ID mortality rate in US decreases almost 20% since 1980

The overall death rate from many infectious diseases decreased by nearly 20% in the United States over 35 years, according to researchers.

Only the mortality rate associated with diarrheal disease increased, they wrote in JAMA, and mortality rates of many diseases varied greatly among U.S. counties.

“This study showed declining overall trends of infectious diseases mortality in the United States over the last 35 years, in line with advancements in health care,” researcher Charbel el Bcheraoui, PhD, an assistant professor of global health at the University of Washington, and colleagues wrote. “However, there were large variations between counties in both levels of mortality and rates of change. Access and quality of health care may explain some of the observed differences.”

To assess the changes and disparities in mortality associated with infectious diseases, the researchers compiled data on deaths and causes between 1980 and 2014. They used records from the National Center for Health Statistics, the U.S. Census Bureau and the Human Mortality Database, along with county-level demographic information such as income, education and race or ethnicity. They estimated mortality rates based on six disease categories — lower respiratory infections, diarrheal diseases, HIV/AIDS, meningitis, hepatitis and tuberculosis.

The researchers found that, over those 35 years, 4,081,546 people died from infectious diseases. The six disease categories in the study accounted for 95.9% of deaths. The overall mortality rate decreased from 41.95 deaths per 100,000 people in 1980 to 34.1 deaths per 100,000 people in 2014 — an 18.73% decline.

Lower respiratory infections caused 78.8% of mortalities in 2014, at a rate of 26.87 deaths per 100,000 people. Mortality rates of those infections in the 10th and 90th percentiles of all counties differed by 24.5 deaths per 100,000 people, representing the largest gap between counties of all the disease categories. Mortality from lower respiratory infections peaked in counties in Alabama, Arkansas, Georgia, Kentucky, Louisiana and Tennessee.

HIV/AIDS mortality was largely concentrated in the southeastern U.S., with rates in the upper 5% of the counties that were assessed, the researchers said.

Diarrheal diseases accounted for the second most deaths among the six disease categories. They caused 7.07% of infectious disease mortality, at 2.41 deaths per 100,000 people. Diarrheal diseases were especially high in the corridor extending from Missouri to Maine, an area also in the upper 5%.

In related commentary, Emily K. Shuman, MD, an assistant professor in the University of Michigan Department of Internal Medicine, and JAMA associate editor Preeti N. Malani, MD, MSJ, wrote that officials must work to address the disparities in infectious disease mortality.

“Even though the data on infectious diseases mortality presented by el Bcheraoui [and colleagues] suggest that great strides have been made over the past few decades, it is clear that there is still much work to be done,” they wrote. “Disparities in infectious diseases mortality reflect the persistent problems of income inequality and lack of access to health care.”

Shuman and Malani insisted that working to alleviate those problems requires continued support from government agencies and programs.

“Many governmental agencies and programs including the National Institutes of Health, the CDC, the Ryan White HIV/AIDS program and the Center for Public Health Preparedness and Response have supported important research and clinical care related to infectious diseases,” they added. “Continued investment in these and other programs is vital to ensuring that the progress of the past few decades is not undone.” – by Joe Green

Disclosures: The authors report no relevant financial disclosures.