Infectious Disease Mortality Trends Shift in United States

Infectious disease mortality declined from 1900 through 1996 in the United States, excluding the 1918 spike due to the Spanish flu pandemic. But since 1996, major changes have occurred.

In a study published in JAMA, researchers sought to examine these changes by investigating trends in infectious disease mortality from 1980 through 2014.

Overall and infectious disease mortality data — based on underlying causes of death – was extracted from the National Office of Vital Statistics reports from 1900 through 1967, and from the CDC WONDER database from 1968 through 2014.

The results of the study showed that overall and infectious disease mortality decreased from 1900 through 1950, except for the 1918 spike, and then leveled off.

From 1980 through 2014, infectious diseases comprised 5.4% (95% CI, 5.15% to 5.8%) of overall mortality rates, according to the study. Per 100,000 population, infectious disease mortality increased from 42 in 1980 to 63.5 in 1995, which paralleled trends in HIV/AIDS mortality.

The decline in overall and HIV/AIDS mortality in 1995 was associated with the introduction of antiretroviral therapy.

From 1980 through 2014, the overall average annual percentage change (AAPC) was 0.4 (95% CI, -0.4 to 1.2). The AAPC was calculated using a 2-sided permutation test.

A majority of infectious disease deaths between 1980 and 2014 were due to pneumonia and influenza (38% [95% CI, 37.1% - 39.4%]).

Since 1980, vaccine-preventable disease death rates have decreased. Mortality due to hepatitis B alone showed an increase coincident with the HIV/AIDS epidemic, the study found. Mortality due to pathogens with drug-resistant strains remained stable since 1980.

Mortality due to the drug-resistant infection, Clostridium difficile, increased from nearly 0 in 1989, until reaching a plateau since 2007.

“Grouping related diseases (eg, vector-borne disease) and using national-level data allow for the evaluation of general trends,” the authors wrote. “However, trends in population subgroups and at the community level, such as measles outbreaks within low-vaccination communities, were not captured. Nonetheless, these trends illustrate the continued US vulnerability to infectious diseases.”