This study examined occurrence of drug-resistance mutations in apparently healthy blood donors who tested positive for HIV-1.The proportion of males to females in this study does not concord with HIV-1 trends. The same could be said for the distribution of HIV infection across the age groups. Although, the number of females infected with HIV nationwide is more than males , voluntary blood donors are usually males. Females are usually disqualified due to relatively lower hemoglobin (Hb) levels that arise partly because of monthly blood loss during menstruation and the toll of pregnancy. Also, it is physically active men usually between the ages of 25–50 years who volunteer to donate blood. Thus, these reasons could have accounted for the pattern seen in this study.
The predominance of CRF02_AG and absence of HIV-2 and dual HIV-1/2 infections agrees with studies reporting HIV-1 infection as the predominant HIV type in Ghana and CRF02_AG as the main subtype [19, 20]. The twenty (21) samples that were later confirmed to be HIV negative indicate the need for diagnostic methods with higher sensitivity at blood banks to minimize the probability of transfusing infected blood .
HIV-1 TDR occurs when recently infected individuals who are not exposed to antiretroviral drugs harbor drug resistant viruses. In this study, HIV-1 TDR is defined as the presence of at least one major HIV-1 DRM in a study participant. Two (2) major DRMs were found in two (2) samples sequenced in the RT gene (E138A and K65R) and none in the PR gene. Other mutations were also found, which do not confer drug resistance by themselves but only when they occur in combination with other mutations. The accessory and minor mutations found were F77L and L10F in RT gene and PR gene respectively.
The E138A mutation is a polymorphic mutation that occurs in an appreciable number of drug-naïve patients such as the population studied and confers resistance to etravirine (ETR) and rilpivirine (RPV), which are NNRTIs [21, 22]. In a similar study, E138A was found in ART-naïve pregnant women attending antenatal care in a teaching hospital in Accra, Ghana . This mutation, has been shown to reduce susceptibility to ETR and RPV by 2-folds. The K65R mutation is found to reduce viral susceptibility to most NRTIs by approximately 2-fold and rather increase susceptibility to AZT and hence reduced viral replication with zidovudine-containing therapy .
The findings of this study are consistent with other studies previously conducted among drug naïve infected individuals, in which PI-associated DRM were rarely found [23, 25]. Generally, low level DRMs against PIs in the Ghanaian population could be attributed to the high genetic barrier of protease inhibitors and that the virus would have to mutate several times to develop resistance to such drugs. Additionally, sparing use of protease inhibitors reserved for use mostly in second-line regimen while majority of those on treatment are on reverse transcriptase inhibitors may have accounted for this phenomenon.
Viral sequence subtyping showed CRF02_AG as most predominant subtype in the study population. Other subtypes found were B, A and CRF09_cpx. This result is similar to some studies conducted in West Africa [26, 27] and in Ghana [19, 25]. The predominance of CRF02_AG has been associated with high viral infectivity and productivity, possible replicative fitness and high viral loads which favour viral transmission [19, 20]. Subtype B was the next predominant subtype and was relatively frequent compared to previous studies in Ghana . Subtype B is most predominant in the Americas [28, 29] and Western Europe [30, 31].
The occurrence of HIV-1 subtypes in different geographical areas has been linked to socio-epidemiologic factors such as mobility and migration [32, 33]. These factors, however, cannot be confirmed for this population due to lack of data on residence and citizenship of the participants studied. However, phylogenetic analysis revealed evolutionary relationship of studied sequences with reference sequences from Nigeria, Cameroon, Kingdom of Saudi Arabia, Democratic Republic of Congo, United States of America, Peru, Uruguay and Britain.
The study observed low amplification rate of samples. This could be due to low viral loads in some samples. However, it is not entirely the reason for low amplification rate as samples with low viral loads were successfully amplified whilst others with higher loads were not amplified. Previous research shows that samples from patients with persistently low viral load could be genotyped by a nested PCR method [18, 24].
The inability to obtain peripheral blood mononuclear cells (PBMC) to amplify alongside the plasma could also account for a lower amplification rate. Amplification success with proviral DNA from PBMC was found to be relatively higher than viral RNA from plasma [22, 26]. Genotyping from plasma RNA and proviral DNA concurrently could have increased amplification success since some plasma samples may be amplified and not their PBMC samples and vice versa.
Despite these limitations, the study obtained data that is important for HIV management in Ghana.