Diagnostic Value of Histological Analysis of Punch Biopsies in Suspected Cutaneous Buruli Ulcer: A Study on 32 Cases of Confirmed Buruli Ulcer in Cameroon.

BACKGROUND: Buruli ulcer (BU) is a cutaneous infectious disease caused by Mycobacterium ulcerans. In this prospective study, we aim to clarify the main histopathological features of cutaneous BU based on 4-mm skin punch biopsies and to evaluate the diagnostic value of this method. METHODS: Between 2011 and 2013, a prospective study was conducted in Cameroon. Dry swabs from ulcerative lesions and fine-needle aspirates of nonulcerative lesions were examined for Ziehl-Neelsen (ZN) staining, followed by PCR targeting IS2404 and culture. Two 4-mm punch biopsies were performed in the center and in the periphery of each lesion. RESULTS: The 364 patients included in the study had 422 lesions (381 were ulcerative and 357 lesions were biopsied). Among the 99 ulcerated lesions with a final diagnosis of BU, histological features for BU were fulfilled in 32 lesions. 32/32 showed subcutaneous necrosis with a neutrophilic inflammatory infiltrate. 26/32 presented alcohol-resistant bacilli confirmed by ZN stain on histology. CONCLUSION: Punch biopsies help in establishing the correct diagnosis of BU and also in the differential diagnosis of chronic ulcers. The main histological feature for BU is diffuse coagulative necrosis of subcutaneous tissue, with acid-fast bacilli detected by ZN stain.

Progress and Challenges in Using Oral Cholera Vaccines to Control Outbreaks: The Médecins Sans Frontières Experience.

The use of oral cholera vaccine (OCV) has increased since 2011, when Shanchol, the first OCV suitable for large-scale use, became available. Médecins Sans Frontières considers OCVs an essential cholera outbreak control tool and has contributed to generating new evidence on OCV use in outbreaks. We showed that large-scale mass campaigns are feasible during outbreaks, documented high short-term effectiveness and showed that vaccines are likely safe in pregnancy. We found that a single-dose regimen has high short-term effectiveness, making rapid delivery of vaccine during outbreaks easier, especially given the on-going global vaccine shortage. Despite progress, OCV has still not been used widely in some of the largest recent outbreaks and thousands of cholera deaths are reported every year. While working towards improving our tools to protect those most at-risk of cholera, we must strive to use all available effective interventions in efficient ways, including OCV, to prevent avoidable deaths today.

Evaluation of the SD bioline cholera rapid diagnostic test during the 2016 cholera outbreak in Lusaka, Zambia.

OBJECTIVE: To assess the performance of the SD Bioline Cholera Ag O1/O139 rapid diagnostic test (RDT) compared to a reference standard combining culture and PCR for the diagnosis of cholera cases during an outbreak. METHODS: RDT and bacterial culture were performed on site using fresh stools collected from cholera suspected cases, and from stools enriched in alkaline peptone water. Dried stool samples on filter paper were tested for V. cholerae by PCR in Lusaka (as part of a laboratory technology transfer project) and at a reference laboratory in Paris, France. A sample was considered positive for cholera by the reference standard if any of the culture or PCR tests was positive for V. cholerae O1 or O139. RESULTS: Among the 170 samples tested with SD Bioline and compared to the reference standard, the RDT showed a sensitivity of 90.9% (95% CI: 81.3-96.6) and specificity of 95.2% (95% CI: 89.1-98.4). After enrichment, the sensitivity was 95.5% (95% CI: 87.3-99.1) and specificity 100% (95% CI: 96.5-100). CONCLUSION: The observed sensitivity and specificity were within recommendations set by the Global Task Force for Cholera Control on the use of cholera RDT (sensitivity = 90%; specificity = 85%). Although the sample size was small, our findings suggest that the SD Bioline RDT could be used in the field to rapidly alert public health officials to the likely presence of cholera cases when an outbreak is suspected.

Risk factors for measles mortality and the importance of decentralized case management during an unusually large measles epidemic in eastern Democratic Republic of Congo in 2013.

In 2013, a large measles epidemic occurred in the Aketi Health Zone of the Democratic Republic of Congo. We conducted a two-stage, retrospective cluster survey to estimate the attack rate, the case fatality rate, and the measles-specific mortality rate during the epidemic. 1424 households containing 7880 individuals were included. The estimated attack rate was 14.0%, (35.0% among children aged <5 years). The estimated case fatality rate was 4.2% (6.1% among children aged <5 years). Spatial analysis and linear regression showed that younger children, those who did not receive care, and those living farther away from Aketi Hospital early in the epidemic had a higher risk of measles related death. Vaccination coverage prior to the outbreak was low (76%), and a delayed reactive vaccination campaign contributed to the high attack rate. We provide evidences suggesting that a comprehensive case management approach reduced measles fatality during this epidemic in rural, inaccessible resource-poor setting.

Cholera Rapid Test with Enrichment Step Has Diagnostic Performance Equivalent to Culture.

Cholera rapid diagnostic tests (RDT) could play a central role in outbreak detection and surveillance in low-resource settings, but their modest performance has hindered their broad adoption. The addition of an enrichment step may improve test specificity. We describe the results of a prospective diagnostic evaluation of the Crystal VC RDT (Span Diagnostics, India) with enrichment step and of culture, each compared to polymerase chain reaction (PCR), during a cholera outbreak in South Sudan. RDTs were performed on alkaline peptone water inoculated with stool and incubated for 4-6 hours at ambient temperature. Cholera culture was performed from wet filter paper inoculated with stool. Molecular detection of Vibrio cholerae O1 by PCR was done from dry Whatman 903 filter papers inoculated with stool, and from wet filter paper supernatant. In August and September 2015, 101 consecutive suspected cholera cases were enrolled, of which 36 were confirmed by PCR. The enriched RDT had 86.1% (95% CI: 70.5-95.3) sensitivity and 100% (95% CI: 94.4-100) specificity compared to PCR as the reference standard. The sensitivity of culture versus PCR was 83.3% (95% CI: 67.2-93.6) for culture performed on site and 72.2% (95% CI: 54.8-85.8) at the international reference laboratory, where samples were tested after an average delay of two months after sample collection, and specificity was 98.5% (95% CI: 91.7-100) and 100% (95% CI: 94.5-100), respectively. The RDT with enrichment showed performance comparable to that of culture and could be a sustainable alternative to culture confirmation where laboratory capacity is limited.

Community-Based Surveillance to Monitor Mortality in a Malaria-Endemic and Ebola-Epidemic Setting in Rural Guinea.

Multiple community-based approaches can aid in quantifying mortality in the absence of reliable health facility data. Community-based sentinel site surveillance that was used to document mortality and the systems utility for outbreak detection was evaluated. We retrospectively analyzed data from 46 sentinel sites in three sous-préfectures with a reinforced malaria control program and one sous-préfecture without (Koundou) in Guinea. Deaths were recorded by key informants and classified as due to malaria or another cause. Malaria deaths were those reported as due to malaria or fever in the 3 days before death with no other known cause. Suspect Ebola virus disease (sEVD) deaths were those due to select symptoms in the EVD case definition. Deaths were aggregated by sous-préfecture and analyzed by a 6-month period. A total of 43,000 individuals were monitored by the surveillance system; 1,242 deaths were reported from July 2011-June 2014, of which 55.2% (N = 686) were reported as due to malaria. Malaria-attributable proportional mortality decreased by 26.5% (95% confidence interval [CI] = 13.9-33.1, P < 0.001) in the program area and by 6.6% (95% CI = -17.3-30.5, P = 0.589) in Koundou. Sixty-eight deaths were classified as sEVD and increased by 6.1% (95% CI = 1.3-10.8, P = 0.021). Seventeen sEVD deaths were reported from November 2013 to March 2014 including the first two laboratory-confirmed EVD deaths. Community surveillance can capture information on mortality in areas where data collection is weak, but determining causes of death remains challenging. It can also be useful for outbreak detection if timeliness of data collection and reporting facilitate real-time data analysis.

Encouraging impact following 2.5 years of reinforced malaria control interventions in a hyperendemic region of the Republic of Guinea.

BACKGROUND: Malaria is one of the principal causes of morbidity and mortality in the Republic of Guinea, particularly in the highly endemic regions. To assist in malaria control efforts, a multi-component malaria control intervention was implemented in the hyperendemic region of Guéckédou Prefecture. The coverage of the intervention and its impact on malaria parasite prevalence were assessed. METHODS: Five cross-sectional surveys using cluster-based sampling and stratified by area were conducted from 2011 to 2013 in three sous-préfectures of Guéckédou Préfecture that received the intervention: Guéckédou City, Tékoulo and Guendembou in addition to one comparison sous-préfecture that did not receive the intervention, Koundou. Surveys were repeated every 6 months, corresponding with the dry and rainy seasons. Rapid diagnostic tests (RDT) were used to diagnose malaria infection. In each selected household, bed net use and ownership were assessed. RESULTS: A total of 35,123 individuals participated in the surveys. Malaria parasite prevalence declined in all intervention sous-préfectures from 2011 to 2013 (56.4-45.9 % in Guéckédou City, 64.9-54.1 % in Tékoulo and 69.4-56.9 % in Guendembou) while increasing in the comparison sous-préfecture (64.5-69 %). It was consistently higher in children 5-14 years of age followed by those 1-59 months and ≥15 years. Indicators of intervention coverage, the proportion of households reporting ownership of at least one bed net and the proportion of survey participants with fever who received treatment from a health facility or community health worker also increased significantly in the intervention areas. CONCLUSIONS: Implementation of the multi-component malaria control intervention significantly reduced the prevalence of malaria in the sous-préfectures of intervention while also increasing the coverage of bed nets. However, malaria prevalence remains unacceptably high and disproportionately affects children <15 years of age. In such situations additional vector control interventions and age specific interventions should be considered.

Effect of Artesunate-Amodiaquine on Mortality Related to Ebola Virus Disease.

BACKGROUND: Malaria treatment is recommended for patients with suspected Ebola virus disease (EVD) in West Africa, whether systeomatically or based on confirmed malaria diagnosis. At the Ebola treatment center in Foya, Lofa County, Liberia, the supply of artemether-lumefantrine, a first-line antimalarial combination drug, ran out for a 12-day period in August 2014. During this time, patients received the combination drug artesunate-amodiaquine; amodiaquine is a compound with anti-Ebola virus activity in vitro. No other obvious change in the care of patients occurred during this period. METHODS: We fit unadjusted and adjusted regression models to standardized patient-level data to estimate the risk ratio for death among patients with confirmed EVD who were prescribed artesunate-amodiaquine (artesunate-amodiaquine group), as compared with those who were prescribed artemether-lumefantrine (artemether-lumefantrine group) and those who were not prescribed any antimalarial drug (no-antimalarial group). RESULTS: Between June 5 and October 24, 2014, a total of 382 patients with confirmed EVD were admitted to the Ebola treatment center in Foya. At admission, 194 patients were prescribed artemether-lumefantrine and 71 were prescribed artesunate-amodiaquine. The characteristics of the patients in the artesunate-amodiaquine group were similar to those in the artemether-lumefantrine group and those in the no-antimalarial group. A total of 125 of the 194 patients in the artemether-lumefantrine group (64.4%) died, as compared with 36 of the 71 patients in the artesunate-amodiaquine group (50.7%). In adjusted analyses, the artesunate-amodiaquine group had a 31% lower risk of death than the artemether-lumefantrine group (risk ratio, 0.69; 95% confidence interval, 0.54 to 0.89), with a stronger effect observed among patients without malaria. CONCLUSIONS: Patients who were prescribed artesunate-amodiaquine had a lower risk of death from EVD than did patients who were prescribed artemether-lumefantrine. However, our analyses cannot exclude the possibility that artemether-lumefantrine is associated with an increased risk of death or that the use of artesunate-amodiaquine was associated with unmeasured patient characteristics that directly altered the risk of death.

Pregnancy Outcomes after a Mass Vaccination Campaign with an Oral Cholera Vaccine in Guinea: A Retrospective Cohort Study.

INTRODUCTION: Since 2010, WHO has recommended oral cholera vaccines as an additional strategy for cholera control. During a cholera episode, pregnant women are at high risk of complications, and the risk of fetal death has been reported to be 2-36%. Due to a lack of safety data, pregnant women have been excluded from most cholera vaccination campaigns. In 2012, reactive campaigns using the bivalent killed whole-cell oral cholera vaccine (BivWC), included all people living in the targeted areas aged ≥ 1 year regardless of pregnancy status, were implemented in Guinea. We aimed to determine whether there was a difference in pregnancy outcomes between vaccinated and non-vaccinated pregnant women. METHODS AND FINDINGS: From 11 November to 4 December 2013, we conducted a retrospective cohort study in Boffa prefecture among women who were pregnant in 2012 during or after the vaccination campaign. The primary outcome was pregnancy loss, as reported by the mother, and fetal malformations, after clinical examination. Primary exposure was the intake of the BivWC vaccine (Shanchol) during pregnancy, as determined by a vaccination card or oral history. We compared the risk of pregnancy loss between vaccinated and non-vaccinated women through binomial regression analysis. A total of 2,494 pregnancies were included in the analysis. The crude incidence of pregnancy loss was 3.7% (95%CI 2.7-4.8) for fetuses exposed to BivWC vaccine and 2.6% (0.7-4.5) for non-exposed fetuses. The incidence of malformation was 0.6% (0.1-1.0) and 1.2% (0.0-2.5) in BivWC-exposed and non-exposed fetuses, respectively. In both crude and adjusted analyses, fetal exposure to BivWC was not significantly associated with pregnancy loss (adjusted risk ratio (aRR = 1.09 [95%CI: 0.5-2.25], p = 0.818) or malformations (aRR = 0.50 [95%CI: 0.13-1.91], p = 0.314). CONCLUSIONS: In this large retrospective cohort study, we found no association between fetal exposure to BivWC and risk of pregnancy loss or malformation. Despite the weaknesses of a retrospective design, we can conclude that if a risk exists, it is very low. Additional prospective studies are warranted to add to the evidence base on OCV use during pregnancy. Pregnant women are particularly vulnerable during cholera episodes and should be included in vaccination campaigns when the risk of cholera is high, such as during outbreaks.

Use of Vibrio cholerae vaccine in an outbreak in Guinea.

BACKGROUND: The use of vaccines to prevent and control cholera is currently under debate. Shanchol is one of the two oral cholera vaccines prequalified by the World Health Organization; however, its effectiveness under field conditions and the protection it confers in the first months after administration remain unknown. The main objective of this study was to estimate the short-term effectiveness of two doses of Shanchol used as a part of the integrated response to a cholera outbreak in Africa. METHODS: We conducted a matched case-control study in Guinea between May 20 and October 19, 2012. Suspected cholera cases were confirmed by means of a rapid test, and controls were selected among neighbors of the same age and sex as the case patients. The odds of vaccination were compared between case patients and controls in bivariate and adjusted conditional logistic-regression models. Vaccine effectiveness was calculated as (1-odds ratio)×100. RESULTS: Between June 8 and October 19, 2012, we enrolled 40 case patients and 160 controls in the study for the primary analysis. After adjustment for potentially confounding variables, vaccination with two complete doses was associated with significant protection against cholera (effectiveness, 86.6%; 95% confidence interval, 56.7 to 95.8; P=0.001). CONCLUSIONS: In this study, Shanchol was effective when used in response to a cholera outbreak in Guinea. This study provides evidence supporting the addition of vaccination as part of the response to an outbreak. It also supports the ongoing efforts to establish a cholera vaccine stockpile for emergency use, which would enhance outbreak prevention and control strategies. (Funded by Médecins sans Frontières.).

The urgent need for clinical, diagnostic, and operational research for management of Buruli ulcer in Africa.

Despite great advances in the diagnosis and treatment of Buruli ulcer, it is one of the least studied major neglected tropical diseases. In Africa, major constraints in the management of Buruli ulcer relate to diagnosis and treatment, and accessibility, feasibility, and delivery of services. In this Personal View, we outline key areas for clinical, diagnostic, and operational research on this disease in Africa and propose a research agenda that aims to advance the management of Buruli ulcer in Africa. A model of care is needed to increase early case detection, to diagnose the disease accurately, to simplify and improve treatment, to reduce side-effects of treatment, to deal with populations with HIV and tuberculosis appropriately, to decentralise care, and to scale up coverage in populations at risk. This approach will require commitment and support to strategically implement research by national Buruli ulcer programmes and international technical and donor organisations, combined with adaptations in programme design and advocacy. A critical next step is to build consensus for a research agenda with WHO and relevant groups experienced in Buruli ulcer care or related diseases, and we call on on them to help to turn this agenda into reality.

Impact of human immunodeficiency virus on the severity of buruli ulcer disease: results of a retrospective study in cameroon.

BACKGROUND: Buruli ulcer is the third most common mycobacterial disease after tuberculosis and leprosy and is particularly frequent in rural West and Central Africa. However, the impact of HIV infection on BU severity and prevalence remains unclear. METHODS: This was a retrospective study of data collected at the Akonolinga District Hospital, Cameroon, from January 1, 2002 to March 27, 2013. Human immunodeficiency virus prevalence among BU patients was compared with regional HIV prevalence. Baseline characteristics of BU patients were compared between HIV-negative and HIV-positive patients and according to CD4 cell count strata in the latter group. Buruli ulcer time-to-healing was assessed in different CD4 count strata, and factors associated with BU main lesion size at baseline were identified. RESULTS: Human immunodeficiency virus prevalence among BU patients was significantly higher than the regional estimated prevalence in each group (children, 4.00% vs 0.68% [P < .001]; men, 17.0% vs 4.7% [P < .001]; women, 36.0% vs 8.0% [P < .001]). Individuals who were HIV positive had a more severe form of BU, with an increased severity in those with a higher level of immunosuppression. Low CD4 cell count was significantly associated with a larger main lesion size (ß-coefficient, -0.50; P = .015; 95% confidence interval [CI], -0.91-0.10). Buruli ulcer time-to-healing was more than double in patients with a CD4 cell count below 500 cell/mm(3) (hazard ratio, 2.39; P = .001; 95% CI, 1.44-3.98). CONCLUSION: Patients who are HIV positive are at higher risk for BU. Human immunodeficiency virus-induced immunosuppression seems to have an impact on BU clinical presentation and disease evolution.

First outbreak response using an oral cholera vaccine in Africa: vaccine coverage, acceptability and surveillance of adverse events, Guinea, 2012.

BACKGROUND: Despite World Health Organization (WHO) prequalification of two safe and effective oral cholera vaccines (OCV), concerns about the acceptability, potential diversion of resources, cost and feasibility of implementing timely campaigns has discouraged their use. In 2012, the Ministry of Health of Guinea, with the support of Médecins Sans Frontières organized the first mass vaccination campaign using a two-dose OCV (Shanchol) as an additional control measure to respond to the on-going nationwide epidemic. Overall, 316,250 vaccines were delivered. Here, we present the results of vaccination coverage, acceptability and surveillance of adverse events. METHODOLOGY/PRINCIPAL FINDINGS: We performed a cross-sectional cluster survey and implemented adverse event surveillance. The study population included individuals older than 12 months, eligible for vaccination, and residing in the areas targeted for vaccination (Forécariah and Boffa, Guinea). Data sources were household interviews with verification by vaccination card and notifications of adverse events from surveillance at vaccination posts and health centres. In total 5,248 people were included in the survey, 3,993 in Boffa and 1,255 in Forécariah. Overall, 89.4% [95%CI:86.4-91.8%] and 87.7% [95%CI:84.2-90.6%] were vaccinated during the first round and 79.8% [95%CI:75.6-83.4%] and 82.9% [95%CI:76.6-87.7%] during the second round in Boffa and Forécariah respectively. The two dose vaccine coverage (including card and oral reporting) was 75.8% [95%CI: 71.2-75.9%] in Boffa and 75.9% [95%CI: 69.8-80.9%] in Forécariah respectively. Vaccination coverage was higher in children. The main reason for non-vaccination was absence. No severe adverse events were notified. CONCLUSIONS/SIGNIFICANCE: The well-accepted mass vaccination campaign reached high coverage in a remote area with a mobile population. Although OCV should not be foreseen as the long-term solution for global cholera control, they should be integrated as an additional tool into the response.