Impact of plague
Human plague cases from 1989 to 2003
Under the International Health Regulations, WHO Member States are obliged to notify plague when it occurs in humans in their territories. However, plague cases remain largely under-reported for several reasons: the reluctance of certain endemic countries to declare cases, the lack of diagnosis because the clinical picture of cases is not very specific and the absence of laboratory confirmation.
During this period, 38,310 cases (2845 deaths) were recorded in 25 countries, with the highest number of human plague cases being notified in 1991 and the lowest number being reported in 1989.
Since the early 1990s, an increased incidence of human plague has been observed, which was particularly apparent in Africa. The reasons for such a trend may be associated with both an actual increase in plague activity in its natural foci and an improvement of notification to WHO by Member States. During the last ten years, at least three geographical areas experienced outbreaks of human plague after silent periods of about 30-50 years:
- India - 1994, 2002
- Indonesia - 1997
- Algeria - 2003
Human plague cases in 2002-2003
Human plague was reported in 6 countries in 2002 (Democratic Republic of the Congo, Madagascar, Malawi, Mozambique, Uganda and the United Republic of Tanzania), amounting to a total of 1822 cases including 171 deaths, representing 94.6% and 96.6% of the corresponding world totals. In 2003, 5 countries (Algeria, Democratic Republic of the Congo, Madagascar, Mozambique and Uganda) reported 2091 cases with 180 deaths. These figures represent 98.7% and 98.9% of the corresponding world totals.
Two countries (Peru and the United States) reported 4 cases of human plague in 2002. In 2003, no cases were reported in Peru; 1 case was reported in the United States. All cases recovered.
In 2002, 5 countries (China, India, Kazakhstan, Mongolia and Viet Nam) reported 99 human plague cases with 6 deaths, giving 5.1% and 3.4% of the corresponding world totals. In 2003, 3 countries (China, Kazakhstan and Mongolia) reported 26 cases of human plague, including 2 deaths, representing 1.2% and 1.1% of the corresponding world totals.
For more details on the total number of cases and deaths reported to WHO in 2002 and 2003, please see: Human plague in 2002 and 2003.