Browsing by Author "Ngeleja, C."

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Elucidating the phylodynamics of endemic rabies virus in eastern Africa using whole-genome sequencing
(Virus Evolution, 2015) Brunker, K.; Marston, D. A.; Horton, D. L.; Cleaveland, S.; Fooks, A. R.; Kazwala, R. R.; Ngeleja, C.; Lembo, T.; Sambo, M; Mtema, Z. J.; Sikana, L.; Wilkie, G.; Biek, R.; Hampson, K.
Many of the pathogens perceived to pose the greatest risk to humans are viral zoonoses, responsible for a range of emerging and endemic infectious diseases. Phylogeography is a useful tool to understand the processes that give rise to spatial patterns and drive dynamics in virus populations. Increasingly, whole-genome information is being used to uncover these patterns, but the limits of phylogenetic resolution that can be achieved with this are unclear. Here, whole-genome variation was used to uncover fine-scale population structure in endemic canine rabies virus circulating in Tanzania. This is the first whole-genome population study of rabies virus and the first comprehensive phylogenetic analysis of rabies virus in East Africa, providing important insights into rabies transmission in an endemic system. In addition, sub-continental scale patterns of population structure were identified using partial gene data and used to determine population structure at larger spatial scales in Africa. While rabies virus has a defined spatial structure at large scales, increasingly frequent levels of admixture were observed at regional and local levels. Discrete phylogeographic analysis revealed long-distance dispersal within Tanzania, which could be attributed to human-mediated movement, and we found evidence of multiple persistent, co-circulating lineages at a very local scale in a single district, despite on-going mass dog vaccination campaigns. This may reflect the wider endemic circulation of these lineages over several decades alongside increased admixture due to humanmediated introductions. These data indicate that successful rabies control in Tanzania could be established at a national level, since most dispersal appears to be restricted within the confines of country borders but some coordination with neighbouring countries may be required to limit transboundary movements. Evidence of complex patterns of rabies circulation within Tanzania necessitates the use of whole-genome sequencing to delineate finer scale population structure that can that can guide interventions, such as the spatial scale and design of dog vaccination campaigns and dog movement controls to achieve and maintain freedom from disease.
Retrospective Study on Laboratory results of African Swine fever Virus in Tanzania
(TANZANIA VETERINARY ASSOCIATION, 2017) Chang’a, J. S.; Jeremiah, M.; Kalabi, D.; Francis, G.; Mwanandota, J.; Mathias, M.; Magidanga, B.; Chang’a, A.; Ngeleja, C.
A 10-years records on diseases was retrieved so as to investigate the occurrences of African Swine Fever (ASF) disease in Tanzania over a period of year 2007/2008 to 2016/2017. A total of 640 samples were tested for ASF virus at the Centre for Infectious Diseases and Biotechnology (CIDB), Dar es Salaam. The samples included whole blood, swabs and internal organs from domestic pigs in different areas of Tanzania. Annual, monthly and origin distribution of suspect cases was analyzed. ASF occurrences was confirmed in each year from 465 (72.6%) samples. High numbers of positive cases were in recorded in February 94 (20.2%), March 198 (42.5%), April 35 (7.5%), May 36 (7.7) and June 56 (12.0%). Regional distribution of positive samples were 45.8% from Iringa, 16.9% from Dar es Salaam, 12.3% from Mbeya, 10.3% from Coast,9.4% from Morogoro and the remaining 0.51% were from Kilimanjaro, Rukwa, Arusha and Tanga, Kagera regions. Largest number of samples were tested in 2012/2013 (255 (39.8%) and 2011/2012 (96 (15%). The study reveals endemicity of ASF disease in Tanzania and its trend in occurrence. Further studies need to be undertaken to establish factors for the endemicity of the disease so as to mitigate its occurrence and spread for the control of the disease.
Toward Elimination of Dog-Mediated Human Rabies: Experiences from Implementing a Large-scale Demonstration Project in Southern Tanzania
(Original research article., 2017) Mpolya, E. A; Lembo, T.; Lushasi, K.; Mancy, R.; Mbunda, E. M.; Makungu, S.; Maziku, M.; Sikana, L.; Jaswant, G.; Townsend, S.; Meslin, F. X.; Abela, B.; Ngeleja, C.; Changalucha, J.; Mtema, Z.; Sambo, M.; Mchau, G.; Rysava, K.; Nanai, A.; Kazwala, R.; Cleaveland, S.; Hampson, K.
A Rabies Elimination Demonstration Project was implemented in Tanzania from 2010 through to 2015, bringing together government ministries from the health and veterinary sectors, the World Health Organization, and national and international research institutions. Detailed data on mass dog vaccination campaigns, bite exposures, use of post-exposure prophylaxis (PEP), and human rabies deaths were collected throughout the project duration and project areas. Despite no previous experience in dog vaccination within the project areas, district veterinary officers were able to implement district-wide vaccination campaigns that, for most part, progressively increased the numbers of dogs vaccinated with each phase of the project. Bite exposures declined, particularly in the southernmost districts with the smallest dog populations, and health workers successfully transitioned from primarily intramuscular administration of PEP to intradermal administration, resulting in major cost savings. However, even with improved PEP provision, vaccine shortages still occurred in some districts. In laboratory diagnosis, there were several logistical challenges in sample handling and submission but compared to the situation before the project started, there was a moderate increase in the number of laboratory samples submitted and tested for rabies in the project areas with a decrease in the proportion of rabies-positive samples over time. The project had a major impact on public health policy and practice with the formation of a One Health Coordination Unit at the Prime Minister’s Office and development of the Tanzania National Rabies Control Strategy, which lays a roadmap for elimination of rabies in Tanzania by 2030 by following the Stepwise Approach towards Rabies Elimination (SARE). Overall, the project generated many important lessons relevant to rabies prevention and control in particular and disease surveillance in general. Lessons include the need for (1) a specific unit in the government for managing disease surveillance; (2) application of innovative data collection and management approaches such as the use of mobile phones; (3) close cooperation and effective communication among all key sectors and stakeholders; and (4) flexible and adaptive programs that can incorporate new information to improve their delivery, and overcome challenges of logistics and procurement.