MSc Thesis
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.
Southern African Centre for Infectious diseases (SACIDS)