Abstract

Awobode HO*, Efenovwe MO, Anumudu CI

Background: Malaria and toxoplasmosis utilize similar known cellular and biochemical pathways to modulate immune responses. Co-infections with malaria and toxoplasmosis occur in malaria endemic regions but not much is known about immune response modulation in these co-infections. The study aimed to assess the prevalence of Toxoplasma gondii and Plasmodium co-infections and associated risk factors, as well as cytokine profiles in a population living in Akinyele Local Government Area, Ibadan, Oyo State, Nigeria.

Method: In a cross-sectional survey, blood from 192 volunteers was screened for Plasmodium falciparum, Toxoplasma gondii antibodies (IgG and IgM) and cytokine (IL2, IL6, IL10 and IL12) levels. Packed Cell Volume (PCV) and epidemiological factors associated with toxoplasmosis and malaria were also determined.

Result: Out of the 192 participants, 27.1% and 8.9% tested positive for T. gondii IgG and IgM antibodies, while malaria was prevalent in 72.4% of participants. Co-infection of T. gondii and Plasmodium was observed in 20.4% of participants. Malaria prevalence was highest in individuals below 20 years of age, while toxoplasmosis was most prevalent in 51-60 year olds. Toxoplasma sero-positivity, malaria prevalence and Plasmodium intensity were significantly higher (P<0.05) in females. High Toxoplasma IgG was associated (P<0.05) with increased Plasmodium intensity and high IgM with decreased intensity (P>0.05). Environmental factors, such as the presence of cats, were significantly associated with T. gondii IgG seropositivity. IL-2 and IL-6 were significantly lower (P<0.05) with Toxoplasma gondii (IgM) while IL-10 levels were lower with malaria infections and chronic (IgG) T. gondii co-infection, although this was not statistically significant (P>0.05).

Conclusion: Active Toxoplasma gondii co-infection with malaria may suppress malaria pathology while Plasmodium and chronic T. gondii co-infection may lead to increased production of IL-2 which may facilitate malaria parasite clearance. The study also found that IL-12 may be a potential biomarker for disease severity and response to treatment in co-infected individuals.