Aflatoxin exposure and viral hepatitis in the etiology of liver cirrhosis in the Gambia, West Africa.

BACKGROUND: Cirrhosis of the liver is thought to be a major cause of morbidity and mortality in sub-Saharan Africa, but few controlled studies on the etiology of cirrhosis have been conducted in this region. OBJECTIVES: We aimed to elucidate the association between environmental and infectious exposures and cirrhosis in The Gambia. METHODS: Ninety-seven individuals were diagnosed with cirrhosis using a validated ultrasound scoring system and were compared with 397 controls. Participants reported demographic and food frequency information. Blood samples were tested for hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), hepatitis C virus (HCV) antibody, HCV RNA, and the aflatoxin-associated 249(ser) TP53 mutation. RESULTS: HBsAg seropositivity was associated with a significant increase in risk of cirrhosis [odds ratio (OR) = 8.0; 95% confidence interval (CI), 4.4-14.7] as was the presence of HBeAg (OR = 10.3; 95% CI, 2.0-53.9) and HCV infection (OR = 3.3; 95% CI, 1.2-9.5). We present novel data that exposure to aflatoxin, as assessed both by high lifetime groundnut (peanut) intake and by the presence of the 249(ser) TP53 mutation in plasma, is associated with a significant increase in the risk for cirrhosis (OR = 2.8; 95% CI, 1.1-7.7 and OR = 3.8; 95% CI, 1.5-9.6, respectively). Additionally, aflatoxin and hepatitis B virus exposure appeared to interact synergistically to substantially increase the risk of cirrhosis, although this was not statistically significant. CONCLUSIONS: Our results suggest that the spectrum of morbidity associated with aflatoxin exposure could include cirrhosis.

Stroke risk factors, subtypes, and 30-day case fatality in Abuja, Nigeria.

BACKGROUND: Stroke is the second leading cause of death and the leading cause of adult disability worldwide. A better understanding of stroke risk factors and outcome may help guide efforts at reducing the community burden of stroke. This study aimed to understand stroke risk factors, imaging subtypes, and 30-day outcomes among adult Nigerians. MATERIALS AND METHODS: We prospectively recruited all patients presenting with acute stroke at the National Hospital Abuja between January 2010 and June 2012. We assessed clinical and laboratory variables, as well as brain computerized tomography, magnetic resonance imaging, and carotid Doppler ultrasound scans. We also assessed case fatality and functional outcome at 30 days after stroke. RESULTS: Of 272 patients studied, 168 (61.8%) were males. Age at presentation (mean ± standard deviation) was 56.4 ± 12.7 years in males and 52.9 ± 14.8 years in females (P = 0.039). Neuroimaging was obtained in 96.7% patients, revealing cerebral infarction (61.8%), intracerebral hemorrhage (ICH) (34.8%), and subarachnoid hemorrhage (SAH) (3.4%). Carotid plaques or stenosis ≥50% were detected in 53.2% patients with cerebral infarction. Stroke risk factors included hypertension (82.7%), obesity (32.6%), diabetes (23.5%), hyperlipidemia (18.4%), atrial fibrillation (9.2%), and cigarette smoking (7.7%). At 30 days after stroke, case-fatality rate was 18.8%, whereas modified Rankin Scale (mRS) scores for cerebral infarction, ICH, and SAH were 3.71, 4.21, and 4.56, respectively. Atrial fibrillation, a previous stroke, and age older than 50 years were all associated with worse mRS scores at 30 days. CONCLUSION: Although hypertension, obesity, diabetes mellitus, and atrial fibrillation were important stroke risk factors, in many patients, these were detected only after a stroke. While the commonest stroke subtype was cerebral infarction, observed in almost two-third of patients, SAH was associated with the highest case-fatality rate at 30 days of 44.4%. Larger population-based studies may provide additional data on stroke incidence and outcome among Nigerians.

The Gambia Liver Cancer Study: Infection with hepatitis B and C and the risk of hepatocellular carcinoma in West Africa.

Hepatocellular carcinoma (HCC) is the most common cancer in The Gambia. Hepatitis B virus (HBV) infection is endemic, with 15% to 20% of the population being chronic carriers, whereas hepatitis C virus (HCV) prevalence is low. We recruited 216 incident cases of HCC and 408 controls from three sites. HBV carriage was present in 61% (129/211) of HCC patients and 16% (64/402) of controls, whereas 19% (36/191) of HCC patients were HCV seropositive compared with 3% (11/382) of controls. HCC patients with HCV were notably older and were more likely to be female than those with HBV. Increased HCC risk was strongly associated with chronic HBV (odds ratio, 16.7; 95% CI, 9.7-28.7), HCV (16.7; 6.9-40.1), and dual infection (35.3; 3.9-323). We interpret the additive nature of risk with coinfection as representative of HBV and HCV acting primarily through shared steps in the multistage process of hepatocarcinogenesis. HCV infection was not observed among younger participants, suggesting a possible cohort effect. Reasons for the striking age and gender differences in HCC associated with HBV compared with HCV are unclear, but transmission patterns and age at exposure may be factors. In conclusion, in a standardized evaluation of well-characterized study participants from The Gambia, most cases of HCC are attributable to HBV (57%), but HCV adds a significant fraction (20%), especially among older patients and females. If HCV transmission is not perpetuated in future cohorts, focusing available resources on HB vaccination efforts could greatly ameliorate a major cause of cancer death in sub-Saharan Africa.