Epidemics of Malaria in Major Deserts

Abstract

An epidemic is, in principle, defined as any sudden increase in disease incidence beyond what is considered normal (cf. Najera et al. 1998). Epidemics differ not only in their causality but also in their form of presentation, evolution, incidence by age groups, severity and socio-economic impact (Najera et al. 1992). The epidemics, in the outset, characteristically follow a 2–5 or 7 years’ cycles, recurring in associating with a similar periodicity of abnormal meteorological conditions (heavy rains, floods, draughts, etc.). These abiotic factors actually help in increasing proliferation and survival of vectors such as Anopheles arabiensis, in the desert fringes of Sahara Desert. The higher the favourable temperature and humidity in the desert fringes, the higher is also the transmission rate of malaria and the resultant morbimortality. The impact of epidemics could be minimized through prediction, improved prevention through timely vector control and deployment of appropriate control measures. The implementation of a Malaria Early Warning System may enable regional/national health ministries and/or control managers to focus on epidemiological surveillance and be better prepared to take necessary actions.