Prostate cancer incidence is 1.6-fold higher in African Americans than in other populations. The risk factors that drive this disparity are unknown and potentially consist of social, environmental, and genetic influences. To investigate the genetic basis of prostate cancer in men of African ancestry, we performed a genome-wide association meta-analysis using two-sided statistical tests in 10 202 case subjects and 10 810 control subjects. We identified novel signals on chromosomes 13q34 and 22q12, with the risk-associated alleles found only in men of African ancestry (13q34: rs75823044, risk allele frequency = 2.2%, odds ratio [OR] = 1.55, 95% confidence interval [CI] = 1.37 to 1.76, P = 6.10 × 10−12; 22q12.1: rs78554043, risk allele frequency = 1.5%, OR = 1.62, 95% CI = 1.39 to 1.89, P = 7.50 × 10−10). At 13q34, the signal is located 5’ of the gene IRS2 and 3’ of a long noncoding RNA, while at 22q12 the candidate functional allele is a missense variant in the CHEK2 gene. These findings provide further support for the role of ancestry-specific germline variation in contributing to population differences in prostate cancer risk.

Although breast cancer is becoming more prevalent in Africa, few epidemiologic studies have been undertaken and appropriate methodologic approaches remain uncertain. We therefore conducted a population-based case-control study in Accra and Kumasi, Ghana, enrolling 2,202 women with lesions suspicious for breast cancer and 2,161 population controls. Biopsy tissue for cases prior to neoadjuvant therapy (if given), blood, saliva and fecal samples were sought for study subjects. Response rates, risk factor prevalences, and odds ratios (OR) for established breast cancer risk factors were calculated. A total of 54.5% of the recruited cases were diagnosed with malignancies, 36.0% with benign conditions and 9.5% with indeterminate diagnoses. Response rates to interviews were 99.2% in cases and 91.9% in controls, with the vast majority (82-99%) of interviewed subjects providing blood and saliva samples; lower proportions (46-58%) provided fecal samples. While risk factor prevalences were quite unique as compared to women in other countries (e.g., less education, higher parity), cancer risk factors resembled patterns identified elsewhere (elevated risks associated with higher levels of education, familial histories of breast cancer, low parity, and larger body sizes). Subjects with benign conditions were younger and exhibited higher socioeconomic profiles (e.g., higher education, lower parity) than those with malignancies, suggesting selective referral influences. While further defining breast cancer risk factors in Africa, this study showed that successful population-based interdisciplinary studies of cancer in Africa are possible but require close attention to diagnostic referral biases and standardized and documented approaches for high-quality data collection, including biospecimens.

Detection of Plasmodium falciparum parasites in patients with malaria necessitates drawing blood, which increases the risk of accidental infections and is poorly accepted in communities with blood taboos. Thus, non-invasive, cost-effective malaria tests that minimize the need for blood collection are needed. Plasmodium falciparum histidine-rich protein II (PfHRP II) levels in plasma and saliva were compared in malaria-positive and -negative patients in Ghana. Plasma and saliva obtained from 30 thick-film positive and 10 negative children were evaluated for PfHRP II by ELISA. Among the 30 children with positive blood smear, 16 (53%) were PfHRP II positive in plasma and 13 (43%) had PfHRP II positive saliva. The sensitivity of PfHRP II detection was 53% for plasma and 43% for saliva. The specificity was 100% with no false positive for both plasma and saliva when compared with blood smear. Thus, rapid detection of PfHRP II antigen in saliva may be a useful non-invasive and cost-effective malaria diagnostic technique.

IntroductionThough giardiasis is an important public health problem in Ghana, several aspects of its epidemiology, particularly the molecular epidemiology has not been investigated adequately. This could be a major hindrance to effective surveillance and control of giardiasis in the country. The study was carried out to determine the prevalence, risk factors and genotypes of Giardia lamblia infecting children at a paediatric hospital in Ghana.MethodsA total of 485 patients including 365 diarrhoea and 120 non-diarrhoea children were enrolled into the study. Stool samples were collected and analysed for parasite presence using microscopy, ELISA and PCR. Positive samples were subsequently characterized into assemblages by PCR-RFLP, and further confirmed with sequencing of the glutamate dehydrogenase (gdh) gene. Epidemiological data on demographic, clinical and behavioral features of the study subjects were also collected.ResultsPrevalence of G. lamblia infections in diarrhoea and non-diarrhoea children were 5.8% and 5% respectively (P>0.5). Sequence data confirmed Giardia lamblia assemblage B as the predominant genotype in both diarrhoea and non-diarrhoea cases. There was no significant association of G. lamblia infection with any of the epidemiological variables investigated.ConclusionOur findings suggest that assemblage B could be the predominant genotype causing giardiasis in children. Increased public health education focusing on good sanitary practices, particularly among mothers and children, could decrease the risk of G. lamblia infection.