Journal Article > ResearchFull Text
Int J Infect Dis. 2022 September 1; Volume 122; 215-221.; DOI:10.1016/j.ijid.2022.05.039
Zheng Q, Luquero FJ, Ciglenecki I, Wamala JF, Abubakar A, et al.
Int J Infect Dis. 2022 September 1; Volume 122; 215-221.; DOI:10.1016/j.ijid.2022.05.039
BACKGROUND
Cholera remains a public health threat but is inequitably distributed across sub-Saharan Africa. Lack of standardized reporting and inconsistent outbreak definitions limit our understanding of cholera outbreak epidemiology.
METHODS
From a database of cholera incidence and mortality, we extracted data from sub-Saharan Africa and reconstructed outbreaks of suspected cholera starting in January 2010 to December 2019 based on location-specific average weekly incidence rate thresholds. We then described the distribution of key outbreak metrics.
RESULTS
We identified 999 suspected cholera outbreaks in 744 regions across 25 sub-Saharan African countries. The outbreak periods accounted for 1.8 billion person-months (2% of the total during this period) from January 2010 to January 2020. Among 692 outbreaks reported from second-level administrative units (e.g., districts), the median attack rate was 0.8 per 1000 people (interquartile range (IQR), 0.3-2.4 per 1000), the median epidemic duration was 13 weeks (IQR, 8-19), and the median early outbreak reproductive number was 1.8 (range, 1.1-3.5). Larger attack rates were associated with longer times to outbreak peak, longer epidemic durations, and lower case fatality risks.
CONCLUSIONS
This study provides a baseline from which the progress toward cholera control and essential statistics to inform outbreak management in sub-Saharan Africa can be monitored.
Cholera remains a public health threat but is inequitably distributed across sub-Saharan Africa. Lack of standardized reporting and inconsistent outbreak definitions limit our understanding of cholera outbreak epidemiology.
METHODS
From a database of cholera incidence and mortality, we extracted data from sub-Saharan Africa and reconstructed outbreaks of suspected cholera starting in January 2010 to December 2019 based on location-specific average weekly incidence rate thresholds. We then described the distribution of key outbreak metrics.
RESULTS
We identified 999 suspected cholera outbreaks in 744 regions across 25 sub-Saharan African countries. The outbreak periods accounted for 1.8 billion person-months (2% of the total during this period) from January 2010 to January 2020. Among 692 outbreaks reported from second-level administrative units (e.g., districts), the median attack rate was 0.8 per 1000 people (interquartile range (IQR), 0.3-2.4 per 1000), the median epidemic duration was 13 weeks (IQR, 8-19), and the median early outbreak reproductive number was 1.8 (range, 1.1-3.5). Larger attack rates were associated with longer times to outbreak peak, longer epidemic durations, and lower case fatality risks.
CONCLUSIONS
This study provides a baseline from which the progress toward cholera control and essential statistics to inform outbreak management in sub-Saharan Africa can be monitored.
Journal Article > ResearchFull Text
Lancet Global Health. 2018 May 3; Volume 6 (Issue 6); DOI:10.1016/S2214-109X(18)30230-4
Camacho A, Bouhenia M, Alyusfi R, Alkohlani A, Naji MAM, et al.
Lancet Global Health. 2018 May 3; Volume 6 (Issue 6); DOI:10.1016/S2214-109X(18)30230-4
In war-torn Yemen, reports of confirmed cholera started in late September, 2016. The disease continues to plague Yemen today in what has become the largest documented cholera epidemic of modern times. We aimed to describe the key epidemiological features of this epidemic, including the drivers of cholera transmission during the outbreak.
Journal Article > ResearchFull Text
Lancet Global Health. 2016 November 1; Volume 4 (Issue 11); e856-e863.; DOI:10.1016/S2214-109X(16)30211-X
Azman AS, Parker LA, Rumunu J, Tadesse F, Grandesso F, et al.
Lancet Global Health. 2016 November 1; Volume 4 (Issue 11); e856-e863.; DOI:10.1016/S2214-109X(16)30211-X
BACKGROUND
Oral cholera vaccines represent a new effective tool to fight cholera and are licensed as two-dose regimens with 2-4 weeks between doses. Evidence from previous studies suggests that a single dose of oral cholera vaccine might provide substantial direct protection against cholera. During a cholera outbreak in May, 2015, in Juba, South Sudan, the Ministry of Health, Médecins Sans Frontières, and partners engaged in the first field deployment of a single dose of oral cholera vaccine to enhance the outbreak response. We did a vaccine effectiveness study in conjunction with this large public health intervention.
METHODS
We did a case-cohort study, combining information on the vaccination status and disease outcomes from a random cohort recruited from throughout the city of Juba with that from all the cases detected. Eligible cases were those aged 1 year or older on the first day of the vaccination campaign who sought care for diarrhoea at all three cholera treatment centres and seven rehydration posts throughout Juba. Confirmed cases were suspected cases who tested positive to PCR for Vibrio cholerae O1. We estimated the short-term protection (direct and indirect) conferred by one dose of cholera vaccine (Shanchol, Shantha Biotechnics, Hyderabad, India).
FINDINGS
Between Aug 9, 2015, and Sept 29, 2015, we enrolled 87 individuals with suspected cholera, and an 898-person cohort from throughout Juba. Of the 87 individuals with suspected cholera, 34 were classified as cholera positive, 52 as cholera negative, and one had indeterminate results. Of the 858 cohort members who completed a follow-up visit, none developed clinical cholera during follow-up. The unadjusted single-dose vaccine effectiveness was 80·2% (95% CI 61·5-100·0) and after adjusting for potential confounders was 87·3% (70·2-100·0).
INTERPRETATION
One dose of Shanchol was effective in preventing medically attended cholera in this study. These results support the use of a single-dose strategy in outbreaks in similar epidemiological settings.
Oral cholera vaccines represent a new effective tool to fight cholera and are licensed as two-dose regimens with 2-4 weeks between doses. Evidence from previous studies suggests that a single dose of oral cholera vaccine might provide substantial direct protection against cholera. During a cholera outbreak in May, 2015, in Juba, South Sudan, the Ministry of Health, Médecins Sans Frontières, and partners engaged in the first field deployment of a single dose of oral cholera vaccine to enhance the outbreak response. We did a vaccine effectiveness study in conjunction with this large public health intervention.
METHODS
We did a case-cohort study, combining information on the vaccination status and disease outcomes from a random cohort recruited from throughout the city of Juba with that from all the cases detected. Eligible cases were those aged 1 year or older on the first day of the vaccination campaign who sought care for diarrhoea at all three cholera treatment centres and seven rehydration posts throughout Juba. Confirmed cases were suspected cases who tested positive to PCR for Vibrio cholerae O1. We estimated the short-term protection (direct and indirect) conferred by one dose of cholera vaccine (Shanchol, Shantha Biotechnics, Hyderabad, India).
FINDINGS
Between Aug 9, 2015, and Sept 29, 2015, we enrolled 87 individuals with suspected cholera, and an 898-person cohort from throughout Juba. Of the 87 individuals with suspected cholera, 34 were classified as cholera positive, 52 as cholera negative, and one had indeterminate results. Of the 858 cohort members who completed a follow-up visit, none developed clinical cholera during follow-up. The unadjusted single-dose vaccine effectiveness was 80·2% (95% CI 61·5-100·0) and after adjusting for potential confounders was 87·3% (70·2-100·0).
INTERPRETATION
One dose of Shanchol was effective in preventing medically attended cholera in this study. These results support the use of a single-dose strategy in outbreaks in similar epidemiological settings.
Journal Article > ResearchFull Text
Am J Trop Med Hyg. 2017 December 4; Volume 98 (Issue 2); DOI:10.4269/ajtmh.17-0339
Bliss JR, Bouhenia M, Hale P, Couturier BA, Iyer AS, et al.
Am J Trop Med Hyg. 2017 December 4; Volume 98 (Issue 2); DOI:10.4269/ajtmh.17-0339
Displaced persons living in camps are at an increased risk of diarrheal diseases. Subclinical carriage of pathogens may contribute to the spread of disease, especially for microbes that require a low infectious dose. Multiplex real-time polymerase chain reaction was performed to detect a panel of 20 bacterial, viral, and protozoal targets, and we report a high prevalence of enteropathogen carriage, including Shigella spp. or enteroinvasive Escherichia coli in 14%, among a sample of 88 asymptomatic individuals in an internally displaced persons camp in South Sudan. Further studies are needed to determine the contribution of such carriage to the spread of disease.
Journal Article > ResearchFull Text
Lancet. 2018 May 1; Volume 391 (Issue 10133); DOI:10.1016/S0140-6736(17)33050-7
Lessler J, Moore SM, Luquero FJ, McKay H, Grais RF, et al.
Lancet. 2018 May 1; Volume 391 (Issue 10133); DOI:10.1016/S0140-6736(17)33050-7
Cholera remains a persistent health problem in sub-Saharan Africa and worldwide. Cholera can be controlled through appropriate water and sanitation, or by oral cholera vaccination, which provides transient (∼3 years) protection, although vaccine supplies remain scarce. We aimed to map cholera burden in sub-Saharan Africa and assess how geographical targeting could lead to more efficient interventions.
Journal Article > CommentaryFull Text
Trop Med Int Health. 2021 June 3; Volume 26 (Issue 9); 1088-1097.; DOI:10.1111/tmi.13630
Isah S, Amirtharajah M, Farley ES, Adetunji AS, Samuel J, et al.
Trop Med Int Health. 2021 June 3; Volume 26 (Issue 9); 1088-1097.; DOI:10.1111/tmi.13630
The Nigerian Ministry of Health has been offering care for noma patients for many years at the Noma Children's Hospital (NCH) in Sokoto, northwest Nigeria, and Médecins Sans Frontières has supported these initiatives since 2014. The comprehensive model of care consists of four main components: acute care, care for noma sequelae, integrated hospital-based services and community-based services. The model of care is based on the limited evidence available for prevention and treatment of noma and follows WHO's protocols for acute patients and best practice guidelines for the surgical treatment of noma survivors. The model is updated continually as new evidence becomes available, including evidence generated through the operational research studies performed at NCH. By describing the model of care, we wish to share the lessons learned with other actors working in the noma and neglected tropical disease sphere in the hope of guiding programme development.
Journal Article > ResearchFull Text
PLoS Negl Trop Dis. 2020 January 23; Volume 14 (Issue 1); e0007972.; DOI:10.1371/journal.pntd.0007972
Farley ES, Lenglet AD, Abubakar A, Bil K, Fotso A, et al.
PLoS Negl Trop Dis. 2020 January 23; Volume 14 (Issue 1); e0007972.; DOI:10.1371/journal.pntd.0007972
BACKGROUND
Noma is an orofacial gangrene that rapidly disintegrates the tissues of the face. Little is known about noma, as most patients live in underserved and inaccessible regions. We aimed to assess the descriptive language used and beliefs around noma, at the Noma Children's Hospital in Sokoto, Nigeria. Findings will be used to inform prevention programs.
METHODS
Five focus group discussions (FGD) were held with caretakers of patients with noma who were admitted to the hospital at the time of interview, and 12 in-depth interviews (IDI) were held with staff at the hospital. Topic guides used for interviews were adapted to encourage the natural flow of conversation. Emergent codes, patterns and themes were deciphered from the data derived from IDI's and FGDs.
RESULTS
Our study uncovered two main themes: names, descriptions and explanations for the disease, and risks and consequences of noma. Naming of the disease differed between caretakers and heath care workers. The general names used for noma illustrate the beliefs and social system used to explain the disease. Beliefs were varied; participant responses demonstrate a wide range of understanding of the disease and its causes. Difficulty in accessing care for patients with noma was evident and the findings suggest a variety of actions taking place before reaching a health center or health worker. Patient caretakers mentioned that barriers to care included a lack of knowledge regarding this medical condition, as well as a lack of trust in seeking medical care. Participants in our study spoke of the mental health strain the disease placed on them, particularly due to the stigma that is associated with noma.
CONCLUSIONS
Caretaker and practitioner perspectives enhance our understanding of the disease in this context and can be used to improve treatment and prevention programs, and to better understand barriers to accessing health care. Differences in disease naming illustrate the difference in beliefs about the disease. This has an impact on health seeking behaviours, which for noma cases has important ramifications on outcomes, due to the rapid progression of the disease.
Noma is an orofacial gangrene that rapidly disintegrates the tissues of the face. Little is known about noma, as most patients live in underserved and inaccessible regions. We aimed to assess the descriptive language used and beliefs around noma, at the Noma Children's Hospital in Sokoto, Nigeria. Findings will be used to inform prevention programs.
METHODS
Five focus group discussions (FGD) were held with caretakers of patients with noma who were admitted to the hospital at the time of interview, and 12 in-depth interviews (IDI) were held with staff at the hospital. Topic guides used for interviews were adapted to encourage the natural flow of conversation. Emergent codes, patterns and themes were deciphered from the data derived from IDI's and FGDs.
RESULTS
Our study uncovered two main themes: names, descriptions and explanations for the disease, and risks and consequences of noma. Naming of the disease differed between caretakers and heath care workers. The general names used for noma illustrate the beliefs and social system used to explain the disease. Beliefs were varied; participant responses demonstrate a wide range of understanding of the disease and its causes. Difficulty in accessing care for patients with noma was evident and the findings suggest a variety of actions taking place before reaching a health center or health worker. Patient caretakers mentioned that barriers to care included a lack of knowledge regarding this medical condition, as well as a lack of trust in seeking medical care. Participants in our study spoke of the mental health strain the disease placed on them, particularly due to the stigma that is associated with noma.
CONCLUSIONS
Caretaker and practitioner perspectives enhance our understanding of the disease in this context and can be used to improve treatment and prevention programs, and to better understand barriers to accessing health care. Differences in disease naming illustrate the difference in beliefs about the disease. This has an impact on health seeking behaviours, which for noma cases has important ramifications on outcomes, due to the rapid progression of the disease.
Journal Article > CommentaryFull Text
PLOS Med. 2015 November 17; Volume 12 (Issue 11); e1001901.; DOI:10.1371/journal.pmed.1001901
Abubakar A, Azman AS, Rumunu J, Ciglenecki I, Helderman T, et al.
PLOS Med. 2015 November 17; Volume 12 (Issue 11); e1001901.; DOI:10.1371/journal.pmed.1001901
SUMMARY POINTS
• A global oral cholera vaccine (OCV) stockpile was established in 2013 to improve rapid access to the vaccine in outbreaks and emergencies in which cholera risk is high. The first deployment from the global OCV stockpile was to South Sudan in 2014 because of high cholera risk from massive population displacements within the civil war.
•. 256,700 doses of OCV were delivered, with high coverage, throughout the country as part of a comprehensive cholera prevention strategy by multiple agencies, some of which had little to no previous experience with this vaccine.
• A cholera epidemic began during vaccination, and a basic comparison of epidemic curves in vaccinated and unvaccinated areas suggests little to no transmission occurred in vaccinated areas, though more in depth analysis is needed.
• This deployment highlights the feasibility of effective deployments from the OCV stockpile and the importance of strong coordination between governmental and nongovernmental agencies in cholera prevention and control planning from the assessment of cholera risk to the deployment of the vaccines.
•. A larger global supply of OCV is urgently needed to cover those most in need. With limited vaccine availability now and likely in the upcoming years, more work is needed on deciding how to most efficiently use the vaccine, which may include alternative dosing regimens and targeting specific subpopulation
• A global oral cholera vaccine (OCV) stockpile was established in 2013 to improve rapid access to the vaccine in outbreaks and emergencies in which cholera risk is high. The first deployment from the global OCV stockpile was to South Sudan in 2014 because of high cholera risk from massive population displacements within the civil war.
•. 256,700 doses of OCV were delivered, with high coverage, throughout the country as part of a comprehensive cholera prevention strategy by multiple agencies, some of which had little to no previous experience with this vaccine.
• A cholera epidemic began during vaccination, and a basic comparison of epidemic curves in vaccinated and unvaccinated areas suggests little to no transmission occurred in vaccinated areas, though more in depth analysis is needed.
• This deployment highlights the feasibility of effective deployments from the OCV stockpile and the importance of strong coordination between governmental and nongovernmental agencies in cholera prevention and control planning from the assessment of cholera risk to the deployment of the vaccines.
•. A larger global supply of OCV is urgently needed to cover those most in need. With limited vaccine availability now and likely in the upcoming years, more work is needed on deciding how to most efficiently use the vaccine, which may include alternative dosing regimens and targeting specific subpopulation
Journal Article > CommentaryFull Text
Emerg Infect Dis. 2018 May 1; Volume 24 (Issue 5); 883-887.; DOI:10.3201/eid2405.171651
Abubakar A, Bwire GS, Azman AS, Bouhenia M, Deng LO, et al.
Emerg Infect Dis. 2018 May 1; Volume 24 (Issue 5); 883-887.; DOI:10.3201/eid2405.171651
Combining the official cholera line list data and outbreak investigation reports from the ministries of health in Uganda and South Sudan with molecular analysis of Vibrio cholerae strains revealed the interrelatedness of the epidemics in both countries in 2014. These results highlight the need for collaboration to control cross-border outbreaks.
Journal Article > LetterFull Text
Nature. 2019 January 2; Volume 565 (Issue 7738); DOI:10.1038/s41586-018-0818-3
Weill FX, Domman D, Njamkepo E, Almesbahi AA, Naji MAM, et al.
Nature. 2019 January 2; Volume 565 (Issue 7738); DOI:10.1038/s41586-018-0818-3
Yemen is currently experiencing, to our knowledge, the largest cholera epidemic in recent history. The first cases were declared in September 2016, and over 1.1 million cases and 2,300 deaths have since been reported1. Here we investigate the phylogenetic relationships, pathogenesis and determinants of antimicrobial resistance by sequencing the genomes of Vibrio cholerae isolates from the epidemic in Yemen and recent isolates from neighbouring regions. These 116 genomic sequences were placed within the phylogenetic context of a global collection of 1,087 isolates of the seventh pandemic V. cholerae serogroups O1 and O139 biotype El Tor2-4. We show that the isolates from Yemen that were collected during the two epidemiological waves of the epidemic1-the first between 28 September 2016 and 23 April 2017 (25,839 suspected cases) and the second beginning on 24 April 2017 (more than 1 million suspected cases)-are V. cholerae serotype Ogawa isolates from a single sublineage of the seventh pandemic V. cholerae O1 El Tor (7PET) lineage. Using genomic approaches, we link the epidemic in Yemen to global radiations of pandemic V. cholerae and show that this sublineage originated from South Asia and that it caused outbreaks in East Africa before appearing in Yemen. Furthermore, we show that the isolates from Yemen are susceptible to several antibiotics that are commonly used to treat cholera and to polymyxin B, resistance to which is used as a marker of the El Tor biotype.