Recent Cholera Publications on PubMed

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Genetic Characterization of Vibrio cholerae O1 isolates from outbreaks between 2011 and 2015 in Tanzania.

February 22, 2017
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Genetic Characterization of Vibrio cholerae O1 isolates from outbreaks between 2011 and 2015 in Tanzania.

BMC Infect Dis. 2017 Feb 20;17(1):157

Authors: Kachwamba Y, Mohammed AA, Lukupulo H, Urio L, Majigo M, Mosha F, Matonya M, Kishimba R, Mghamba J, Lusekelo J, Nyanga S, Almeida M, Li S, Domman D, Massele SY, Stine OC

Abstract
BACKGROUND: Cholera outbreaks have occurred in Tanzania since 1974. To date, the genetic epidemiology of these outbreaks has not been assessed.
METHODS: 96 Vibrio cholerae O1 isolates from five regions were characterized, and their genetic relatedness assessed using multi-locus variable-number tandem-repeat analysis (MLVA) and whole genome sequencing (WGS).
RESULTS: Of the 48 MLVA genotypes observed, 3 were genetically unrelated to any others, while the remaining 45 genotypes separated into three MLVA clonal complexes (CCs) - each comprised of genotypes differing by a single allelic change. In Kigoma, two separate outbreaks, 4 months apart (January and May, 2015), were each caused by genetically distinct strains by MLVA and WGS. Remarkably, one MLVA CC contained isolates from both the May outbreak and ones from the 2011/2012 outbreak in Dar-es-Salaam. However, WGS revealed the isolates from the two outbreaks to be distinct clades. The outbreak that started in August 2015 in Dar-es-Salaam and spread to Morogoro, Singida and Mara was comprised of a single MLVA CC and WGS clade. Isolates from within an outbreak were closely related differing at fewer than 5 nucleotides. All isolates were part of the 3(rd) wave of the 7(th) pandemic and were found in four clades related to isolates from Kenya and Asia.
CONCLUSIONS: We conclude that genetically related V. cholerae cluster in outbreaks, and distinct strains circulate simultaneously.

PMID: 28219321 [PubMed - in process]

Emergence and serovar profiling of non-typhoidal Salmonellae (NTS) isolated from gastroenteritis cases-A study from South India.

February 22, 2017
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Emergence and serovar profiling of non-typhoidal Salmonellae (NTS) isolated from gastroenteritis cases-A study from South India.

Infect Dis (Lond). 2016 Nov-Dec;48(11-12):847-51

Authors: Ballal M, Devadas SM, Shetty V, Bangera SR, Ramamurthy T, Sarkar A

Abstract
Human infection with non-typhoidal Salmonella (NTS) serovars is often a neglected and undiagnosed infection in the developing world. Invasive NTS is now being established as having a new and emerging pathogenic role. There is not sufficient data on the prevalence of NTS serovars and their antibiotic susceptibility pattern from India. Faecal specimens collected from patients with acute gastroenteritis were processed to isolate Salmonella according to the standard protocol for a period from January 2011-December 2014. Salmonella isolates were serotyped and tested for antibiotic susceptibility. Of the total 320 (10.04%) bacterial enteric pathogens isolated, 64 (20%) were non-typhoidal Salmonella. Among the serogroup, O:4 (B) (n = 26; 40.6%) was found to be the commonest followed by O:7 (C1) (n = 11; 17.1%) and O:3,10 (E1) (n = 11; 17.1%). NTS infection in cancer patients could also be termed as nosocomial NTS diarrhoea due to primary community infection with prolonged incubation periods, consumption of contaminated food during hospital stay or Nosocomially acquired infection. Serovar Oslo has been predominant (9/17) in NTS isolates from cancer patients, whereas serovars Bovismorbificans, Wangata and Schleissheim have been reported for the first time in the country. The isolates were mostly susceptible to antibiotics except Salmonella ser Kentucky, which showed resistance to ciprofloxacin is reported for the first time in the country. Continuous surveillance is required to monitor resistance of NTS isolates.

PMID: 27300440 [PubMed - indexed for MEDLINE]

The epidemiology and antimicrobial resistance of cholera cases in Iran during 2013.

February 18, 2017
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The epidemiology and antimicrobial resistance of cholera cases in Iran during 2013.

Iran J Microbiol. 2016 Aug;8(4):232-237

Authors: Masoumi-Asl H, Gouya MM, Rahbar M, Sabourian R

Abstract
BACKGROUND AND OBJECTIVES: Cholera is an endemic diarrheal disease in Iran, caused by Vibrio Cholerae. The epidemiology, transmission route, environmental determinants and antimicrobial resistant pattern of cholera have been changed during recent years. In this study the epidemiology and antimicrobial resistance of cholera in Iran during 2013 outbreak was investigated.
MATERIALS AND METHODS: A retrospective, cross-sectional study was carried out using cholera national surveillance system collected data in 2013. Bacterial identification and antimicrobial susceptibility testing were done on 60 Vibrio cholerae isolates, serotype Inaba.
RESULTS: During July to November 2013, 256 confirmed cholera cases were diagnosed by stool culture. Two hundred and eleven out of 256 (83%) cases were imported from Afghanistan and Pakistan. The prevalent age group was 16-30 years old, 90% were male, 98.8% affected by Inaba serotype and case fatality rate was 2.7%. The results of antimicrobial susceptibility testing on 60 V. cholerae, serotype Inaba showed that all isolates were resistant to nalidixic acid, tetracyclin and trimethoprim-sulfamethoxazole and intermediate resistance to erythromycin but sensitive to ciprofloxacin, cefixime and ampicillin.
CONCLUSION: Migrants from neighboring countries played a key role in cholera outbreak in Iran during 2013. The results of antimicrobial susceptibility testing on 60 V. cholerae, serotype Inaba showed an increasing resistance rate in comparison with previous years.

PMID: 28210461 [PubMed - in process]

Cholera outbreak following a marriage ceremony in Medinya, Western Ghana.

February 18, 2017
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Cholera outbreak following a marriage ceremony in Medinya, Western Ghana.

Pan Afr Med J. 2016;25(Suppl 1):3

Authors: Acquah H, Malm K, Der J, Kye-Duodu G, Mensah EK, Sackey SO, Nyarko KM, Afari E

Abstract
INTRODUCTION: Cholera is a diarrhoea disease caused by the bacterium e. On 13th June 2011, there was a reported outbreak of acute watery diarrhoea at Medinya among people who eat at a mass traditional wedding ceremony in the Western Region of Ghana. We investigated to characterize the outbreak, and implement control and preventive measures.
METHODS: We conducted a retrospective cohort study. We interviewed health workers, reviewed medical records, conducted environmental assessment and obtained water and stool samples for laboratory investigation. A suspected cholera-case defined as a person with acute watery diarrhoea, with or without vomiting, who ate food prepared at the mass traditional wedding in Medinya on 10th June 2011. We performed univariate and bivariate analysis.
RESULTS: Of the 17 case-patients, 9 (52.9%) were males. The overall attack rate was 11.18% and case fatality rate was 5.9%. The most affected age group was 6-10 years (23.53%) with median age of 20 and ranged 6 to 38 years. Time of onset of symptoms was 2.00am and peaked at 10.am on 13th June. Compared to other food served, fufu with groundnut soup was more likely to have been contaminated (RR=7.3, 95%CI: 1.8-29.3). We isolated e serotype ogawa from stool samples. We observed open defaecation and poor personal hygiene.
CONCLUSION: e serotype ogawa caused a high case-fatality outbreak in Medinya. Contaminated fufu and groundnut soup were the sources. Hand washing with soap was initiated and a make shift latrine constructed following our health education and recommendations.

PMID: 28210372 [PubMed - in process]

Genomic profile of antibiotic resistant, classical ctxB positive Vibrio cholerae O1 biotype El Tor isolated in 2003 and 2005 from Puri, India: A retrospective study.

February 18, 2017
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Genomic profile of antibiotic resistant, classical ctxB positive Vibrio cholerae O1 biotype El Tor isolated in 2003 and 2005 from Puri, India: A retrospective study.

Indian J Med Microbiol. 2016 Oct-Dec;34(4):462-470

Authors: Bhotra T, Das MM, Pal BB, Singh DV

Abstract
OBJECTIVES: To examine eight strains of Vibrio cholerae O1 isolated in 2003 and 2005 from Puri, India, for antibiotic susceptibility, presence of virulence and regulatory genes, cholera toxin (CT) production, CTX arrangement and genomic profiles.
MATERIALS AND METHODS: Bacterial strains were tested for antibiotic susceptibility using disc diffusion assay. Polymerase chain reaction determined the presence of antibiotic resistance, virulence and regulatory genes. To determine the type of cholera toxin subunit B (ctxB), nucleotide sequencing was performed. Southern hybridisation determined the number and arrangement of CTXΦ. Ribotyping and pulsed-field gel electrophoresis (PFGE) were used to determine the genomic profile of isolates.
RESULTS: All the eight strains, except one strain, showed resistant to nalidixic acid, sulphamethoxazole, streptomycin and trimethoprim and possessed the sullI, strB, dfrA1 and int SXT genes. All the strains carried the toxin-co-regulated pilus pathogenicity island, the CTX genetic element, the repeat in toxin and produced CT. Restriction fragment length polymorphism (RFLP) analysis showed that V. cholerae O1 possess a single copy of the CTX element flanked by tandemly arranged RS element. Nucleotide sequencing of the ctxB gene showed the presence of classical ctxB. RFLP analysis of conserved rRNA gene showed two ribotype patterns. PFGE analysis also showed at least three PFGE patterns, irrespective of year of isolations, indicating the genomic relatedness among them.
CONCLUSION: Overall, these data suggest that classical ctxB-positive V. cholerae O1 El Tor strains that appeared in 2003 continue to cause infection in 2005 in Puri, India, and belong to identical ribotype(s) and/or pulsotype(s). There is need to continuous monitor the emergence of variant of El Tor because it will improve our understanding of the evolution of new clones of variant of V. cholerae.

PMID: 27934824 [PubMed - indexed for MEDLINE]

Vibrio alginolyticus infections in the USA, 1988-2012.

February 17, 2017
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Vibrio alginolyticus infections in the USA, 1988-2012.

Epidemiol Infect. 2017 Feb 16;:1-9

Authors: Jacobs Slifka KM, Newton AE, Mahon BE

Abstract
Vibrio alginolyticus causes soft tissue and bloodstream infection; little systematically collected clinical and epidemiological information is available. In the USA, V. alginolyticus infections are reported to the Cholera and Other Vibrio Illness Surveillance system. Using data from 1988 to 2012, we categorised infections using specimen source and exposure history, analysed case characteristics, and calculated incidence rates using US Census Bureau data. Most (96%) of the 1331 V. alginolyticus infections were from coastal states. Infections of the skin and ear were most frequent (87%); ear infections occurred more commonly in children, lower extremity infections more commonly in older adults. Most (86%) infections involved water activity. Reported incidence of infections increased 12-fold over the study period, although the extent of diagnostic or surveillance bias is unclear. Prevention efforts should target waterborne transmission in coastal areas and provider education to promote more rapid diagnosis and prevent complications.

PMID: 28202099 [PubMed - as supplied by publisher]

Feasibility and acceptability of oral cholera vaccine mass vaccination campaign in response to an outbreak and floods in Malawi.

February 12, 2017
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Feasibility and acceptability of oral cholera vaccine mass vaccination campaign in response to an outbreak and floods in Malawi.

Pan Afr Med J. 2016;23:203

Authors: Msyamboza KP, M'bang'ombe M, Hausi H, Chijuwa A, Nkukumila V, Kubwalo HW, Desai S, Pezzoli L, Legros D

Abstract
INTRODUCTION: Despite some improvement in provision of safe drinking water, proper sanitation and hygiene promotion, cholera still remains a major public health problem in Malawi with outbreaks occurring almost every year since 1998. In response to 2014/2015 cholera outbreak, ministry of health and partners made a decision to assess the feasibility and acceptability of conducting a mass oral cholera vaccine (OCV) as an additional public health measure. This paper highlights the burden of the 2014/15 cholera outbreak, successes and challenges of OCV campaign conducted in March and April 2015.
METHODS: This was a documentation of the first OCV campaign conducted in Malawi. The campaign targeted over 160,000 people aged one year or more living in 19 camps of people internally displaced by floods and their surrounding communities in Nsanje district. It was a reactive campaign as additional measure to improved water, sanitation and hygiene in response to the laboratory confirmed cholera outbreak.
RESULTS: During the first round of the OCV campaign conducted from 30 March to 4 April 2015, a total of 156,592 (97.6%) people out of 160,482 target population received OCV. During the second round (20 to 25 April 2015), a total of 137,629 (85.8%) people received OCV. Of these, 108,247 (67.6%) people received their second dose while 29,382 (18.3%) were their first dose. Of the 134,836 people with known gender and sex who received 1 or 2 doses, 54.4% were females and over half (55.4%) were children under the age of 15 years. Among 108,237 people who received 2 doses (fully immunized), 54.4% were females and 51.9% were children under 15 years of age. No severe adverse event following immunization was reported. The main reason for non-vaccination or failure to take the 2 doses was absence during the period of the campaign.
CONCLUSION: This documentation has demonstrated that it was feasible, acceptable by the community to conduct a large-scale mass OCV campaign in Malawi within five weeks. Of 320,000 OCV doses received, Malawi managed to administer at least 294,221 (91.9%) of the doses. OCV could therefore be considered to be introduced as additional measure in cholera hot spot areas in Malawi.

PMID: 27347292 [PubMed - indexed for MEDLINE]

Assessment of the response to cholera outbreaks in two districts in Ghana.

February 9, 2017
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Assessment of the response to cholera outbreaks in two districts in Ghana.

Infect Dis Poverty. 2016 Nov 02;5(1):99

Authors: Ohene SA, Klenyuie W, Sarpeh M

Abstract
BACKGROUND: Despite recurring outbreaks of cholera in Ghana, very little has been reported on assessments of outbreak response activities undertaken in affected areas. This study assessed the response activities undertaken in two districts, Akatsi District in Volta Region and Komenda-Edina-Eguafo-Abirem (KEEA) Municipal in Central Region during the 2012 cholera epidemic in Ghana.
METHODS: We conducted a retrospective assessment of the events, strengths and weaknesses of the cholera outbreak response activities in the two districts making use of the WHO cholera evaluation tool. Information sources included surveillance and facility records, reports and interviews with relevant health personnel involved in the outbreak response from both district health directorates and health facilities. We collected data on age, sex, area of residence, date of reporting to health facility of cholera cases, district population data and information on the outbreak response activities and performed descriptive analyses of the outbreak data by person, time and place.
RESULTS: The cholera outbreak in Akatsi was explosive with a high attack rate (AR) of 374/100,000 and case fatality rate (CFR) of 1.2 % while that in KEEA was on a relatively smaller scale AR of 23/100,000 but with a high case fatality rate of 18.8 %. For both districts, we identified multiple strengths in the response to the outbreak including timely notification of the district health officials which triggered prompt investigation of the suspected outbreak facilitating confirmation of cholera and initiation of public health response activities. Others were coordination of the activities by multi-sectoral committees, instituting water, sanitation and hygiene measures and appropriate case management at health facilities. We also found areas that needed improvement in both districts including incomplete surveillance data, sub-optimal community based surveillance considering the late reporting and the deaths in the community and the inadequate community knowledge about cholera preventive measures.
CONCLUSION: The assessment of the cholera outbreak response in the two districts highlighted strengths in the epidemic control activities. There was however need to strengthen preparedness especially in the area of improving community surveillance and awareness about cholera prevention and the importance of seeking prompt treatment in health facilities in the event of an outbreak.

PMID: 27802834 [PubMed - indexed for MEDLINE]

Impact of co-infections with enteric pathogens on children suffering from acute diarrhea in southwest China.

February 9, 2017
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Impact of co-infections with enteric pathogens on children suffering from acute diarrhea in southwest China.

Infect Dis Poverty. 2016 Jun 27;5(1):64

Authors: Zhang SX, Zhou YM, Xu W, Tian LG, Chen JX, Chen SH, Dang ZS, Gu WP, Yin JW, Serrano E, Zhou XN

Abstract
BACKGROUND: Acute diarrhea is a global health problem, resulting in high morbidity and mortality in children. It has been suggested that enteric pathogen co-infections play an important role in gastroenteritis, but most research efforts have only focused on a small range of species belonging to a few pathogen groups. This study aimed to assess the impact of co-infections with a broad range of enteric pathogens on children aged below five years who suffer from acute diarrhea in southwest China.
METHOD: A total of 1020 subjects (850 diarrhea cases and 170 healthy controls) were selected from four sentinel hospitals in Kunming, Yunnan province, southwest China, from June 2014 to July 2015. Stool specimens were collected to detect five virus (rotavirus group A, RVA; norovirus, NoV; Sapovirus, SaV; astrovirus, As; and adenovirus, Ad), seven bacterial (diarrheagenic Escherichia coli, DEC; non-typhoidal Salmonella, NTS; Shigella spp.; Vibrio cholera; Vibrio parahaemolyticus; Aeromonas spp.; and Plesiomonas spp.), and three protozoan (Cryptosporidium spp., Giardia lamblia, and Blastocystis hominis, B. hominis) species using standard microbiologic and molecular methods. Data were analyzed using the partial least square regression technique and chi-square test.
RESULTS: At least one enteric pathogen was detected in 46.7 % (n = 397) of acute gastroenteritis cases and 13.5 % (n = 23) of healthy controls (χ(2) = 64.4, P < 0.05). Single infection with RVA was associated with acute diarrhea (26.5 % vs. 5.8 %, P < 0.05). The prevalence of a single infection with B. hominis in diarrhea cases was higher than in healthy controls (3.1 % vs. 0.5 %, OR = 4.7, 95 % CI: 1.01-112.0). Single infection with NoV GII was not associated with diarrhea (4.4 % vs. 3.5 %, OR = 1.2, 95 % CI: 0.5-3.3). Single infections with bacterial species were not observed. The prevalence of co-infections with two enteric pathogens in diarrhea cases was higher than in asymptomatic children (20.1 % vs. 5.3 %, P < 0.05). RVA-NoV GII was the most common co-infection in symptomatic children (4.4 %), with it aggravating the severity of diarrhea.
CONCLUSIONS: Although it is clear that RVA has an overwhelming impact on diarrhea illnesses in children, co-infection with other enteric pathogens appears to also aggravate diarrhea severity. These findings should serve as evidence for public health services when planning and developing intervention programs.

PMID: 27349521 [PubMed - indexed for MEDLINE]

Prevalence of cholera risk factors between migrant Haitians and Dominicans in the Dominican Republic.

February 7, 2017
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Prevalence of cholera risk factors between migrant Haitians and Dominicans in the Dominican Republic.

Rev Panam Salud Publica. 2015 Mar;37(3):125-32

Authors: Lund AJ, Keys HM, Leventhal S, Foster JW, Freeman MC

Abstract
OBJECTIVE: To determine whether cholera risk factor prevalence in the Dominican Republic can be explained by nationality, independent of other factors, given the vulnerability of many Haitians in the country and the need for targeted prevention.
METHODS: A cross-sectional, observational household survey (103 Haitian and 260 Dominican) was completed in 18 communities in July 2012. The survey included modules for demographics, knowledge, socioeconomic status, and access to adequate water, sanitation, and hygiene (WASH) infrastructure. Logistic regression assessed differential access to WASH infrastructure and Poisson regression assessed differences in cholera knowledge, controlling for potential confounders.
RESULTS: Dominican and Haitian households differed on demographic characteristics. Haitians had lower educational attainment, socioeconomic status, and less knowledge of cholera than Dominicans (adjusted odds ratio [aOR] = 0.66; 95% confidence interval [95%CI] = 0.55-0.81). Access to improved drinking water was low for both groups, but particularly low among rural Haitians (aOR = 0.21; 95%CI: 0.04-1.01). No differences were found in access to sanitation after adjusting for sociodemographic confounders (aOR = 1.00; 95%CI: 0.57-1.76).
CONCLUSIONS: Urban/rural geography and socioeconomic status play a larger role in cholera risk factor prevalence than nationality, indicating that Haitians' perceived vulnerability to cholera is confounded by contextual factors. Understanding the social dynamics that lead to cholera risk can inform control strategies, leading to better targeting and the possibility of eliminating cholera from the island.

PMID: 25988248 [PubMed - indexed for MEDLINE]

Phenotypic and genetic characteristics of Vibrio cholerae O1 carrying Haitian ctxB and attributes of classical and El Tor biotypes isolated from Silvassa, India.

February 2, 2017
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Phenotypic and genetic characteristics of Vibrio cholerae O1 carrying Haitian ctxB and attributes of classical and El Tor biotypes isolated from Silvassa, India.

J Med Microbiol. 2016 Aug;65(8):720-8

Authors: Das MM, Bhotra T, Zala D, Singh DV

Abstract
Vibrio cholerae O1 biotype El Tor, the causative agent of the seventh pandemic, has recently been replaced by strains carrying classical and Haitian ctxB in India, Haiti and other parts of the world. We conducted phenotypic and genetic tests to characterize V. cholerae O1 isolated between 2012 and 2014 from Silvassa, India, to examine the presence of virulence and regulatory genes, seventh pandemic marker, ctxB type and biofilm formation and to study genomic diversity. Of the 59 V. cholerae O1, eight isolates belong to El Tor prototype, one to classical prototype and the remaining isolates have attributes of both classical and El Tor biotypes. PCR and ctxB gene sequencing revealed the presence of classical ctxB in four strains and Haitian ctxB in 55 isolates; indicating that isolates were either an El Tor or hybrid variant. All isolates carried virulence, regulatory, adherence, Vibrio seventh pandemic pathogenicity island I and seventh pandemic group-specific marker VC2346, in addition to tcpAET and rstRET, the features of seventh pandemic strains, and produced cholera toxin and biofilm. PFGE analysis showed that the majority of isolates are clonal and belong to fingerprint pattern A; however, pattern B is unrelated and patterns C and D are distinct, suggesting considerable diversity in the genomic content among them. These data thus show that isolates from Silvassa are genetically diverse and that Haitian ctxB and hybrid phenotypes are undergoing global dissemination.

PMID: 27255911 [PubMed - indexed for MEDLINE]

Model distinguishability and inference robustness in mechanisms of cholera transmission and loss of immunity.

January 29, 2017
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Model distinguishability and inference robustness in mechanisms of cholera transmission and loss of immunity.

J Theor Biol. 2017 Jan 24;:

Authors: Lee EC, Kelly MR, Ochocki BM, Akinwumi SM, Hamre KE, Tien JH, Eisenberg MC

Abstract
Mathematical models of cholera and waterborne disease vary widely in their structures, in terms of transmission pathways, loss of immunity, and a range of other features. These differences can affect model dynamics, with different models potentially yielding different predictions and parameter estimates from the same data. Given the increasing use of mathematical models to inform public health decision-making, it is important to assess model distinguishability (whether models can be distinguished based on fit to data) and inference robustness (whether inferences from the model are robust to realistic variations in model structure). In this paper, we examined the effects of uncertainty in model structure in the context of epidemic cholera, testing a range of models with differences in transmission and loss of immunity structure, based on known features of cholera epidemiology. We fit these models to simulated epidemic and long-term data, as well as data from the 2006 Angola epidemic. We evaluated model distinguishability based on fit to data, and whether the parameter values, model behavior, and forecasting ability can accurately be inferred from incidence data. In general, all models were able to successfully fit to all data sets, both real and simulated, regardless of whether the model generating the simulated data matched the fitted model. However, in the long-term data, the best model fits were achieved when the loss of immunity structures matched those of the model that simulated the data. Two parameters, one representing person-to-person transmission and the other representing the reporting rate, were accurately estimated across all models, while the remaining parameters showed broad variation across the different models and data sets. The basic reproduction number (R0) was often poorly estimated even using the correct model, due to practical unidentifiability issues in the waterborne transmission pathway which were consistent across all models. Forecasting efforts using noisy data were not successful early in the outbreaks, but once the epidemic peak had been achieved, most models were able to capture the downward incidence trajectory with similar accuracy. Forecasting from noise-free data was generally successful for all outbreak stages using any model. Our results suggest that we are unlikely to be able to infer mechanistic details from epidemic case data alone, underscoring the need for broader data collection, such as immunity/serology status, pathogen dose response curves, and environmental pathogen data. Nonetheless, with sufficient data, conclusions from forecasting and some parameter estimates were robust to variations in the model structure, and comparative modeling can help to determine how realistic variations in model structure may affect the conclusions drawn from models and data.

PMID: 28130096 [PubMed - as supplied by publisher]

Tracking Disease: Digital Epidemiology Offers New Promise in Predicting Outbreaks.

January 28, 2017

Tracking Disease: Digital Epidemiology Offers New Promise in Predicting Outbreaks.

IEEE Pulse. 2017 Jan-Feb;8(1):18-22

Authors: Bates M

Abstract
On 19 October 2010, ten months after a devastating earthquake hit Haiti, the Haitian Ministry of Public Health and Population (MSPP) was notified of a sudden surge in patients suffering from watery diarrhea and dehydration. Two days later, the Haiti National Public Health Laboratory identified the culprit: Vibrio cholerae. On 22 October, officials announced the first cholera outbreak in Haiti in more than a century.

PMID: 28129137 [PubMed - in process]

Mobile phone data highlights the role of mass gatherings in the spreading of cholera outbreaks.

January 28, 2017
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Mobile phone data highlights the role of mass gatherings in the spreading of cholera outbreaks.

Proc Natl Acad Sci U S A. 2016 Jun 07;113(23):6421-6

Authors: Finger F, Genolet T, Mari L, de Magny GC, Manga NM, Rinaldo A, Bertuzzo E

Abstract
The spatiotemporal evolution of human mobility and the related fluctuations of population density are known to be key drivers of the dynamics of infectious disease outbreaks. These factors are particularly relevant in the case of mass gatherings, which may act as hotspots of disease transmission and spread. Understanding these dynamics, however, is usually limited by the lack of accurate data, especially in developing countries. Mobile phone call data provide a new, first-order source of information that allows the tracking of the evolution of mobility fluxes with high resolution in space and time. Here, we analyze a dataset of mobile phone records of ∼150,000 users in Senegal to extract human mobility fluxes and directly incorporate them into a spatially explicit, dynamic epidemiological framework. Our model, which also takes into account other drivers of disease transmission such as rainfall, is applied to the 2005 cholera outbreak in Senegal, which totaled more than 30,000 reported cases. Our findings highlight the major influence that a mass gathering, which took place during the initial phase of the outbreak, had on the course of the epidemic. Such an effect could not be explained by classic, static approaches describing human mobility. Model results also show how concentrated efforts toward disease control in a transmission hotspot could have an important effect on the large-scale progression of an outbreak.

PMID: 27217564 [PubMed - indexed for MEDLINE]

Mind the Gap: Gaps in Antidepressant Treatment, Treatment Adjustments, and Outcomes among Patients in Routine HIV Care in a Multisite U.S. Clinical Cohort.

January 27, 2017

Mind the Gap: Gaps in Antidepressant Treatment, Treatment Adjustments, and Outcomes among Patients in Routine HIV Care in a Multisite U.S. Clinical Cohort.

PLoS One. 2017;12(1):e0166435

Authors: Cholera R, Pence BW, Bengtson AM, Crane HM, Christopoulos K, Cole SR, Fredericksen R, Gaynes BN, Heine A, Mathews WC, Mimiaga MJ, Moore R, Napravnik S, O'Clerigh C, Safren S, Mugavero MJ

Abstract
BACKGROUND: Depression affects 20-30% of HIV-infected patients and is associated with worse HIV outcomes. Although effective depression treatment is available, depression is largely untreated or undertreated in this population.
METHODS: We quantified gaps in antidepressant treatment, treatment adjustments, and outcomes among US patients in routine HIV care in the nationally distributed CNICS observational clinical cohort. This cohort combines detailed clinical data with regular, self-reported depressive severity assessments (Patient Health Questionnaire-9, PHQ-9). We considered whether participants with likely depression received antidepressants, whether participants on antidepressants with persistently high depressive symptoms received timely dose adjustments, and whether participants achieved depression remission. We considered a cross-sectional analysis (6,219 participants in care in 2011-2012) and a prospective analysis (2,936 participants newly initiating CNICS care when PHQ-9 screening was active).
RESULTS: The cross-sectional sample was 87% male, 53% Caucasian, 25% African American, and 18% Hispanic; the prospective sample was similar. In both samples, 39-44% had likely depression, with 44-60% of those receiving antidepressants. Of participants receiving antidepressants, 20-26% experienced persistently high depressive symptoms; only a small minority of those received antidepressant dose adjustments. Overall, 35-40% of participants on antidepressants achieved full depression remission. Remission among participants with persistently high depressive symptoms was rare regardless of dose adjustments.
CONCLUSIONS: In this large, diverse cohort of US patients engaged in routine HIV care, we observed large gaps in antidepressant treatment, timely dose adjustment to address persistently high depressive symptoms, and antidepressant treatment outcomes. These results highlight the importance of more effective pharmacologic depression treatment models for HIV-infected patients.

PMID: 28125593 [PubMed - in process]

Gender-based differences in water, sanitation and hygiene-related diarrheal disease and helminthic infections: a systematic review and meta-analysis.

January 25, 2017
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Gender-based differences in water, sanitation and hygiene-related diarrheal disease and helminthic infections: a systematic review and meta-analysis.

Trans R Soc Trop Med Hyg. 2017 Jan 22;:

Authors: Sevilimedu V, Pressley KD, Snook KR, Hogges JV, Politis MD, Sexton JK, Duke CH, Smith BA, Swander LC, Baker KK, Gambhir M, Fung IC

Abstract
BACKGROUND: Qualitative evidence suggests that inadequate water, sanitation and hygiene (WASH) may affect diarrheal and helminthic infection in women disproportionately. We systematically searched PubMed in June 2014 (updated 2016) and the WHO website, for relevant articles.
METHODS: Articles dealing with the public health relevance of helminthic and diarrheal diseases, and highlighting the role of gender in WASH were included. Where possible, we carried out a meta-analysis.
RESULTS: In studies of individuals 5 years or older, cholera showed lower prevalence in males (OR 0.56; 95% CI 0.34-0.94), while Schistosoma mansoni (1.38; 95% CI 1.14-1.67), Schistosoma japonicum (1.52; 95% CI 1.13-2.05), hookworm (1.43; 95% CI 1.07-1.89) and all forms of infectious diarrhea (1.21; 95% CI 1.06-1.38) showed a higher prevalence in males. When studies included all participants, S. mansoni and S. japonicum showed higher prevalence with males (OR 1.40; 95% CI 1.27-1.55 and 1.84; 95% CI 1.27-2.67, respectively). Prevalence of Trichiuris and hookworm infection showed effect modification with continent.
CONCLUSIONS: Evidence of gender differences in infection may reflect differences in gender norms, suggesting that policy changes at the regional level may help ameliorate gender related disparities in helminthic and diarrheal disease prevalence.

PMID: 28115686 [PubMed - as supplied by publisher]

Complete genotyping of unusual species A rotavirus G12P[11] and G10P[14] isolates and evidence of frequent in vivo reassortment among the rotaviruses detected in children with diarrhea in Kolkata, India, during 2014.

January 24, 2017
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Complete genotyping of unusual species A rotavirus G12P[11] and G10P[14] isolates and evidence of frequent in vivo reassortment among the rotaviruses detected in children with diarrhea in Kolkata, India, during 2014.

Arch Virol. 2016 Oct;161(10):2773-85

Authors: Mandal P, Mullick S, Nayak MK, Mukherjee A, Ganguly N, Niyogi P, Panda S, Chawla-Sarkar M

Abstract
Species A rotaviruses (RVA) are the most important cause of acute gastroenteritis in the young of humans and many animal species globally. G1P[8], G2P[4], G3P[8], G4P[8], G9P[6/8] and G12P[6/8] are the predominantly isolated genotypes throughout the world including India. Unusual genotypes from different host species such as G5, G6, G8, G10 and G11 have also been reported in humans with low frequency. In the present study, among >650 RVA positive stool samples collected from children with diarrhea in Kolkata, India, during 2014, two isolates each of the genotype G12P[11] and G10P[14] were obtained and their genomes completely sequenced. The full genotype constellations were G12-P[11]-I1-R1-C1-M2-A1-N1-T2-E1-H1 and G12-P[11]-I1-R1-C1-M1-A5-N1-T1-E1-H1 for G12P[11] viruses, suggesting several reassortments between Wa- and DS-1-like human RVA strains, including possible reassortment of a simian NSP1 gene. The G10P[14] viruses (G10-P[14]-I2-R2-C2-M2-A11-N2-T6-E2-H3) were found to contain multiple genes closely related to RVAs of artiodactyl origin, highlighting the role of inter-host species transmissions of RVAs. From the G/P constellation of all RVA isolates, it could be concluded that approximately one quarter had likely arisen from reassortment events in vivo among RVAs of 'usual' genotypes.

PMID: 27447463 [PubMed - indexed for MEDLINE]

Adapting to the global shortage of cholera vaccines: targeted single dose cholera vaccine in response to an outbreak in South Sudan.

January 23, 2017
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Adapting to the global shortage of cholera vaccines: targeted single dose cholera vaccine in response to an outbreak in South Sudan.

Lancet Infect Dis. 2017 Jan 18;:

Authors: Parker LA, Rumunu J, Jamet C, Kenyi Y, Lino RL, Wamala JF, Mpairwe AM, Ciglenecki I, Luquero FJ, Azman AS, Cabrol JC

Abstract
Shortages of vaccines for epidemic diseases, such as cholera, meningitis, and yellow fever, have become common over the past decade, hampering efforts to control outbreaks through mass reactive vaccination campaigns. Additionally, various epidemiological, political, and logistical challenges, which are poorly documented in the literature, often lead to delays in reactive campaigns, ultimately reducing the effect of vaccination. In June 2015, a cholera outbreak occurred in Juba, South Sudan, and because of the global shortage of oral cholera vaccine, authorities were unable to secure sufficient doses to vaccinate the entire at-risk population-approximately 1 million people. In this Personal View, we document the first public health use of a reduced, single-dose regimen of oral cholera vaccine, and show the details of the decision-making process and timeline. We also make recommendations to help improve reactive vaccination campaigns against cholera, and discuss the importance of new and flexible context-specific dose regimens and vaccination strategies.

PMID: 28109819 [PubMed - as supplied by publisher]

Characterization and Genetic Variation of Vibrio cholerae Isolated from Clinical and Environmental Sources in Thailand.

January 20, 2017
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Characterization and Genetic Variation of Vibrio cholerae Isolated from Clinical and Environmental Sources in Thailand.

PLoS One. 2017;12(1):e0169324

Authors: Siriphap A, Leekitcharoenphon P, Kaas RS, Theethakaew C, Aarestrup FM, Sutheinkul O, Hendriksen RS

Abstract
Cholera is still an important public health problem in several countries, including Thailand. In this study, a collection of clinical and environmental V. cholerae serogroup O1, O139, and non-O1/non-O139 strains originating from Thailand (1983 to 2013) was characterized to determine phenotypic and genotypic traits and to investigate the genetic relatedness. Using a combination of conventional methods and whole genome sequencing (WGS), 78 V. cholerae strains were identified. WGS was used to determine the serogroup, biotype, virulence, mobile genetic elements, and antimicrobial resistance genes using online bioinformatics tools. In addition, phenotypic antimicrobial resistance was determined by the minimal inhibitory concentration (MIC) test. The 78 V. cholerae strains belonged to the following serogroups O1: (n = 44), O139 (n = 16) and non-O1/non-O139 (n = 18). Interestingly, we found that the typical El Tor O1 strains were the major cause of clinical cholera during 1983-2000 with two Classical O1 strains detected in 2000. In 2004-2010, the El Tor variant strains revealed genotypes of the Classical biotype possessing either only ctxB or both ctxB and rstR while they harbored tcpA of the El Tor biotype. Thirty O1 and eleven O139 clinical strains carried CTXϕ (Cholera toxin) and tcpA as well four different pathogenic islands (PAIs). Beside non-O1/non-O139, the O1 environmental strains also presented chxA and Type Three Secretion System (TTSS). The in silico MultiLocus Sequence Typing (MLST) discriminated the O1 and O139 clinical strains from other serogroups and environmental strains. ST69 was dominant in the clinical strains belonging to the 7th pandemic clone. Non-O1/non-O139 and environmental strains showed various novel STs indicating genetic variation. Multidrug-resistant (MDR) strains were observed and conferred resistance to ampicillin, azithromycin, nalidixic acid, sulfamethoxazole, tetracycline, and trimethoprim and harboured variants of the SXT elements. For the first time since 1986, the presence of V. cholerae O1 Classical was reported causing cholera outbreaks in Thailand. In addition, we found that V. cholerae O1 El Tor variant and O139 were pre-dominating the pathogenic strains in Thailand. Using WGS and bioinformatic tools to analyze both historical and contemporary V. cholerae circulating in Thailand provided a more detailed understanding of the V. cholerae epidemiology, which ultimately could be applied for control measures and management of cholera in Thailand.

PMID: 28103259 [PubMed - in process]

Evaluation of a Smartphone Decision-Support Tool for Diarrheal Disease Management in a Resource-Limited Setting.

January 20, 2017
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Evaluation of a Smartphone Decision-Support Tool for Diarrheal Disease Management in a Resource-Limited Setting.

PLoS Negl Trop Dis. 2017 Jan 19;11(1):e0005290

Authors: Haque F, Ball RL, Khatun S, Ahmed M, Kache S, Chisti MJ, Sarker SA, Maples SD, Pieri D, Vardhan Korrapati T, Sarnquist C, Federspiel N, Rahman MW, Andrews JR, Rahman M, Nelson EJ

Abstract
The emergence of mobile technology offers new opportunities to improve clinical guideline adherence in resource-limited settings. We conducted a clinical pilot study in rural Bangladesh to evaluate the impact of a smartphone adaptation of the World Health Organization (WHO) diarrheal disease management guidelines, including a modality for age-based weight estimation. Software development was guided by end-user input and evaluated in a resource-limited district and sub-district hospital during the fall 2015 cholera season; both hospitals lacked scales which necessitated weight estimation. The study consisted of a 6 week pre-intervention and 6 week intervention period with a 10-day post-discharge follow-up. Standard of care was maintained throughout the study with the exception that admitting clinicians used the tool during the intervention. Inclusion criteria were patients two months of age and older with uncomplicated diarrheal disease. The primary outcome was adherence to guidelines for prescriptions of intravenous (IV) fluids, antibiotics and zinc. A total of 841 patients were enrolled (325 pre-intervention; 516 intervention). During the intervention, the proportion of prescriptions for IV fluids decreased at the district and sub-district hospitals (both p < 0.001) with risk ratios (RRs) of 0.5 and 0.2, respectively. However, when IV fluids were prescribed, the volume better adhered to recommendations. The proportion of prescriptions for the recommended antibiotic azithromycin increased (p < 0.001 district; p = 0.035 sub-district) with RRs of 6.9 (district) and 1.6 (sub-district) while prescriptions for other antibiotics decreased; zinc adherence increased. Limitations included an absence of a concurrent control group and no independent dehydration assessment during the pre-intervention. Despite limitations, opportunities were identified to improve clinical care, including better assessment, weight estimation, and fluid/ antibiotic selection. These findings demonstrate that a smartphone-based tool can improve guideline adherence. This study should serve as a catalyst for a randomized controlled trial to expand on the findings and address limitations.

PMID: 28103233 [PubMed - as supplied by publisher]

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