Increased incidences of Salmonella, Plasmodium falciparum and hepatitis C viral specific circulating immune complexes in participants from malaria endemic and HIV prevalent area of Nigeria

The present study used dissociated circulating immune complexes (CIC) to identity the burden of exposure to certain infectious agents. The participants were divided into HIV seropositive group (n=100) and HIV seronegative group (n=100). Polyethylene glycol (PEG) 6000 and phosphate buffer techniques were used for precipitation and dissociation of CIC in sera. The dissociated CIC were tested for Salmonella typhi antibody, Plasmodium falciparum histidine rich protein (Pf-hrp)-2 antigen and HCV antibody using commercially available kits. Result showed that Salmonella typhi antibody was detected in 76 (76%) of the HIV seropositive participants; Plasmodium falciparum histidine rich protein-2 (Pf-hrp-2) antigen was detected in 48 (48%) of HIV seropositive participants while Hepatitis C viral antibodies was detected in 20 (20%) of the HIV seropositive participants. Similarly, Salmonella typhi antibody was detected in 24(24%) of the HIV seronegative participants, Pf-hrp-2 antigen was detected in 47(47%) of the participants while Hepatitis C viral antibody was detected in 5(5%) of the HIV seronegative participants. There were significant differences between the number of HIV seropositive and seronegative participants with positive Salmonella typhi (P<0.05) and HCV antibody (P<0.05). The rates of homogeniuty and heterogeniuty of CIC in HIV seropositive participants was; 26 (34%) and 50 (66%) for Salmonella typhi antibody, 3 (6%) and 45 (94%) for Pf-hrp-2 antigen and 0 (0%) and 20 (100%) for HCV antibody, respectively. While the rates of homogeniuty and heterogeniuty of CIC in HIV seronegative participants was 1 (4.2%) and 23 (95.8%) for Salmonella typhi antibody; 25 (53%) and 22 (47%) for Pf-hrp-2 antigen and 3 (60%) and 2 (40%) for HCV antibody respectively in all cases. The finding of the present study suggest that HIV infection may enhance susceptibilty to both salmonella typhi and HCV infection but not Plasmodium falciparum. The study thus revealed that Salmonella and HCV infections may constitute the major secondary infection in HIV infected patients and could be a cause for concern as HIV progressed to AIDS.