Malaria Epidemic Forecasting and Preparedness Manual

2. Characteristics ofMalaria Epidemicsin EritreaIn Eritrea, there is also a lot of variation in transmission fromplace to place in the country. In some parts, for example thesouthwest, there is transmission year-round, but the number ofcases is usually much higher in some months than other. Inthese places, the seasonal rise in transmission is expected everyyear. In other places, such as on the Red Sea coast, there is a risein malaria cases in some years, but not every year.Therefore there are two distinct types of malaria epidemicswhich occur:• The seasonal increase in malaria transmission is muchgreater than expected.• Increased malaria transmission occurs in a place thatusually has very low numbers of cases.An example of the first type of epidemic is given in Fig. 1.Eritrea Epidemic Manual, June 2003 3