Transfusion associated Hepatitis B virus (TAHBV) continues to be a major problem despite mandatory screening for Hepatitis B surface Antigen (HBsAg). Presence of HBsAg is the common method for detecting hepatitis B infection. Unfortunately, this marker is not detected during the window period of the infection. Nigeria being a developing country cannot afford DNA testing of all collected units of blood which serve as the only possibility of achieving zero risk of transfusion associated HBV. Five different serological makers of hepatitis B virus (HBV) infection were therefore assessed to evaluate the reliability of using HBsAg marker alone in diagnosis of HBV infection among blood donors and to detect the serological evidence of the infection at the window period. This will preclude the possibility of transmitting hepatitis B through transfusion of Hepatitis B surface antigen (HBsAg) negative blood in Nigeria.

As the global effort to eradicate hepatitis B continues, immune escape mutations (IEMs) and drug resistance mutations (DRMs) affecting its diagnosis, treatment, and prevention are compromising this goal. However, knowledge about the prevalence and circulation of these mutations in Nigeria is scarce. Serum samples (n = 199) from apparently healthy prospective blood donors, pregnant women, and individuals presenting with fever in southwestern Nigeria were analyzed for the presence of IEMs and DRMs by means of nested PCR in the HBV S (HBs) and HBV polymerase (Pol) genes, followed by phylogenetic and mutational analyses. In total, 25.1% (n = 50/199) of samples were positive for HBV, as measured by PCR. In 41 samples (20.6%), both fragments could be amplified, whereas the HBs gene and the Pol gene fragment alone were detected in 0.5% (n = 1/199) and 4% (n = 8/199) of samples, respectively. Sequences were successfully obtained for all 42 HBs gene fragments but for only 31/49 Pol gene fragments (totaling 73 sequences from 44 individuals). All sequences were identified as HBV genotype E. IEMs were present in 18.2% (n = 8/44) of the sequences of HBV-positive individuals with available sequences. IEM Q129H was detected in eight out of the 44 (18.2%) HBV isolates sequenced in this study; however, no DRMs were observed. This study confirms the circulation of HBV IEMs and reports the presence of Q129H IEM for the first time in Nigeria. Intensified research on the dynamics of IEM is necessary in order to enhance the elimination of HBV.

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. Key words: Febrile, malaria, Chikungunya virus, West Nile virus, Dengue virus, reverse transcription-polymerase chain reaction (RT-PCR).

INCIDENCE OF DENGUE VIRUS INFECTIONS IN FEBRILE EPISODES IN ILE-IFE, NIGERIA