Browsing by Author "Mwanyika, Gaspary O."

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Circulation of dengue serotype 1 viruses during the 2019 outbreak in Dar es Salaam, Tanzania
(Informa UK Limited, trading as Taylor & Francis Group., 2021) Mwanyika, Gaspary O.; Mboera, Leonard E. G.; Rugarabamu, Sima; Makange, Mariam; Sindato, Calvin; Lutwama, Julius J.; Paweska, Janusz T.; Misinzo, Gerald
Dengue is an important mosquito-borne viral disease in humans in tropical and subtropical countries. In 2019, a total of 6917 dengue cases were reported in Tanzania based on serological analysis. The aim of this study was to confirm the presence of dengue virus (DENV) and conduct its genetic characterization. A total of 191 serum samples were collected from the outpatients seeking care from health facilities in Kinondoni and Ilala districts between March and May 2019. All the samples were initially tested for the presence of non-structural protein 1 and anti-DENV immunoglobulin G (IgG) and IgM using a commercial OnSite Duo Dengue Ag-IgG/IgM rapid test. Of the 191 sera, 110 (57.6%) were DENV seropositive. The presence of DENV ribonucleic acid was confirmed in 18.2% of the seropositive sera by reverse transcription polymerase chain reaction (RT-PCR). The RT-PCR products were cleaned and partial sequences of DENV poly protein gene determined using dideoxynucleotide cycle sequencing followed by phylogenetic analysis. We present the occurrence of DENV serotype 1 (DENV-1) during the 2019 outbreak in Tanzania. The DENV-1 strains reported in the present study are highly identical and cluster with Asian DENV-1 strains indicating the possibility of intercontinental spread of DENV through globalization. We advocate for the need for molecular surveillance of dengue viruses during outbreaks to provide rapid evidence of the disease to guide public health interventions.
Dengue virus infection and associated risk factors in Africa: a systematic review and meta-analysis
(MDPI, 2021) Mwanyika, Gaspary O.; Mboera, Leonard E. G.; Rugarabamu, Sima; Ngingo, Baraka; Sindato, Calvin; Lutwama, Julius J.; Paweska, Janusz T.; Misinzo, Gerald
Dengue contributes a significant burden on global public health and economies. In Africa, the burden of dengue virus (DENV) infection is not well described. This review was undertaken to determine the prevalence of dengue and associated risk factors. A literature search was done on PubMed/MEDLINE, Scopus, Embase, and Google Scholar databases to identify articles published be- tween 1960 and 2020. Meta-analysis was performed using a random-effect model at a 95% confidence interval, followed by subgroup meta-analysis to determine the overall prevalence. Between 1960 and 2020, 45 outbreaks were identified, of which 17 and 16 occurred in East and West Africa, respectively. Dengue virus serotype 1 (DENV-1) and DENV-2 were the dominant serotypes contributing to 60% of the epidemics. Of 2211 cases reported between 2009 and 2020; 1954 (88.4%) were reported during outbreaks. Overall, the prevalence of dengue was 29% (95% CI: 20–39%) and 3% (95% CI: 1–5%) during the outbreak and non-outbreak periods, respectively. Old age (6/21 studies), lack of mosquito control (6/21), urban residence (4/21), climate change (3/21), and recent history of travel (3/21) were the leading risk factors. This review reports a high burden of dengue and increased risk of severe disease in Africa. Our findings provide useful information for clinical practice and health policy decisions to implement effective interventions.
Seroprevalence and associated risk factors of chikungunya, dengue, and zika in eight districts in Tanzania
(Elsevier Ltd, 2021) Mwanyika, Gaspary O.; Sindato, Calvin; Rugarabamu, Sima; Rumisha, Susan F.; Karimuribo, Esron D.; Misinzo, Gerald; Rweyemamu, Mark M.; Hamid, Muzamil M. Abdel; Haider, Najmul; Vairo, Francesco; Kock, Richard; Mboera, Leonard E.G.
Background: This study was conducted to determine the seroprevalence and risk factors of chikungunya (CHIKV), dengue (DENV), and Zika (ZIKV) viruses in Tanzania. Methods: The study covered the districts of Buhigwe, Kalambo, Kilindi, Kinondoni, Kondoa, Kyela, Mvomero, and Ukerewe in Tanzania. Blood samples were collected from individuals recruited from house- holds and healthcare facilities. An ELISA was used to screen for immunoglobulin G antibodies against CHIKV, DENV, and ZIKV. Results: A total of 1818 participants (median age 34 years) were recruited. The overall CHIKV, DENV, and ZIKV seroprevalence rates were 28.0%, 16.1%, and 6.8%, respectively. CHIKV prevalence was highest in Buhigwe (46.8%), DENV in Kinondoni (43.8%), and ZIKV in Ukerewe (10.6%) and Mvomero (10.6%). Increas- ing age and frequent mosquito bites were significantly associated with CHIKV and DENV seropositivity ( P < 0.05). Having piped water or the presence of stagnant water around the home ( P < 0.01) were as- sociated with higher odds of DENV seropositivity. Fever was significantly associated with increased odds of CHIKV seropositivity ( P < 0.001). Visiting mines had higher odds of ZIKV seropositivity ( P < 0.05). Conclusions: These findings indicate that DENV, CHIKV, and ZIKV are circulating in diverse ecological zones of Tanzania. There is a need to strengthen the control of mosquito-borne viral diseases in Tanzania.