Detection of Chikungunya and West Nile viruses in febrile patients in Ile-Ife Osun State, Nigeria using real time reverse transcription-polymerase chain reaction (RT-PCR)

Abstract

Most patients presenting with febrile conditions are often treated for malaria, especially in the developing world, whereas some of them may be of arboviral origin as they also present with similar symptoms. Reverse transcription-polymerase chain reaction (RT-PCR) has been found to be the method of choice for the early detection and confirmation of virus in clinical samples, especially where there is an overlap of symptoms. The objective of this study was to detect the involvement of some arboviruses in febrile conditions in humans visiting two health institutions in Ile-Ife, Nigeria. Consenting febrile patients numbering one hundred and sixty five that were to be screened for malaria parasites at the hospitals were recruited for the study. From each patient, 2 ml venous blood was collected and processed for RNA extraction using QiAmp RNA Extraction kit (Qiagen, Hilden, Germany) and amplified using one step RT-PCR and appropriate primers for West Nile, Chikungunya, Dengue and Rift valley fever viruses. The detection was done in 2% agarose gel electrophoresis and viewed using a gel imager. The study reports the detection of West Nile RNA in 6 (3.6%) patients and Chikungunya RNA in 3 (1.8%) out of the 165 serum samples which have been pre-screened for malaria parasite by the hospital where the samples were collected from. Rift valley fever virus RNA and Dengue virus RNA were not detected in any of the samples. Out of the malaria parasite negative patients, 3 tested positive for the West Nile RNA and 1 showed detectable Chikungunya virus RNA, thus suggesting the role of these arboviruses in febrile conditions, first to be reported in Osun state, Nigeria. The involvement of viruses in febrile conditions as shown by this study has buttressed the need to extend laboratory examination of febrile conditions beyond malaria parasite to some of these arboviruses whose vectors are abundant and extending geographical coverage.