Browsing by Author "Kumalija, Medard"

Now showing 1 - 2 of 2

Detection of Rift Valley Fever Virus Interepidemic Activity in Lower Moshi area of Kilimanjaro Region, North Eastern Tanzania: A Community Survey
(Research Square, 2021-01-22) Chilongola, Jaffu; Kumalija, Medard; Budodo, Rule; Horumpende, Pius; Mkumbaye, Sixbert; Vianney, John-Mary; Mwakapuja, Richard; Mmmbaga, Blandina
Background: Rift Valley fever virus (RVFV) is a zoonotic arbovirus of public health impact infecting livestock, wildlife, and humans mainly in Africa and other parts of the world. Despite its public health importance, mechanisms of RVFV maintenance during inter-epidemic (IEPS) periods and potentially spread to new areas remain unclear.We aimed to comparatively examine exposure to RVFV and RVFV infection among humans, goats and mosquitoes in an agro-pastoral community in Lower Moshi area of Moshi rural district. Results:Results show that the male gender was related to RVFV seropositivity (χ2 = 5.351; p=0.030). Being 50 years and above was related to seropositivity (χ2=14.430; p=0.006) whereas bed net use, larger numbers of persons living in the same house (>7 persons) and RVFV seropositivity in goats were related to higher seropositivity to RVFV among humans (χ2=6.003; p=0.021, χ2=23.213; p=0.000 and 27.053; p=0.000), respectively.RVFV antibody concentrations were only marginally higher in humans without statistically significant difference [t (112) =0.526; p=0.60)]. By the use of RT-qPCR, goats exhibited the highest RVFV infection rate of 4.1%, followed by humans (2.6%), Aedes spp(2.3%), and Culex spp(1.5%). Conclusions: In the absence of RVFV infection data in areas nearby the study site, our findings suggest Lower Moshi area as a potential hotspot for RVF, posing the danger of being a source of RVFV spread to other areas. Goats had the highest infection rate, suggesting goats as important hosts in the virus maintenance during IEPs. We recommend the design and implementation of strategies that will warrant effective active surveillance of RVF through the identification of RVF hotspots for targeted control of RVF.
Detection of Rift Valley Fever Virus Interepidemic Activity in Lower Moshi Area of Kilimanjaro Region, Northeastern Tanzania: A Community Survey
(NM-AIST, 2025-08) Kumalija, Medard
Rift Valley fever virus (RVFV) is a zoonotic viral disease of public health importance that affects livestock, wildlife and humans, mainly in sub-Saharan Africa. Despite its public health importance, the ways in which RVFVs circulate during the inter-epidemics (IEPs) stages and potentially spread to new areas remain unclear. The IEPs are the period during which transmissions pass without being detected, whereas surveillance is not performed. This study aimed to compare the rates of exposure to RVFV and RVFV infection among humans, goats and mosquito vectors in an agricultural and pastoral community in the lower Moshi area of the Moshi rural district. The area is located along the Great Rift Valley and is characterized by animal maintenance and heavy seasonal rains, making it swampy and favoring mosquito reproduction throughout. Although the spread of RVFV by mosquito vectors to animals and humans during interepidemic periods has been established, less is known about the roles that animals, humans, and vector mosquitoes play in maintaining the virus during IEPs. The reservoirs in the IEPs have become an area of interest for research. Therefore, a cross-sectional study survey was conducted in Lower Moshi in the Kilimanjaro region from June to December 2020. The RVFV exposure was determined via the detection of IgG/IgM to RVFV via a competitive enzyme-linked immunosorbent assay (cELISA), whereas infection was determined via real-time quantitative polymerase chain reaction (RT‒qPCR). In humans, male sex was more related to RVFV seropositivity than female sex was (χ² = 5.351; p=0.030). People aged 50 years and above were seropositive (χ² =14.430; p=0.006). The RVFV seropositivity in goats was related to increased seropositivity in humans (χ² =6.003; p=0.021, χ² =23.213; p=0.000 and 27.053; p=0.000). The RVFV antibody concentrations were only marginally higher in humans than in goats [t (112) =0.526; p=0.60)]. The RT‒qPCR revealed that goats presented the highest RVFV infection rate (4.1%), followed by humans (2.6%), Aedes aegypti (2.3%), and the Culex pipiens complex (1.5%). Similarly, a greater proportion of goats (23.3%) were RVFV seropositive than were humans (13.2%). These findings suggest that northeastern Tanzania may serve as a persistent hotspot for RVF transmission and call for the implementation of integrated, health-based active surveillance strategies targeting livestock, humans and vectors. Enhanced diagnostics, targeted vaccination and climate-informed risk mapping are recommended to enable timely interventions and reduce the likelihood of future RVF outbreaks.