Recent Cholera Publications on PubMed

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Characterization of highly virulent multidrug resistant Vibrio cholerae isolated from a large cholera outbreak in Ghana.

August 14, 2018
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Characterization of highly virulent multidrug resistant Vibrio cholerae isolated from a large cholera outbreak in Ghana.

BMC Res Notes. 2018 Jan 18;11(1):45

Authors: Feglo PK, Sewurah M

Abstract
OBJECTIVE: The purpose of this study was to investigate the virulent factors of Vibrio cholerae which caused an unprecedented large cholera outbreak in Ghana in 2014 and progressed into 2015, affected 28,975 people with 243 deaths.
RESULTS: The V. cholerae isolates were identified to be the classical V. cholerae 01 biotype El Tor, serotype Ogawa, responsible for the large cholera outbreak in Ghana. These El Tor strains bear CtxAB and Tcp virulent genes, making the strains highly virulent. The strains also bear SXT transmissible element coding their resistance to antibiotics, causing high proportions of the strains to be multidrug resistant, with resistant proportions of 95, 90 and 75% to trimethoprim/sulfamethoxazole, ampicillin and ceftriaxone respectively. PFGE patterns indicated that the isolates clustered together with the same pattern and showed clusters similar to strains circulating in DR Congo, Cameroun, Ivory Coast and Togo. The strains carried virulence genes which facilitated the disease causation and spread. This is the first time these virulent genes were determined on the Ghanaian Vibrio strains.

PMID: 29347965 [PubMed - indexed for MEDLINE]

The Cholera Epidemic in Zimbabwe, 2008-2009: A Review and Critique of the Evidence.

August 7, 2018
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The Cholera Epidemic in Zimbabwe, 2008-2009: A Review and Critique of the Evidence.

Health Hum Rights. 2017 Dec;19(2):249-264

Authors: Cuneo CN, Sollom R, Beyrer C

Abstract
The 2008-2009 Zimbabwe cholera epidemic resulted in 98,585 reported cases and caused more than 4,000 deaths. In this study, we used a mixed-methods approach that combined primary qualitative data from a 2008 Physicians for Human Rights-led investigation with a systematic review and content analysis of the scientific literature. Our initial investigation included semi-structured interviews of 92 key informants, which we supplemented with reviews of the social science and human rights literature, as well as international news reports. Our systematic review of the scientific literature retrieved 59 unique citations, of which 30 met criteria for inclusion in the content analysis: 14 of the 30 (46.7%) articles mentioned the political dimension of the epidemic, while 7 (23.3%) referenced Mugabe or his political party (ZANU-PF). Our investigation revealed that the 2008-2009 Zimbabwean cholera epidemic was exacerbated by a series of human rights abuses, including the politicization of water, health care, aid, and information. The failure of the scientific community to directly address the political determinants of the epidemic exposes challenges to maintaining scientific integrity in the setting of humanitarian responses to complex health and human rights crises. While the period of the cholera epidemic and the health care system collapse is now nearly a decade in the past, the findings of this work remain highly relevant for Zimbabwe and other countries, as complex health and rights interactions remain widespread, and governance concerns continue to limit improvements in human health.

PMID: 29302180 [PubMed - indexed for MEDLINE]

Impact of adding hand-washing and water disinfection promotion to oral cholera vaccination on diarrhoea-associated hospitalization in Dhaka, Bangladesh: evidence from a cluster randomized control trial.

August 7, 2018
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Impact of adding hand-washing and water disinfection promotion to oral cholera vaccination on diarrhoea-associated hospitalization in Dhaka, Bangladesh: evidence from a cluster randomized control trial.

Int J Epidemiol. 2017 Dec 01;46(6):2056-2066

Authors: Najnin N, Leder K, Qadri F, Forbes A, Unicomb L, Winch PJ, Ram PK, Leontsini E, Nizame FA, Arman S, Begum F, Biswas SK, Clemens JD, Ali M, Cravioto A, Luby SP

Abstract
Background: Information on the impact of hygiene interventions on severe outcomes is limited. As a pre-specified secondary outcome of a cluster-randomized controlled trial among >400 000 low-income residents in Dhaka, Bangladesh, we examined the impact of cholera vaccination plus a behaviour change intervention on diarrhoea-associated hospitalization.
Methods: Ninety neighbourhood clusters were randomly allocated into three areas: cholera-vaccine-only; vaccine-plus-behaviour-change (promotion of hand-washing with soap plus drinking water chlorination); and control. Study follow-up continued for 2 years after intervention began. We calculated cluster-adjusted diarrhoea-associated hospitalization rates using data we collected from nearby hospitals, and 6-monthly census data of all trial households.
Results: A total of 429 995 people contributed 500 700 person-years of data (average follow-up 1.13 years). Vaccine coverage was 58% at the start of analysis but continued to drop due to population migration. In the vaccine-plus-behaviour-change area, water plus soap was present at 45% of hand-washing stations; 4% of households had detectable chlorine in stored drinking water. Hospitalization rates were similar across the study areas [events/1000 person-years, 95% confidence interval (CI), cholera-vaccine-only: 9.4 (95% CI: 8.3-10.6); vaccine-plus-behaviour-change: 9.6 (95% CI: 8.3-11.1); control: 9.7 (95% CI: 8.3-11.6)]. Cholera cases accounted for 7% of total number of diarrhoea-associated hospitalizations.
Conclusions: Neither cholera vaccination alone nor cholera vaccination combined with behaviour-change intervention efforts measurably reduced diarrhoea-associated hospitalization in this highly mobile population, during a time when cholera accounted for a small fraction of diarrhoea episodes. Affordable community-level interventions that prevent infection from multiple pathogens by reliably separating faeces from the environment, food and water, with minimal behavioural demands on impoverished communities, remain an important area for research.

PMID: 29025064 [PubMed - indexed for MEDLINE]

Confirmation of cholera by rapid diagnostic test amongst patients admitted to the cholera treatment centre in Uvira, Democratic Republic of the Congo.

August 2, 2018

Confirmation of cholera by rapid diagnostic test amongst patients admitted to the cholera treatment centre in Uvira, Democratic Republic of the Congo.

PLoS One. 2018;13(8):e0201306

Authors: Jeandron A, Cumming O, Rumedeka BB, Saidi JM, Cousens S

Abstract
INTRODUCTION: Cholera is endemic in the Eastern provinces of the Democratic Republic of the Congo since 1978, and Uvira in South-Kivu has been reporting suspected cholera cases nearly every week for over a decade. The clinical case definition for suspected cholera is relatively non-specific, and cases are rarely confirmed by laboratory methods, especially in endemic settings. This may lead to over-estimation of cholera cases and limit effective public health responses.
METHODS AND RESULTS: Between April 2016 and November 2017, 69% of the 2,059 patients admitted to the Uvira Cholera Treatment Centre (CTC) were tested for cholera with rapid diagnostic tests (RDTs). Of those admitted as suspected cholera cases, only 40% tested positive for cholera, equivalent to an estimated annual incidence of suspected/confirmed cholera in Uvira of 43.8 and 16.3 cases per 10,000 inhabitants respectively. A multivariable logistic regression indicates that boys aged 2 to 4 years, girls aged 5 to 15 years and adult men are respectively 1.9, 2.1 and 1.8 times more likely to test positive than adult women. On the contrary, boys under 2 are 10 times less likely to test positive. The odds of testing positive also increase as weekly admissions to the CTC rise, with up to a 5-fold increase observed during the weeks with the highest numbers of admissions compared to the lowest ones. Other predictors of cholera confirmation include duration of stay at the CTC, clinical outcome of admission, lower weekly rainfall and area of residence in Uvira, with the northern part of town having the highest confirmation rate.
CONCLUSION: Cholera is an on-going public health problem in Uvira but the majority of suspected cases admitted to the CTC were found to be negative for cholera after RDT testing. These findings may have important implications for cholera control strategies in favour of interventions that address cholera and other diarrhoeal diseases alike.

PMID: 30067824 [PubMed - in process]

Impact of Awareness Programs on Cholera Dynamics: Two Modeling Approaches.

July 31, 2018
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Impact of Awareness Programs on Cholera Dynamics: Two Modeling Approaches.

Bull Math Biol. 2017 Sep;79(9):2109-2131

Authors: Yang C, Wang X, Gao D, Wang J

Abstract
We propose two differential equation-based models to investigate the impact of awareness programs on cholera dynamics. The first model represents the disease transmission rates as decreasing functions of the number of awareness programs, whereas the second model divides the susceptible individuals into two distinct classes depending on their awareness/unawareness of the risk of infection. We study the essential dynamical properties of each model, using both analytical and numerical approaches. We find that the two models, though closely related, exhibit significantly different dynamical behaviors. Namely, the first model follows regular threshold dynamics while rich dynamical behaviors such as backward bifurcation may arise from the second one. Our results highlight the importance of validating key modeling assumptions in the development and selection of mathematical models toward practical application.

PMID: 28748506 [PubMed - indexed for MEDLINE]

Cholera: recent updates.

July 27, 2018
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Cholera: recent updates.

Curr Opin Infect Dis. 2018 Jul 25;:

Authors: Weil AA, Ryan ET

Abstract
PURPOSE OF REVIEW: In this review, we will examine updates in cholera epidemiology, advances in our understanding of pathogenesis and protective immunity, and changes to prevention strategies.
RECENT FINDINGS: New modeling techniques and molecular epidemiology have led to advancements in our understanding of how Vibrio cholerae has persisted and re-emerged in new areas during the seventh pandemic. Use of next-generation sequencing has shed new light on immune responses to disease and vaccination, and the role of the gut microbiome in cholera. Increased efficacy and availability of vaccines have made long-term goals of global control of cholera more achievable.
SUMMARY: Advancements in our understanding of immunity and susceptibility to cholera, in addition to an increased global commitment to disease prevention, have led to optimism for the future of cholera prevention.

PMID: 30048254 [PubMed - as supplied by publisher]

Protocol for developing a Database of Zoonotic disease Research in India (DoZooRI).

July 22, 2018
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Protocol for developing a Database of Zoonotic disease Research in India (DoZooRI).

BMJ Open. 2017 Dec 10;7(12):e017825

Authors: Chatterjee P, Bhaumik S, Chauhan AS, Kakkar M

Abstract
INTRODUCTION: Zoonotic and emerging infectious diseases (EIDs) represent a public health threat that has been acknowledged only recently although they have been on the rise for the past several decades. On an average, every year since the Second World War, one pathogen has emerged or re-emerged on a global scale. Low/middle-income countries such as India bear a significant burden of zoonotic and EIDs. We propose that the creation of a database of published, peer-reviewed research will open up avenues for evidence-based policymaking for targeted prevention and control of zoonoses.
METHODS AND ANALYSIS: A large-scale systematic mapping of the published peer-reviewed research conducted in India will be undertaken. All published research will be included in the database, without any prejudice for quality screening, to broaden the scope of included studies. Structured search strategies will be developed for priority zoonotic diseases (leptospirosis, rabies, anthrax, brucellosis, cysticercosis, salmonellosis, bovine tuberculosis, Japanese encephalitis and rickettsial infections), and multiple databases will be searched for studies conducted in India. The database will be managed and hosted on a cloud-based platform called Rayyan. Individual studies will be tagged based on key preidentified parameters (disease, study design, study type, location, randomisation status and interventions, host involvement and others, as applicable).
ETHICS AND DISSEMINATION: The database will incorporate already published studies, obviating the need for additional ethical clearances. The database will be made available online, and in collaboration with multisectoral teams, domains of enquiries will be identified and subsequent research questions will be raised. The database will be queried for these and resulting evidence will be analysed and published in peer-reviewed journals.

PMID: 29229654 [PubMed - indexed for MEDLINE]

Anxiety-related adverse events following immunization (AEFI): A systematic review of published clusters of illness.

July 18, 2018
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Anxiety-related adverse events following immunization (AEFI): A systematic review of published clusters of illness.

Vaccine. 2018 01 04;36(2):299-305

Authors: Loharikar A, Suragh TA, MacDonald NE, Balakrishnan MR, Benes O, Lamprianou S, Hyde TB, McNeil MM

Abstract
BACKGROUND: Clusters of anxiety-related adverse events following immunization (AEFI) have been observed in several countries and have disrupted country immunization programs. We conducted a systematic literature review to characterize these clusters, to generate prevention and management guidance for countries.
METHODS: We searched seven peer-reviewed databases for English language reports of anxiety-related AEFI clusters (≥2 persons) with pre-specified keywords across 4 categories: symptom term, cluster term, vaccine term, and cluster AEFI phenomenon term/phrase. All relevant reports were included regardless of publication date, case-patient age, or vaccine. Two investigators independently reviewed abstracts and identified articles for full review. Data on epidemiologic/clinical information were extracted from full text review including setting, vaccine implicated, predominant case-patient symptoms, clinical management, community and media response, and outcome/impact on the vaccination program.
RESULTS: Of 1472 abstracts reviewed, we identified eight published clusters, from all six World Health Organization (WHO) regions except the African Region. Seven clusters occurred among children in school settings, and one was among adult military reservists. The size and nature of these clusters ranged from 7 patients in one school to 806 patients in multiple schools. Patients' symptoms included dizziness, headache, and fainting with rapid onset after vaccination. Implicated vaccines included tetanus (2), tetanus-diphtheria (1), hepatitis B (1), oral cholera (1), human papillomavirus (1), and influenza A (H1N1)pdm09 (2). In each report, all affected individuals recovered rapidly; however, vaccination program disruption was noted in some instances, sometimes for up to one year.
CONCLUSIONS: Anxiety-related AEFI clusters can be disruptive to vaccination programs, reducing public trust in immunizations and impacting vaccination coverage; response efforts to restore public confidence can be resource intensive. Health care providers should have training on recognition and clinical management of anxiety-related AEFI; public health authorities should have plans to prevent and effectively manage anxiety-related AEFI clusters. Prompt management of these occurrences can be even more important in an era of social media, in which information is rapidly spread.

PMID: 29198916 [PubMed - indexed for MEDLINE]

Speciation, clinical profile & antibiotic resistance in Aeromonas species isolated from cholera-like illnesses in a tertiary care hospital in north India.

July 13, 2018
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Speciation, clinical profile & antibiotic resistance in Aeromonas species isolated from cholera-like illnesses in a tertiary care hospital in north India.

Indian J Med Res. 2017 Jul;146(Supplement):S53-S58

Authors: Mohan B, Sethuraman N, Verma R, Taneja N

Abstract
BACKGROUND & OBJECTIVES: Aeromonas species have been reported to cause various illnesses in humans such as wound infections, septicaemia, peritonitis and pneumonia. Their role in causation of cholera-like illness is also being increasingly recognized. This retrospective study was done to know the presence of Aeromonas as a cause of acute diarrhoea in a tertiary care hospital and to find the common species of Aeromonas causing diarrhoea and their antibiotic susceptibility patterns.
METHODS: Fifty isolates of Aeromonas were obtained over a period of 15 yr from 2000 to 2014 from patients of suspected acute gastroenteritis resembling cholera. Biotyping was done for 35 of these isolates available in culture collection, based on a panel of 13 biochemical reactions. Antibiogram was put up for all of these isolates by disk diffusion methods and interpreted according to the Clinical and Laboratory Standards Institute guidelines.
RESULTS: Of the 50 patients of Aeromonas-related acute gastroenteritis, 13 (26%) had typical features of cholera with rice water stools and severe dehydration. Eight patients (16%) had dysentery-like picture. One patient died of severe dehydration and septicaemia. The most common species were found to be Aeromonas caviae (34%) followed by Aeromonas veronii biovar veronii (29%), Aeromonas veronii biovar sobria (26%) and Aeromonas hydrophila (9%). All tested isolates were uniformly susceptible to cefepime, amikacin, azithromycin and meropenem; 14 per cent were susceptible to amoxicillin, 32 per cent to nalidixic acid, 60 per cent to co-trimoxazole, 54 per cent to ciprofloxacin, 60 per cent to ofloxacin, 74 per cent to chloramphenicol, 76 per cent to ceftriaxone, 74 per cent to cefotaxime, 88 per cent to gentamicin and 86 per cent to furoxone.
INTERPRETATION & CONCLUSIONS: Aeromonas is an important, often neglected pathogen capable of causing a variety of gastrointestinal tract symptoms such as acute diarrhoea and dysentery and may even mimic cholera. It is, therefore, pertinent to recognize this pathogen as an important agent in the causation of severe diarrhoea.

PMID: 29205196 [PubMed - indexed for MEDLINE]

The role of CTX and RS1 satellite phages genomic arrangement in Vibrio cholera toxin production in two recent cholera outbreaks (2012 and 2013) in IR Iran.

July 10, 2018
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The role of CTX and RS1 satellite phages genomic arrangement in Vibrio cholera toxin production in two recent cholera outbreaks (2012 and 2013) in IR Iran.

Microb Pathog. 2017 Nov;112:89-94

Authors: Rezaie N, Bakhshi B, Najar-Peerayeh S

Abstract
The objective of the present study was to investigate the genomic arrangement of CTX/RS1 prophages in 30 Vibrio cholerae strains obtained from 2 consecutive years of cholera outbreak and to compare the role of different CTX/RS1 arrangements in cholera toxin expression among the El Tor strains. Profile A with TLC-RS1-CTX-RTX arrangement was observed in 46.7% of the isolates with RS1 phage locating adjacent to TLC element. About 50% of the isolates showed Profile B with TLC-CTX-RS1-RTX arrangement and one single isolate (3.3%) revealed TLC-CTX-RS1-RS1-RTX arrangement (Profile C). No RS1 element was detected to be adjacent to TLC element in B and C profiles. No truncated CTX phage genome was detected among the isolates of 2 years. Different CTX-RS1 arrangement profiles (A, B, and C) with different RS1 copy numbers and locations uniformly showed low level of cholera toxin production in El Tor strains with no significant difference, revealing that different RS1 copy numbers and locations have no effect on cholera toxin production level (p-value >0.05). However, increased cholera toxin expression was observed for control V. cholerae classical biotype strain. In conclusion, variations in RS1 prophage did not affect CT expression level in related El Tor V. cholerae strains. CTX genotyping establishes a more valuable database for epidemiologic, pathogenesis, and source tracking purposes.

PMID: 28923607 [PubMed - indexed for MEDLINE]

Highly targeted cholera vaccination campaigns in urban setting are feasible: The experience in Kalemie, Democratic Republic of Congo.

June 30, 2018
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Highly targeted cholera vaccination campaigns in urban setting are feasible: The experience in Kalemie, Democratic Republic of Congo.

PLoS Negl Trop Dis. 2018 05;12(5):e0006369

Authors: Massing LA, Aboubakar S, Blake A, Page AL, Cohuet S, Ngandwe A, Mukomena Sompwe E, Ramazani R, Allheimen M, Levaillant P, Lechevalier P, Kashimi M, de la Motte A, Calmejane A, Bouhenia M, Dabire E, Bompangue D, Kebela B, Porten K, Luquero F

Abstract
INTRODUCTION: Oral cholera vaccines are primarily recommended by the World Health Organization for cholera control in endemic countries. However, the number of cholera vaccines currently produced is very limited and examples of OCV use in endemic countries, and especially in urban settings, are scarce. A vaccination campaign was organized by Médecins Sans Frontières and the Ministry of Health in a highly endemic area in the Democratic Republic of Congo. This study aims to describe the vaccine coverage achieved with this highly targeted vaccination campaign and the acceptability among the vaccinated communities.
METHODS AND FINDINGS: We performed a cross-sectional survey using random spatial sampling. The study population included individuals one year old and above, eligible for vaccination, and residing in the areas targeted for vaccination in the city of Kalemie. Data sources were household interviews with verification by vaccination card. In total 2,488 people were included in the survey. Overall, 81.9% (95%CI: 77.9-85.3) of the target population received at least one dose of vaccine. The vaccine coverage with two doses was 67.2% (95%CI: 61.9-72.0) among the target population. The vaccine coverage was higher during the first round (74.0, 95%CI: 69.3-78.3) than during the second round of vaccination (69.1%, 95%CI: 63.9-74.0). Vaccination coverage was lower in male adults. The main reason for non-vaccination was to be absent during the campaign. No severe adverse events were notified during the interviews.
CONCLUSIONS: Cholera vaccination campaigns using highly targeted strategies are feasible in urban settings. High vaccination coverage can be obtained using door to door vaccination. However, alternative strategies should be considered to reach non-vaccinated populations like male adults and also in order to improve the efficiency of the interventions.

PMID: 29734337 [PubMed - indexed for MEDLINE]

Cholera outbreak caused by drinking contaminated water from a lakeshore water-collection site, Kasese District, south-western Uganda, June-July 2015.

June 28, 2018
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Cholera outbreak caused by drinking contaminated water from a lakeshore water-collection site, Kasese District, south-western Uganda, June-July 2015.

PLoS One. 2018;13(6):e0198431

Authors: Pande G, Kwesiga B, Bwire G, Kalyebi P, Riolexus A, Matovu JKB, Makumbi F, Mugerwa S, Musinguzi J, Wanyenze RK, Zhu BP

Abstract
On 20 June 2015, a cholera outbreak affecting more than 30 people was reported in a fishing village, Katwe, in Kasese District, south-western Uganda. We investigated this outbreak to identify the mode of transmission and to recommend control measures. We defined a suspected case as onset of acute watery diarrhoea between 1 June and 15 July 2015 in a resident of Katwe village; a confirmed case was a suspected case with Vibrio cholerae cultured from stool. For case finding, we reviewed medical records and actively searched for cases in the community. In a case-control investigation we compared exposure histories of 32 suspected case-persons and 128 age-matched controls. We also conducted an environmental assessment on how the exposures had occurred. We found 61 suspected cases (attack rate = 4.9/1000) during this outbreak, of which eight were confirmed. The primary case-person had onset on 16 June; afterwards cases sharply increased, peaked on 19 June, and rapidly declined afterwards. After 22 June, eight scattered cases occurred. The case-control investigation showed that 97% (31/32) of cases and 62% (79/128) of controls usually collected water from inside a water-collection site "X" (ORM-H = 16; 95% CI = 2.4-107). The primary case-person who developed symptoms while fishing, reportedly came ashore in the early morning hours on 17 June, and defecated "near" water-collection site X. We concluded that this cholera outbreak was caused by drinking lake water collected from inside the lakeshore water-collection site X. At our recommendations, the village administration provided water chlorination tablets to the villagers, issued water boiling advisory to the villagers, rigorously disinfected all patients' faeces and, three weeks later, fixed the tap-water system.

PMID: 29949592 [PubMed - in process]

Lessons Learned from Emergency Response Vaccination Efforts for Cholera, Typhoid, Yellow Fever, and Ebola.

June 28, 2018
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Lessons Learned from Emergency Response Vaccination Efforts for Cholera, Typhoid, Yellow Fever, and Ebola.

Emerg Infect Dis. 2017 Dec;23(13):

Authors: Walldorf JA, Date KA, Sreenivasan N, Harris JB, Hyde TB

Abstract
Countries must be prepared to respond to public health threats associated with emergencies, such as natural disasters, sociopolitical conflicts, or uncontrolled disease outbreaks. Rapid vaccination of populations vulnerable to epidemic-prone vaccine-preventable diseases is a major component of emergency response. Emergency vaccination planning presents challenges, including how to predict resource needs, expand vaccine availability during global shortages, and address regulatory barriers to deliver new products. The US Centers for Disease Control and Prevention supports countries to plan, implement, and evaluate emergency vaccination response. We describe work of the Centers for Disease Control and Prevention in collaboration with global partners to support emergency vaccination against cholera, typhoid, yellow fever, and Ebola, diseases for which a new vaccine or vaccine formulation has played a major role in response. Lessons learned will help countries prepare for future emergencies. Integration of vaccination with emergency response augments global health security through reducing disease burden, saving lives, and preventing spread across international borders.

PMID: 29155670 [PubMed - indexed for MEDLINE]

Genetic relatedness of Vibrio cholerae isolates within and between households during outbreaks in Dhaka, Bangladesh.

June 27, 2018
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Genetic relatedness of Vibrio cholerae isolates within and between households during outbreaks in Dhaka, Bangladesh.

BMC Genomics. 2017 Nov 25;18(1):903

Authors: George CM, Rashid M, Almeida M, Saif-Ur-Rahman KM, Monira S, Bhuyian MSI, Hasan K, Mahmud TT, Li S, Brubaker J, Perin J, Rahman Z, Mustafiz M, Sack DA, Sack RB, Alam M, Stine OC

Abstract
BACKGROUND: Household contacts of cholera patients have a 100 times higher risk of developing a cholera infection than the general population. To compare the genetic relatedness of clinical and water source Vibrio cholerae isolates from cholera patients' households across three outbreaks, we analyzed these isolates using whole-genome-sequencing (WGS) and multilocus variable-number tandem-repeat analysis (MLVA).
RESULTS: The WGS analyses revealed that 80% of households had source water isolates that were more closely related to clinical isolates from the same household than to any other isolates. While in another 20% of households an isolate from a person was more closely related to clinical isolates from another household than to source water isolates from their own household. The mean pairwise differences in single nucleotide-variant (SNV) counts for isolates from the same household were significantly lower than those for different households (2.4 vs. 7.7 p < 0.0001), and isolates from the same outbreak had significantly fewer mean pairwise differences compared to isolates from different outbreaks (mean: 6.2 vs. 8.0, p < 0.0001). Based on MLVA in outbreak 1, we observed that the majority of households had clinical isolates with MLVA genotypes related to other clinical isolates and unrelated to water source isolates from the same household. While in outbreak 3, there were different MLVA genotypes between households, however within the majority of households, the clinical and water source isolates had the same MLVA genotypes. The beginning of outbreak 2 resembled outbreak 1 and the latter part resembled outbreak 3. We validated our use of MLVA by comparing it to WGS. Isolates with the identical MLVA genotype had significantly fewer mean pairwise SNV differences than those isolates with different MLVA genotypes (mean: 4.8 vs. 7.7, p < 0.0001). Furthermore, consistent with WGS results, the number of pairwise differences in the five MLVA loci for isolates within the same household was significantly lower than isolates from different households (mean: 1.6 vs. 3.0, p < 0.0001).
CONCLUSION: These results suggest that transmission patterns for cholera are a combination of person-to-person and water-to-person cholera transmission with the proportions of the two modes varying within and between outbreaks.

PMID: 29178823 [PubMed - indexed for MEDLINE]

Cholera: an overview with reference to the Yemen epidemic.

June 24, 2018
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Cholera: an overview with reference to the Yemen epidemic.

Front Med. 2018 Jun 22;:

Authors: Rabaan AA

Abstract
Cholera is a secretory diarrhoeal disease caused by infection with Vibrio cholerae, primarily the V. cholerae O1 El Tor biotype. There are approximately 2.9 million cases in 69 endemic countries annually, resulting in 95 000 deaths. Cholera is associated with poor infrastructure and lack of access to sanitation and clean drinking water. The current cholera epidemic in Yemen, linked to spread of V. cholerae O1 (Ogawa serotype), is associated with the ongoing war. This has devastated infrastructure and health services. The World Health Organization had estimated that 172 286 suspected cases arose between 27th April and 19th June 2017, including 1170 deaths. While there are three oral cholera vaccines prequalified by the World Health Organization, there are issues surrounding vaccination campaigns in conflict situations, exacerbated by external factors such as a global vaccine shortage. Major movements of people complicates surveillance and administration of double doses of vaccines. Cholera therapy mainly depends on rehydration, with use of antibiotics in more severe infections. Concerns have arisen about the rise of antibiotic resistance in cholera, due to mobile genetic elements. In this review, we give an overview of cholera epidemiology, virulence, antibiotic resistance, therapy and vaccines, in the light of the ongoing epidemic in Yemen.

PMID: 29934743 [PubMed - as supplied by publisher]

Development of a new dipstick (Cholkit) for rapid detection of Vibrio cholerae O1 in acute watery diarrheal stools.

June 19, 2018
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Development of a new dipstick (Cholkit) for rapid detection of Vibrio cholerae O1 in acute watery diarrheal stools.

PLoS Negl Trop Dis. 2018 03;12(3):e0006286

Authors: Sayeed MA, Islam K, Hossain M, Akter NJ, Alam MN, Sultana N, Khanam F, Kelly M, Charles RC, Kováč P, Xu P, Andrews JR, Calderwood SB, Amin J, Ryan ET, Qadri F

Abstract
Recognizing cholera cases early, especially in the initial phase of an outbreak and in areas where cholera has not previously circulated, is a high public health priority. Laboratory capacity in such settings is often limited. To address this, we have developed a rapid diagnostic test (RDT) termed Cholkit that is based on an immunochromatographic lateral flow assay for the diagnosis of cholera cases using stool. Cholkit contains a monoclonal antibody (ICL-33) to the O-specific polysaccharide (OSP) component of V. cholerae O1 lipopolysaccharide, and recognizes both Inaba and Ogawa serotypes. We tested the Cholkit dipstick using fresh stool specimens of 76 adults and children presenting with acute watery diarrhea at the icddr,b hospital in Dhaka, Bangladesh. We compared Cholkit's performance with those of microbial culture, PCR (targeting the rfb and ctxA genes of V. cholerae) and the commercially available RDT, Crystal VC (Span Diagnostics; Surat, India). We found that all stool specimens with a positive culture for V. cholerae O1 (n = 19) were positive by Cholkit as well as Crystal VC. We then used Bayesian latent class modeling to estimate the sensitivity and specificity of each diagnostic assay. The sensitivity of Cholkit, microbiological culture, PCR and Crystal VC was 98% (95% CI: 88-100), 71% (95% CI: 59-81), 74% (95% CI: 59-86) and 98% (95% CI: 88-100), respectively. The specificity for V. cholerae O1 was 97% (95% CI: 89-100), 100%, 97% (95% CI: 93-99) and 98% (95% CI: 92-100), respectively. Of note, two Crystal VC dipsticks were positive for V. cholerae O139 but negative by culture and PCR in this area without known circulating epidemic V. cholerae O139. In conclusion, the Cholkit dipstick is simple to use, requires no dedicated laboratory capacity, and has a sensitivity and specificity for V. cholerae O1 of 98% and 97%, respectively. Cholkit warrants further evaluation in other settings.

PMID: 29538377 [PubMed - indexed for MEDLINE]

Screening for dysglycaemia using anthropometric indices in an adult population in Oman.

June 17, 2018
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Screening for dysglycaemia using anthropometric indices in an adult population in Oman.

East Mediterr Health J. 2018 Jun 10;24(3):254-261

Authors: Ganguly SS, Sarkar K, Al-Adawi S, Al-Mahrezi AA

Abstract
Background: A previous community-based cross-sectional survey conducted in a semi-urban community revealed that 44% of people aged 18+ years manifest dysglycaemia, which appears to echo the national trend. There is lack of studies examining the role of anthropometric indices in people with dysglycaemia.
Aim: We explored the screening ability of anthropometric indices, body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR) to detect dysglycaemia in the adult Omani population based on a community-based survey conducted in 2005. The potential of anthropometric indices to detect the presence of glycaemic disorder could aid in detection, prevention and health education.
Methods: A total of 480 male and 795 female subjects aged 18+ years were included in this study. The prevalence of dysglycaemia was analysed using the American Diabetic Association criteria. Logistic regression approach and Receiver- Operating Characteristic (ROC) curve analysis was performed.
Results: The analysis revealed that mean values of age, BMI, WC, WHR and WHtR increased significantly from normoglycemic to pre-diabetic and further to diabetic in both sexes (P<0.0001). Dysglycemia showed an increasing prevalence with age. WHtR showed the highest sensitivity for detecting dysglycemia in all age groups compared to other anthropometric indices with sensitivity rate of 94.4% in ≥45 years, 88.6% in (25- 44) years and 45.6% in age group <25 years.
Conclusion: Among the anthropometric indices we investigated, WHtR was the best predictor of dysglycaemia among Omani adults aged > 25 years.

PMID: 29908020 [PubMed - in process]

Oral cholera vaccine in cholera prevention and control, Malawi.

June 16, 2018
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Oral cholera vaccine in cholera prevention and control, Malawi.

Bull World Health Organ. 2018 Jun 01;96(6):428-435

Authors: M'bangombe M, Pezzoli L, Reeder B, Kabuluzi S, Msyamboza K, Masuku H, Ngwira B, Cavailler P, Grandesso F, Palomares A, Beck N, Shaffer A, MacDonald E, Senbete M, Lessler J, Moore SM, Azman AS

Abstract
Problem: With limited global supplies of oral cholera vaccine, countries need to identify priority areas for vaccination while longer-term solutions, such as water and sanitation infrastructure, are being developed.
Approach: In 2017, Malawi integrated oral cholera vaccine into its national cholera control plan. The process started with a desk review and analysis of previous surveillance and risk factor data. At a consultative meeting, researchers, national health and water officials and representatives from nongovernmental and international organizations reviewed the data and local epidemiological knowledge to determine priority districts for oral cholera vaccination. The final stage was preparation of an application to the global oral cholera vaccine stockpile for non-emergency use.
Local setting: Malawi collects annual data on cholera and most districts have reported cases at least once since the 1970s.
Relevant changes: The government's application for 3.2 million doses of vaccine to be provided over 20 months in 12 districts was accepted in April 2017. By April 2018, over 1 million doses had been administered in five districts. Continuing surveillance in districts showed that cholera outbreaks were notably absent in vaccinated high-risk areas, despite a national outbreak in 2017-2018.
Lessons learnt: Augmenting advanced mapping techniques with local information helped us extend priority areas beyond those identified as high-risk based on cholera incidence reported at the district level. Involvement of the water, sanitation and hygiene sectors is key to ensuring that short-term gains from cholera vaccine are backed by longer-term progress in reducing cholera transmission.

PMID: 29904226 [PubMed - in process]

Systems, supplies, and staff: a mixed-methods study of health care workers' experiences and health facility preparedness during a large national cholera outbreak, Kenya 2015.

June 13, 2018
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Systems, supplies, and staff: a mixed-methods study of health care workers' experiences and health facility preparedness during a large national cholera outbreak, Kenya 2015.

BMC Public Health. 2018 Jun 11;18(1):723

Authors: Curran KG, Wells E, Crowe SJ, Narra R, Oremo J, Boru W, Githuku J, Obonyo M, De Cock KM, Montgomery JM, Makayotto L, Langat D, Lowther SA, O'Reilly C, Gura Z, Kioko J

Abstract
BACKGROUND: From December 2014 to September 2016, a cholera outbreak in Kenya, the largest since 2010, caused 16,840 reported cases and 256 deaths. The outbreak affected 30 of Kenya's 47 counties and occurred shortly after the decentralization of many healthcare services to the county level. This mixed-methods study, conducted June-July 2015, assessed cholera preparedness in Homa Bay, Nairobi, and Mombasa counties and explored clinic- and community-based health care workers' (HCW) experiences during outbreak response.
METHODS: Counties were selected based on cumulative cholera burden and geographic characteristics. We conducted 44 health facility cholera preparedness checklists (according to national guidelines) and 8 focus group discussions (FGDs). Frequencies from preparedness checklists were generated. To determine key themes from FGDs, inductive and deductive codes were applied; MAX software for qualitative data analysis (MAXQDA) was used to identify patterns.
RESULTS: Some facilities lacked key materials for treating cholera patients, diagnosing cases, and maintaining infection control. Overall, 82% (36/44) of health facilities had oral rehydration salts, 65% (28/43) had IV fluids, 27% (12/44) had rectal swabs, 11% (5/44) had Cary-Blair transport media, and 86% (38/44) had gloves. A considerable number of facilities lacked disease reporting forms (34%, 14/41) and cholera treatment guidelines (37%, 16/43). In FDGs, HCWs described confusion regarding roles and reporting during the outbreak, which highlighted issues in coordination and management structures within the health system. Similar to checklist findings, FGD participants described supply challenges affecting laboratory preparedness and infection prevention and control. Perceived successes included community engagement, health education, strong collaboration between clinic and community HCWs, and HCWs' personal passion to help others.
CONCLUSIONS: The confusion over roles, reporting, and management found in this evaluation highlights a need to adapt, implement, and communicate health strategies at the county level, in order to inform and train HCWs during health system transformations. International, national, and county stakeholders could strengthen preparedness and response for cholera and other public health emergencies in Kenya, and thereby strengthen global health security, through further investment in the existing Integrated Disease Surveillance and Response structure and national cholera prevention and control plan, and the adoption of county-specific cholera control plans.

PMID: 29890963 [PubMed - in process]

Dried Blood Spots for Measuring Vibrio cholerae-specific Immune Responses.

June 13, 2018
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Dried Blood Spots for Measuring Vibrio cholerae-specific Immune Responses.

PLoS Negl Trop Dis. 2018 01;12(1):e0006196

Authors: Iyer AS, Azman AS, Bouhenia M, Deng LO, Anderson CP, Graves M, Kováč P, Xu P, Ryan ET, Harris JB, Sack DA, Luquero FJ, Leung DT

Abstract
BACKGROUND: Vibrio cholerae causes over 2 million cases of cholera and 90,000 deaths each year. Serosurveillance can be a useful tool for estimating the intensity of cholera transmission and prioritizing populations for cholera control interventions. Current methods involving venous blood draws and downstream specimen storage and transport methods pose logistical challenges in most settings where cholera strikes. To overcome these challenges, we developed methods for determining cholera-specific immune responses from dried blood spots (DBS).
METHODOLOGY/PRINCIPAL FINDINGS: As conventional vibriocidal assay methods were unsuitable for DBS eluates from filter paper, we adopted a drop-plate culture method. We show that DBS collected from volunteers in South Sudan, and stored for prolonged periods in field conditions, retained functional vibriocidal antibodies, the titers of which correlated with paired serum titers determined by conventional spectrophotometric methods (r = 0.94, p = 0.00012). We also showed that eluates from DBS Serum Separator cards could be used with conventional spectrophotometric vibriocidal methods, and that they correlated with paired serum at a wide range of titers (r = 0.96, p<0.0001). Similarly, we used ELISA methods to show that V. cholerae O-specific polysaccharide antibody responses from DBS eluates correlated with results from paired serum for IgG (r = 0.85, p = 0.00006), IgM (r = 0.79, p = 0.00049) and IgA (r = 0.73, p = 0.0019), highlighting its potential for use in determination of isotype-specific responses. Storage of DBS cards at a range of temperatures did not change antibody responses.
CONCLUSION: In conclusion, we have developed and demonstrated a proof-of-concept for assays utilizing DBS for assessing cholera-specific immune responses.

PMID: 29377882 [PubMed - indexed for MEDLINE]

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