Asthma in Africa 英文参考文献.docVIP

Essay Asthma in Africa Matthias Wjst , Daniel Boakye * Whatever does not exist does not have a name (African proverb). A colleagues, and published in new survey conducted by Emmanuel Addo-Yobo and PLoS Medicine [1], shows an increase in the prevalence of asthma and allergic diseases in children in Ghana between 1993 and 2003. In this essay, we discuss the context for this new study by exploring what is known about the epidemiology of asthma in Africa. Research on Asthma in Africa Looking at about 120 papers from Medline on asthma in Africa, we found that asthma research is currently dominated by authors from South Africa, followed by authors from Nigeria, Tanzania, Ethiopia, Kenya, and The Gambia. Most are case studies, closely followed by cross- sectional studies, and then case-control studies. There have been very few cohort studies. Only a few studies use objective measures [2,3], which makes the new PLoS Medicine study unusual, since the researchers used repeated measurements of skin prick tests and bronchial reactivity [1]. doi:10.1371/journal.pmed.0040072.g001 Figure 1. Hookworms (Ancylostoma caninum) Attached to the Intestinal Mucosa Barely visible larvae penetrate the skin (often through bare feet), are carried to the lungs, migrate through the respiratory tract to the mouth, are swallowed, and eventually reach the small intestine. This journey takes about a week. (Photo: Centers for Disease Control) kerosene heating, grass mats, mud and cow dung, smoking, and car and truck diesel exhaust. In the occupational setting isocyanate and latex sensitivity have been reported as risk factors, and poultry workers, hairdressers, gold miners, and wood choppers are reported as having an increased risk of asthma. Annual rainfall seems to have an in?uence on symptom presentation. Despite the risk factors discussed above, there is no overall hypothesis to explain asthma causation in Africa. In one study, traditional healers in Dar es Salaam, Tanzania were convinced that