[Seasonal patterns of infectious disease: similarity and differences].

BACKGROUND

Most infectious diseases in template climates have seasonal pattern, that can be influenced by climatic, social and host factors.

AIM: To study the seasonal patterns of seven human infectious diseases in Chile.

MATERIAL AND

METHODS

Series of monthly cases of measles, whooping cough, scarlet fever, meningitis, diphtheria, typhoid fever and poliomyelitis were obtained from yearly reports of infectious disease of the Ministry of Health. Descriptive statistical parameters and multivariate methods were used to analyze data.

RESULTS

Diseases that have an enteric mode of transmission predominate in summer, independent of the type of agent (viral or bacterial) or presence of carriers. Diseases with a respiratory mode of transmission have two different patterns. Those without carriers (measles and whooping cough) predominate in spring and those with carriers (scarlet fever, diphtheria and meningitis) have a winter predominance.

CONCLUSIONS

This work confirms the seasonal variation of enteric and respiratory infectious diseases and defines patterns that can be useful for future studies.