The multiplicity of malaria transmission: a review of entomological inoculation rate measurements and methods across sub-Saharan Africa

Plasmodium falciparum malaria is a serious tropical disease that causes more than one million deaths each year, most of them in Africa. It is transmitted by a range of Anopheles mosquitoes and the risk of disease varies greatly across the continent. The "entomological inoculation rate" is the commonly-used measure of the intensity of malaria transmission, yet the methods used are currently not standardized, nor do they take the ecological, demographic, and socioeconomic differences across populations into account. To better understand the multiplicity of malaria transmission, this study examines the distribution of transmission intensity across sub-Saharan Africa, reviews the range of methods used, and explores ecological parameters in selected locations. It builds on an extensive geo-referenced database and uses geographical information systems to highlight transmission patterns, knowledge gaps, trends and changes in methodologies over time, and key differences between land use, population density, climate, and the main mosquito species. The aim is to improve the methods of measuring malaria transmission, to help develop the way forward so that we can better assess the impact of the large-scale intervention programmes, and rapid demographic and environmental change taking place across Africa

Herkunft numerischer und struktureller Aberrationen des X-Chromosoms

Nachdem 1956 durch Tjio und Levan die Darstellung der Metaphasenchromosomen eingeführt worden war, wurden in kurzer Folge ab 1959 verschiedene menschliche Aneuploidien als Ursache häufiger und z.T. bereits vorher bekannter klinischer Syndrome entdeckt (47,XXY als Ursache des Klinefelter-Syndroms: Jacobs u. Strong 1959; Trisomie 21 beim Down-Syndrom: Lejeune et al. 1959; 45,X als Basis des Turner-Syndroms: Ford et al. 1959). Später stellte sich heraus, daß fast die Hälfte der Patienten mit den klinischen Befunden des Turner-Syndroms 46 Chromosomen besitzt, aber entweder ein Mosaik oder eine strukturelle Aberration eines X-Chromosoms oder beides aufweist (Schmid et al. 1974)