Innocent T. Gangaidzo

Impact of HIV infection on meningitis in Harare, Zimbabwe : a prospective study of 406 predominantly adult patients

ObjectiveTo determine the causative organisms and characteristics of patients presenting with features of meningitis. DesignA prospective cross-sectional study. SettingTwo tertiary university-affiliated hospitals in Harare, Zimbabwe. PatientsFour-hundred and six patients clinically suspected to have meningitis. Main outcome measuresCausative organisms of meningitis; clinical and cerebrospinal fluid characteristics. ResultsFour-hundred and six predominantly adult (95% were aged ⩾ 18 years) patients were suspected to have meningitis. Of the 200 patients confirmed to have meningitis, 89 (45%) had cryptococcal meningitis (CM), 54 (27%) had mononuclear meningitis (MM), 31 (16%) had pyogenic meningitis (PM), 24 (12%) had tuberculous meningitis (TBM) and 2 (1%) had undefined meningitis. HIV seropositivity was 100% in CM, 83% in MM, 81% in PM and 88% in TBM patients. In-hospital mortality rate was 38.8% for CM, 34.9% for MM, 68% for PM and 66.7% for TBM. HIV seropositivity was 80% in the 206 patients not found to have meningitis. ConclusionsAll patients suspected to have meningitis had a high HIV sero positivity irrespective of whether they were later confirmed to have meningitis or not. CM was the most common type of meningitis seen. In-hospital mortality was high irrespective of the cause of meningitis.

Iron overload in Africans and African-Americans and a common mutation in the SCL40A1 (ferroportin 1) gene

The product of the SLC40A1 gene, ferroportin 1, is a main iron export protein. Pathogenic mutations in ferroportin 1 lead to an autosomal dominant hereditary iron overload syndrome characterized by high serum ferritin concentration, normal transferrin saturation, iron accumulation predominantly in macrophages, and marginal anemia. Iron overload occurs in both the African and the African-American populations, but a possible genetic basis has not been established. We analyzed the ferroportin 1 gene in 19 unrelated patients from southern Africa (N = 15) and the United States (N = 4) presenting with primary iron overload. We found a new c. 744 C-->T (Q248H) mutation in the SLC40A1 gene in 4 of these patients (3 Africans and 1 African-American). Among 22 first degree family members, 10 of whom were Q248H heterozygotes, the mutation was associated with a trend to higher serum ferritin to amino aspartate transferase ratios (means of 14.8 versus 4.3 microg/U; P = 0.1) and lower hemoglobin concentrations (means of 11.8 versus 13.2 g/dL; P = 0.1). The ratio corrects serum ferritin concentration for alcohol-induced hepatocellular damage. We also found heterozygosity for the Q248H mutation in 7 of 51 (14%) southern African community control participants selected because they had a serum ferritin concentration below 400 microg/L and in 5 of 100 (5%) anonymous African-Americans, but we did not find the change in 300 Caucasians with normal iron status and 25 Caucasians with non-HFE iron overload. The hemoglobin concentration was significantly lower in the African community controls with the Q248H mutation than in those without it. We conclude that the Q248H mutation is a common polymorphism in the ferroportin 1 gene in African populations that may be associated with mild anemia and a tendency to iron loading.

Association of Pulmonary Tuberculosis with Increased Dietary Iron

To determine whether increased dietary iron could be a risk factor for active tuberculosis, dietary iron history and human immunodeficiency virus (HIV) status were studied in 98 patients with pulmonary tuberculosis and in 98 control subjects from rural Zimbabwe. Exposure to high levels of dietary iron in the form of traditional beer is associated with increased iron stores in rural Africans. HIV seropositivity was associated with a 17.3-fold increase in the estimated odds of developing active tuberculosis (95% confidence interval [95% CI], 7.4-40.6; P<.001), and increased dietary iron was associated with a 3.5-fold increase (95% CI, 1.4-8.9; P=.009). Among patients treated for tuberculosis, HIV seropositivity was associated with a 3.8-fold increase in the estimated hazard ratio of death (95% CI, 1.0-13.8; P=.046), and increased dietary iron was associated with a 1.3-fold increase (95% CI, 0.4-6.4; P=.2). These findings are consistent with the hypothesis that elevated dietary iron may increase the risk of active pulmonary tuberculosis.

Cryptococcal Meningitis in Human Immunodeficiency Virus-Infected Patients in Harare, Zimbabwe

A prospective observational study was conducted over a 10-month period to determine the clinical and laboratory manifestations of cryptococcal meningitis in Zimbabwe, a country where antifungal agents are not widely available. Eighty-nine patients with cryptococcal meningitis (median age, 34 years; range, 11-63 years; 56 males) were identified from 406 patients for whom a clinical diagnosis of meningitis had been made. All patients tested were positive for antibody to human immunodeficiency virus. Cryptococcal meningitis was the first AIDS-defining illness in 88% of patients. Typical presentations were headache, mental impairment, and meningism (median duration, 14 days; range, 1-180 days). The median CD4+ cell count was 70/microL (range, 0-651/microL). The cumulative median survival from the time of diagnosis was 14 days (range, 0-233 days); 22% of patients survived for >30 days. Independent indicators of a good prognosis were not identified. This study provides a unique basis for the development of novel management strategies for patients with cryptococcal meningitis who reside in resource-poor countries.

Intestinal parasites in patients with diarrhea and human immunodeficiency virus infection in Zimbabwe

OBJECTIVES To determine the prevalence of intestinal parasites and risk factors for infection associated with diarrhea in HIV-infected patients in Harare, Zimbabwe. DESIGN Prospective observational study. METHODS Single stool samples were collected from 88 HIV-infected individuals presenting with diarrhea of greater than 1 week duration. Stools were examined for intestinal parasites using modified acid fast stain, fluorescence- labeled monoclonal antibody for Cryptosporidium parvum, as well as a modified trichrome stain and a PCR-based protocol for Enterocytozoon bieneusi. RESULTS C. parvum was detected in 9% (seven out of 82) of samples evaluated, but no Cyclospora was detected. E. bieneusi was detected in 18% (10 out of 55) of stool by trichrome staining and in 51% (28 out of 55) of stool examined by PCR. Risk factors for E. bieneusi infection were: living in rural areas, consumption of nonpiped water, contact with cow dung and household contact with an individual with diarrhea. CONCLUSION E. bieneusi infection was common in HIV-infected patients with diarrhea in Zimbabwe and may be acquired through person-to-person and fecal-oral transmission.

Vitamin B12 deficiency is the primary cause of megaloblastic anaemia in Zimbabwe

Summary. In a study of the pathogenesis and clinical features of megaloblastic anaemia in southern Africa, we evaluated 144 consecutive Zimbabwean patients with megaloblastic haemopoiesis. Vitamin B12 deficiency was diagnosed in 86.1% of patients and was usually due to pernicious anaemia; isolated folate deficiency accounted for only 5/5% of cases. Anaemia was present in 95.8% of patients; the haemoglobin (Hb) was 6 g/dl in 63.9%. Neurological dysfunction was noted in 70.2% of vitamin B12‐deficient patients and was most striking in those with Hb values > 6 g/dl. Serum levels of methylmalonic acid, homocysteine, or both, were increased in 98.5% of patients.

Cryptococcus neoformans meningoencephalitis in African children with acquired immunodeficiency syndrome.

Background. The number of children with AIDS in Africa is high. Such children may be at risk for cryptococcal meningoencephalitis, but data are scarce regarding this disease in our population. Methods. We examined records of HIV-infected children (≤16 years) diagnosed with cryptococcal meningoencephalitis in Harare, Zimbabwe, between 1995 and 2000. To elucidate features unique to pediatric disease, the children were compared with adult patients with HIV-associated cryptococcal meningoencephalitis. Results. Thirteen children presented to our institution with headache (85%), nuchal rigidity (69%), vomiting (46%), impaired mental status (38%), convulsions (38%) and focal neurologic signs (23%). The mean duration of symptoms before diagnosis was 9 days. Cerebrospinal fluid examination revealed normal white blood cell counts in 64%, protein value in 67% and glucose concentration in 57% of patients. Children were more likely than adults to have seizures (38%vs. 11%, P = 0.02) and normal cerebrospinal fluid protein (67%vs. 10%, P < 0.01). The in-hospital mortality was 43%. Convulsions (P = 0.05) and impaired mental status (P < 0.01) were associated with increased mortality Conclusions. Cryptococcal meningoencephalitis in African children presents acutely or subacutely, can have a fulminant picture and is consistent with progressive meningoencephalitis.

Cytokine Profiles in Cerebrospinal Fluid of Human Immunodeficiency Virus—Infected Patients with Cryptococcal Meningitis: No Leukocytosis despite High Interleukin-8 Levels

Cytokine levels were studied in the cerebrospinal fluid (CSF) of 16 adults with cryptococcal meningitis (CM). Low levels of tumor necrosis factor (TNF)-alpha and interferon-gamma, high levels of interleukin (IL)-1beta, IL-6, and IL-8, and the presence of IL-10 were documented. There were no significant differences in levels of TNF-alpha and interferon-gamma for CM and control patients. Mean CSF levels of IL-1beta (139.5 pg/mL), IL-6 (346 pg/mL), IL-8 (1160 pg/mL), and IL-10 (9.27 pg/mL) were significantly (P < .01) elevated in CM patients compared with levels in control patients. Despite the high CSF levels of IL-8, minimal leukocytosis was seen. Significant correlations between cryptococcal antigen titers and IL-10 levels (r = .8, P < .05), protein and cryptococcal antigen titer (r = .9, P < .05), and protein and IL-10 levels (r = .8, P < .05) were found.

Haptoglobin polymorphism and mortality in patients with tuberculosis

SETTING A rural Zimbabwean hospital and the surrounding community. OBJECTIVES To determine whether a particular haptoglobin phenotype is associated with increased susceptibility to clinical pulmonary tuberculosis, and to determine the outcome of treatment for pulmonary tuberculosis according to haptoglobin phenotype. DESIGN A case-control study, and a prospective cohort study. RESULTS We studied 98 consecutive patients with sputum-positive pulmonary tuberculosis and 98 sex- and age-matched controls. The haptoglobin (Hp) phenotype distributions did not differ significantly between the tuberculosis patients and controls (P = 0.5). During the 18-month follow-up period after the start of tuberculosis treatment, 6/18 (33%) cases with Hp 2-2 phenotype died compared to 9/47 (19%) with Hp 2-1 and 3/31 (10%) with Hp 1-1. In a logistic regression model, the odds of dying were 6.1-fold greater with Hp 2-2 than with Hp 1-1 (95%CI 1.04-35.1, P = 0.04). CONCLUSION Our results suggest that there is equal susceptibility to clinical pulmonary tuberculosis disease amongst different haptoglobin phenotypes. Nonetheless, tuberculosis patients with Hp 2-2 phenotype had a higher risk of mortality.

Pancytopenia in Zimbabwe

BACKGROUND There has been little systematic study of the clinical spectrum of pancytopenia, and the optimal diagnostic approach to pancytopenia remains undefined. METHODS The authors studied 134 hospitalized pancytopenic patients in Zimbabwe in both consecutive and nonconsecutive fashion. RESULTS The most common cause of pancytopenia was megaloblastic anemia, followed by aplastic anemia, acute leukemia, acquired immunodeficiency syndrome (AIDS), and hypersplenism. Severe pancytopenia was usually due to aplastic anemia. Patients with aplastic anemia and acute leukemia were usually children, whereas those with megaloblastic anemia were adults. Moderate to severe anemia was noted throughout the series, but was most striking in patients with megaloblastic anemia, aplastic anemia, and acute leukemia. The mean corpuscular volume (MCV) was elevated in most patients with megaloblastic hematopoiesis, aplastic anemia, and acute nonlymphocytic leukemia. Normal or low MCV values were noted in almost one third of patients with megaloblastic anemia. Anisocytosis, poikilocytosis, macroovalocytosis, microcytosis, fragmentation, and teardrop erythrocytes were more prominent on the blood films of patients with megaloblastic anemia. CONCLUSIONS Megaloblastic anemia, aplastic anemia, and AIDS are the most common causes of pancytopenia in Zimbabwe. Aplasia is the most frequent cause of severe pancytopenia. The authors have formulated tentative guidelines for the evaluation of pancytopenic patients in this setting.