For five long years, countries in several parts of the world have been closely responding to outbreaks of H5N1 avian influenza in animals, and sporadic cases in humans.
In epidemiological terms, there is generally a background of sporadic cases, with occasional outbreaks.
H5N1 virus has been identified in poultry outbreaks in Nigeria and similar to other affected countries, sporadic cases of human infection with avian influenza are not unexpected.
Meningococcal disease is endemic in Delhi and sporadic cases of meningococcal meningitis have been occurring in Delhi in previous years.
In Hungary, human trichinellosis has not been reported for many years, however, sporadic cases were recorded in swine over last 2 years.
