Clinical, demographic factors identify patients at risk for measles transmission

SAN DIEGO — Clinical and demographic features of patients in particular regions may be used to identify those at risk for measles transmission during an outbreak, according to data presented at IDWeek 2015.

“Our preliminary findings indicate that certain demographic and clinical features of measles cases are associated with transmitting measles (or not),” Jennifer Zipprich, PhD, of the immunization branch of the California Department of Public Health, told Infectious Diseases in Children. “These findings are part of a larger project to help us understand how to prioritize measles contact investigations in the setting where multiple investigations are occurring, such as a large, statewide measles outbreak.”

The researchers reviewed all cases of measles reported to the California Department of Public Health from January 2000 to July 1, 2015. Epidemiologic linkage was used to classify patients as “measles transmitters,” if they were found to have transferred measles to another adult or child. The researchers identified factors associated with measles transmission, including vaccination status, fever, cough and conjunctivitis.

During the study period, 397 cases of measles were confirmed. Study results showed that coughing increased the likelihood of measles transmission (OR = 3.3; 95% CI, 1.1-9.7). Furthermore, children who received at least two doses of measles vaccine reported coughing (P < .0001), coryza (P < .0001), conjunctivitis (P < .0001), fever (P <. 01) and hospitalization (P = .03) less frequently than children who received one dose or no vaccine.

Study results also showed that children aged younger than 12 months (OR = 0.1; 95% CI, 0.03-0.06) and those vaccinated against measles (OR = 0.3; 95% CI, 0.1-0.9) had a decreased likelihood of being a measles transmitter.

“Understanding what cases or situations present the highest risk for measles transmission will help us to use public health resources efficiently,” Zipprich said. – by David Costill

Reference:
Zipprich J, et al. LB-4. Presented at: IDWeek; Oct. 7-11, 2015; San Diego.

Disclosure: The researchers report no relevant financial disclosures.