Lessons From an Outbreak of Legionnaires' Disease on a Hematology-Oncology Unit.

OBJECTIVES To define the scope of an outbreak of Legionnaires' disease (LD), to identify the source, and to stop transmission. DESIGN AND SETTING Epidemiologic investigation of an LD outbreak among patients and a visitor exposed to a newly constructed hematology-oncology unit. METHODS An LD case was defined as radiographically confirmed pneumonia in a person with positive urinary antigen testing and/or respiratory culture for Legionella and exposure to the hematology-oncology unit after February 20, 2014. Cases were classified as definitely or probably healthcare-associated based on whether they were exposed to the unit for all or part of the incubation period (2-10 days). We conducted an environmental assessment and collected water samples for culture. Clinical and environmental isolates were compared by monoclonal antibody (MAb) and sequence-based typing. RESULTS Over a 12-week period, 10 cases were identified, including 6 definite and 4 probable cases. Environmental sampling revealed Legionella pneumophila serogroup 1 (Lp1) in the potable water at 9 of 10 unit sites (90%), including all patient rooms tested. The 3 clinical isolates were identical to environmental isolates from the unit (MAb2-positive, sequence type ST36). No cases occurred with exposure after the implementation of water restrictions followed by point-of-use filters. CONCLUSIONS Contamination of the unit's potable water system with Lp1 strain ST36 was the likely source of this outbreak. Healthcare providers should routinely test patients who develop pneumonia at least 2 days after hospital admission for LD. A single case of LD that is definitely healthcare associated should prompt a full investigation. Infect Control Hosp Epidemiol 2017;38:306-313.

System-level factors as predictors of adherence to clinical appointment schedules in antiretroviral therapy in Cambodia.

Adherence to clinical appointment schedules by patients on antiretroviral therapy (ART) is necessary for the prevention of medication interruptions, viral rebound, and the development of drug resistance. An observational study conducted in 2010, Enablers and Adherence to Antiretroviral Therapy in Cambodia, sought to identify factors that predict on-time clinical appointment attendance by patients on ART. Clinical data, including appointment attendance across five consecutive visits, were collected from hospital records on a random sample of ART patients at government referral hospitals (RHs) in Battambang Province, Cambodia. Interviews were conducted to obtain quantitative information from patients on their experiences of support services provided by local NGOs and RHs. This information was used to identify ART patient care and support system factors that could potentially enable patients to adhere to clinical appointment schedules. These factors included adherence counseling, support groups, home-based care (HBC) services, and support provided for transportation to ART appointments. Bivariate and multivariable logistic regression analysis was done to assess relationships between system variables and the ART appointment adherence outcome. Of the 289 study participants, 20.4% had missed at least one of the five appointments in the study period. The hospital source of ART services, participation in a hospital-based support group, receiving a loan from a microfinance institution, and the frequency of adherence counseling were found to be associated with ART appointment adherence. No significant associations were found between other support system factors such as HBC, transportation support, food/monetary support, and appointment adherence.