Clostridium difficile is transmitted at higher rates in hospitals or long-term care facilities than in community settings, but more efforts need to be directed at reducing community transmission of the infection, report David P. Durham, Ph.D., and his associates.
Hospitalized symptomatic patients transmit C. difficile at a rate 15 times that of patients who are asymptomatic, according to a model created from U.S. national databases described in the paper. Long-term care facility (LTCF) residents transmit C. difficile at a rate of 27% that of hospitalized patients, while people in the community transmit the infection at a rate of less than 0.1% that of hospitalized patients, the model found.
“Despite the lower community transmission rate, we found that because of the much larger pool of colonized persons in the community, interventions that reduce community transmission hold substantial potential to reduce hospital-onset C. difficile infection by reducing the number of patients entering the hospital with asymptomatic colonization,” reported Dr. Durham, associate research scientist in epidemiology at Yale University, New Haven, Conn., and his associates.
The researchers also estimated the effect of transmission-control interventions on C. difficile incidence by computing the percentage reduction in hospital-onset C. difficile, community-onset C. difficile, and LTCF C. difficile per percentage in improvement in hospital C. difficile diagnosis rate, effectiveness of isolation protocols, overall hospital hygiene, transmission in the community, and transmission in an LTCF.
“We found that C. difficile infection diagnosis rate, effectiveness of isolation, overall hospital hygiene, and transmission in the community, but not transmission in an LTCF, affected hospital-onset C. difficile infection,” the researchers wrote. “In addition, community-onset C. difficile infection and LTCF C. difficile infection were not affected by hospital-based transmission interventions.”
Additionally, as the relative risk for antimicrobial drug class prescribed increased in each of the three settings, the C. difficile incidence increased within the respective setting.
The researchers suggested that the use of vaccines and other toxin-targeting treatments, nontoxigenic C. difficile, and monoclonal antibodies could lead to reductions in primary C. difficile cases and transmission of the infection.
“These results underscore the need for empirical quantification of community-associated transmission and the need of understanding transmission dynamics in all settings when evaluating C. difficile interventions and control strategies,” researchers said.
Read the study in Emerging Infectious Diseases (doi: 10.3201.eid2204.1540455).