Mosley and Kendrick1 in their comprehensive review of hepatitis as a world problem noted that 111 member states of the World Health Organization (WHO) reported data on the incidence of the disease. The number of reporting countries has increased to 125 but the amount of information provided is variable. Nearly all transmit the total number of cases reported to them and about 80% report mortality, but two thirds give the monthly distribution, one third give deaths by age and sex, and one third give cases by age and sex.
Difficulties of diagnosis, especially in tropical areas where infectious hepatitis is only one of several pathological conditions which may be accompanied by liver damage with or without jaundice, are superimposed on the variability in reporting.
Furthermore, in interpreting these data we must consider the prevalence of malnutrition, but also the influence of social and environmental factors. In rural areas in
Cockburn WC. The Epidemiology of Viral Hepatitis in Tropical Countries. Am J Dis Child. 1972;123(4):345-349. doi:10.1001/archpedi.1972.02110100077029