Allergic Disorders in Africa and Africans: Is it Primarily a Priority?

In Africa, the burden of some diseases has been a problem for centuries. The spectrum of African diseases includes allergies, infections, nutritional deficiencies, and natural disasters. Efforts made by scientists to search for possible means of disease control have been outstanding; however, in some infections, solutions are still out of reach. In disease control programs, it might be worthwhile to pay attention to the most striking diseases than merely follow a holistic approach. This short review tackles the problems of allergy and allergens in Africa as compared with other disease burdens that may suggest the need for a more balanced approach based on priority

Identifying gaps in the practices of rural health extension workers in Ethiopia:A task analysis study

Background: Health extension workers (HEWs) are the frontline health workers for Ethiopia's primary health care system. The Federal Ministry of Health is seeking to upgrade and increase the number of HEWs, particularly in remote areas, and address concerns about HEWs' pre-service education and practices. The aim of this study was to identify gaps in HEWs' practices and recommend changes in their training and scope of practice. Methods: A cross-sectional descriptive task analysis was conducted to assess the work of rural HEWs who had been in practice for six months to five years. One hundred participants were invited from 100 health posts in five regions of Ethiopia. HEWs self-reported on 62 tasks on: frequency, criticality (importance), where the task was learned, and ability to perform the task. Descriptive statistics, including frequencies and percentages, were computed for each variable. Task combinations were examined to identify tasks performed infrequently or for which HEWs are inadequately prepared. Results: A total of 82 rural HEWs participated in the study. Nearly all HEWs rated every task as highly critical to individual and public health outcomes. On average, most HEWs (51.5%-57.4%) reported learning hygiene and environmental sanitation tasks, disease prevention and control tasks, family health tasks, and health education and communication tasks outside of their pre-service education, primarily through in-service and on-the-job training. Over half of HEWs reported performing certain critical tasks infrequently, including management of supplies, stocks and maintenance at the facility and management of the cold chain system. Almost all HEWs (95.7-97.2%) perceived themselves as competent and proficient in performing tasks in all program areas. Conclusion: HEWs were insufficiently prepared during pre-service education for all tasks that fall within their scope of practice. Many learned tasks through in-service or on-the-job training, and some tasks were not learned at all. Some tasks that are part of expected HEW practice were performed infrequently, potentially reducing the effectiveness of the Health Extension Program to provide preventive and basic curative health care services to communities. Findings should alert policy makers to the need to review HEWs' scope of practice, update pre-service education curricula and prioritize in-service training modules

Association between infection with H. pylori and atopy in young Ethiopian children: a longitudinal study

Background: Epidemiological evidence from developed countries indicates that Helicobacter pylori infection correlates with a reduced risk of atopy and allergic disorders, however limited data are available from low-income countries. Objective: We examined associations between H. pylori infection in early childhood and atopy and reported allergic disorders at the age of 6.5 years in an Ethiopian birth cohort. Methods: A total of 856 children (85.1% of the 1006 original singletons in a population-based birth cohort) were followed up at age six and half years. An interviewer-led questionnaire administered to mothers provided information on demographic and lifestyle variables. Questions on allergic disease symptoms were based on the International Study of Asthma and Allergies in Children (ISAAC) core allergy and environmental questionnaire. Serum samples were analysed for total IgE levels and anti-H. pylori cytotoxin associated gene A (CagA) IgG antibody using commercially available ELISA kits. Stool samples were analysed for H. pylori antigen using a rapid immunochromatographic test. The independent effects of H. pylori infection (measured at age 3, 5 and 6.5 years) on prevalence and incidence of atopy and reported allergic disorders (measured at age 6.5 years) were determined using multiple logistic regression. Results: In cross-sectional analysis, current H. pylori infection at age 6.5 years was inversely, though not significantly, related to prevalence of atopy and ‘any allergic condition’ at age 6.5 years. However detection of H. pylori infection at any point up to age 6.5 years was associated with a significantly reduced odds of both atopy and ‘any allergic condition’ (adjusted OR AOR, 95% CI, 0.54; 0.32 to 0.92, p=0.02, and 0.31; 0.10 to 0.94, p=0.04, respectively). In longitudinal analyses, H. pylori infection at age 3 was inversely associated with incidence of atopy (AOR, 95% CI, 0.49; 0.27 to 0.89, p=0.02). Furthermore, among H. pylori infected children, those with a CagA+ strain had a more pronounced reduction in odds of atopy (AOR=0.35 vs. 0.63 for CagA+ vs. CagA-) and this reduction reached borderline significance. Conclusion: These data are consistent with the hypothesis that early exposure to H. pylori is inversely associated with atopy and allergic conditions. A possible modest protective association against atopy was observed in those infected with a more virulent CagA+ strain of H. pylori. This article is protected by copyright. All rights reserved

Prevalence and risk factors for soil-transmitted helminth infection in mothers and their infants in Butajira, Ethiopia: a population based study

BACKGROUND: Soil-transmitted helminths (STHs) are widespread in underdeveloped countries. In Ethiopia, the prevalence and distribution of helminth infection varies by place and with age. We therefore investigated the prevalence of and risk factors for STH infection in mothers and their one year-old children living in Butajira town and surrounding rural areas in southern Ethiopia. METHODS: In 2005-2006, 1065 pregnant women were recruited in their third trimester of pregnancy. In 2006-2007, when children reached their first birthdays, data on the infants and their mothers were collected, including stool samples for qualitative STH analysis. Questionnaire data on various demographic, housing and lifestyle variables were available. Logistic regression analysis was employed to determine the independent risk factors for STH infection in the mothers and children. RESULTS: 908 mothers and 905 infants provided complete data for analysis. Prevalence of any STH infection was 43.5% (95% confidence interval (CI) 40.2-46.8%) in mothers and 4.9% (95%CI 3.6-6.5%) in children. In the fully adjusted regression model, infrequent use of soap by the mother was associated with increased risk (odds ratio (OR) 1.40, 95% CI 1.04-1.88, and 1.66, 95% CI 0.92-2.99, for use at least once a week and less frequent than once a week respectively, relative to daily use; p for trend = 0.018), and urban place of residence (OR 0.45, 95% CI 0.28-0.73, p = 0.001) was associated with reduced risk of maternal STH infection. The only factor associated with STH infection in infants was household source of water, with the greatest risk in those using piped water inside the compound (OR 0.09, 95% CI 0.02-0.38 for river water, 0.20, 95% CI 0.56-0.69 for either well or stream water and 0.21, 95% CI 0.09-0.51 for piped water outside compared with piped water inside the compound, overall p = 0.002) CONCLUSION: In this rural Ethiopian community with a relatively high prevalence of STH infection, we found a reduced risk of infection in relation to maternal hygiene and urban living. Daily use of soap and a safe supply of water are likely to reduce the risk of STH infection

Effects of Helicobacter pylori, geohelminth infection, and selected commensal bacteria on the risk of allergic disease and sensitization in 3 year old Ethiopian children

Background Epidemiological studies have suggested that gastro-intestinal infections including Helicobacter pylori, intestinal microflora (commensal bacteria) and geohelminths may influence the risk of asthma and allergy but data from early life are lacking. Objective We aimed to determine the independent effects of these infections on allergic disease symptoms and sensitization in an Ethiopian birth cohort. Methods In 2008/09, 878 children (87% of the 1006 original singletons in a population-based birth cohort) were followed up at age 3 and interview data obtained on allergic symptoms and potential confounders. Allergen skin tests to Dermatophagoides pteronyssinus and cockroach were performed, levels of Der p 1 and Bla g 1 in the child's bedding measured and stool samples analysed for geohelminths and, in a random subsample, enterococci, lactobacilli, bifidobacteria and H. pylori antigen. The independent effects of each exposure on wheeze, eczema, hayfever and sensitization were determined using multiple logistic regression. Results Children were commonly infected with H. pylori (41%; 253/616), enterococci (38.1%; 207/544), lactobacilli (31.1%; 169/544) and bifidobacteria (18.9%; 103/544) whereas geohelminths were only found in 8.5% (75/866). H. pylori infection was associated with a borderline significant reduced risk of eczema (adjusted OR 0.49, 95% CI 0.24–1.01, P=0.05) and D. pteronyssinus sensitization (adjusted OR 0.42, 95% CI 0.17–1.08, P=0.07). Geohelminths and intestinal microflora were not significantly associated with any of the outcomes measured. Conclusion and Clinical Relevance Among young children in a developing country, we found evidence to support the hypothesis of a protective effect of H. pylori infection on the risk of allergic disease. Further investigation of the mechanism of this effect is therefore of potential therapeutic and preventive value

Impact of early life exposures to geohelminth infections on the development of vaccine immunity, allergic sensitization, and allergic inflammatory diseases in children living in tropical Ecuador: the ECUAVIDA birth cohort study.

Background Geohelminth infections are highly prevalent infectious diseases of childhood in many regions of the Tropics, and are associated with significant morbidity especially among pre-school and school-age children. There is growing concern that geohelminth infections, particularly exposures occurring during early life in utero through maternal infections or during infancy, may affect vaccine immunogenicity in populations among whom these infections are endemic. Further, the low prevalence of allergic disease in the rural Tropics has been attributed to the immune modulatory effects of these infections and there is concern that widespread use of anthelmintic treatment in high-risk groups may be associated with an increase in the prevalence of allergic diseases. Because the most widely used vaccines are administered during the first year of life and the antecedents of allergic disease are considered to occur in early childhood, the present study has been designed to investigate the impact of early exposures to geohelminths on the development of protective immunity to vaccines, allergic sensitization, and allergic disease. Methods/Design A cohort of 2,403 neonates followed up to 8 years of age. Primary exposures are infections with geohelminth parasites during the last trimester of pregnancy and the first 2 years of life. Primary study outcomes are the development of protective immunity to common childhood vaccines (i.e. rotavirus, Haemophilus influenzae type B, Hepatitis B, tetanus toxoid, and oral poliovirus type 3) during the first 5 years of life, the development of eczema by 3 years of age, the development of allergen skin test reactivity at 5 years of age, and the development of asthma at 5 and 8 years of age. Potential immunological mechanisms by which geohelminth infections may affect the study outcomes will be investigated also. Discussion The study will provide information on the potential effects of early exposures to geohelminths (during pregnancy and the first 2 years of life) on the development of vaccine immunity and allergy. The data will inform an ongoing debate of potential effects of geohelminths on child health and will contribute to policy decisions on new interventions designed to improve vaccine immunogenicity and protect against the development of allergic diseases