Mycobacterium ulcerans ecological dynamics and its association with freshwater ecosystems and aquatic communities : results from a 12-month environmental survey in Cameroon

Background: Mycobacterium ulcerans (MU) is the agent responsible for Buruli Ulcer (BU), an emerging skin disease with dramatic socioeconomic and health outcomes, especially in rural settings. BU emergence and distribution is linked to aquatic ecosystems in tropical and subtropical countries, especially to swampy and flooded areas. Aquatic animal organisms are likely to play a role either as host reservoirs or vectors of the bacilli. However, information on MU ecological dynamics, both in space and time, is dramatically lacking. As a result, the ecology of the disease agent, and consequently its mode of transmission, remains largely unknown, which jeopardizes public health attempts for its control. The objective of this study was to gain insight on MU environmental distribution and colonization of aquatic organisms through time. Methodology/Principal Findings: Longitudinal sampling of 32 communities of aquatic macro-invertebrates and vertebrates was conducted from different environments in two BU endemic regions in Cameroon during 12 months. As a result, 238,496 individuals were classified and MU presence was assessed by qPCR in 3,084 sample-pools containing these aquatic organisms. Our study showed a broad distribution of MU in all ecosystems and taxonomic groups, with important regional differences in its occurrence. Colonization dynamics fluctuated along the year, with the highest peaks in August and October. The large variations observed in the colonization dynamics of different taxonomic groups and aquatic ecosystems suggest that the trends shown here are the result of complex ecological processes that need further investigation. Conclusion/Perspectives: This is the largest field study on MU ecology to date, providing the first detailed description of its spatio-temporal dynamics in different aquatic ecosystems within BU endemic regions. We argue that coupling this data with fine-scale epidemiological data through statistical and mathematical models will provide a major step forward in the understanding of MU ecology and mode of transmission

A Qualitative Exploration of Community Ownership of a Maternity Waiting Home Model in Rural Zambia

Context Ownership is an important construct of sustainability for community-based health programming, though it is often not clearly defined or measured. We implemented and evaluated a community-driven maternity waiting home (MWH) model in rural Zambia. We engaged stakeholders at all levels and provided intensive mentorship to an MWH governance committee comprised of community-selected members. We then examined how different stakeholders perceive community ownership of the MWH. Methods We conducted 42 focus group discussions with community stakeholders (pregnant women, fathers, elders, and community health volunteers) and 161 in-depth interviews with MWH stakeholders (health facility staff, district health officials, and MWH governance committee and management unit members) at multiple time-points over 24 months. We conducted a content analysis and triangulated findings to understand community ownership of the MWH and observe changes in perceptions of ownership over time. Results Community members’ perceptions of ownership were related to their ability to use the MWH and a responsibility toward its success. Community and MWH stakeholders described increasingly more specific responsibilities over time. Governance committee and management unit members perceived their ability to represent the community as a crucial component of their role. Multiple respondent types saw collaboration between the governance committee and the health facility staff as key to allowing the MWH to meet its goal of serving the community. Conclusion The perceptions of community ownership evolved as the intervention became more established. Use of the MWH, and clear understanding of roles and responsibilities in management of the MWH, seemed to foster feelings of community ownership. To improve the sustainability of community-based maternal and child health programs, interventions should be accessible to target communities and clear roles should be established among stakeholders

Age- and sex-specific HIV-1 prevalence in the urban community setting of Addis Ababa, Ethiopia

Objective: To estimate the age and sex-specific prevalence of HIV infection in th

Plasmodium vivax Recurrence Following Falciparum and Mixed Species Malaria: Risk Factors and Effect of Antimalarial Kinetics

On the Thai-Myanmar border, Plasmodium vivax is the most common cause of parasitological failure following treatment for acute falciparum malaria. Slowly eliminated antimalarials significantly reduce the risk of early recurrence

Risk Factors for Buruli Ulcer: A Case Control Study in Cameroon

Buruli ulcer (BU) is a neglected tropical infectious disease caused by Mycobacterium ulcerans. While BU is associated with areas where the water is slow-flowing or stagnant, the exact mechanism of transmission of the bacillus is unknown, impairing efficient control programs. Two hypotheses are proposed in the literature: previous trauma at the lesion site, and transmission through aquatic insect bites. Using results from a face-to-face questionnaire, our study compared characteristics from Cameroonian patients with Buruli ulcer to people without Buruli ulcer. This latter group of people was chosen within the community or within the family of case patients. The statistical analysis confirmed some well-known factors associated with the presence of BU, such as wearing short lower-body clothing while farming, but it showed that the use of bed nets and the treatment of wounds with leaves is less frequent in case patients. These newly identified factors may provide new insight into the mode of transmission of M. ulcerans. The implication of domestic or peridomestic insects, suggested by the influence of the use of bed nets, should be confirmed in specific studies

Multiple Introductions and Recent Spread of the Emerging Human Pathogen Mycobacterium ulcerans across Africa

YesBuruli ulcer (BU) is an insidious neglected tropical disease. Cases are reported around the world but the rural regions of West and Central Africa are most affected. How BU is transmitted and spreads has remained a mystery, even though the causative agent, Mycobacterium ulcerans, has been known for more than 70 years. Here, using the tools of population genomics, we reconstruct the evolutionaryhistoryofM. ulceransbycomparing165isolatesspanning48yearsandrepresenting11endemiccountriesacrossAfrica. The genetic diversity of African M. ulcerans was found to be restricted due to the bacterium’s slow substitution rate coupled with its relatively recent origin. We identified two specific M. ulcerans lineages within the African continent, and inferred that M. ulcerans lineage Mu_A1 existed in Africa for several hundreds of years, unlike lineage Mu_A2, which was introduced much more recently, approximately during the 19th century. Additionally, we observed that specific M. ulcerans epidemic Mu_A1 clones were introduced during the same time period in the three hydrological basins that were well covered in our panel. The estimated time span of the introduction events coincides with the Neo-imperialism period, during which time the European colonial powers divided the African continent among themselves. Using this temporal association, and in the absence of a known BU reservoir or—vector on the continent, we postulate that the so-called "Scramble for Africa" played a significant role in the spread of the disease across the continent.K.V. was supported by a PhD-grant of the Flemish Interuniversity Council—University Development Cooperation (Belgium). B.d.J. and C.M. were supported by the European Research Council-INTERRUPTB starting grant (no. 311725). T.P.S. was supported by a fellowship from the National Health and Medical Research Council of Australia (1105525). Funding for this work was provided by the Department of Economy, Science and Innovation of the Flemish Government, the Stop Buruli Consortium supported by the UBS Optimus Foundation, and the Fund for Scientific Research Flanders (Belgium) (FWO grant no. G.0321.07N). The computational resources used in this work were provided by the HPC core facility CalcUA and VSC (Flemish Supercomputer Center), funded by the University of Antwerp, the Hercules Foundation and the Flemish Government—department EWI. Aspects of the research in Cameroon and Benin were funded by the Raoul Follereau Fondation France

Seasonal and Regional Dynamics of M. ulcerans Transmission in Environmental Context: Deciphering the Role of Water Bugs as Hosts and Vectors

Buruli ulcer, caused by Mycobacterium ulcerans, is a devastating skin disease. Most cases of Buruli ulcer occur in poor rural communities. As a result, treatment is frequently sought too late and about 25% of those infected—particularly children—become permanently disabled. Outbreaks of Buruli ulcer have always been associated with swampy areas. However, the route(s) of bacillus transmission is (are) still unclear. This Mycobacterium species resides in water where it colonizes many ecological niches such as aquatic plants, herbivorous animals and predatory/carnivorous insects. For several years the role of water bugs as hosts and vectors of M. ulcerans was suspected and was demonstrated under laboratory conditions. The aim of this work was to further assess the role of water bugs as hosts and vectors of M. ulcerans in environmental context. This work identifies several water bug families as hosts of M. ulcerans in Buruli ulcer endemic area. The detection of bacilli in saliva of human biting insects provides further evidence for their role in M. ulcerans transmission. Interestingly, three of these insects are good flyers, and as such could participate in M. ulcerans dissemination

Injection Drug Use Is a Risk Factor for HCV Infection in Urban Egypt

OBJECTIVE: To identify current risk factors for hepatitis C virus (HCV) transmission in Greater Cairo. DESIGN AND SETTING: A 1:1 matched case-control study was conducted comparing incident acute symptomatic hepatitis C patients in two "fever" hospitals of Greater Cairo with two control groups: household members of the cases and acute hepatitis A patients diagnosed at the same hospitals. Controls were matched on the same age and sex to cases and were all anti-HCV antibody negative. Iatrogenic, community and household exposures to HCV in the one to six months before symptoms onset for cases, and date of interview for controls, were exhaustively assessed. RESULTS: From 2002 to 2007, 94 definite acute symptomatic HCV cases and 188 controls were enrolled in the study. In multivariate analysis, intravenous injections (OR = 5.0; 95% CI = 1.2-20.2), medical stitches (OR = 4.2; 95% CI = 1.6-11.3), injection drug use (IDU) (OR = 7.9; 95% CI = 1.4-43.5), recent marriage (OR = 3.3; 95% CI = 1.1-9.9) and illiteracy (OR = 3.9; 95% CI = 1.8-8.5) were independently associated with an increased HCV risk. CONCLUSION: In urban Cairo, invasive health care procedures remain a source of HCV transmission and IDU is an emerging risk factor. Strict application of standard precautions during health care is a priority. Implementation of comprehensive infection prevention programs for IDU should be considered