With the history of HIV/AIDS in Nigeria spanning well over two decades, it is not surprising that the number of people living with HIV (PLHIV) has substantially increased over these years. Nigeria currently has one of the highest HIV burden worldwide, with 3.1 million PLHIV and about 215, 000 annual AIDS deaths [1,2]. In response to the raging epidemic of HIV/AIDS, the government of Nigeria in partnership with international collaborators established the national antiretroviral therapy (ART) program in 2002 which led to increased access to HIV care and treatment [3]. The total number of PLHIV on ART steadily increased from 50,581 at the early stages of ART in Nigeria in 2005 to 302,973 in 2009 [2]. So far, the efforts are still sub-optimal as only one-third of individuals requiring treatment in Nigeria have access to ART [2].
The hallmark of HIV infection is immunosuppression which predisposes to opportunistic infections (OIs) and malignancies. Opportunistic infections constitute a major cause of morbidity and mortality in PLHIV [4,5]. This is even more critical in sub-Saharan Africa (SSA) where the standard of living is generally poor and access to ART is still inadequate. A striking feature of the reported clinical spectra of OIs in HIV/AIDS has been the contrasting findings from divergent socio-economic settings. In developed regions such as North America, Europe, and Australia, Pneumocystis carinii pneumonia (PCP), Kaposi’s sarcoma (KS), oesophageal candidiasis, cytomegalovirus (CMV)-related disease and disseminated Mycobacterium avium complex (MAC) infection were the prevalent OIs in PLHIV in the pre-ART era [6,7]. In developing regions such as SSA and South East Asia, where an estimated 90% of PLHIV reside, the predominant HIV-associated OIs in the pre-ART era were tuberculosis (TB), candidiasis, infective diarrhea, meningitis, dermatitis and recurrent Herpes simplex infection [8,9].
Since the introduction of Highly Active Anti-retroviral Therapy (HAART), a significant decline in OIs and AIDS progression has been observed [10-12]. However, significant differences still exist in the burden of OIs between high income and resource-limited settings. Most of the evidence for decline in OIs has come from high-income settings with relatively less burden of OIs in the pre-HAART era, early and widespread access to ART and sophisticated diagnostic tools. There is insufficient knowledge about the burden and risk factors for OIs in HIV-infected populations receiving HAART in SSA. Unfortunately, the findings of studies in high-income settings may not be generalizable to resource-limited settings.
An evidence-based assessment of the prevalent OIs in PLHIV in the era of HAART is necessary in order to define local priorities in HIV care and inform targeted expenditure on prophylaxis and treatment of HIV-related co-morbidities. Since the current spectrum of OIs and their associated risk factors in HAART-experienced populations in Nigeria remain largely undetermined, it will be difficult to fully assess the impact of the ART program in the country. This study determined the prevalence of OIs in HIV-infected Nigerian adults on HAART and also investigated the socio-demographic and clinical risk factors associated with their occurrence.