According to the analysis of the health situation in the WHO Eighth General Programme of Work, communicable diseases continue to account for an unduly high proportion of the health budgets of developing countries. Acute diarrhoea is responsible for more than 30% of deaths in children in their first five years of life and results in as many as 4 million deaths annually. Acute respiratory infections (primarily pneumonia) are another important cause of death, resulting in an estimated 2.2 million deaths each year throughout the world. Analysis of data on lung aspirates appears to indicate that, in developing countries, bacteria such as Haemophilus influenzae and Streptococcus pneumoniae, rather than viruses, are the predominant pathogens in childhood pneumonia. Beta-lactamase-producing H. influenzae and S. pneumoniae with decreased sensitivity to penicillin have recently appeared in different parts of the world, making the surveillance of these pathogens increasingly important.
Sexually transmitted diseases are on the increase everywhere. There are still threats of epidemics and pandemics of viral or bacterial origin, made more likely by inadequate epidemiological surveillance and deficient preventive measures. To prevent and control the main bacterial diseases, there is a need to develop simple tools for use in epidemiological surveillance and disease monitoring, as well as simplified and reliable diagnostic techniques.
To meet the challenge that this situation represents, the health laboratory services must be based on a network of laboratories carrying out microbiological diagnostic work for health centres, hospital doctors, and epidemiologists. The complexity of the work will increase from the peripheral to the intermediate and central laboratories. Only in this way will it be possible to gather, quickly enough, sufficient relevant information to improve surveillance, and permit the early recognition of epidemics or unusual infections and the development, application, and evaluation of specific intervention measures.