What to know
- In 2021, 1,550 confirmed malaria cases and 9 deaths were reported to the CDC National Malaria Surveillance System.
- This is 2.5 times higher than the number of cases reported in the U.S. during 2020, however still only approximately 75% of the cases reported in 2019.
Key findings
- In 2021, of the 1,550 confirmed cases, 1,044 (67.4%) occurred among U.S. civilians, 11 (<1.0%) among U.S. military members, 191 (12.3%) among non-U.S. residents, and 304 (19.6%) had an unknown residence status.
- P. falciparum species causes the most severe disease and death, and 1,125 cases (88.7%) with a species determination in 2021 were P. falciparum. The second and third most common species determined were P. vivax (69 cases, 5.4%) and P. ovale (37 cases, 2.9%).
- Case classification
- Travel associated (imported): 1,470 (94.8%) cases
- Blood exposure (induced): 1 (<1.0%) case
- The source of malaria could not be determined after an investigation for 4 (<1.0%) cases. For these isolated cases, all reported travel to an endemic country, more than two years prior to illness onset.
- Lost to follow-up: 75 (4.8%) cases whose classification was unable to be determined
- Among 1,470 imported cases, the region of travel was reported for 1,412 cases (96.0%). Of these, Africa was the most common region of travel, reported by 1,327 (94.0%), followed by Asia 63 (4.5%) and less than 1% of cases reported travel in South America, Central America, the Caribbean, Oceania, and the Middle East. Among the 1,327 cases reporting travel in Africa, 935 (70.5%) traveled in West Africa.
- Nine people with malaria died in 2021, a case fatality rate of 0.6%. In 2021, eight of the fatal cases were diagnosed with P. falciparum, and one case had an undetermined species. Two children less than 18 years old died, three people who died were 50 to 59 years old, and four were 65 years or older. Six people who died were female and three were male, and all nine had traveled in Africa. Four had traveled to visit friends and relatives, and five had unknown travel reasons. Seven of the people who died were U.S. civilians, and two had unknown residence status. Two patients who died reported having taken any medication during travel to prevent malaria; one of these was not adherent to the regimen and adherence for the other patient was unknown.
- Thirteen jurisdictions were in the top quartile for having the most malaria cases in 2021 (range from 44 to 212 cases).
Results
Number of malaria cases by demographics, region of acquisition, and primary reason for travel, by patient resident status — United States, 2021
| Demographic Table, 2021 | |||||||||||||||||||
| U.S. Military | U.S. Civilian | Non-U.S. | Not recorded | Total | |||||||||||||||
| Demographics | No. | (%)1 | (%)2 | No. | (%)1 | (%)2 | No. | (%)1 | (%)2 | No. | (%)1 | (%)2 | No. | (%)1 | (%)2 | ||||
| Total | 11 | 0.7 | — | 1044 | 67.4 | — | 191 | 12.3 | — | 304 | 19.6 | — | 1550 | 100 | — | ||||
| Male sex | 10 | 90.9 | — | 645 | 61.8 | — | 112 | 58.6 | 58.6 | 214 | 70.4 | 70.6 | 981 | 63.3 | 63.3 | ||||
| Female sex | 1 | 9.1 | — | 339 | 38.2 | — | 79 | 41.4 | 41.4 | 89 | 29.3 | 29.4 | 568 | 36.6 | 36.7 | ||||
| Unknown | 0 | 0 | — | 0 | 0.0 | — | 0 | 0.0 | — | 1 | 0.3 | — | 1 | 0.1 | — | ||||
| Age less than 18 years | 0 | 0 | — | 176 | 16.9 | — | 81 | 42.4 | — | 34 | 11.2 | — | 291 | 18.8 | — | ||||
| Age 18 – 64 years | 11 | 100 | — | 796 | 76.2 | — | 102 | 53.4 | — | 244 | 80.3 | — | 1153 | 74.4 | — | ||||
| Age 65 years and older | 0 | 0 | — | 72 | 6.9 | — | 8 | 4.2 | — | 26 | 8.6 | — | 106 | 6.8 | — | ||||
| Age unknown | 0 | 0 | — | 0 | 0.0 | — | 0 | 0.0 | — | 0 | 0.0 | — | 0 | 0.0 | — | ||||
| Not Hispanic or Latino | 7 | 63.6 | 87.5 | 830 | 79.5 | 97.1 | 145 | 75.9 | 98.0 | 247 | 81.3 | 97.2 | 1229 | 79.3 | 97.2 | ||||
| Hispanic or Latino | 1 | 9.1 | 12.5 | 25 | 2.4 | 2.9 | 3 | 1.6 | 2.0 | 7 | 2.3 | 2.8 | 36 | 2.3 | 2.8 | ||||
| Unknown | 3 | 27.3 | — | 189 | 18.1 | — | 43 | 22.5 | — | 50 | 16.4 | — | 285 | 18.4 | — | ||||
| Race Asian | 0 | 0.0 | 0.0 | 7 | 0.7 | 0.7 | 14 | 7.3 | 8.9 | 3 | 1.0 | 1.4 | 24 | 1.5 | 1.8 | ||||
| Race Black or African American | 6 | 54.5 | 60.0 | 773 | 74.0 | 82.2 | 91 | 47.6 | 57.6 | 173 | 56.9 | 81.6 | 1043 | 67.3 | 79.0 | ||||
| Race White | 4 | 36.4 | 40.0 | 69 | 6.6 | 7.3 | 10 | 5.2 | 6.3 | 15 | 4.9 | 7.1 | 98 | 6.3 | 7.4 | ||||
| Race Other | 0 | 0.0 | 0.0 | 91 | 8.7 | 9.7 | 43 | 22.5 | 27.2 | 21 | 6.9 | 9.9 | 155 | 10.0 | 11.7 | ||||
| Race Unknown | 1 | 9.1 | — | 104 | 10.0 | — | 33 | 17.3 | — | 92 | 30.3 | — | 230 | 14.8 | — | ||||
| Region of acquisition3 | No. | (%)1 | (%)2 | No. | (%)1 | (%)2 | No. | (%)1 | (%)2 | No. | (%)1 | (%)2 | No. | (%)1 | (%)2 | ||||
| Total | 11 | 0.7 | — | 1012 | 68.8 | — | 190 | 12.9 | — | 257 | 17.5 | — | 1470 | 100.0 | — | ||||
| Africa | 9 | 81.8 | — | 975 | 96.3 | 97.7 | 135 | 71.1 | 71.8 | 208 | 80.9 | 96.7 | 1327 | 90.3 | 94.0 | ||||
| Asia | 2 | 18.2 | — | 9 | 0.9 | 0.9 | 46 | 24.2 | 24.5 | 6 | 2.3 | 2.8 | 63 | 4.3 | 4.5 | ||||
| South America | 0 | 0.0 | — | 3 | 0.3 | 0.3 | 5 | 2.6 | 2.7 | 0 | 0.0 | 0.0 | 8 | 0.5 | 0.6 | ||||
| Central America / Caribbean | 0 | 0.0 | — | 6 | 0.6 | 0.6 | 1 | 0.5 | 0.5 | 1 | 0.4 | 0.5 | 8 | 0.5 | 0.6 | ||||
| Oceania | 0 | 0.0 | — | 3 | 0.3 | 0.3 | 0 | 0.0 | 0.0 | 0 | 0.0 | 0.0 | 3 | 0.2 | 0.2 | ||||
| Middle East | 0 | 0.0 | — | 2 | 0.2 | 0.2 | 1 | 0.5 | 0.5 | 0 | 0.0 | 0.0 | 3 | 0.2 | 0.2 | ||||
| Unknown | 0 | 0.0 | — | 14 | 1.4 | — | 2 | 1.1 | — | 42 | 16.3 | — | 58 | 3.9 | — | ||||
| Africa, West | 5 | 45.5 | — | 702 | 69.4 | 70.3 | 84 | 44.2 | 44.7 | 144 | 56.0 | 67.0 | 935 | 63.6 | 66.2 | ||||
| Primary reason for travel3 | No. | (%)1 | (%)2 | No. | (%)1 | (%)2 | No. | (%)1 | (%)2 | No. | (%)1 | (%)2 | No. | (%)1 | (%)2 | ||||
| Total | 11 | 0.7 | — | 1012 | 68.8 | — | 190 | 12.9 | — | 257 | 17.5 | — | 1470 | 100.0 | — | ||||
| Visiting friends and relatives | 2 | 18.2 | — | 590 | 58.3 | 84.6 | 18 | 9.5 | 14.3 | 25 | 9.7 | 80.6 | 635 | 43.2 | 73.4 | ||||
| Tourist | 0 | 0.0 | — | 29 | 2.9 | 4.2 | 1 | 0.5 | 0.8 | 1 | 0.4 | 3.2 | 31 | 2.1 | 3.6 | ||||
| Missionary or dependent | 0 | 0.0 | — | 26 | 2.6 | 3.7 | 0 | 0.0 | 0.0 | 0 | 0.0 | 0.0 | 26 | 1.8 | 3.0 | ||||
| Business | 0 | 0.0 | — | 34 | 3.4 | 4.9 | 4 | 2.1 | 3.2 | 5 | 1.9 | 16.1 | 43 | 2.9 | 5.0 | ||||
| Student or teacher | 0 | 0.0 | — | 10 | 1.0 | 1.4 | 12 | 6.3 | 9.5 | 0 | 0.0 | 0.0 | 22 | 1.5 | 2.5 | ||||
| Airline/ship crew | 0 | 0.0 | — | 1 | 0.1 | 0.1 | 0 | 0.0 | 0.0 | 0 | 0.0 | 0.0 | 1 | 0.1 | 0.1 | ||||
| Peace Corps | 0 | 0.0 | — | 3 | 0.3 | 0.4 | 0 | 0.0 | 0.0 | 0 | 0.0 | 0.0 | 3 | 0.2 | 0.3 | ||||
| Refugee or immigrant | 0 | 0.0 | — | 0 | 0.0 | 0.0 | 90 | 47.4 | 71.4 | 0 | 0.0 | 0.0 | 90 | 6.1 | 10.4 | ||||
| Military deployment | 9 | 81.8 | — | 0 | 0.0 | 0.0 | 0 | 0.0 | 0.0 | 0 | 0.0 | 0.0 | 9 | 0.6 | 1.0 | ||||
| Other | 0 | 0.0 | — | 4 | 0.4 | 0.6 | 1 | 0.5 | 0.8 | 0 | 0.0 | 0.0 | 5 | 0.3 | 0.6 | ||||
| Unknown | 0 | 0.0 | — | 315 | 31.1 | — | 64 | 33.7 | — | 226 | 87.9 | — | 605 | 41.2 | — | ||||
| 1 Percentage calculated among all subjects | |||||||||||||||||||
| 2 Percentage calculated among subjects with known responses | |||||||||||||||||||
| 3 Among imported cases | |||||||||||||||||||
In 2021, most people diagnosed with malaria in the United States were male, 18 – 64 years old, non-Hispanic or Latino ethnicity, and Black/African American race. Case patients predominantly traveled in Africa. More than half of all case patients traveled to or from West Africa. More than half of U.S. civilians with malaria traveled to visit friends and relatives in 2021.
Supplementary data files
Tables with case counts by species, country of acquisition, and diagnostic confirmation method (e.g., blood smear microscopy only, or polymerase chain reaction confirmed [with or without blood smear microscopy]) are available for download for years 2021.