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Frontier Warriors-Combating Cholera in Rural India.

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Frontier Warriors-Combating Cholera in Rural India.

Am J Trop Med Hyg. 2019 05;100(5):1071-1072

Authors: Viswanathan R, Kumar A

PMID: 31088605 [PubMed - indexed for MEDLINE]

Feasibility of a Comprehensive Targeted Cholera Intervention in The Kathmandu Valley, Nepal.

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Feasibility of a Comprehensive Targeted Cholera Intervention in The Kathmandu Valley, Nepal.

Am J Trop Med Hyg. 2019 05;100(5):1088-1097

Authors: Roskosky M, Acharya B, Shakya G, Karki K, Sekine K, Bajracharya D, von Seidlein L, Devaux I, Lopez AL, Deen J, Sack DA

Abstract
A comprehensive targeted intervention (CTI) was designed and deployed in the neighborhoods of cholera cases in the Kathmandu Valley with the intent of reducing rates among the neighbors of the case. This was a feasibility study to determine whether clinical centers, laboratories, and field teams were able to mount a rapid, community-based response to a case within 2 days of hospital admission. Daily line listings were requested from 15 participating hospitals during the monsoon season, and a single case initiated the CTI. A standard case definition was used: acute watery diarrhea, with or without vomiting, in a patient aged 1 year or older. Rapid diagnostic tests and bacterial culture were used for confirmation. The strategy included household investigation of cases; water testing; water, sanitation, and hygiene (WASH) intervention; and health education. A CTI coverage survey was conducted 8 months postintervention. From June to December of 2016, 169 cases of Vibrio cholerae O1 were confirmed by bacterial culture. Average time to culture result was 3 days. On average, the CTI Rapid Response Team (RRT) was able to visit households 1.7 days after the culture result was received from the hospital (3.9 days from hospital admission). Coverage of WASH and health behavior messaging campaigns were 30.2% in the target areas. Recipients of the intervention were more likely to have knowledge of cholera symptoms, treatment, and prevention than non-recipients. Although the RRT were able to investigate cases at the household within 2 days of a positive culture result, the study identified several constraints that limited a truly rapid response.

PMID: 30887946 [PubMed - indexed for MEDLINE]

Machine Learning Model for Imbalanced Cholera Dataset in Tanzania.

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Machine Learning Model for Imbalanced Cholera Dataset in Tanzania.

ScientificWorldJournal. 2019;2019:9397578

Authors: Leo J, Luhanga E, Michael K

Abstract
Cholera epidemic remains a public threat throughout history, affecting vulnerable population living with unreliable water and substandard sanitary conditions. Various studies have observed that the occurrence of cholera has strong linkage with environmental factors such as climate change and geographical location. Climate change has been strongly linked to the seasonal occurrence and widespread of cholera through the creation of weather patterns that favor the disease's transmission, infection, and the growth of Vibrio cholerae, which cause the disease. Over the past decades, there have been great achievements in developing epidemic models for the proper prediction of cholera. However, the integration of weather variables and use of machine learning techniques have not been explicitly deployed in modeling cholera epidemics in Tanzania due to the challenges that come with its datasets such as imbalanced data and missing information. This paper explores the use of machine learning techniques to model cholera epidemics with linkage to seasonal weather changes while overcoming the data imbalance problem. Adaptive Synthetic Sampling Approach (ADASYN) and Principal Component Analysis (PCA) were used to the restore sampling balance and dimensional of the dataset. In addition, sensitivity, specificity, and balanced-accuracy metrics were used to evaluate the performance of the seven models. Based on the results of the Wilcoxon sign-rank test and features of the models, XGBoost classifier was selected to be the best model for the study. Overall results improved our understanding of the significant roles of machine learning strategies in health-care data. However, the study could not be treated as a time series problem due to the data collection bias. The study recommends a review of health-care systems in order to facilitate quality data collection and deployment of machine learning techniques.

PMID: 31427903 [PubMed - indexed for MEDLINE]

Evaluation of an Emergency Bulk Chlorination Project Targeting Drinking Water Vendors in Cholera-Affected Wards of Dar es Salaam and Morogoro, Tanzania.

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Evaluation of an Emergency Bulk Chlorination Project Targeting Drinking Water Vendors in Cholera-Affected Wards of Dar es Salaam and Morogoro, Tanzania.

Am J Trop Med Hyg. 2019 06;100(6):1335-1341

Authors: Rajasingham A, Hardy C, Kamwaga S, Sebunya K, Massa K, Mulungu J, Martinsen A, Nyasani E, Hulland E, Russell S, Blanton C, Nygren B, Eidex R, Handzel T

Abstract
In August 2015, an outbreak of cholera was reported in Tanzania. In cholera-affected areas of urban Dar es Salaam and Morogoro, many households obtained drinking water from vendors, who sold water from tanks ranging in volume from 1,000 to 20,000 L. Water supplied by vendors was not adequately chlorinated. The Tanzanian Ministry of Health, Community Development, Gender, Elderly and Children and the U.N. Children's Fund, Tanzania, collaborated to enroll and train vendors to treat their water with 8.68-g sodium dichloroisocyanurate tablets (Medentech, Ireland). The Centers for Disease Control and Prevention (CDC) provided monitoring and evaluation support. Vendors were provided a 3-month supply of chlorine tablets. A baseline assessment and routine monitoring were conducted by ward environmental health officers. Approximately 3 months after chlorine tablet distribution, an evaluation of the program was conducted. The evaluation included a full enumeration of all vendors, an in-depth survey with half of the vendors enumerated, and focus group discussions. In total, 797 (88.9%) vendors were included in the full enumeration and 392 in the in-depth survey. Free residual chlorine (FRC) was detected in 12.0% of tanks at baseline and 69.6% of tanks during the evaluation; however, only 17.4% of these tanks had FRC ≥ 0.5 mg/L. The results suggest high acceptability and use of the chlorine tablets by water vendors. However, given variation in the water source used and longer storage times, dosing could be increased in future programming. Bulk chlorination using chlorine tablets offers an efficient community-level approach to treating water closer to the point of use.

PMID: 31017078 [PubMed - indexed for MEDLINE]

Detection of Haitian ctxB7 & tcpA alleles in Vibrio cholerae O1 El Tor biotype in Puri, Odisha, India.

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Detection of Haitian ctxB7 & tcpA alleles in Vibrio cholerae O1 El Tor biotype in Puri, Odisha, India.

Indian J Med Res. 2019 04;149(4):558-560

Authors: Kerketta AS, Kar SK, Khuntia HK

PMID: 31411182 [PubMed - indexed for MEDLINE]

Geographical distribution of primary & secondary dengue cases in India - 2017: A cross-sectional multicentric study.

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Geographical distribution of primary & secondary dengue cases in India - 2017: A cross-sectional multicentric study.

Indian J Med Res. 2019 04;149(4):548-553

Authors: Rao C, Kaur H, Gupta N, Sabeena SP, Ambica R, Jain A, Yadav A, Dwibedi B, Malhotra B, Kakru DK, Biswas D, Savargaonkar D, Ganesan M, Sabat J, Dhingra K, Lalitha S, Valecha N, Madhavilatha P, Barde PV, Joshi PD, Sharma P, Gupta R, Ratho RK, Sidhu S, Shrivastava SS, Dutta S, Shantala GB, Imtiaz S, Sethi S, Kalawat U, Vijayachari P, Raj V, Vijay N, Borkakoty B, Barua P, Majumdar T, Arunkumar G

Abstract
Background & objectives: Dengue virus infection is endemic in India with all the four serotypes of dengue virus in circulation. This study was aimed to determine the geographic distribution of the primary and secondary dengue cases in India.
Methods: A multicentre cross-sectional study was conducted at Department of Health Research / Indian Council of Medical Research (DHR)/(ICMR) viral research and diagnostic laboratories (VRDLs) and selected ICMR institutes located in India. Only laboratory-confirmed dengue cases with date of onset of illness less than or equal to seven days were included between September and October 2017. Dengue NS1 antigen ELISA and anti-dengue IgM capture ELISA were used to diagnose dengue cases while anti-dengue IgG capture ELISA was used for identifying the secondary dengue cases.
Results: Of the 1372 dengue cases, 897 (65%) were classified as primary dengue and 475 (35%) as secondary dengue cases. However, the proportion varied widely geographically, with Theni, Tamil Nadu; Tirupati, Andhra Pradesh and Udupi-Manipal, Karnataka reporting more than 65 per cent secondary dengue cases while Srinagar, Jammu and Kashmir reporting as low as 10 per cent of the same. The median age of primary dengue cases was 25 yr [interquartile range (IQR 17-35] while that of secondary dengue cases was 23 yr (IQR 13.5-34). Secondary dengue was around 50 per cent among the children belonging to the age group 6-10 yr while it ranged between 20-43 per cent among other age groups.
Interpretation & conclusions: Our findings showed a wide geographical variation in the distribution of primary and secondary dengue cases in India. It would prove beneficial to include primary and secondary dengue differentiation protocol in the national dengue surveillance programme.

PMID: 31411180 [PubMed - indexed for MEDLINE]

Emerging/re-emerging viral diseases & new viruses on the Indian horizon.

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Emerging/re-emerging viral diseases & new viruses on the Indian horizon.

Indian J Med Res. 2019 04;149(4):447-467

Authors: Mourya DT, Yadav PD, Ullas PT, Bhardwaj SD, Sahay RR, Chadha MS, Shete AM, Jadhav S, Gupta N, Gangakhedkar RR, Khasnobis P, Singh SK

Abstract
Infectious diseases remain as the major causes of human and animal morbidity and mortality leading to significant healthcare expenditure in India. The country has experienced the outbreaks and epidemics of many infectious diseases. However, enormous successes have been obtained against the control of major epidemic diseases, such as malaria, plague, leprosy and cholera, in the past. The country's vast terrains of extreme geo-climatic differences and uneven population distribution present unique patterns of distribution of viral diseases. Dynamic interplays of biological, socio-cultural and ecological factors, together with novel aspects of human-animal interphase, pose additional challenges with respect to the emergence of infectious diseases. The important challenges faced in the control and prevention of emerging and re-emerging infectious diseases range from understanding the impact of factors that are necessary for the emergence, to development of strengthened surveillance systems that can mitigate human suffering and death. In this article, the major emerging and re-emerging viral infections of public health importance have been reviewed that have already been included in the Integrated Disease Surveillance Programme.

PMID: 31411169 [PubMed - indexed for MEDLINE]

Inconsistency in Diarrhea Measurements when Assessing Intervention Impact in a Non-Blinded Cluster-Randomized Controlled Trial.

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Inconsistency in Diarrhea Measurements when Assessing Intervention Impact in a Non-Blinded Cluster-Randomized Controlled Trial.

Am J Trop Med Hyg. 2019 07;101(1):51-58

Authors: Najnin N, Leder K, Forbes A, Unicomb L, Qadri F, Ram PK, Winch PJ, Begum F, Biswas S, Parvin T, Yeasmin F, Cravioto A, Luby SP

Abstract
To explore the consistency in impact evaluation based on reported diarrhea, we compared diarrhea data collected through two different surveys and with observed diarrhea-associated hospitalization for children aged ≤ 5 years from a non-blinded cluster-randomized trial conducted over 2 years in urban Dhaka. We have previously reported that the interventions did not reduce diarrhea-associated hospitalization for children aged ≤ 5 years in this trial. We randomly allocated 90 geographic clusters comprising > 60,000 low-income households into three groups: cholera vaccine only, vaccine plus behavior change (cholera vaccine and handwashing plus drinking water chlorination promotion), and control. We calculated reported diarrhea prevalence within the last 2 days using data collected from two different survey methods. The "census" data were collected from each household every 6 months for updating household demographic information. The "monthly survey" data were collected every month from a subset of randomly selected study households for monitoring the uptake of behavior change interventions. We used binomial regression with a logarithmic link accounting for clustering to compare diarrhea prevalence across intervention and control groups separately for both census and monthly survey data. No intervention impact was detected in the census (vaccine only versus control: 2.32% versus 2.53%; P = 0.49; vaccine plus behavior change versus control: 2.44% versus 2.53%; P = 0.78) or in the vaccine only versus control in the monthly survey (3.39% versus 3.80%; P = 0.69). However, diarrhea prevalence was lower in the vaccine-plus-behavior-change group than control in the monthly survey (2.08% versus 3.80%; P = 0.02). Although the reasons for different observed treatment effects in the census and monthly survey data in this study are unclear, these findings emphasize the importance of assessing objective outcomes along with reported outcomes from non-blinded trials.

PMID: 31162005 [PubMed - indexed for MEDLINE]

Spatial and temporal distribution of infectious disease epidemics, disasters and other potential public health emergencies in the World Health Organisation Africa region, 2016-2018.

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Spatial and temporal distribution of infectious disease epidemics, disasters and other potential public health emergencies in the World Health Organisation Africa region, 2016-2018.

Global Health. 2020 Jan 15;16(1):9

Authors: Talisuna AO, Okiro EA, Yahaya AA, Stephen M, Bonkoungou B, Musa EO, Minkoulou EM, Okeibunor J, Impouma B, Djingarey HM, Yao NKM, Oka S, Yoti Z, Fall IS

Abstract
BACKGROUND: Emerging and re-emerging diseases with pandemic potential continue to challenge fragile health systems in Africa, creating enormous human and economic toll. To provide evidence for the investment case for public health emergency preparedness, we analysed the spatial and temporal distribution of epidemics, disasters and other potential public health emergencies in the WHO African region between 2016 and 2018.
METHODS: We abstracted data from several sources, including: the WHO African Region's weekly bulletins on epidemics and emergencies, the WHO-Disease Outbreak News (DON) and the Emergency Events Database (EM-DAT) of the Centre for Research on the Epidemiology of Disasters (CRED). Other sources were: the Program for Monitoring Emerging Diseases (ProMED) and the Global Infectious Disease and Epidemiology Network (GIDEON). We included information on the time and location of the event, the number of cases and deaths and counter-checked the different data sources.
DATA ANALYSIS: We used bubble plots for temporal analysis and generated graphs and maps showing the frequency and distribution of each event. Based on the frequency of events, we categorised countries into three: Tier 1, 10 or more events, Tier 2, 5-9 events, and Tier 3, less than 5 or no event. Finally, we compared the event frequencies to a summary International Health Regulations (IHR) index generated from the IHR technical area scores of the 2018 annual reports.
RESULTS: Over 260 events were identified between 2016 and 2018. Forty-one countries (87%) had at least one epidemic between 2016 and 2018, and 21 of them (45%) had at least one epidemic annually. Twenty-two countries (47%) had disasters/humanitarian crises. Seven countries (the epicentres) experienced over 10 events and all of them had limited or developing IHR capacities. The top five causes of epidemics were: Cholera, Measles, Viral Haemorrhagic Diseases, Malaria and Meningitis.
CONCLUSIONS: The frequent and widespread occurrence of epidemics and disasters in Africa is a clarion call for investing in preparedness. While strengthening preparedness should be guided by global frameworks, it is the responsibility of each government to finance country specific needs. We call upon all African countries to establish governance and predictable financing mechanisms for IHR implementation and to build resilient health systems everywhere.

PMID: 31941554 [PubMed - in process]

Accumulating evidence suggests that some waterbird species are potential vectors of Vibrio cholerae.

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Accumulating evidence suggests that some waterbird species are potential vectors of Vibrio cholerae.

PLoS Pathog. 2019 08;15(8):e1007814

Authors: Laviad-Shitrit S, Izhaki I, Halpern M

Abstract
Vibrio cholerae is the causative agent of cholera, a life-threatening diarrheal disease. Cholera causes epidemics and pandemics, but the ways this disease spreads worldwide is still unclear. This review highlights a relatively new hypothesis regarding the way V. cholerae can be globally dispersed. Copepods and chironomids are natural reservoirs of V. cholerae and are part of different fish species' diet. Furthermore, V. cholerae inhabits marine and freshwater fish species. Waterbird species feed on fish or on small invertebrates such as copepods and chironomids. Waterbirds have also been found to carry living copepods and/or chironomids internally or externally from one waterbody to another. All of the above points to the fact that some waterbird species might be vectors of V. cholerae. Indeed, we and others have found evidence for the presence of V. cholerae non-O1 as well as O1 in waterbird cloacal swabs, feces, and intestine samples. Moreover, hand-reared cormorants that were fed on tilapia, a fish that naturally carries V. cholerae, became infected with this bacterial species, demonstrating that V. cholerae can be transferred to cormorants from their fish prey. Great cormorants as well as other waterbird species can cover distances of up to 1,000 km/day and thus may potentially transfer V. cholerae in a short time across and between continents. We hope this review will inspire further studies regarding the understanding of the waterbirds' role in the global dissemination of V. cholerae.

PMID: 31437258 [PubMed - indexed for MEDLINE]

Molecular characterization of NDM-1-producing Klebsiella pneumoniae ST29, ST347, ST1224, and ST2558 causing sepsis in neonates in a tertiary care hospital of North-East India.

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Molecular characterization of NDM-1-producing Klebsiella pneumoniae ST29, ST347, ST1224, and ST2558 causing sepsis in neonates in a tertiary care hospital of North-East India.

Infect Genet Evol. 2019 04;69:166-175

Authors: Mukherjee S, Bhattacharjee A, Naha S, Majumdar T, Debbarma SK, Kaur H, Dutta S, Basu S

Abstract
Geographical differences can manifest in different spectra of microorganisms and patterns of antibiotic resistance. Considering this, Enterobacteriacae isolated from septicemic neonates from a tertiary care centre in Agartala, India were studied with focus on carbapenem resistance. Two hundred non-duplicate Enterobacteriaceae, of which 12 NDM-1-producing Klebsiella pneumoniae were recovered. Antibiotic susceptibility tests and detection of ESBLs and carbapenemases were performed for all Enterobacteriaceae. For NDM-1-producing isolates, plasmid-mediated quinolone resistance genes, addiction systems, genetic environment of blaNDM-1 and virulence genes was investigated by PCR. Bacterial clonal relatedness was established using REP-PCR, PFGE, and multi-locus sequence typing (MLST). Transferability of blaNDM-1 was tested by conjugation and transconjugants were characterized. K. pneumoniae was the primary organism causing sepsis in neonates. Resistance to different antimicrobials was high except for aminoglycosides and carbapenems. blaCTX-M was present in all isolates. All carbapenem-resistant isolates harboured blaNDM-1 as the only carbapenemase. blaCTX-M-15 and qnrS1 were detected in all NDM-1-producing isolates. Plasmid analysis of transconjugants revealed that blaNDM-1 along with blaCTX-M-15, qnrS1, qnrB1, aac(6')-Ib, aac(6')-Ib-cr and ccdAB or vagCD addiction systems were carried on large IncFIIK conjugative plasmids of varied sizes. blaNDM-1 was associated with ISAba125 or ISEc33 element at its 5'-end. In addition, isolates also harboured wabG, uge, fimH, mrkD, and entB virulence genes. The NDM-1-producing K. pneumoniae belonged to four distinct clones and were distributed in 4 STs (ST347, ST29, ST2558, and ST1224), of which ST347 was predominant. The association of blaNDM-1 with diverse STs in K. pneumoniae from neonates indicates the promiscuity of the gene and its widespread dissemination.

PMID: 30677535 [PubMed - indexed for MEDLINE]

Risk and Protective Factors for Cholera Deaths during an Urban Outbreak-Lusaka, Zambia, 2017-2018.

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Risk and Protective Factors for Cholera Deaths during an Urban Outbreak-Lusaka, Zambia, 2017-2018.

Am J Trop Med Hyg. 2020 Jan 13;:

Authors: Mutale LS, Winstead AV, Sakubita P, Kapaya F, Nyimbili S, Mulambya NL, Nanzaluka FH, Gama A, Mwale V, Kim S, Ngosa W, Yard E, Sinyange N, Mintz E, Brunkard J, Mukonka V

Abstract
The Republic of Zambia declared a cholera outbreak in Lusaka, the capital, on October 6, 2017. By mid-December, 20 of 661 reported cases had died (case fatality rate 3%), prompting the CDC and the Zambian Ministry of Health through the Zambia National Public Health Institute to investigate risk factors for cholera mortality. We conducted a study of cases (cholera deaths from October 2017 to January 2018) matched by age-group and onset date to controls (persons admitted to a cholera treatment center [CTC] and discharged alive). A questionnaire was administered to each survivor (or relative) and to a family member of each decedent. We used univariable exact conditional logistic regression to calculate matched odds ratios (mORs) and 95% CIs. In the analysis, 38 decedents and 76 survivors were included. Median ages for decedents and survivors were 38 (range: 0.5-95) and 25 (range: 1-82) years, respectively. Patients aged > 55 years and those who did not complete primary school had higher odds of being decedents (matched odds ratio [mOR] 6.3, 95% CI: 1.2-63.0, P = 0.03; mOR 8.6, 95% CI: 1.8-81.7, P < 0.01, respectively). Patients who received immediate oral rehydration solution (ORS) at the CTC had lower odds of dying than those who did not receive immediate ORS (mOR 0.1, 95% CI: 0.0-0.6, P = 0.02). Cholera prevention and outbreak response should include efforts focused on ensuring access to timely, appropriate care for older adults and less educated populations at home and in health facilities.

PMID: 31933465 [PubMed - as supplied by publisher]

Outbreak of Cholera Due to Cyclone Kenneth in Northern Mozambique, 2019.

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Outbreak of Cholera Due to Cyclone Kenneth in Northern Mozambique, 2019.

Int J Environ Res Public Health. 2019 08 15;16(16):

Authors: Cambaza E, Mongo E, Anapakala E, Nhambire R, Singo J, Machava E

Abstract
Cyclone Kenneth was the strongest in the recorded history of the African continent. It landed in the Cabo Delgado province in northern Mozambique on 25 April 2019, causing 45 deaths, destroying approximately 40,000 houses, and leaving 374,000 people in need for assistance, most at risk of acquiring waterborne diseases such as cholera. This short article aims to explain how the resulting cholera outbreak occurred and the response by the government and partner organizations. The outbreak was declared on 2 May 2019, after 14 cases were recorded in Pemba city (11 cases) and the Mecúfi district (3 cases). The disease spread to Metuge, and by the 12th of May 2019, there were 149 cases. Aware of the risk of an outbreak of cholera, the government and partners took immediate action as the cyclone ended, adapting the Cholera Response Plan for Beira, revised after the experience with cyclone Idai (4-21 March 2019). The response relevant to cholera epidemics consisted of social mobilization campaigns for prevention, establishment of treatment centers and units, coordination to improve of water, sanitation and hygiene, and surveillance. By 26 May 2019, 252,448 people were immunized in the area affected by cyclone Kenneth. The recovery process is ongoing but the number of new cases has been reducing, seemingly due to an efficient response, support of several organizations and collaboration of the civil society. Future interventions shall follow the same model of response but the government of Mozambique shall keep a contingency fund to manage disasters such as cyclone Idai and Kenneth. The unlikeliness of two cyclones (Idai and Kenneth) within two months after decades without such kind of phenomena points towards the problem of climate change, and Mozambique needs to prepare effective, proven response plans to combat outbreaks of waterborne diseases due to cyclones.

PMID: 31443180 [PubMed - indexed for MEDLINE]

Simple Visualized Detection Method of Virulence-Associated Genes of Vibrio cholerae by Loop-Mediated Isothermal Amplification.

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Simple Visualized Detection Method of Virulence-Associated Genes of Vibrio cholerae by Loop-Mediated Isothermal Amplification.

Front Microbiol. 2019;10:2899

Authors: Xu M, Fu H, Chen D, Shao Z, Zhu J, Alali WQ, Chen L

Abstract
Vibrio cholerae is a leading waterborne pathogenic bacterium worldwide. It can cause human cholera that is still pandemic in developing nations. Detection of V. cholerae contamination in drinking water and aquatic products is imperative for assuring food safety. In this study, a simple, sensitive, specific, and visualized method was developed based on loop-mediated isothermal amplification (LAMP) (designated sssvLAMP) to detect virulence-associated (ctxA, tcpA, hapA, mshA, pilA, and tlh) and species-specific (lolB) genes of V. cholerae. Three pairs of oligonucleotide primers (inner, outer, and loop primers) were designed and or synthesized to target each of these genes. The optimal conditions of the sssvLAMP method was determined, and one-step sssvLAMP reaction was performed at 65°C for 40 min. Positive results were simply read by the naked eye via color change (from orange to light green) under the visible light, or by the production of green fluorescence under the UV light (260 nm). The sssvLAMP method was more efficient in detecting 6.50 × 101-6.45 × 104-fold low number of V. cholerae cells, and more sensitive in V. cholerae genomic DNA (1.36 × 10-2-4.42 × 10-6 ng/reaction) than polymerase chain reaction (PCR) method. Among 52 strains of V. cholerae and 50 strains of non-target species (e.g., other Vibrios and common pathogens) examined, the sensitivity and specificity of the sssvLAMP method were 100% for all the target genes. Similar high efficiency of the method was observed when tested with spiked samples of water and aquatic products, as well as human stool specimens. Water from various sources and commonly consumed fish samples were promptly screened by this simple and efficient visualized method and diversified variation in the occurrence of the target genes was observed. V. cholerae strains could be mostly detected by the presence of hapA and tlh alone or in combination with other genes, indicating a variable risk of potentially pathogenic non-O1/O139 strains in edible food products. This novel LAMP method can be a promising tool to address the increasing need of food safety control of aquatic products.

PMID: 31921074 [PubMed]

Prevention and control of cholera with household and community water, sanitation and hygiene (WASH) interventions: A scoping review of current international guidelines.

Prevention and control of cholera with household and community water, sanitation and hygiene (WASH) interventions: A scoping review of current international guidelines.

PLoS One. 2020;15(1):e0226549

Authors: D'Mello-Guyett L, Gallandat K, Van den Bergh R, Taylor D, Bulit G, Legros D, Maes P, Checchi F, Cumming O

Abstract
INTRODUCTION: Cholera remains a frequent cause of outbreaks globally, particularly in areas with inadequate water, sanitation and hygiene (WASH) services. Cholera is spread through faecal-oral routes, and studies demonstrate that ingestion of Vibrio cholerae occurs from consuming contaminated food and water, contact with cholera cases and transmission from contaminated environmental point sources. WASH guidelines recommending interventions for the prevention and control of cholera are numerous and vary considerably in their recommendations. To date, there has been no review of practice guidelines used in cholera prevention and control programmes.
METHODS: We systematically searched international agency websites to identify WASH intervention guidelines used in cholera programmes in endemic and epidemic settings. Recommendations listed in the guidelines were extracted, categorised and analysed. Analysis was based on consistency, concordance and recommendations were classified on the basis of whether the interventions targeted within-household or community-level transmission.
RESULTS: Eight international guidelines were included in this review: three by non-governmental organisations (NGOs), one from a non-profit organisation (NPO), three from multilateral organisations and one from a research institution. There were 95 distinct recommendations identified, and concordance among guidelines was poor to fair. All categories of WASH interventions were featured in the guidelines. The majority of recommendations targeted community-level transmission (45%), 35% targeted within-household transmission and 20% both.
CONCLUSIONS: Recent evidence suggests that interventions for effective cholera control and response to epidemics should focus on case-centred approaches and within-household transmission. Guidelines did consistently propose interventions targeting transmission within households. However, the majority of recommendations listed in guidelines targeted community-level transmission and tended to be more focused on preventing contamination of the environment by cases or recurrent outbreaks, and the level of service required to interrupt community-level transmission was often not specified. The guidelines in current use were varied and interpretation may be difficult when conflicting recommendations are provided. Future editions of guidelines should reflect on the inclusion of evidence-based approaches, cholera transmission models and resource-efficient strategies.

PMID: 31914164 [PubMed - in process]

Impact of a Large-Scale Handwashing Intervention on Reported Respiratory Illness: Findings from a Cluster-Randomized Controlled Trial.

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Impact of a Large-Scale Handwashing Intervention on Reported Respiratory Illness: Findings from a Cluster-Randomized Controlled Trial.

Am J Trop Med Hyg. 2019 03;100(3):742-749

Authors: Najnin N, Leder K, Forbes A, Unicomb L, Winch PJ, Ram PK, Nizame FA, Arman S, Begum F, Biswas S, Cravioto A, Luby SP

Abstract
We assessed the impact of handwashing promotion on reported respiratory illness as a secondary outcome from among > 60,000 low-income households enrolled in a cluster-randomized trial conducted in Bangladesh. Ninety geographic clusters were randomly allocated into three groups: cholera-vaccine-only; vaccine-plus-behavior-change (handwashing promotion and drinking water chlorination); and control. Data on respiratory illness (fever plus either cough or nasal congestion or breathing difficulty within previous 2 days) and intervention uptake (presence of soap and water at handwashing station) were collected through monthly surveys conducted among a different subset of randomly selected households during the intervention period. We determined respiratory illness prevalence across groups and used log-binomial regression to examine the association between respiratory illness and presence of soap and water in the handwashing station. Results were adjusted for age, gender, wealth, and cluster-randomized design. The vaccine-plus-behavior-change group had more handwashing stations with soap and water present than controls (45% versus 25%; P < 0.001). Reported respiratory illness prevalence was similar across groups (vaccine-plus-behavior-change versus control: 2.8% versus 2.9%; 95% confidence interval [CI]: -0.008, 0.006; P = 0.6; cholera-vaccine-only versus control: 3.0% versus 2.9%; 95% CI: -0.006, 0.009; P = 0.4). Irrespective of intervention assignment, respiratory illness was lower among people who had soap and water present in the handwashing station than among those who did not (risk ratioadjusted: 0.82; 95% CI: 0.69-0.98). With modest uptake of the handwashing intervention, we found no impact of this large-scale intervention on respiratory illness. However, those who actually had a handwashing station with soap and water had less illness. This suggests improving the effectiveness of handwashing promotion in achieving sustained behavior change could result in health benefits.

PMID: 30608050 [PubMed - indexed for MEDLINE]

The Cholera Phone: Diarrheal Disease Surveillance by Mobile Phone in Bangladesh.

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The Cholera Phone: Diarrheal Disease Surveillance by Mobile Phone in Bangladesh.

Am J Trop Med Hyg. 2019 03;100(3):510-516

Authors: Carstensen LS, Tamason CC, Sultana R, Tulsiani SM, Phelps MD, Gurley ES, Jensen PKM

Abstract
Existing methodologies to record diarrheal disease incidence in households have limitations due to a high-episode recall error outside a 48-hour window. Our objective was to use mobile phones for reporting diarrheal episodes in households to provide real-time incidence data with minimum resource consumption and low recall error. From June 2014 to June 2015, we enrolled 417 low-income households in Dhaka, Bangladesh, and asked them to report diarrheal episodes to a call center. A team of data collectors then visited persons reporting the episode to collect data. In addition, each month, the team conducted in-home surveys on diarrhea incidence for a preceding 48-hour period. The mobile phone surveillance reported an incidence of 0.16 cases per person-year (95% CI: 0.13-0.19), with 117 reported diarrhea cases, and the routine in-home survey detected an incidence of 0.33 cases per person-year (95% CI: 0.18-0.60), the incidence rate ratio was 2.11 (95% CI: 1.08-3.78). During focus group discussions, participants reported a lack in motivation to report diarrhea by phone because of the absence of provision of intervening treatment following reporting. Mobile phone technology can provide a unique tool for real-time disease reporting. The phone surveillance in this study reported a lower incidence of diarrhea than an in-home survey, possibly because of the absence of intervention and, therefore, a perceived lack of incentive to report. However, this study reports the untapped potential of mobile phones in monitoring infectious disease incidence in a low-income setting.

PMID: 30693862 [PubMed - indexed for MEDLINE]

Lessons Learned from Enhancing Sentinel Surveillance for Cholera in Post-Earthquake Nepal in 2016.

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Lessons Learned from Enhancing Sentinel Surveillance for Cholera in Post-Earthquake Nepal in 2016.

Am J Trop Med Hyg. 2019 03;100(3):494-496

Authors: Sekine K, Roskosky M

Abstract
A major earthquake in 2015 that struck Nepal created a favorable environment for the rapid spread of infectious diseases. In anticipation of a cholera outbreak in 2016, UNICEF, Johns Hopkins University, and the Group for Technical Assistance, Nepal, collaborated to assist the government of Nepal to strengthen early warning surveillance, laboratory-based diagnosis, and field investigation. This article outlines the challenges and lessons learned in cholera prevention and control based on the authors' experiences in 2016. Priorities for the future plan should include sustaining the enhanced surveillance system for acute gastroenteritis and cholera, rolling out a rapid diagnostic test, and ensuring rapid and systematic epidemiological investigation and environmental testing.

PMID: 30652658 [PubMed - indexed for MEDLINE]

Modelling cholera transmission dynamics in the presence of limited resources.

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Modelling cholera transmission dynamics in the presence of limited resources.

BMC Res Notes. 2019 Aug 01;12(1):475

Authors: Nyabadza F, Aduamah JM, Mushanyu J

Abstract
OBJECTIVES: We study the transmission dynamics of cholera in the presence of limited resources, a common feature of the developing world. The model is used to gain insight into the impact of available resources of the health care system on the spread and control of the disease. A deterministic model that includes a nonlinear recovery rate is formulated and rigorously analyzed. Limited treatment is described by inclusion of a special treatment function. Center manifold theory is used to show that the model exhibits the phenomenon of backward bifurcation. Matlab has been used to carry out numerical simulations to support theoretical findings.
RESULTS: The model analysis shows that the disease free steady state is locally stable when the threshold [Formula: see text]. It is also shown that the model has multiple equilibria and the model exhibits the phenomenon of backward bifurcation whose implications to cholera infection are discussed. The results are useful for the public health planning in resource allocation for the control of cholera transmission.

PMID: 31370867 [PubMed - indexed for MEDLINE]

Epidemiology of Cholera in Bangladesh: Findings From Nationwide Hospital-based Surveillance, 2014-2018.

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Epidemiology of Cholera in Bangladesh: Findings From Nationwide Hospital-based Surveillance, 2014-2018.

Clin Infect Dis. 2019 Dec 31;:

Authors: Khan AI, Rashid MM, Islam MT, Afrad MH, Salimuzzaman M, Hegde ST, Zion MMI, Khan ZH, Shirin T, Habib ZH, Khan IA, Begum YA, Azman AS, Rahman M, Clemens JD, Flora MS, Qadri F

Abstract
BACKGROUND: Despite advances in prevention, detection, and treatment, cholera remains a major public health problem in Bangladesh and little is known about cholera outside of limited historical sentinel surveillance sites. In Bangladesh, a comprehensive national cholera control plan is essential, although national data are needed to better understand the magnitude and geographic distribution of cholera.
METHODS: We conducted systematic hospital-based cholera surveillance among diarrhea patients in 22 sites throughout Bangladesh from 2014 to 2018. Stool specimens were collected and tested for Vibrio cholerae by microbiological culture. Participants' socioeconomic status and clinical, sanitation, and food history were recorded. We used generalized estimating equations to identify the factors associated with cholera among diarrhea patients.
RESULTS: Among 26 221 diarrhea patients enrolled, 6.2% (n = 1604) cases were V. cholerae O1. The proportion of diarrhea patients positive for cholera in children <5 years was 2.1% and in patients ≥5 years was 9.5%. The proportion of cholera in Dhaka and Chittagong Division was consistently high. We observed biannual seasonal peaks (pre- and postmonsoon) for cholera across the country, with higher cholera positivity during the postmonsoon in western regions and during the pre-monsoon season in eastern regions. Cholera risk increased with age, occupation, and recent history of diarrhea among household members.
CONCLUSIONS: Cholera occurs throughout a large part of Bangladesh. Cholera-prone areas should be prioritized to control the disease by implementation of targeted interventions. These findings can help strengthen the cholera-control program and serve as the basis for future studies for tracking the impact of cholera-control interventions in Bangladesh.

PMID: 31891368 [PubMed - as supplied by publisher]

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