Nine-year study of WHO virus reports on fatal viral infections.

In 1963, the World Health Organization established a system for the collection and distribution of information on viruses. The present study is based on 2737 reports of fatal viral infections received from laboratories in 39 out of a total of 47 countries participating in the scheme. In the industrially developed countries, from which most of the reports came, more than one-third of the total number of deaths were associated with influenza A virus, while in the developing countries, the enteroviruses, and in particular poliovirus, came high on the list.In general, a steady increase in the number of reports received by WHO has been noted, especially during the last three years. The greatest variations in the yearly number of reports were seen in those concerning influenza A virus, and coincided with the clinical and epidemiological patterns observed since the advent of the A/Hong Kong/68 strain.In children, death was most frequently associated with enteroviruses, and in adults, with influenza A virus. However, some of the viruses, and in particular herpesvirus, were reported in both children and adults.Overall, respiratory diseases were the most frequent cause of death, mainly because of influenza A virus infection; next most frequent were herpesvirus infections, especially of the central nervous system, and particularly among young adults. The findings in this study confirm that it is the most serious central nervous system viral infection in the developed world.In contrast to the above, the enteroviruses are still the most important killers in the developing world and the cases occur among infants and young children. Poliovirus, in particular type 1, is still the most prevalent.