Mosquito Diversity And Febrile Illness In Karagwe And Kyerwa Districts, North Western Tanzania

ABSTRACT

Mosquito-borne viruses cause emerging and re-emerging infections affecting humans and animals. These diseases present themselves mainly with fever. The present study aimed at determining socio-demographic and clinical characteristics among febrile patients, and detection of selected mosquito-borne viruses circulating in Aedes aegypti and Ae. albopictus. Using a hospital-based cross-sectional descriptive study design, in total 400 febrile patients were recruited after consenting into the present study. A structured questionnaire was administered to collect socio-demographic and clinical data. The results showed that most of the febrile patients (n=400) were aged between 20-29 years (25.25 %), followed by those aged 10-19 years (23.25 %), and only 13.15% were older than 50 years. The results show that fever (100 %) was the most common symptom reported, followed by headache (68.75 %), joint aches (67.75 %), seizures (63.50 %), vomiting (61.50 %) weakness in legs (59.50 %), laboured breathing (58.50%) and the least observed symptoms were abdominal pains (41.75 %), neck stiffness (33.75 %), and rashes (33 %). Screening 22 pools of Ae. aegypti and Ae. albopictus using reverse transcription polymerase chain reaction (RT-PCR) showed the presence of Flaviviruses, Bunyaviruses and Alphaviruses. Further screening of specific viruses in Aedes mosquitoes showed the presence of Chikungunya virus. Furthermore, the risk factors for mosquito-borne viral infections were investigated in the present study. The findings of this study show that 12.75 % of patients were in contact in forests and 79 % had been bitten by day-biting mosquitoes within three months prior to sampling. Only 28.75 % of febrile patients had malaria, indicating the widespread nature of febrile illness other than malaria. It can be concluded from the results of present study that Aedes mosquitoes are infected with Chikungunya virus and that interaction between humans and forests predisposes humans to mosquito bites.