A preliminary study of the frequency of focal neurological deficits in HIV/AIDS patients seropositive for Toxoplasma gondii IgG in Lagos, Nigeria

Abstract

Background: Cerebral toxoplasmosis is a common cause of focal neurologic deficits in HIV/AIDS. Financial constraints and access to neuroradiological facilities limit definitive  diagnosis  and  first-line  treatments  are  largely expensive and cumbersome.

ObjectiveThis study examined the frequency of focal neurological signs in HIV/AIDS patients with positive Toxoplasma gondii IgG antibodies (and thus at high risk of reactivation), and the relationship to CD4 count.

Methods: Using a case-control design, T. gondii IgG serology was determined in 83 HIV/AIDS patients on HAART and 42 HIV seronegative controls. Neurological evaluation and CD4 count (mm³) was conducted in all subjects.

Results: A total of 71 (85.5%) HIV/AIDS patients were seropositive for T. gondii IgG. The IgG seroprevalence was 84.8% for cases with CD4 count <200 and 86.0% with CD4>200 (P=0.46). Of the cases with positive Toxoplasma antibodies, the frequency of neurological lateralizing signs was higher in those with CD4 count <200 (32.6%) compared to persons with CD4 count >200 (7.1%) (X₂ = 4.90, Fisher exact P < 0.01). The mean CD4 count of cases with lateralizing signs was 113.7±113.9 in contrast to 254.0±218.9 in those without lateralizing signs (P < 0.01).

Conclusion: In our study, a higher frequency of focal neurological signs was found in the T. gondii seropositive HIV/AIDS patients with a higher degree of immune compromise (CD4 count <200). We suggest the adoption of routine prophylactic anti-toxoplasma therapy in this subgroup given that cerebral toxoplasmosis is a leading cause of intracranial space occupying lesions in HIV/AIDS.

Keyword: Cerebral toxoplasmosis, IgG antibodies, focal neurological signs, HIV/AIDS, Nigeria