Clinical spectrum and outcomes for toxoplasma encephalitis among aids patients before and during the era of anti-retroviral therapy in Mangalore, India

Background: Toxoplasmosis (TS) which is associated with HIV infection is typically caused by the reactivation of a chronic infection and it manifests primarily as toxoplasmic encephalitis. This disease is an important cause of focal brain lesions in HIVinfected patients. This study was done to determine the clinical presentations and outcomes of CNS toxoplasmosis and to find out their association with the CD4 counts at the time of diagnosis and at the initiation of anti-retroviral therapy. Materials and Methods This was a retrospective study which was done over 6 months at Kasturba Medical College Hospital (KMCH), Attavar, Mangalore, by reviewing the medical records of HIV-positive patients who were diagnosed with toxoplasmosis, who were admitted there from Jan 2001 to Dec 2010. The diagnosis was based on the clinical features, the demonstration of elevated IgG by ELISA and associated CT findings. The data which was obtained was then correlated with the CD4 counts and with the fact as to whether the patient was on ART or not. The analysis was done by using SPSS version 11.5. Results: 2826 HIV positive patients attended the Infections Disease Cell clinic of our hospital from the year 2001 -2010, of which 33 (1.12%) had CNS toxoplasmosis. Among the 33 cases, 29 were males (88%) and 4 were females (12%). The mean age was 37.33 yrs, with an S.D of 6 yrs. 73% were married, 24% were single and 3% were widows. 10 out of the 33 cases (30.3%) had CNS toxoplasmosis as the initial manifestation of HIV. The most common clinical presentations were fever (58%) and headache (52%). 64% of the cases were already on ART when they were diagnosed with toxoplasmosis and 6% were started on ART after the diagnosis of toxoplasmosis. The mean CD4 count at the time of diagnosis of toxoplasmosis was 160.6, with an S.D. of 112. The mean level of IgG was 255.69, with an S.D of 99.62. The CT/MRI finding of the ringenhancing lesion or cerebritis was seen in 79% of the cases, with 18% of the lesions being seen in both the basal ganglia and the parietal lobes. Cerebritis was the most common lesion which was found in the CT/MRI, which was seen in 16 (61.5%) cases, while ring enhancing lesions were seen in 10 (38.5%) cases. 82% of the cases improved with the treatment and 18% expired. Recurrence was seen in 6% cases, with seizures as the most common presentation. 6 (18.18%) toxoplasmosis cases in our study had IRIS. The mean CD4 count in them was 363, while the mean CD4 count in the absence of IRIS was 125, with a p value of 0.001. Conclusions: The possibility of cerebral toxoplasmosis should be considered in every HIV-positive patient with neurological symptoms. In our study, we saw toxoplasmosis occurring at CD4 levels which were >150, which could warrant a prophylaxis for toxoplasmosis at a higher CD4 count. Parietal lobe lesions were common in our study, which was contrary to the other existing data, which have referred to the toxoplasma lesions usually as midline lesions. Cerebritis, which was more common than the ring enhancing lesions in our study, could have occurred due to the weakened immune response.