Serologic evidence of seasonal influenza A and B viruses in HIV patients on combined antiretroviral therapy in Lagos, Nigeria

Abstract

We investigated serologic evidence of seasonal influenza A and B, and the possibility of their co-infection in HIV patients on combined antiretroviral therapy (cART) in Lagos, Nigeria. A prospective cross-sectional study was designed. A total of 174 HIV positive patients were bled by venipuncture after filling structured questionnaire at the APIN-LUTH clinic, from August to September, 2018. Clear sera were analysed for the detection and quantitative determination of immunoglobulin M specific antibodies to seasonal influenza A subtypes-H1N1 and H3N2, and influenza B by Enzyme Immunoassay (Demeditec, Germany). Results were analysed with Chi-square at 95 % confidence interval. Demographic characteristics showed median age of 44 (mean 45.1, mode 40, range: 18-74) years. Out of the 174 HIV positive patients, 39.7 % (69/174) were seropositive for influenza A and/or B viruses with 58/69 (84.1 %) being positive for influenza A, 11/69 (16 %) for influenza B, and 9/69 (13.4 %) co-infection of influenza A and B. Of the 69 influenza-seropositive patients, age group 41‒ 50 had the highest seroprevalence of 39.1 % (27/69). Females recorded the highest seropositivity of 65.2 % (45/69). Eighty eight (88) % (61/ 69) were on fixed dose cART while 74 % (51/69) were virologically suppressed with HIV RNA < 400 copies/ml. In addition, 2/69 (2.9 %) were positive for HbsAg. Out of the 19/69 (27.5 %) immunocompromised patients (CD4 < 400 cells/mm3), 4/19 (21.1 %) were severely immunosuppressed (CD4 < 200 cells/mm3). This study revealed serologic evidence of recent circulation of wild influenza A and B viruses in highly suppressed HIV RNA patients on cART. Nonetheless, co-infection with HbsAg and immunocompromised state may further predispose them to serious influenza life threatening complications. Strong advocacy on the need to reduce risk of exposure to influenza, and provision of influenza vaccine in Nigeria are recommended to prevent such complications.