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Member Research & Reports

Member Research & Reports

Columbia Researchers Study Bacterial Infections among New York City-born Infants

Researchers at the Mailman School of Public Health and the New York City Department of Health and Mental Hygiene studied the reported cases of bacterial infections among infants in New York City to identify the populations at risk for this preventable cause of morbidity. Findings indicated there were distinct patterns of risk factors among infants born to mothers of Asian/Pacific Islander descent and, of Chinese background in particular, who resided in Brooklyn, New York, for example. The study is published online in the Journal of Pediatrics.  For the first author, Ms. Beth Isaac (MPH ’14, now at NYC Department of Health & Mental Hygiene), this began as her Epidemiology practicum and MPH thesis at Mailman.

[Photo: Dr. Stephen S. Morse]

Live births in New York City from 2001-2009 were matched to reported cases of bacterial infections among infants less than one year of age. Characteristics recorded on birth certificates were compared between infants with bacterial enteric infections (usually foodborne), bacterial nonenteric infections (such as strep, or pertussis — whooping cough), and no reported bacterial infection.

A bacterial infection was reported in 4.6 cases per 1000 live births.  Enteric infections were generally the most common.  Of 4524 infants with a reportable infection, 63 percent had an enteric infection. Asian/Pacific Islanders in Brooklyn had the highest enteric infection rate (8.5 per 1000 live births). In contrast, infants with nonenteric infections were more likely to have low birthweight, mothers characterized as U.S.-born and be of African-American or white Hispanic race ethnicity. “This study shows clear differences in patterns of disease and risk factors in different populations in the city,” said Dr. Stephen S. Morse, professor of epidemiology at the Mailman School. “This can help to target interventions where they’ll do the most good.”

Salmonellosis was the most frequent infection, at 39 percent of all infections reported, both across the entire study period and for every year of birth. The five infections with the highest incidence (salmonellosis, campylobacteriosis, Group B Strep, pertussis, and chlamydia) comprised 85 percent of all reported infant bacterial infections, with salmonellosis and campylobacteriosis constituting nearly 61 percent. Of all infants reported with bacterial infection, 63 percent met the definition for enteric infection. Thirteen infants were reported with both enteric and nonenteric bacterial infections.

Citywide, infants with enteric infections were disproportionately male, from higher poverty neighborhoods, born to foreign-born mothers, and enrolled in Special Supplemental Food Program for Women, Infants, and Children, or Medicaid.

Studies typically focus on identifying risk factors for individual diseases, according to the researchers. “This study demonstrates how linking different data sources – in this case, public health surveillance data and birth records – can provide new insights,” noted Dr. Morse.