Only 8% of California Legionnaires’ cases are Healthcare Associated - Legionella

Only 8% of California Legionnaires’ cases are Healthcare Associated

Why does CDC, CMS, and VA concentrate on this 8%?
What about the other 92%?

925. Healthcare-Associated Legionnaires’ Disease, California, 2015–2017

Open Forum Infectious Diseases [26 Nov 2018, 5(Suppl 1):S28-S28] 2018/12.
Janice Kim, MD, MPH; Kyle Rizzo, MPH; Sean O’Malley, MPH; Monise Magro, DVM, MPVM and Jon Rosenberg, MD, Healthcare-Associated Infections Program, California Department of Public Health, Richmond, California


Legionnaires’ disease (LD) causes significant morbidity and mortality to hospital patients and residents of skilled nursing facilities (SNF). In California, LD is reportable to local health departments via the California Reportable Disease Information Exchange (CalREDIE) surveillance system.

Cases are classified as suspected or confirmed using Centers for Disease Control and Prevention (CDC) definitions. The California Department of Public Health (CDPH) Healthcare-Associated Infections (HAI) Program maintains a database of healthcare-associated LD (HA-LD) and consults with local public health departments for single cases and outbreaks.

We described characteristics of confirmed HA-LD cases in 2015–2017. We classified HA-LD as definite if patient had continuous exposure in a facility for 2–10 days prior to symptom onset and possible if patient had overnight exposure in a facility for a portion of 2–10 days prior to symptom onset.

From 2015 to 2017, 125 (8%) of 1,554 confirmed LD cases were HA-LD. Of these, 73 (58%) were definite HA-LD and 52 (42%) were possible HA-LD. The majority of HA-LD cases (N = 99, 79%) occurred in southern California. SNF were associated with 57 cases (46%) and hospitals with 44 cases (35%); 23 cases (18%) had exposures in both SNF and hospitals during the incubation period.

Among the definite HA-LD cases, 50 cases (68%) had exposures in a single SNF. The median age of patients with HA-LD was 77 years. The HAI Program consulted with 15 local public health agencies on 33 HA-LD investigations, including 7 outbreaks and 26 single-case investigations.

Conclusion. HA-LD represented a small but important percentage of LD in California; the majority occurred in SNF. To prevent HA-LD, California hospitals and skilled nursing facilities should implement water management programs, as recommended by CDC and required by the Centers for Medicare and Medicaid Services (CMS) since June 2017. Public health agencies should respond rapidly to investigate HA-LD cases and control outbreaks.