http://ucatlas.ucsc.edu/health/diphtheria/diphtheria.html
Diphtheria is a highly infectious disease that is spread from person to person through the inhalation of "respiratory droplets" produced from coughing or sneezing. An untreated person will remain contagious for two to three weeks. With treatment an infected person will be non-infectious within twenty-four hours. If a person is not immunized, they may be repeatedly infected with the disease (WHO, Factsheet 89). The disease is fatal between 5% and 10% of the time, even when properly treated. When infected persons are not treated the mortality rate is even higher (WHO). Immunization process involves at least three different injections of vaccine over a span of a year. Source: World Health Organization, 2002.
As the maps show diphtheria
has largely been eliminated over the past twenty years. However
it is still prevalent in some regions, mainly eastern European former
Soviet Bloc countries, as well as many countries in Africa. There
was a sudden increase in the number of cases world wide in the 1990's,
this was due to a "massive epidemic" in the former Soviet Union
(WHO, Vaccine-Preventable Disease Monitoring System, 2002 global summary).
"Since the 1990, outbreaks were also reported from Algeria, Iraq,
Lao People's Republic, Mongolia, Papua New Guinea, Sudan, and Thailand"
(WHO). By contrast in most Western nations, cases are rarely reported.
WHO notes that reporting changes may generate misleading data in some cases. Such was the case in 2000 to 2001 when China and India changed the methodology they used to produce "official national estimates" of national coverage. This resulted in a lowering of their reported immunization coverage, for that year (WHO).
References:
World Health Organization. 2000. Fact Sheet 89-Diphtheria.
http://www.who.int/inf-fs/en/fact089.html
World
Health Organization. 2002. Vaccines and Biologicals: WHO Vaccine-Preventable
Diseases: Monitoring System 2002 Global Summary.
http://www.who.int/vaccines-documents/GlobalSummary/Globalsummary.pdf
