Poisson regression models. We calculated the time between reporting of TB and cHBV diagnoses for those with both conditions. RESULTS: We identified 8,435 persons with TB, including 316 (3.7%) with cHBV.- Among persons with TB and cHBV, 256 (81.0%) were non-U.S.-born Asian vs 4,186 (51.6%) with TB only (P <0.0001). End-stage renal disease (26 [8.2%] vs 322 [4.0%]; P <0.001) and HIV (21 [6.7%] vs 247 [3.0%]; P value = 0.02) were more frequent among those with TB and cHBV compared with those with TB only. Among those with both conditions, 35 (11.1%) had TB diagnosed >60 days before cHBV (median 363 days) and 220 (69.6%) had TB diagnosed >60 days after cHBV (median 3,411 days). CONCLUSION: Persons with TB and cHBV were found more frequently in certain groups compared with TB only, and infrequently had their conditions diagnosed together. This highlights an opportunity to improve screening and treatment of TB and cHBV in those at high risk for coinfection. |
Correction: Testing and treatment for malaria elimination: a systematic review
Newby G , Cotter C , Roh ME , Harvard K , Bennett A , Hwang J , Chitnis N , Fine S , Stresman G , Chen I , Gosling R , Hsiang MS . Malar J 2024 23 (1) 63 |
Tuberculosis diagnostic delays and treatment outcomes among patients with COVID-19, California, USA, 2020
Han E , Nabity SA , Dasgupta-Tsinikas S , Guevara RE , Moore M , Kadakia A , Henry H , Cilnis M , Buhain S , Chitnis A , Chakrabarty M , Ky A , Nguyen Q , Low J , Jain S , Higashi J , Barry PM , Flood J . Emerg Infect Dis 2024 30 (1) 136-140 We assessed tuberculosis (TB) diagnostic delays among patients with TB and COVID-19 in California, USA. Among 58 persons, 43% experienced TB diagnostic delays, and a high proportion (83%) required hospitalization for TB. Even when viral respiratory pathogens circulate widely, timely TB diagnostic workup for at-risk persons remains critical for reducing TB-related illness. |
Testing and treatment for malaria elimination: A systematic review
Newby G , Cotter C , Roh ME , Harvard K , Bennett A , Hwang J , Chitnis N , Fine S , Stresman G , Chen I , Gosling R , Hsiang MS . Malar J 2023 22 (1) 254 BACKGROUND: Global interest in malaria elimination has prompted research on active test and treat (TaT) strategies. METHODS: A systematic review and meta-analysis were conducted to assess the effectiveness of TaT strategies to reduce malaria transmission. RESULTS: A total of 72 empirical research and 24 modelling studies were identified, mainly focused on proactive mass TaT (MTaT) and reactive case detection (RACD) in higher and lower transmission settings, respectively. Ten intervention studies compared MTaT to no MTaT and the evidence for impact on malaria incidence was weak. No intervention studies compared RACD to no RACD. Compared to passive case detection (PCD) alone, PCD + RACD using standard diagnostics increased infection detection 52.7% and 11.3% in low and very low transmission settings, respectively. Using molecular methods increased this detection of infections by 1.4- and 1.1-fold, respectively. CONCLUSION: Results suggest MTaT is not effective for reducing transmission. By increasing case detection, surveillance data provided by RACD may indirectly reduce transmission by informing coordinated responses of intervention targeting. |
Serological and metagenomic interrogation of cerebrospinal fluid implicates enteroviruses in pediatric acute flaccid myelitis (preprint)
Schubert RD , Hawes IA , Ramachandran PS , Ramesh A , Crawford ED , Pak JE , Wu W , Cheung CK , O'Donovan BD , Tato CM , Lyden A , Tan M , Sit R , Sowa GA , Sample HA , Zorn KC , Banerji D , Khan LM , Bove R , Hauser SL , Gelfand AA , Johnson-Kerner BL , Nash K , Krishnamoorthy KS , Chitnis T , Ding JZ , McMillan HJ , Chiu CY , Briggs B , Glaser CA , Yen C , Chu V , Wadford DA , Dominguez SR , Ng TFF , Marine RL , Lopez AS , Nix WA , Soldatos A , Gorman MP , Benson L , Messacar K , Konopka-Anstadt JL , Oberste MS , DeRisi JL , Wilson MR . bioRxiv 2019 666230 Background Since 2014, the United States has experienced a biennial spike in pediatric acute flaccid myelitis (AFM). Epidemiologic evidence suggests non-polio enteroviruses (EVs) are a potential etiology, yet EV RNA is rarely detected in cerebrospinal fluid (CSF) and only inconsistently identified from the respiratory tract, serum, or stool.Methods We interrogated CSF from children with AFM (n=42) and pediatric controls with other neurologic diseases (OND) (n=58). Samples were incubated with T7 bacteriophage expressing 481,966 sixty-two amino acid peptides with a fourteen amino acid overlap tiled across all known vertebrate virus and arbovirus genomes, an adaption of the VirScan method. Antibody-bound phage were deep sequenced to quantify enriched peptides with normalized counts expressed as reads per hundred thousand (rpK). EV antibody findings were confirmed with ELISA using whole viral protein 1 (VP1) from contemporary enterovirus (EV) A71 and D68 strains. Separately, metagenomic next-generation sequencing (mNGS) of CSF RNA, both unbiased and with targeted enrichment for EVs, was performed.Results The most significantly enriched viral family by VirScan of CSF in AFM versus OND controls was Picornaviridae (mean rpK 11,266 versus mean rpK 950, p-adjusted < 0.001, Wilcoxon signed-rank test with Bonferroni adjustment). Enriched Picornaviridae peptides belonged almost entirely to the genus Enterovirus. The mean EV VP1 ELISA signal in AFM (mean OD 0.51) was significantly higher than OND controls (mean OD 0.08, p-value < 0.001, Mann-Whitney test). mNGS did not detect additional enterovirus RNA in CSF.Conclusion Despite the rare detection of EV RNA in the CNS of patients with AFM, a pan-viral serologic assay identified high levels of CSF EV antibodies in AFM CSF compared to CSF from OND controls. These results provide further evidence for a causal role of non-polio enteroviruses in AFM. |
Incidence and consequences of damage to insecticide-treated mosquito nets in Kenya
Smith T , Denz A , Ombok M , Bayoh N , Koenker H , Chitnis N , Briet O , Yukich J , Gimnig JE . Malar J 2021 20 (1) 476 BACKGROUND: Efforts to improve the impact of long-lasting insecticidal nets (LLINs) should be informed by understanding of the causes of decay in effect. Holes in LLINs have been estimated to account for 7-11% of loss in effect on vectorial capacity for Plasmodium falciparum malaria in an analysis of repeated cross-sectional surveys of LLINs in Kenya. This does not account for the effect of holes as a cause of net attrition or non-use, which cannot be measured using only cross-sectional data. There is a need for estimates of how much these indirect effects of physical damage on use and attrition contribute to decay in effectiveness of LLINs. METHODS: Use, physical integrity, and survival were assessed in a cohort of 4514 LLINs followed for up to 4 years in Kenya. Flow diagrams were used to illustrate how the status of nets, in terms of categories of use, physical integrity, and attrition, changed between surveys carried out at 6-month intervals. A compartment model defined in terms of ordinary differential equations (ODEs) was used to estimate the transition rates between the categories. Effects of physical damage to LLINs on use and attrition were quantified by simulating counterfactuals in which there was no damage. RESULTS: Allowing for the direct effect of holes, the effect on use, and the effect on attrition, 18% of the impact on vectorial capacity was estimated to be lost because of damage. The estimated median lifetime of the LLINs was 2.9 years, but this was extended to 5.7 years in the counterfactual without physical damage. Nets that were in use were more likely to be in a damaged state than unused nets but use made little direct difference to LLIN lifetimes. Damage was reported as the reason for attrition for almost half of attrited nets, but the model estimated that almost all attrited nets had suffered some damage before attrition. CONCLUSIONS: Full quantification of the effects of damage will require measurement of the supply of new nets and of household stocks of unused nets, and also of their impacts on both net use and retention. The timing of mass distribution campaigns is less important than ensuring sufficient supply. In the Kenyan setting, nets acquired damage rapidly once use began and the damage led to rapid attrition. Increasing the robustness of nets could substantially increase their lifetime and impact but the impact of LLIN programmes on malaria transmission is ultimately limited by levels of use. Longitudinal analyses of net integrity data from different settings are needed to determine the importance of physical damage to nets as a driver of attrition and non-use, and the importance of frequent use as a cause of physical damage in different contexts. |
Sociodemographic Characteristics, Comorbidities, and Mortality Among Persons Diagnosed With Tuberculosis and COVID-19 in Close Succession in California, 2020.
Nabity SA , Han E , Lowenthal P , Henry H , Okoye N , Chakrabarty M , Chitnis AS , Kadakia A , Villarino E , Low J , Higashi J , Barry PM , Jain S , Flood J . JAMA Netw Open 2021 4 (12) e2136853 IMPORTANCE: Tuberculosis (TB) and COVID-19 are respiratory diseases that disproportionately occur among medically underserved populations; little is known about their epidemiologic intersection. OBJECTIVE: To characterize persons diagnosed with TB and COVID-19 in California. DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional analysis of population-based public health surveillance data assessed the sociodemographic, clinical, and epidemiologic characteristics of California residents who were diagnosed with TB (including cases diagnosed and reported between September 3, 2019, and December 31, 2020) and COVID-19 (including confirmed cases based on positive results on polymerase chain reaction tests and probable cases based on positive results on antigen assays reported through February 2, 2021) in close succession compared with those who were diagnosed with TB before the COVID-19 pandemic (between January 1, 2017, and December 31, 2019) or diagnosed with COVID-19 alone (through February 2, 2021). This analysis included 3 402 713 California residents with COVID-19 alone, 6280 with TB before the pandemic, and 91 with confirmed or probable COVID-19 diagnosed within 120 days of a TB diagnosis (ie, TB/COVID-19). EXPOSURES: Sociodemographic characteristics, medical risk factors, factors associated with TB severity, and health equity index. MAIN OUTCOMES AND MEASURES: Frequency of reported successive TB and COVID-19 (TB/COVID-19) diagnoses within 120 days, frequency of deaths, and age-adjusted mortality rates. RESULTS: Among the 91 persons with TB/COVID-19, the median age was 58.0 years (range, 3.0-95.0 years; IQR, 41.0-73.0 years); 52 persons (57.1%) were male; 81 (89.0%) were born outside the US; and 28 (30.8%) were Asian or Pacific Islander, 4 (4.4%) were Black, 55 (60.4%) were Hispanic or Latino, 4 (4.4%) were White. The frequency of reported COVID-19 among those who received a TB diagnosis between September 3, 2019, and December 31, 2020, was 225 of 2210 persons (10.2%), which was similar to that of the general population (3 402 804 of 39 538 223 persons [8.6%]). Compared with persons with TB before the pandemic, those with TB/COVID-19 were more likely to be Hispanic or Latino (2285 of 6279 persons [36.4%; 95% CI, 35.2%-37.6%] vs 55 of 91 persons [60.4%; 95% CI, 49.6%-70.5%], respectively; P < .001), reside in low health equity census tracts (1984 of 6027 persons [32.9%; 95% CI, 31.7%-34.1%] vs 40 of 89 persons [44.9%; 95% CI, 34.4%-55.9%]; P = .003), live in the US longer before receiving a TB diagnosis (median, 19.7 years [IQR, 7.2-32.3 years] vs 23.1 years [IQR, 15.2-31.5 years]; P = .03), and have diabetes (1734 of 6280 persons [27.6%; 95% CI, 26.5%-28.7%] vs 42 of 91 persons [46.2%; 95% CI, 35.6%-56.9%]; P < .001). The frequency of deaths among those with TB/COVID-19 successively diagnosed within 30 days (8 of 34 persons [23.5%; 95% CI, 10.8%-41.2%]) was more than twice that of persons with TB before the pandemic (631 of 5545 persons [11.4%; 95% CI, 10.6%-12.2%]; P = .05) and 20 times that of persons with COVID-19 alone (42 171 of 3 402 713 persons [1.2%; 95% CI, 1.2%-1.3%]; P < .001). Persons with TB/COVID-19 who died were older (median, 81.0 years; IQR, 75.0-85.0 years) than those who survived (median, 54.0 years; IQR, 37.5-68.5 years; P < .001). The age-adjusted mortality rate remained higher among persons with TB/COVID-19 (74.2 deaths per 1000 persons; 95% CI, 26.2-122.1 deaths per 1000 persons) compared with either disease alone (TB before the pandemic: 56.3 deaths per 1000 persons [95% CI, 51.2-61.4 deaths per 1000 persons]; COVID-19 only: 17.1 deaths per 1000 persons [95% CI, 16.9-17.2 deaths per 1000 persons]). CONCLUSIONS AND RELEVANCE: In this cross-sectional analysis, TB/COVID-19 was disproportionately diagnosed among California residents who were Hispanic or Latino, had diabetes, or were living in low health equity census tracts. These results suggest that tuberculosis and COVID-19 occurring together may be associated with increases in mortality compared with either disease alone, especially among older adults. Addressing health inequities and integrating prevention efforts could avert the occurrence of concurrent COVID-19 and TB and potentially reduce deaths. |
Clinical presentation and management of childhood intussusception in South Africa
Cox S , Withers A , Arnold M , Chitnis M , de Vos C , Kirsten M , le Grange SM , Loveland J , Machaea S , Maharaj A , Madhi SA , Tate JE , Parashar UD , Groome MJ . Pediatr Surg Int 2021 37 (10) 1361-1370 PURPOSE: We assessed management and outcomes for intussusception at nine academic hospitals in South Africa. METHODS: Patients ≤ 3 years presenting with intussusception between September 2013 and December 2017 were prospectively enrolled at all sites. Additionally, patients presenting between July 2012 and August 2013 were retrospectively enrolled at one site. Demographics, clinical information, diagnostic modality, reduction methods, surgical intervention and outcomes were reviewed. RESULTS: Four hundred seventy-six patients were enrolled, [54% males, median age 6.5 months (IQR 2.6-32.6)]. Vomiting (92%), bloody stool (91%), abdominal mass (57%), fever (32%) and a rectal mass (29%) represented advanced disease: median symptom duration was 3 days (IQR 1-4). Initial reduction attempts included pneumatic reduction (66%) and upfront surgery (32%). The overall non-surgical reduction rate was 28% and enema perforation rate was 4%. Surgery occurred in 334 (70%), 68 (20%) patients had perforated bowel, bowel resection was required in 61%. Complications included recurrence (2%) and nosocomial sepsis (4%). Length of stay (LOS) was significantly longer in patients who developed complications. Six patients died-a mortality rate of 1%. There was a significant difference in reduction rates, upfront surgery, bowel resection, LOS and mortality between centres with shorter symptom duration compared longer symptom duration. CONCLUSION: Delayed presentation was common and associated with low success for enema reduction, higher operative rates, higher rates of bowel resection and increased LOS. Improved primary health-care worker education and streamlining referral pathways might facilitate timely management. |
Cytokine signatures of Plasmodium vivax infection during pregnancy and delivery outcomes.
Dobano C , Bardaji A , Arevalo-Herrera M , Martinez-Espinosa FE , Botto-Menezes C , Padilla N , Menegon M , Kochar S , Kochar SK , Unger H , Ome-Kaius M , Rosanas-Urgell A , Malheiros A , Castellanos ME , Hans D , Desai M , Casellas A , Chitnis CE , Severini C , Mueller I , Rogerson S , Menendez C , Requena P . PLoS Negl Trop Dis 2020 14 (5) e0008155 Plasmodium vivax malaria is a neglected disease, particularly during pregnancy. Severe vivax malaria is associated with inflammatory responses but in pregnancy immune alterations make it uncertain as to what cytokine signatures predominate, and how the type and quantity of blood immune mediators influence delivery outcomes. We measured the plasma concentrations of a set of thirty-one biomarkers, comprising cytokines, chemokines and growth factors, in 987 plasma samples from a cohort of 572 pregnant women from five malaria-endemic tropical countries and related these concentrations to delivery outcomes (birth weight and hemoglobin levels) and malaria infection. Samples were collected at recruitment (first antenatal visit) and at delivery (periphery, cord and placenta). At recruitment, we found that P. vivax-infected pregnant women had higher plasma concentrations of proinflammatory (IL-6, IL-1beta, CCL4, CCL2, CXCL10) and TH1-related cytokines (mainly IL-12) than uninfected women. This biomarker signature was essentially lost at delivery and was not associated with birth weight nor hemoglobin levels. Antiinflammatory cytokines (IL-10) were positively associated with infection and poor delivery outcomes. CCL11 was the only biomarker to show a negative association with P. vivax infection and its concentration at recruitment was positively associated with hemoglobin levels at delivery. Birth weight was negatively associated with peripheral IL-4 levels at delivery. Our multi-biomarker multicenter study is the first comprehensive one to characterize the immunological signature of P. vivax infection in pregnancy thus far. In conclusion, data show that while TH1 and pro-inflammatory responses are dominant during P. vivax infection in pregnancy, antiinflammatory cytokines may compensate excessive inflammation avoiding poor delivery outcomes, and skewness toward a TH2 response may trigger worse delivery outcomes. CCL11, a chemokine largely neglected in the field of malaria, emerges as an important marker of exposure or mediator in this condition. |
VAR2CSA serology to detect Plasmodium falciparum transmission patterns in pregnancy
Fonseca AM , Gonzalez R , Bardaji A , Jairoce C , Ruperez M , Jimenez A , Quinto L , Cistero P , Vala A , Sacoor C , Gupta H , Hegewisch-Taylor J , Brew J , Ndam NT , Kariuki S , Lopez M , Dobano C , Chitnis CE , Ouma P , Ramharter M , Abdulla S , Aponte JJ , Massougbodji A , Briand V , Mombo-Ngoma G , Desai M , Cot M , Nhacolo A , Sevene E , Macete E , Menendez C , Mayor A . Emerg Infect Dis 2019 25 (10) 1851-1860 Pregnant women constitute a promising sentinel group for continuous monitoring of malaria transmission. To identify antibody signatures of recent Plasmodium falciparum exposure during pregnancy, we dissected IgG responses against VAR2CSA, the parasite antigen that mediates placental sequestration. We used a multiplex peptide-based suspension array in 2,354 samples from pregnant women from Mozambique, Benin, Kenya, Gabon, Tanzania, and Spain. Two VAR2CSA peptides of limited polymorphism were immunogenic and targeted by IgG responses readily boosted during infection and with estimated half-lives of <2 years. Seroprevalence against these peptides reflected declines and rebounds of transmission in southern Mozambique during 2004-2012, reduced exposure associated with use of preventive measures during pregnancy, and local clusters of transmission that were missed by detection of P. falciparum infections. These data suggest that VAR2CSA serology can provide a useful adjunct for the fine-scale estimation of the malaria burden among pregnant women over time and space. |
Pan-viral serology implicates enteroviruses in acute flaccid myelitis.
Schubert RD , Hawes IA , Ramachandran PS , Ramesh A , Crawford ED , Pak JE , Wu W , Cheung CK , O'Donovan BD , Tato CM , Lyden A , Tan M , Sit R , Sowa GA , Sample HA , Zorn KC , Banerji D , Khan LM , Bove R , Hauser SL , Gelfand AA , Johnson-Kerner BL , Nash K , Krishnamoorthy KS , Chitnis T , Ding JZ , McMillan HJ , Chiu CY , Briggs B , Glaser CA , Yen C , Chu V , Wadford DA , Dominguez SR , Ng TFF , Marine RL , Lopez AS , Nix WA , Soldatos A , Gorman MP , Benson L , Messacar K , Konopka-Anstadt JL , Oberste MS , DeRisi JL , Wilson MR . Nat Med 2019 25 (11) 1748-1752 Since 2012, the United States of America has experienced a biennial spike in pediatric acute flaccid myelitis (AFM)(1-6). Epidemiologic evidence suggests non-polio enteroviruses (EVs) are a potential etiology, yet EV RNA is rarely detected in cerebrospinal fluid (CSF)(2). CSF from children with AFM (n = 42) and other pediatric neurologic disease controls (n = 58) were investigated for intrathecal antiviral antibodies, using a phage display library expressing 481,966 overlapping peptides derived from all known vertebrate and arboviruses (VirScan). Metagenomic next-generation sequencing (mNGS) of AFM CSF RNA (n = 20 cases) was also performed, both unbiased sequencing and with targeted enrichment for EVs. Using VirScan, the viral family significantly enriched by the CSF of AFM cases relative to controls was Picornaviridae, with the most enriched Picornaviridae peptides belonging to the genus Enterovirus (n = 29/42 cases versus 4/58 controls). EV VP1 ELISA confirmed this finding (n = 22/26 cases versus 7/50 controls). mNGS did not detect additional EV RNA. Despite rare detection of EV RNA, pan-viral serology frequently identified high levels of CSF EV-specific antibodies in AFM compared with controls, providing further evidence for a causal role of non-polio EVs in AFM. |
Blood cytokine, chemokine and growth factor profiling in a cohort of pregnant women from tropical countries
Dobano C , Bardaji A , Kochar S , Kochar SK , Padilla N , Lopez M , Unger HW , Ome-Kaius M , Castellanos ME , Arevalo-Herrera M , Hans D , Martinez-Espinosa FE , Botto-Menezes C , Malheiros A , Desai M , Casellas A , Chitnis CE , Rogerson S , Mueller I , Menendez C , Requena P . Cytokine 2019 125 154818 The immune status of women changes during and after pregnancy, differs between blood compartments at delivery and is affected by environmental factors particularly in tropical areas endemic for multiple infections. We quantified the plasma concentration of a set of thirty-one TH1, TH2, TH17 and regulatory cytokines, pro-inflammatory and anti-inflammatory cytokines and chemokines, and growth factors (altogether biomarkers), in a cohort of 540 pregnant women from five malaria-endemic tropical countries. Samples were collected at recruitment (first antenatal visit), delivery (periphery, cord and placenta) and postpartum, allowing a longitudinal analysis. We found the lowest concentration of biomarkers at recruitment and the highest at postpartum, with few exceptions. Among them, IL-6, HGF and TGF-beta had the highest levels at delivery, and even higher concentrations in the placenta compared to peripheral blood. Placental concentrations were generally higher than peripheral, except for eotaxin that was lower. We also compared plasma biomarker concentrations between the tropical cohort and a control group from Spain at delivery, presenting overall higher biomarker levels the tropical cohort, particularly pro-inflammatory cytokines and growth factors. Only IL-6 presented lower levels in the tropical group. Moreover, a principal component analysis of biomarker concentrations at delivery showed that women from Spain grouped more homogenously, and that IL-6 and IL-8 clustered together in the tropical cohort but not in the Spanish one. Plasma cytokine concentrations correlated with Plasmodium antibody levels at postpartum but not during pregnancy. This basal profiling of immune mediators over gestation and in different compartments at delivery is important to subsequently understand response to infections and clinical outcomes in mothers and infants in tropical areas. |
Models of effectiveness of interventions against malaria transmitted by Anopheles albimanus
Briet OJT , Impoinvil DE , Chitnis N , Pothin E , Lemoine JF , Frederic J , Smith TA . Malar J 2019 18 (1) 263 BACKGROUND: Most impact prediction of malaria vector control interventions has been based on African vectors. Anopheles albimanus, the main vector in Central America and the Caribbean, has higher intrinsic mortality, is more zoophilic and less likely to rest indoors. Therefore, relative impact among interventions may be different. Prioritizing interventions, in particular for eliminating Plasmodium falciparum from Haiti, should consider local vector characteristics. METHODS: Field bionomics data of An. albimanus from Hispaniola and intervention effect data from southern Mexico were used to parameterize mathematical malaria models. Indoor residual spraying (IRS), insecticide-treated nets (ITNs), and house-screening were analysed by inferring their impact on the vectorial capacity in a difference-equation model. Impact of larval source management (LSM) was assumed linear with coverage. Case management, mass drug administration and vaccination were evaluated by estimating their effects on transmission in a susceptible-infected-susceptible model. Analogous analyses were done for Anopheles gambiae parameterized with data from Tanzania, Benin and Nigeria. RESULTS: While LSM was equally effective against both vectors, impact of ITNs on transmission by An. albimanus was much lower than for An. gambiae. Assuming that people are outside until bedtime, this was similar for the impact of IRS with dichlorodiphenyltrichloroethane (DDT) or bendiocarb, and impact of IRS was less than that of ITNs. However, assuming people go inside when biting starts, IRS had more impact on An. albimanus than ITNs. While house-screening had less impact than ITNs or IRS on An. gambiae, it had more impact on An. albimanus than ITNs or IRS. The impacts of chemoprevention and chemotherapy were comparable in magnitude to those of strategies against An. albimanus. Chemo-prevention impact increased steeply as coverage approached 100%, whilst clinical-case management impact saturated because of remaining asymptomatic infections. CONCLUSIONS: House-screening and repellent IRS are potentially highly effective against An. albimanus if people are indoors during the evening. This is consistent with historical impacts of IRS with DDT, which can be largely attributed to excito-repellency. It also supports the idea that housing improvements have played a critical role in malaria control in North America. For elimination planning, impact estimates need to be combined with feasibility and cost-analysis. |
Evaluation of intussusception after oral monovalent rotavirus vaccination in South Africa
Groome MJ , Tate JE , Arnold M , Chitnis M , Cox S , de Vos C , Kirsten M , le Grange SM , Loveland J , Machaea S , Maharaj A , Andrews N , Madhi SA , Parashar UD . Clin Infect Dis 2019 70 (8) 1606-1612 BACKGROUND: Post-licensure studies have shown an association between rotavirus vaccination and intussusception. We assessed the risk of intussusception associated with Rotarix(R) (RV1) administration, at six and 14 weeks of age, in an upper-middle income country, South Africa. METHODS: Active prospective surveillance for intussusception was conducted in eight hospitals from September 2013-December 2017. Retrospective case enrolment was done at one hospital from July 2012-August 2013. Demographic characteristics, symptom onset and rotavirus vaccine status were ascertained. Using the self-controlled case-series method, we estimated age-adjusted incidence-rate ratios within 1-7, 8-21, and 1-21 days of rotavirus vaccination in children aged 28-275 days at onset of symptoms. In addition, age-matched controls were enrolled for a subset of cases (n=169), and a secondary analysis performed. RESULTS: There were 346 cases included in the case-series analysis. Post-dose one, there were zero intussusception cases within 1-7 days, and five cases within 8-21 days of vaccination. Post-dose two, 15 cases occurred within 1-7 days, and 18 cases within 8-21 days of vaccination. There was no increased risk of intussusception 1-7 days after dose one (no cases observed) or dose two (relative incidence (RI): 1.71; 95% confidence interval (CI) 0.83-3.01). Similarly, there was no increased risk 8-21 days after the first (RI: 4.01; 95% CI 0.87-10.56) or second dose (RI: 0.96; 95% CI 0.52-1.60). Results were similar for the case-control analysis. CONCLUSIONS: The risk of intussusception in the 21 days after the first or second dose of RV1 was not higher than the background risk among South Africa infants. |
Tuberculosis trends in California correctional facilities, 1993-2013
McDaniel CJ , Chitnis AS , Barry PM , Shah N . Int J Tuberc Lung Dis 2017 21 (8) 922-929 BACKGROUND: Incarcerated persons are disproportionately diagnosed with tuberculosis (TB). California has the second highest inmate population in the United States, but reports the highest number of cases. OBJECTIVE: To describe the TB epidemiology among incarcerated patients in California. METHODS : Trends in incidence were assessed using Poisson regression, and trends in percentage were assessed using weighted linear regression. Demographic and clinical characteristics were compared using v2 or Mann-Whitney U tests. RESULTS: During 1993-2013, of the 64 090 TB cases reported, 2323 (4%) were correctional facility residents. Incidence in correctional facilities decreased until 2006 (annual per cent change [APC] -12.3%, 95%CI -14.4 to -10.1), but has since stabilized (APC 4.4%, 95%CI -2.1 to 11.4). Compared with state prisoners, federal prisoners were more likely to be male (98%, P<0.03), persons arriving in the United States within 5 years of diagnosis (62%, P< 0.001), and born in Mexico (88%, P=0.02), whereas local jail inmates were more likely to have a history of substance use (75%, P<0.001) and homelessness (35%, P< 0.001). CONCLUSIONS: TB incidence in correctional facilities had steadily declined over the last two decades, but has recently leveled out. To promote further reduction in incidence among diverse incarcerated populations, health departments and correctional facilities should strengthen collaboration by conducting TB risk-based assessments. |
Burden and impact of Plasmodium vivax in pregnancy: A multi-centre prospective observational study.
Bardaji A , Martinez-Espinosa FE , Arevalo-Herrera M , Padilla N , Kochar S , Ome-Kaius M , Botto-Menezes C , Castellanos ME , Kochar DK , Kochar SK , Betuela I , Mueller I , Rogerson S , Chitnis C , Hans D , Menegon M , Severini C , Del Portillo H , Dobano C , Mayor A , Ordi J , Piqueras M , Sanz S , Wahlgren M , Slutsker L , Desai M , Menendez C . PLoS Negl Trop Dis 2017 11 (6) e0005606 BACKGROUND: Despite that over 90 million pregnancies are at risk of Plasmodium vivax infection annually, little is known about the epidemiology and impact of the infection in pregnancy. METHODOLOGY AND PRINCIPAL FINDINGS: We undertook a health facility-based prospective observational study in pregnant women from Guatemala (GT), Colombia (CO), Brazil (BR), India (IN) and Papua New Guinea PNG). Malaria and anemia were determined during pregnancy and fetal outcomes assessed at delivery. A total of 9388 women were enrolled at antennal care (ANC), of whom 53% (4957) were followed until delivery. Prevalence of P. vivax monoinfection in maternal blood at delivery was 0.4% (20/4461) by microscopy [GT 0.1%, CO 0.5%, BR 0.1%, IN 0.2%, PNG 1.2%] and 7% (104/1488) by PCR. P. falciparum monoinfection was found in 0.5% (22/4463) of women by microscopy [GT 0%, CO 0.5%, BR 0%, IN 0%, PNG 2%]. P. vivax infection was observed in 0.4% (14/3725) of placentas examined by microscopy and in 3.7% (19/508) by PCR. P. vivax in newborn blood was detected in 0.02% (1/4302) of samples examined by microscopy [in cord blood; 0.05% (2/4040) by microscopy, and 2.6% (13/497) by PCR]. Clinical P. vivax infection was associated with increased risk of maternal anemia (Odds Ratio-OR, 5.48, [95% CI 1.83-16.41]; p = 0.009), while submicroscopic vivax infection was not associated with increased risk of moderate-severe anemia (Hb<8g/dL) (OR, 1.16, [95% CI 0.52-2.59]; p = 0.717), or low birth weight (<2500g) (OR, 0.52, [95% CI, 0.23-1.16]; p = 0.110). CONCLUSIONS: In this multicenter study, the prevalence of P. vivax infection in pregnancy by microscopy was overall low across all endemic study sites; however, molecular methods revealed a significant number of submicroscopic infections. Clinical vivax infection in pregnancy was associated with maternal anemia, which may be deleterious for infant's health. These results may help to guide maternal health programs in settings where vivax malaria is endemic; they also highlight the need of addressing a vulnerable population such as pregnant women while embracing malaria elimination in endemic countries. |
Naturally acquired binding-inhibitory antibodies to Plasmodium vivax Duffy binding protein in pregnant women are associated with higher birth weight in a multicenter study
Requena P , Arevalo-Herrera M , Menegon M , Martinez-Espinosa FE , Padilla N , Botto-Menezes C , Malheiro A , Hans D , Castellanos ME , Robinson L , Samol P , Kochar S , Kochar SK , Kochar DK , Desai M , Sanz S , Quintó L , Mayor A , Rogerson S , Mueller I , Severini C , Del Portillo HA , Bardají A , Chitnis CC , Menéndez C , Dobaño C . Front Immunol 2017 8 163 A vaccine to eliminate malaria would need a multi-stage and multi-species composition to achieve robust protection, but the lack of knowledge about antigen targets and mechanisms of protection precludes the development of fully efficacious malaria vaccines, especially for Plasmodium vivax (Pv). Pregnant women constitute a risk population who would greatly benefit from a vaccine preventing the adverse events of Plasmodium infection during gestation. We hypothesized that functional immune responses against putative targets of naturally acquired immunity to malaria and vaccine candidates will be associated with protection against malaria infection and/or poor outcomes during pregnancy. We measured (i) IgG responses to a large panel of Pv and Plasmodium falciparum (Pf) antigens, (ii) the capacity of anti-Pv ligand Duffy binding protein (PvDBP) antibodies to inhibit binding to Duffy antigen, and (iii) cellular immune responses to two Pv antigens, in a subset of 1,056 pregnant women from Brazil, Colombia, Guatemala, India, and Papua New Guinea (PNG). There were significant intraspecies and interspecies correlations for most antibody responses (e.g., PfMSP119 versus PfAMA1, Spearman's rho = 0.81). Women from PNG and Colombia had the highest levels of IgG overall. Submicroscopic infections seemed sufficient to boost antibody responses in Guatemala but not antigen-specific cellular responses in PNG. Brazil had the highest percentage of Duffy binding inhibition (p-values versus Colombia: 0.040; Guatemala: 0.047; India: 0.003, and PNG: 0.153) despite having low anti-PvDBP IgG levels. Almost all antibodies had a positive association with present infection, and coinfection with the other species increased this association. Anti-PvDBP, anti-PfMSP1, and anti-PfAMA1 IgG levels at recruitment were positively associated with infection at delivery (p-values: 0.010, 0.003, and 0.023, respectively), suggesting that they are markers of malaria exposure. Peripheral blood mononuclear cells from Pv-infected women presented fewer CD8+IFN-gamma+ T cells and secreted more G-CSF and IL-4 independently of the stimulus used in vitro. Functional anti-PvDBP levels at recruitment had a positive association with birth weight (difference per doubling antibody levels: 45 g, p-value: 0.046). Thus, naturally acquired binding-inhibitory antibodies to PvDBP might confer protection against poor outcomes of Pv malaria in pregnancy. |
Plasmodium vivax VIR proteins are targets of naturally-acquired antibody and T cell immune responses to malaria in pregnant women
Requena P , Rui E , Padilla N , Martinez-Espinosa FE , Castellanos ME , Botto-Menezes C , Malheiro A , Arevalo-Herrera M , Kochar S , Kochar SK , Kochar DK , Umbers AJ , Ome-Kaius M , Wangnapi R , Hans D , Menegon M , Mateo F , Sanz S , Desai M , Mayor A , Chitnis CC , Bardaji A , Mueller I , Rogerson S , Severini C , Fernandez-Becerra C , Menendez C , Del Portillo H , Dobano C . PLoS Negl Trop Dis 2016 10 (10) e0005009 P. vivax infection during pregnancy has been associated with poor outcomes such as anemia, low birth weight and congenital malaria, thus representing an important global health problem. However, no vaccine is currently available for its prevention. Vir genes were the first putative virulent factors associated with P. vivax infections, yet very few studies have examined their potential role as targets of immunity. We investigated the immunogenic properties of five VIR proteins and two long synthetic peptides containing conserved VIR sequences (PvLP1 and PvLP2) in the context of the PregVax cohort study including women from five malaria endemic countries: Brazil, Colombia, Guatemala, India and Papua New Guinea (PNG) at different timepoints during and after pregnancy. Antibody responses against all antigens were detected in all populations, with PNG women presenting the highest levels overall. P. vivax infection at sample collection time was positively associated with antibody levels against PvLP1 (fold-increase: 1.60 at recruitment -first antenatal visit-) and PvLP2 (fold-increase: 1.63 at delivery), and P. falciparum co-infection was found to increase those responses (for PvLP1 at recruitment, fold-increase: 2.25). Levels of IgG against two VIR proteins at delivery were associated with higher birth weight (27 g increase per duplicating antibody levels, p<0.05). Peripheral blood mononuclear cells from PNG uninfected pregnant women had significantly higher antigen-specific IFN-gamma TH1 responses (p=0.006) and secreted less pro-inflammatory cytokines TNF and IL-6 after PvLP2 stimulation than P. vivax-infected women (p<0.05). These data demonstrate that VIR antigens induce the natural acquisition of antibody and T cell memory responses that might be important in immunity to P. vivax during pregnancy in very diverse geographical settings. |
Microsatellite Genotyping of Plasmodium vivax Isolates from Pregnant Women in Four Malaria Endemic Countries.
Menegon M , Bardaji A , Martinez-Espinosa F , Botto-Menezes C , Ome-Kaius M , Mueller I , Betuela I , Arevalo-Herrera M , Kochar S , Kochar SK , Jaju P , Hans D , Chitnis C , Padilla N , Castellanos ME , Ortiz L , Sanz S , Piqueras M , Desai M , Mayor A , Del Portillo H , Menendez C , Severini C . PLoS One 2016 11 (3) e0152447 Plasmodium vivax is the most widely distributed human parasite and the main cause of human malaria outside the African continent. However, the knowledge about the genetic variability of P. vivax is limited when compared to the information available for P. falciparum. We present the results of a study aimed at characterizing the genetic structure of P. vivax populations obtained from pregnant women from different malaria endemic settings. Between June 2008 and October 2011 nearly 2000 pregnant women were recruited during routine antenatal care at each site and followed up until delivery. A capillary blood sample from the study participants was collected for genotyping at different time points. Seven P. vivax microsatellite markers were used for genotypic characterization on a total of 229 P. vivax isolates obtained from Brazil, Colombia, India and Papua New Guinea. In each population, the number of alleles per locus, the expected heterozygosity and the levels of multilocus linkage disequilibrium were assessed. The extent of genetic differentiation among populations was also estimated. Six microsatellite loci on 137 P. falciparum isolates from three countries were screened for comparison. The mean value of expected heterozygosity per country ranged from 0.839 to 0.874 for P. vivax and from 0.578 to 0.758 for P. falciparum. P. vivax populations were more diverse than those of P. falciparum. In some of the studied countries, the diversity of P. vivax population was very high compared to the respective level of endemicity. The level of inter-population differentiation was moderate to high in all P. vivax and P. falciparum populations studied. |
Modeling the cost effectiveness of malaria control interventions in the highlands of western Kenya
Stuckey EM , Stevenson J , Galactionova K , Baidjoe AY , Bousema T , Odongo W , Kariuki S , Drakeley C , Smith TA , Cox J , Chitnis N . PLoS One 2014 9 (10) e107700 INTRODUCTION: Tools that allow for in silico optimization of available malaria control strategies can assist the decision-making process for prioritizing interventions. The OpenMalaria stochastic simulation modeling platform can be applied to simulate the impact of interventions singly and in combination as implemented in Rachuonyo South District, western Kenya, to support this goal. METHODS: Combinations of malaria interventions were simulated using a previously-published, validated model of malaria epidemiology and control in the study area. An economic model of the costs of case management and malaria control interventions in Kenya was applied to simulation results and cost-effectiveness of each intervention combination compared to the corresponding simulated outputs of a scenario without interventions. Uncertainty was evaluated by varying health system and intervention delivery parameters. RESULTS: The intervention strategy with the greatest simulated health impact employed long lasting insecticide treated net (LLIN) use by 80% of the population, 90% of households covered by indoor residual spraying (IRS) with deployment starting in April, and intermittent screen and treat (IST) of school children using Artemether lumefantrine (AL) with 80% coverage twice per term. However, the current malaria control strategy in the study area including LLIN use of 56% and IRS coverage of 70% was the most cost effective at reducing disability-adjusted life years (DALYs) over a five year period. CONCLUSIONS: All the simulated intervention combinations can be considered cost effective in the context of available resources for health in Kenya. Increasing coverage of vector control interventions has a larger simulated impact compared to adding IST to the current implementation strategy, suggesting that transmission in the study area is not at a level to warrant replacing vector control to a school-based screen and treat program. These results have the potential to assist malaria control program managers in the study area in adding new or changing implementation of current interventions. |
Comparative assessment of diverse strategies for malaria vector population control based on measured rates at which mosquitoes utilize targeted resource subsets
Killeen GF , Kiware SS , Seyoum A , Gimnig JE , Corliss GF , Stevenson J , Drakeley CJ , Chitnis N . Malar J 2014 13 338 BACKGROUND: Eliminating malaria requires vector control interventions that dramatically reduce adult mosquito population densities and survival rates. Indoor applications of insecticidal nets and sprays are effective against an important minority of mosquito species that rely heavily upon human blood and habitations for survival. However, complementary approaches are needed to tackle a broader diversity of less human-specialized vectors by killing them at other resource targets. METHODS: Impacts of strategies that target insecticides to humans or animals can be rationalized in terms of biological coverage of blood resources, quantified as proportional coverage of all blood resources mosquito vectors utilize. Here, this concept is adapted to enable impact prediction for diverse vector control strategies based on measurements of utilization rates for any definable, targetable resource subset, even if that overall resource is not quantifiable. RESULTS: The usefulness of this approach is illustrated by deriving utilization rate estimates for various blood, resting site, and sugar resource subsets from existing entomological survey data. Reported impacts of insecticidal nets upon human-feeding vectors, and insecticide-treated livestock upon animal-feeding vectors, are approximately consistent with model predictions based on measured utilization rates for those human and animal blood resource subsets. Utilization rates for artificial sugar baits compare well with blood resources, and are consistent with observed impact when insecticide is added. While existing data was used to indirectly measure utilization rates for a variety of resting site subsets, by comparison with measured rates of blood resource utilization in the same settings, current techniques for capturing resting mosquitoes underestimate this quantity, and reliance upon complex models with numerous input parameters may limit the applicability of this approach. CONCLUSIONS: While blood and sugar consumption can be readily quantified using existing methods for detecting natural markers or artificial tracers, improved techniques for labelling mosquitoes, or other arthropod pathogen vectors, will be required to assess vector control measures which target them when they utilize non-nutritional resources such as resting, oviposition, and mating sites. |
Clonally related Burkholderia contaminans among ventilated patients without cystic fibrosis
Peterson AE , Chitnis AS , Xiang N , Scaletta JM , Geist R , Schwartz J , Dement J , Lawlor E , Lipuma JJ , O'Connell H , Noble-Wang J , Kallen AJ , Hunt DC . Am J Infect Control 2013 41 (12) 1298-300 We investigated a cluster of 10 Burkholderia cepacia complex-positive cultures among ventilated patients and those with a tracheostomy in an acute care hospital. Isolates from 5 patients had outbreak-strain-related Burkholderia contaminans. Isolates of B. cepacia complex unrelated to the outbreak strain were cultured from a sink drain. The investigation identified practices that might have led to contamination of patient respiratory care supplies with tap water, which might have contributed to the cluster. |
Epidemiology of community-associated clostridium difficile infection, 2009 Through 2011
Chitnis AS , Holzbauer SM , Belflower RM , Winston LG , Bamberg WM , Lyons C , Farley MM , Dumyati GK , Wilson LE , Beldavs ZG , Dunn JR , Gould LH , Maccannell DR , Gerding DN , McDonald LC , Lessa FC . JAMA Intern Med 2013 173 (14) 1359-67 IMPORTANCE Clostridium difficile infection (CDI) has been increasingly reported among healthy individuals in the community. Recent data suggest that community-associated CDI represents one-third of all C difficile cases. The epidemiology and potential sources of C difficile in the community are not fully understood. OBJECTIVES To determine epidemiological and clinical characteristics of community-associated CDI and to explore potential sources of C difficile acquisition in the community. DESIGN AND SETTING Active population-based and laboratory-based CDI surveillance in 8 US states. PARTICIPANTS Medical records were reviewed and interviews performed to assess outpatient, household, and food exposures among patients with community-associated CDI (ie, toxin or molecular assay positive for C difficile and no overnight stay in a health care facility within 12 weeks). Molecular characterization of C difficile isolates was performed. Outpatient health care exposure in the prior 12 weeks among patients with community-associated CDI was a priori categorized into the following 3 levels: no exposure, low-level exposure (ie, outpatient visit with physician or dentist), or high-level exposure (ie, surgery, dialysis, emergency or urgent care visit, inpatient care with no overnight stay, or health care personnel with direct patient care). MAIN OUTCOMES AND MEASURES Prevalence of outpatient health care exposure among patients with community-associated CDI and identification of potential sources of C difficile by level of outpatient health care exposure. RESULTS Of 984 patients with community-associated CDI, 353 (35.9%) did not receive antibiotics, 177 (18.0%) had no outpatient health care exposure, and 400 (40.7%) had low-level outpatient health care exposure. Thirty-one percent of patients without antibiotic exposure received proton pump inhibitors. Patients having CDI with no or low-level outpatient health care exposure were more likely to be exposed to infants younger than 1 year (P = .04) and to household members with active CDI (P = .05) compared with those having high-level outpatient health care exposure. No association between food exposure or animal exposure and level of outpatient health care exposure was observed. North American pulsed-field gel electrophoresis (NAP) 1 was the most common (21.7%) strain isolated; NAP7 and NAP8 were uncommon (6.7%). CONCLUSIONS AND RELEVANCE Most patients with community-associated CDI had recent outpatient health care exposure, and up to 36% would not be prevented by reduction of antibiotic use only. Our data support evaluation of additional strategies, including further examination of C difficile transmission in outpatient and household settings and reduction of proton pump inhibitor use. |
Outbreak of carbapenem-resistant Enterobacteriaceae at a long-term acute care hospital: sustained reductions in transmission through active surveillance and targeted interventions
Chitnis AS , Caruthers PS , Rao AK , Lamb J , Lurvey R , Beau De Rochars V , Kitchel B , Cancio M , Torok TJ , Guh AY , Gould CV , Wise ME . Infect Control Hosp Epidemiol 2012 33 (10) 984-92 OBJECTIVE: To describe a Klebsiella pneumoniae carbapenemase (KPC)-producing carbapenem-resistant Enterobacteriaceae (CRE) outbreak and interventions to prevent transmission. DESIGN, SETTING, AND PATIENTS: Epidemiologic investigation of a CRE outbreak among patients at a long-term acute care hospital (LTACH). METHODS: Microbiology records at LTACH A from March 2009 through February 2011 were reviewed to identify CRE transmission cases and cases admitted with CRE. CRE bacteremia episodes were identified during March 2009-July 2011. Biweekly CRE prevalence surveys were conducted during July 2010-July 2011, and interventions to prevent transmission were implemented, including education and auditing of staff and isolation and cohorting of CRE patients with dedicated nursing staff and shared medical equipment. Trends were evaluated using weighted linear or Poisson regression. CRE transmission cases were included in a case-control study to evaluate risk factors for acquisition. A real-time polymerase chain reaction assay was used to detect the bla(KPC) gene, and pulsed-field gel electrophoresis was performed to assess the genetic relatedness of isolates. RESULTS: Ninety-nine CRE transmission cases, 16 admission cases (from 7 acute care hospitals), and 29 CRE bacteremia episodes were identified. Significant reductions were observed in CRE prevalence (49% vs 8%), percentage of patients screened with newly detected CRE (44% vs 0%), and CRE bacteremia episodes (2.5 vs 0.0 per 1,000 patient-days). Cases were more likely to have received beta-lactams, have diabetes, and require mechanical ventilation. All tested isolates were KPC-producing K. pneumoniae, and nearly all isolates were genetically related. CONCLUSION: CRE transmission can be reduced in LTACHs through surveillance testing and targeted interventions. Sustainable reductions within and across healthcare facilities may require a regional public health approach. |
Device-associated infection rates, device utilization, and antimicrobial resistance in long-term acute care hospitals reporting to the National Healthcare Safety Network, 2010
Chitnis AS , Edwards JR , Ricks PM , Sievert DM , Fridkin SK , Gould CV . Infect Control Hosp Epidemiol 2012 33 (10) 993-1000 OBJECTIVE: To evaluate national data on healthcare-associated infections (HAIs), device utilization, and antimicrobial resistance in long-term acute care hospitals (LTACHs). DESIGN AND SETTING: Comparison of data from LTACHs and from medical and medical-surgical intensive care units (ICUs) in short-stay acute care hospitals reporting to the National Healthcare Safety Network (NHSN) during 2010. METHODS: Rates of central line-associated bloodstream infections (CLABSIs), catheter-associated urinary tract infections (CAUTIs), and ventilator-associated pneumonia (VAP) as well as device utilization ratios were calculated. For each HAI, pathogen profiles and antimicrobial resistance prevalence were evaluated. Comparisons were made using Poisson regression and the Mood median and chi(2) tests. RESULTS: In 2010, 104 LTACHs reported CLABSIs and 57 reported CAUTIs and VAP to the NHSN. Median CLABSI rates in LTACHs (1.25 events per 1,000 device-days reported; range, 0.0-5.96) were comparable to rates in major teaching ICUs and were higher than those in other ICUs. CAUTI rates in LTACHs (median, 2.61; range, 0.0-9.92) were higher and VAP rates (median, 0.0; range, 0.0-3.29) were generally lower than those in ICUs. Central line utilization in LTACHs was higher than that in ICUs, whereas urinary catheter and ventilator utilization was lower. Methicillin resistance among Staphylococcus aureus CLABSIs (83%) and vancomycin resistance among Enterococcus faecalis CAUTIs (44%) were higher in LTACHs than in ICUs. Multidrug resistance among Pseudomonas aeruginosa CAUTIs (25%) was higher in LTACHs than in most ICUs. CONCLUSIONS: CLABSIs and CAUTIs associated with multidrug-resistant organisms present a challenge in LTACHs. Continued HAI surveillance with pathogen-level data can guide prevention efforts in LTACHs. |
Trends in Candida central line-associated bloodstream infections among NICUs, 1999-2009
Chitnis AS , Magill SS , Edwards JR , Chiller TM , Fridkin SK , Lessa FC . Pediatrics 2012 130 (1) e46-52 OBJECTIVES: To assess trends in incidence of Candida spp. central line-associated bloodstream infections (CLABSIs) in US NICUs, 1999-2009. METHODS: Data from NICUs participating in the National Nosocomial Infections Surveillance (1999-2004) and National Healthcare Safety Network (2006-2009) were analyzed. Overall and birth weight-specific incidence rates of Candida spp. CLABSIs per 1000 central line-days were calculated. Trends in incidence were assessed by using Poisson regression, and trends in proportion of CLABSIs identified as Candida albicans were assessed by using weighted-linear regression. RESULTS: Overall, 398 NICUs reported 1407 Candida spp. CLABSIs (706 due to C albicans) among 1400 neonates. Of the 1400 neonates, 963 (69%) were ≤1000 g at the time of birth, and 182 (13%) died. From 1999 to 2009, the overall incidence decreased significantly for CLABSIs due to Candida spp. (0.92 vs 0.2), C albicans (0.53 vs 0.09), and non-albicans Candida spp. (0.39 vs 0.1). Birth weight-specific incidence significantly decreased across all birth weight categories for C albicans. For CLABSIs due to non-albicans Candida spp., significant decreases were detected among all birth weight categories, except among neonates 1501 to 2500 g. The proportion of Candida spp. CLABSIs due to C albicans did not significantly change over time, remaining at approximately 50%. CONCLUSIONS: Incidence of Candida spp. CLABSIs decreased substantially among NICU patients, regardless of birth weight. Decreases in incidence across all birth weight categories, and not only among neonates ≤1000 g in whom antifungal prophylaxis may be more common, suggest that multiple factors contributed to the declining incidence. |
Outbreak of bacterial meningitis among patients undergoing myelography at an outpatient radiology clinic
Chitnis AS , Guh AY , Benowitz I , Srinivasan V , Gertz RE Jr , Shewmaker PL , Beall BW , O'Connell H , Noble-Wang J , Gornet MF , Van Beneden C , Patrick SL , Turabelidze G , Patel PR . J Am Coll Radiol 2012 9 (3) 185-90 PURPOSE: To investigate an outbreak of bacterial meningitis at an outpatient radiology clinic (clinic A) and to determine the source and implement measures to prevent additional infections. METHODS: A case was defined as bacterial meningitis in a patient undergoing myelography at clinic A from October 11 to 25, 2010. Patients who underwent myelography and other procedures at clinic A during that period were interviewed, medical records were reviewed, and infection prevention practices were assessed. Case-patient cerebrospinal fluid (CSF) specimens, oral specimens from health care personnel (HCP), and opened iohexol vials were tested for bacteria. Bacterial isolates were compared using pulsed-field gel electrophoresis. A culture-negative CSF specimen was tested using a real-time polymerase chain reaction assay. RESULTS: Three cases were identified among 35 clinic A patients who underwent procedures from October 11 to 25, 2010. All case-patients required hospitalization, 2 in an intensive care unit. Case-patients had myelography performed by the same radiology physician assistant and technician on October 25; all patients who underwent myelography on October 25 were affected. HCP did not wear facemasks and reused single-dose iohexol vials for multiple patients. Streptococcus salivarius (a bacteria commonly found in oral flora) was detected in the CSF of 2 case-patients (1 by culture, 1 using real-time polymerase chain reaction) and in HCP oral specimens; 1 opened iohexol vial contained Staphylococcus epidermidis. Pulsed-field gel electrophoresis profiles from the case-patient S salivarius and the radiology physician assistant were indistinguishable. CONCLUSIONS: Bacterial meningitis likely occurred because HCP performing myelography did not wear facemasks; lapses in injection practices may have contributed to transmission. Targeted education regarding mask use and safe injection practices is needed among radiology HCP. |
Using PCR-based detection and genotyping to trace Streptococcus salivarius meningitis outbreak strain to oral flora of radiology physician assistant.
Srinivasan V , Gertz RE Jr , Shewmaker PL , Patrick S , Chitnis AS , O'Connell H , Benowitz I , Patel P , Guh AY , Noble-Wang J , Turabelidze G , Beall B . PLoS One 2012 7 (2) e32169 We recently investigated three cases of bacterial meningitis that were reported from a midwestern radiology clinic where facemasks were not worn during spinal injection of contrast agent during myelography procedures. Using pulsed field gel electrophoresis we linked a case strain of S. salivarius to an oral specimen of a radiology physician assistant (RPA). We also used a real-time PCR assay to detect S. salivarius DNA within a culture-negative cerebrospinal fluid (CSF) specimen. Here we extend this investigation through using a nested PCR/sequencing strategy to link the culture-negative CSF specimen to the case strain. We also provide validation of the real-time PCR assay used, demonstrating that it is not solely specific for Streptococcus salivarius, but is also highly sensitive for detection of the closely related oral species Streptococcus vestibularis. Through using multilocus sequence typing and 16S rDNA sequencing we further strengthen the link between the CSF case isolate and the RPA carriage isolate. We also demonstrate that the newly characterized strains from this study are distinct from previously characterized S. salivarius strains associated with carriage and meningitis. |
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