ABSTRACT
Infectious diseases were once the main cause of morbidity and mortality in man. However, diseases such as malaria, schistosomiasis, filariasis, hookworm disease and trachoma still affect hundreds of millions of people today, while the number of people affected by diseases such as leprosy and onchocerciasis is still many tens of millions. Infectious diseases continue to pose public health problems. The methods of statistical analysis described are aimed at improving our understanding of infectious diseases and their spread through communities, with the hope that such additional knowledge will help in the control of these diseases. Infectious disease data are usually obtained from epidemics occurring in nature, which makes it difficult to accumulate precise data and explains why existing data are often lacking in detail. Epidemiologists often regard the mathematical theory of infectious diseases as a theoretical exercise rather than a body of knowledge which has practical relevance.
