Malaria surveillance : annual summary 1974

In 1974, 323 cases of malaria were reported in the United States. This represents a 49.5% increase compared with the 216 cases reported for a similar period in 1973 and was primarily related to a substantial increase in the number of malaria cases that occurred in civilians. In 1974, only 21 cases (7% of all cases reported in the United States) were reported among military personnel, the smallest number since 1960. Coincident with the end of the Vietnam War, only 9 cases originated from Vietnam, down from 31 in 1973. As in previous years, imported Plasmodium vivax infections were more common than falciparum (50.8% versus 28.8%), although P_. falciparum accounted for a larger percentage of malaria cases (an increase of 7.5%) than in 1973.In 7 instances, infection was acquired in the United States, with 3 induced by transfusion, 1 transmitted congenitally, and 3 acquired through local mosquito transmission in the Sacramento Valley of California. The introduced malaria outbreak was the first since 1970. There were 6 malaria deaths reported in 1974, compared with 4 in 1973. All 6 deaths occurred in civilians infected with _P. falciparum malaria acquired in Africa. The P. falciparum malaria death-to-case ratio of 6.4% was slightly lower than that in 1973 (8.6%), but did not differ significantly from the 10-year (1964-1973) ratio of 3.2%.I. SUMMARY -- II. TERMINOLOGY -- III. GENERAL SURVEILLANCE INFORMATION -- IV. MILITARY MALARIA IMPORTED FROM VIETNAM -- V. CIVILIAN MALARIA IMPORTED FROM ABROAD -- VI. MALARIA ACQUIRED IN THE UNITED STATES -- VII. MALARIA DEATHS AND COMPLICATIONS IN THE UNITED STATES -- VIII. REPORT FROM THE NATIONAL MALARIA REPOSITORY -- IX. ADDENDUM I. The Prevention of Malaria -- X. ADDENDUM II. The Microscopic Diagnosis of Malaria.197