The Mbam drainage system and onchocerciasis transmission post ivermectin mass drug administration (MDA) campaign, Cameroon.

Autor: Abong RA; Parasites and Vector Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon.; Research Foundation in Tropical Diseases and Environment (REFOTDE), Buea, Cameroon., Amambo GN; Parasites and Vector Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon.; Research Foundation in Tropical Diseases and Environment (REFOTDE), Buea, Cameroon., Hamid AA; Parasites and Vector Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon.; Research Foundation in Tropical Diseases and Environment (REFOTDE), Buea, Cameroon., Enow BA; Parasites and Vector Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon.; Research Foundation in Tropical Diseases and Environment (REFOTDE), Buea, Cameroon., Beng AA; Parasites and Vector Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon.; Research Foundation in Tropical Diseases and Environment (REFOTDE), Buea, Cameroon., Nietcho FN; Parasites and Vector Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon., Nji TM; Research Foundation in Tropical Diseases and Environment (REFOTDE), Buea, Cameroon.; Department of Sociology and Anthropology, University of Buea, Cameroon., Njouendou AJ; Parasites and Vector Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon.; Department of Biomedical science, Faculty of Health Sciences, University of Buea, Buea, Cameroon., Ritter M; Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany., Esum ME; Parasites and Vector Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon.; Research Foundation in Tropical Diseases and Environment (REFOTDE), Buea, Cameroon., Deribe K; Global Health and Infection Department, Brighton and Sussex Medical School, Brighton, United Kingdom.; School of Public Health, Addis Ababa University, Addis Ababa, Ethiopia., Cho JF; Parasites and Vector Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon.; Research Foundation in Tropical Diseases and Environment (REFOTDE), Buea, Cameroon., Fombad FF; Parasites and Vector Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon.; Research Foundation in Tropical Diseases and Environment (REFOTDE), Buea, Cameroon., Enyong PI; Parasites and Vector Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon.; Research Foundation in Tropical Diseases and Environment (REFOTDE), Buea, Cameroon., Poole C; New England Biolabs, Ipswich, Massachusetts, United States of America., Pfarr K; Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany.; German Center for Infection Research (DZIF), partner site Bonn-Cologne, Bonn, Germany., Hoerauf A; Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany.; German Center for Infection Research (DZIF), partner site Bonn-Cologne, Bonn, Germany., Carlow C; New England Biolabs, Ipswich, Massachusetts, United States of America., Wanji S; Parasites and Vector Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon.; Research Foundation in Tropical Diseases and Environment (REFOTDE), Buea, Cameroon.
Jazyk: angličtina
Zdroj: PLoS neglected tropical diseases [PLoS Negl Trop Dis] 2021 Jan 19; Vol. 15 (1), pp. e0008926. Date of Electronic Publication: 2021 Jan 19 (Print Publication: 2021).
DOI: 10.1371/journal.pntd.0008926
Abstrakt: Background: The impact of large scale Mass Drug Adminstration (MDA) of ivermectin on active onchocerciasis transmission by Simulium damnosum, which transmits the parasite O. volvulus is of great importance for onchocerciasis control programmes. We investigated in the Mbam river system area, the impact of MDA of ivermectin on entomological indices and also verify if there are river system factors that could have favoured the transmission of onchocerciasis in this area and contribute to the persistence of disease. We compared three independent techniques to detect Onchocerca larvae in blackflies and also analyzed the river system within 9 months post-MDA of ivermectin.
Method: Simulium flies were captured before and after 1, 3, 6 and 9months of ivermectin-MDA. The biting rate was determined and 41% of the flies dissected while the rest were grouped into pools of 100 flies for DNA extraction. The extracted DNA was then subjected to O-150 LAMP and real-time PCR for the detection of infection by Onchocerca species using pool screening. The river system was analysed and the water discharge compared between rainy and dry seasons.
Principal Findings: We used human landing collection method (previously called human bait) to collect 22,274 adult female Simulium flies from Mbam River System. Of this number, 9,134 were dissected while 129 pools constituted for molecular screening. Overall biting and parous rates of 1113 flies/man/day and 24.7%, respectively, were observed. All diagnostic techniques detected similar rates of O. volvulus infection (P = 0.9252) and infectivity (P = 0.4825) at all monitoring time points. Onchocerca ochengi larvae were only detected in 2 of the 129 pools. Analysis of the river drainage revealed two hydroelectric dams constructed on the tributaries of the Mbam river were the key contributing factor to the high-water discharge during both rainy and dry seasons.
Conclusion: Results from fly dissection (Microscopy), real-time PCR and LAMP revealed the same trends pre- and post-MDA. The infection rate with animal Onchocerca sp was exceptionally low. The dense river system generate important breeding sites that govern the abundance of Simulium during both dry and rainy seasons.
Competing Interests: The authors have declared that no competing interests exist.
Databáze: MEDLINE
Externí odkaz:
Nepřihlášeným uživatelům se plný text nezobrazuje