Emerging infectious diseases--Brazil.

Brazil’s large size (more than 8.5 million km2 and 150 million population) and inadequate public health infrastructure pose a considerable challenge in assessing the status of emerging infectious diseases. Under the current system, most infectious diseases are not notifiable. In diseases for which notification is required, underreporting is common and varies widely by region and disease, and notification is often delayed, which causes the data to be revised frequently. Moreover, in hospital and clinical settings, the etiologic agent of an infectious disease is often not identified. For example, more than a million hospital admissions are recorded per year by the public health system under parasitic and infectious diseases (the category excludes AIDS and respiratory illnesses); of these diseases, more than 70% are diagnosed as illdefined intestinal infections and a further 10% as food poisoning and septicemia, both without identification of the etiologic agents. For these reasons, the numbers reported here (1996 data, unless otherwise stated) may not reflect the true numbers of cases, and only diseases whose prevalence has changed markedly in recent years will be included in the review.