Salmonella infections among infants have been rising gradually since the mid-2000s, and invasive infections are more common among Black and Asian infants, according to a new study.
“Salmonella among infants continues to be associated with substantial morbidity and mortality,” authors wrote in “Epidemiology of Salmonellosis Among Infants in the United States: 1968-2015,” (Self JS, et al. Pediatrics. May 10, 2023).
Researchers from the Centers for Disease Control and Prevention used two surveillance systems to describe characteristics of nontyphoidal Salmonella infections (salmonellosis) over a 48-year period. They focused on infections in infants, the age group with the highest incidence rates and developing immune systems.
Data from the national surveillance system showed there were 190,627 confirmed Salmonella infections among infants from 1968-2015, although these infections are known to be underreported. Following declines in the 1990s, salmonellosis has been increasing gradually since the mid-2000s, according to the study.
During the 48-year span, about 86.7% of cases were gastroenteritis, 3.5% were bacteremia, 0.2% meningitis and 9.7% had another/unknown cause. Cases of gastroenteritis and bacteremia had a median age of 4 months, while infants with meningitis tended to be younger, with a median age of 2 months.
Data from 2004-’15 showed racial differences in invasive infections (bacteremia and meningitis). Infection rates were about 2.7 times higher for Black infants than White infants and 1.8 times higher for Asian infants than White infants.
The Typhimurium serotype caused the largest percentage of Salmonella infections among infants both overall and for gastroenteritis. The Heidelberg serotype was the most common serotype reported in bacteremia and meningitis cases, according to the study.
Hospitalization and death rates were highest for meningitis. About 96% of infants with meningitis, 70% of those with bacteremia and 26% of those with gastroenteritis were hospitalized. Deaths occurred in about 4% of meningitis cases, 1.6% of bacteremia cases and 0.1% of gastroenteritis cases.
Authors called for more research on risk factors for salmonellosis in infants.
“Many infants are probably exposed to Salmonella in the home; they might become infected from the same exposures that could infect other family members, including consumption of foods and contact with contaminated surfaces, or they might acquire illness from family members,” they wrote. “Food is the major source of salmonellosis for the general population, so the most effective control measure might be to decrease Salmonella contamination of food.”