INDIANAPOLIS, Ind. — African Americans in Marion County are three times more likely to test positive for COVID-19 than white people, according to the Marion County Public Health Department.

About 290 cases per 100,000 African Americans were reported in Indianapolis from March 1 through April 16, compared to 97 per 100,000 white residents.

Black people in Marion County have been 2.5 times more likely than white people to be hospitalized with COVID-19 and twice as likely to die from the virus.

COVID-19 deaths, hospitalizations, and cases of illness per 100,000 African American or white Marion County residents, March 1-April 16, 2020

The difference in impact by race is not just a local problem. National data also shows a higher percentage of hospitalizations and deaths among the black population.

The Marion County Health Department did not offer an explanation for the disproportionate number of cases in African Americans, but medical experts told NPR there could be several causes at play, including genetic factors, stress and a higher prevalence of obesity, high blood pressure and diabetes among the African American population.

Research from Johns Hopkins University also points to racial inequities in socio-economic status, living conditions and access to medical care in the U.S. as potential factors.

The county heath department noted that race information was not available for 37% of confirmed cases and 17% of the deaths that were investigated.

However, the missing data is not sufficient to reverse the large differences in rates of illness and death between black people and white people.

The hospitalization rate among African Americans was 106 per 100,000 residents, compared to 43 per 100,000 for white residents. Deaths reached 20 per 100,000 among African Americans, compared to 11 per 100,000 for whites.

The health department also released data showing the level of elevated risk among men and the elderly, regardless of race.

While similar proportions of men and women have been infected with COVID-19 in Marion County, men have been twice as likely to die from the disease. 20 deaths per 100,000 men have been reported, compared to 10 deaths per 100,000 women.

Not surprisingly, the risk of illness and death increased with age. The number of cases per population increased gradually from age 20 to 64, then jumped substantially in the 65-84 age group and again for the 85-plus age group.

COVID-19 deaths per 100,000 Marion County residents, by age range

Less than one death per 100,000 people was reported among 20 to 44 year olds, compared to more than 200 deaths per 100,000 for people 85 and older.