Browsing by Author "Kasanga, C. J."
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Item Distribution and diversity of mosquitoes and the role of Aedes in the transmission of arboviruses in selected districts of Tanzania(2017-12-25) Patrick, N. P.; Kinimi, E.; Shayo, M/ J.; Ang eenyi, S. O.; Weyer, P.; van Vuren, P. J.; Paweska, J. T.; Mboera, L. E. G.; Rweyemamu, M. M.; Misinzo, G.; Kasanga, C. J.Arboviruses belong to various families of viruses that are transmitted by arthropods, mainly mosquitoes and often cause diseases in humans. The objective of this study was to determine mosquito diversity and transmission of arboviruses by Aedes in selected ecosystems in Tanzania. Adult mosquitoes were collected from rural and urban settings using carbon dioxide-baited CDC light traps, Biogent sentinel traps, and the Mosquito Magnet traps. Reverse Transcription-Polymerase Chain Reaction assay was performed on pooled adult Aedes mosquitoes to detect the presence of Chikungunya, Dengue, Rift Valley fever (RVF) and Yellow fever (YF) viruses. A total of 42, 77 mosquitoes belonging to five genera (Aedes, Anopheles, Culex, Mansonia and Mimomyia) and 18 species were collected. Culex accounted for the largest (62.7%; n= 2,682) proportion of the mosquitoes while Anopheles for the lowest proportion (5.7%; n=245). Of the total mosquitoes collected, Culex quinquefasciatus accounted for more than a half (53.4%; n=2692), followed by Aedes aegypti 12.1% (n=520). Of the 34 adult Ae. aegypti pools tested, arboviruses were detected in 33(97%) pools. Dengue virus was detected in 47.6% (10/ 21) pools which tested positive for Flaviruses. Chikungunya virus was detected in 30% (3/ 10) pools which were positive for Alphavirus genera. Of 2 pools tested positive for Bunyavirus genus, Rift Valley fever virus was detected in 1 pool (50%). The presence of various mosquito vectors and detection of arboviruses in aedes mosquitoes leave the population of Tanzania at great risk of transmission of different pathogens and highlight a need for vector control measures in the country.Item Evidence of anti-chikungunya virus igg and igm antibodies among patients seeking treatment in different health facilities in Kyela District, Tanzania(2018) Patrick, B. N.; Angwenyi, S.; Kinimi, E.; Shayo, M.; Hugo, M.; Kasanga, C. J.Chikungunya is an arboviral disease transmitted by aedes mosquitoes, caused by Chikungungunya virus. It consists of an acute illness characterized by fever, rash, and incapacitating arthralgia. This study aimed to estimate the prevalence of Chikungunya fever in patients presenting fever at different health facilities located in Kyela district. Out of 132 recruited patients, 94(71.2 %) were female and 38 (28.8 %) were male. The majority of them 80 (60.6%) were adults (≥25 years). Anti-Chikungunya virus anti-immunoglobulin G (IgG) and anti-immunoglobulin M (IgM) antibodies were detected in serum samples using indirect enzyme-linked immunosorbent assay. Chikungunya virus IgG or IgM antibodies were detected in 19 among 132 serum specimens tested indicating a seroprevalence of 14.3%. Out of 132 sera tested, 14 (11%) had IgG antibodies and 5(3.8%) had IgM antibodies. The higher anti-CHIKV IgG seroprevalence was found in female patients (OR= 3.22; 95% CI: 1.03-10.06) than in male. Similarly patients who took some medication before going to the health centre were found with high CHIKV IgG antibodies (OR= 13.912; 95% CI: 1.76-109.78) as well as in patients who never been vaccinated (OR=4.6; 95%CI: 0.02 – 1.71). Additionally, the uni-variate analysis results revealed, feeling nausea as the symptom of significant association with Chikungunya IgG seropositivity (OR = 4.5; 95% CI: 1.3– 14.4). These findings confirm that CHIKV infection seems to be among the common causes of febrile illness in Kyela district and appears to be actively circulating in the population but is routinely misdiagnosed. This suggests a need to raise awareness among health facilities and policy makers on the use of specific diagnosis for better control of arbovirus diseases in the study region.Item Evidence of chikungunya virus infection among febrile patients seeking healthcare in selected districts of Tanzania(Taylor & Francis, 2018) Kinimi, E.; Shayo, M. J.; Patrick, B. N.; Angwenyi, S. O.; Kasanga, C. J.; Weyer, J.; Vuren, P. J.; Paweska, J. T.; Mboera, L. E.G.; Misinzo, G.Introduction: Chikungunya virus (CHIKV) infection is an emerging mosquito-borne disease that has been associated with frequent epidemics in the world. However, there is a dearth of information on its magnitude and associated risk factors in Tanzania. Objective: A study was conducted to determine seroprevalence of CHIKV among febrile patients seeking medical care at health facilities in Karagwe, Sengerema, Kilombero and Kyela districts. Methods: Structured questionnaires were administered and 728 serum samples were col- lected between May and June, 2015 and tested for the presence of CHIKV-IgM and IgG- specific antibodies using Enzyme-linked immunosorbent assay. Results and discussion: The common clinical characteristics exhibited by outpatients were fever, headache and joint pains (100%, 70%, and 68.3% respectively). Out of 728 outpatients screened for CHIKV, 105 (14%) tested CHIKV IgG positive whilst 11 (1.5%) tested CHIKV IgM positive. Chikungunya seropositivity was significantly higher than previously reported in Tanzania. The most affected age group was 20–29 years. Our results indicate that CHIKV infection is prevalent and contributes to the burden of febrile illnesses in Tanzania. The seroprevalence varies between districts, reflecting variation in mosquito vector transmission dynamics in different parts of the country. Received 23 September 2018 Accepted 19 November 2018 KEYWORDS Chikungunya; seroprevalence; febrile illness; mosquito-borne; Tanzania Abbreviations: CHIKV: Chikungunya virus; EDTA: Ethylenediaminetetraacetic acid; ELISA: Enzyme-linked immunosorbent assay; IgG: Immunoglobulin G; IgM: Immunoglobulin M; NIMR: National Institute for Medical Research; RU: Relative Units; SACIDS: Southern African Centre for Infectious Disease Surveillance; USA: United States of AmericaItem Molecular characterization of infectious bursal disease virus detected in Morogoro, Tanzania(TANZANIA VETERINARY ASSOCIATION, 2017) Msomi, A.; Kandusi, S.; Ndusilo, N.; Mathis, M.; Kasanga, C. J.; Chengula, A. A.Infectious bursal disease (IBD) virus (IBDV) is a double-stranded RNA virus that belongs to the genus Avibirnavirus of the family Birnaviridae. IBDV is a causative agent of IBD, the highly contagious viral infection of young chickens aged 3 to 6 weeks. IBD outbreaks occur frequently in both vaccinated and non-vaccinated chickens in Tanzania causing significant economic loss among poultry keepers. The control of IBD is mainly done through vaccination, which requires the understanding of molecular and biological characteristics of circulating virus strains in particular geographic location. This study was conducted to determine the genotype of IBDV recovered from confirmed IBD outbreak(s) in 2014 in Morogoro, Tanzania. The investigation was performed by reverse-transcription polymerase chain reaction (RT-PCR), sequencing and phylogeny analysis of nucleotide sequences corresponding to the VP2 hypervariable (VP2-HVR) domain of IBDV. The findings indicated 100% detection rate (n = 10) of IBDV genome from infected bursa of Fabricius samples. Phylogenetic analysis revealed that the sequenced virus belonged to the African very virulent IBDV (VV- IBDV) genotype and was genetically closely related to KZC-109 strain detected in Zambia in 2004. Taken together, our findings suggest that the African VV-IBDV detected in this study was responsible for the IBD outbreak(s) in Morogoro. Further studies are required to examine the transmission dynamics, evolutionary characteristics and antigenicity of field IBDV strains order to design the appropriate control method(s) of IBD in Tanzania and neighboring countries.Item Molecular detection of arboviruses in Aedes mosquitoes collected from Kyela district, Tanzania(2016-01) Bisimwa, N. P.; Angwenye, S.; Kinimi, E; Shayo, M.; Bwihangane, B. A.; Kasanga, C. J.Arboviruses belong to a group of viruses that are transmitted by arthropods, mainly mosquitoes and ticks causing clinical disease symptoms in humans and animals ranging from febrile illnesses to hemorrhagic fevers. The present study aimed at examining the circulation of Chikungunya, Dengue, Yellow fever and Rift valley fever viral genomes in Aedes mosquitoes from Kyela district in Tanzania. A systematic vector surveillance spanning two months and covering 5 sites in Kyela district was carried out in order to evaluate the potential role of Aedes spp in arbovirus transmission in the study area. Mosquitoes were collected, identified to species level by using morphological keys, pooled in respect species and collection sites and screened for arboviruses by RT-PCR. Adult mosquitoes were collected from April to May, 2015 using CO 2 -baited CDC light traps, magnet traps as well as human landing collection (HLC). The study sites included Kyela town, Kajunjumele, Ipida, Matema and Njisi villages. A total of 480 bloodfeed Aedes ssp were collected, identified and grouped in to 24 pools (1-20 mosquitoes per pool) according to species level and location. Out of the 480 Aedes spp collected, Aedes aegypti represented the most abundant species totaling 338 (70.4%), followed by Aedes africanus 102 (21.2%) and Aedes natalensis being the minority 40 (8.3%). Arboviruses were detected in 9 pools (37.5%) including Alphaviruses (8 pools) and Flaviviruses (1 pool). No sample was positive for Bunyaviruses. Chikungunya virus (CHIKV) was detected in 6 (75%) alphavirus positive pools that were collected mostly in the areas where rice cultivation was common. The findings of this study suggest that people from this region are highly likely to be exposed to arbovirus infections which may represent significant public health concerns.Item Molecular detection of tilapia lake virus (TiLV) genome in Nile tilapia (Oreochromis niloticus) from Lake Victoria(TANZANIA VETERINARY ASSOCIATION, 2017) Chengula, A. A.; Mugimba, K. K.; Wamala, S.; Mwega, E. D.; Kasanga, C. J.; Byarugaba, D. K.; Mdegela, R. H.; Dishon, A.; Mutoloki, S.; David, L.; Evensen, Q; Munang’andu, H. M.ilapia lake virus (TiLV) is an emerging pathogen of Tilapiines associated with high mortalities of wild and farmed tilapia posing great threat to the fishery industry worldwide. The virus has been reported in Israel, Ecuador, Colombia, Thailand, Egypt, Taiwan, India and Malaysia. In this study, a reverse transcription polymerase chain reaction (RT-PCR) assay was developed and used to detect TiLV genome in Nile tilapia from Lake Victoria. Nile tilapia samples were collected from the Tanzanian (108 fish) and Ugandan (83 fish) parts of Lake Victoria in 2015 and 2016, respectively. Samples were screened for TiLV by using RT-PCR and the PCR products were sequenced. The findings show that out of the 191 fish examined, 28 had PCR products showing the presence of TiLV genome. The TiLV nucleic acids were detected in the spleen (10.99%, N=191), head kidney (7.69%, N=65), heart (3.45%, N=29) and liver (0.71%, N=140) samples while no PCR amplification was detected in the brain by the developed RT-PCR method. Generally, the findings show that the lymphoid organs, mainly comprising of the head kidney and spleen had the highest number of samples with positive nucleic acids for TiLV followed by heart samples. On the contrary, the liver and brain that have previously been shown to be target organs during acute infection either did not have or had the lowest level of TiLV nucleic acids detected in the present study. All the 28 sequences retrieved had an average length of 768 bp. A blast analysis on NCBI showed that all sequences obtained were homologous to TiLV segment-2 sequences obtained from previous outbreaks in Israel and Thailand. To our knowledge, this is the first detection of TiLV subclinical infections in Nile tilapia in Lake Victoria, a none-outbreak area.Item Partial genetic characterization of peste des petits ruminants virus from goats in northern and eastern Tanzania(Transboundary and Emerging Diseases, 2014) Kgotlele, T.; Macha, E. S.; Kasanga, C. J.; Kusiluka, L. J. M.; Karimuribo, E. D.; Doorsselaere, J. V.; Wensman, J. J.; Munir, M.; Misinzo, G.Peste des petits ruminants (PPR) is an acute viral disease of small ruminants. The disease was first reported in Tanzania in 2008 when it was confined to the Northern Zone districts bordering Kenya. The present study was carried out to confirm the presence of PPR virus (PPRV) in Tanzania and to establish their phylogenetic relationships. Samples (oculonasal swabs, tissues and whole blood) were obtained from live goats with clinical presentation suggestive of PPR and goats that died naturally in Ngorongoro (Northern Tanzania) and Mvomero (Eastern Tanzania) districts. The clinical signs observed in goats suspected with PPR included fever, dullness, diarrhea, lacrimation, matting of eye lids, purulent oculonasal discharges, cutaneous nodules, erosions on the soft palate and gums and labored breathing. Post mortem findings included pneumonia, congestion of the intestines, and hemorrhages in lymph nodes associated with the respiratory and gastrointestinal systems. PPRV was detected in 21 out of 71 tested animals using primers targeting the nucleoprotein (N) gene. Phylogenetic analysis, based on the N gene, indicated that PPRV obtained from Northern and Eastern Tanzania clustered with PPRV strains of Lineage III, together with PPRV from Sudan and Ethiopia. The findings of this study indicate that there are active PPRV infections in Northern and Eastern Tanzania, suggesting risks for potential spread of PPR in the rest of Tanzania.Item Preliminary investigation on presence of peste des petits ruminants in Dakawa, Mvomero district, Morogoro region, Tanzania(2014) Kgotlele, T.; Kasanga, C. J.; Kusiluka, L. J. M.; Misinzo, G.Peste des petits ruminants (PPR) is an acute viral disease of small ruminants characterised by the sudden onset of depression, fever, oculonasal discharges, sores in the mouth, foulsmelling diarrhoea and death. For many years, in Africa, the disease was mainly confined to West and Central Africa but it has now spread southwards to previously PPR-free countries including Tanzania, Democratic Republic of Congo and Angola. The disease was first reported in Tanzania in 2008 when it was confined to the Northern Zone districts bordering Kenya. Presence of the disease has also been confirmed in southern Tanzania especially Mtwara region. Recently, a suspected outbreak of PPR in Dakawa area, Mvomero district, Morogoro region was reported. Clinical samples (lungs, intestines, lymph nodes, whole blood and sera) from suspected goats (n = 8) and sheep (n = 1) were submitted to Sokoine University of Agriculture for analysis. Molecular diagnosis by amplification of the nucleoprotein gene and the fusion gene of PPR virus (PPRV) using PPRV specific primers was done. Five goats and the sheep were positive for PPRV after performing RT-PCR. To our knowledge, this is the first report confirming the presence of PPR in the Mvomero district of the Morogoro region, Tanzania. Hence, more efforts should be put in place to prevent the spread of PPR in Tanzania.