West Nile Virus-Associated Hospitalizations, California, 2004-2017.

BACKGROUND: West Nile virus (WNV) is the most commonly reported mosquito-borne disease in the USA. California reports more WNV disease than any other state. METHODS: We identified WNV-associated hospitalizations from 2004 through 2017 in California and estimated hospitalization incidence using Patient Discharge Data. We described demographic, geographic, and clinical characteristics of WNV hospitalizations; identified risk factors for in-hospital death; and tabulated hospitalization charges. RESULTS: From 2004 through 2017, 3109 Californians were hospitalized with WNV (median, 214 patients/year; range, 72-449). The majority were male (1983; 63.8%) and aged ≥60 years (1766; 56.8%). The highest median annual hospitalization rate (0.88 hospitalizations/100 000 persons) was in the Central Valley, followed by southern California (0.59 hospitalizations/100 000 persons). Most patients (2469; 79.4%) had ≥1 underlying condition, including hypertension, cardiovascular disease, diabetes, chronic kidney disease, or immunosuppression due to medications or disease. Median hospitalization length of stay was 12 days (interquartile range, 6-23 days). During hospitalization, 1317 (42%) patients had acute respiratory failure and/or sepsis/septic shock, 772 (24.8%) experienced acute kidney failure, and 470 (15.1%) had paralysis; 272 (8.8%) patients died. Nearly 47% (1444) of patients were discharged for additional care. During these 14 years, $838 680 664 (mean $59.9 million/year) was charged for WNV hospitalizations, 73.9% through government payers at a median charge of $142 321/patient. CONCLUSIONS: WNV-associated hospitalizations were substantial and costly in California. Hospitalization incidence was higher in males, elderly persons, and patients with underlying conditions. WNV persists as a costly and severe public health threat in California.

Coccidioidomycosis outbreak among inmate wildland firefighters: California, 2017.

BACKGROUND: In California, state prison inmates are employed to fight wildfires, which involves performing soil-disrupting work. Wildfires have become more common, including areas where Coccidioides, the soil-dwelling fungus that causes coccidioidomycosis, proliferates. However, work practices that place wildland firefighters at risk for coccidioidomycosis have not been investigated. METHODS: On August 17, 2017, the California Department of Public Health was notified of a cluster of coccidioidomycosis cases among Wildfire A inmate wildland firefighters. We collected data through medical record abstraction from suspected case-patients and mailed a survey assessing potential job task risk factors to Wildfire A inmate firefighters. We described respondent characteristics and conducted a retrospective case-control investigation to assess coccidioidomycosis risk factors. RESULTS: Among 198 inmate firefighters who worked on Wildfire A, 112 (57%) completed the survey. Of 10 case-patients (four clinical and six laboratory-confirmed), two were hospitalized. In the case-control analysis of 71 inmate firefighters, frequently cutting fire lines with a McLeod tool (odds ratio [OR]: 5.5; 95% confidence interval [CI]: 1.1-37.2) and being in a dust cloud or storm (OR: 4.3; 95% CI: 1.1-17.4) were associated with illness. Two of 112 inmate firefighters reported receiving coccidioidomycosis training; none reported wearing respiratory protection on this wildfire. CONCLUSIONS: Wildland firefighters who use hand tools and work in dusty conditions where Coccidioides proliferates are at risk for coccidioidomycosis. Agencies that employ them should provide training about coccidioidomycosis and risk reduction, limit dust exposure, and implement respiratory protection programs that specify where respirator use is feasible and appropriate.

Coccidioidomycosis Outbreak Among Workers Constructing a Solar Power Farm - Monterey County, California, 2016-2017.

In January 2017, two local health departments notified the California Department of Public Health (CDPH) of three cases of coccidioidomycosis among workers constructing a solar power installation (solar farm) in southeastern Monterey County. Coccidioidomycosis, or Valley fever, is an infection caused by inhalation of the soil-dwelling fungus Coccidioides, which is endemic in the southwestern United States, including California. After a 1-3 week incubation period, coccidioidomycosis most often causes influenza-like symptoms or pneumonia, but rarely can lead to severe disseminated disease or death (1). Persons living, working, or traveling in areas where Coccidioides is endemic can inhale fungal spores; workers who are performing soil-disturbing activities are particularly at risk. CDPH previously investigated one outbreak among solar farm construction workers that started in 2011 and made recommendations for reducing risk for infection, including worker education, dust suppression, and use of personal protective equipment (2,3). For the current outbreak, the CDPH, in collaboration with Monterey County and San Luis Obispo County public health departments, conducted an investigation that identified nine laboratory-confirmed cases of coccidioidomycosis among 2,410 solar farm employees and calculated a worksite-specific incidence rate that was substantially higher than background county rates, suggesting that illness was work-related. The investigation assessed risk factors for potential occupational exposures to identify methods to prevent further workplace illness.

Notes from the Field: Increase in Coccidioidomycosis - California, 2016.

Coccidioidomycosis, or Valley Fever, is an infectious disease caused by inhalation of Coccidioides spp. spores (1). This soil-dwelling fungus is endemic in the southwestern United States, with most (97%) U.S. cases reported from Arizona and California (1,2). Following an incubation period of 1-3 weeks, symptomatic patients most often experience self-limited, influenza-like symptoms, but coccidioidomycosis also can lead to severe pulmonary disease and to rare cases of disseminated disease, including meningitis (1). Those at increased risk for severe disease include persons of African or Filipino descent, pregnant women, adults in older age groups, and persons with weakened immune systems (1). In 2016, a large increase in coccidioidomycosis incidence was observed in California compared with previous years (3). Using data reported by health care providers and laboratories via local health departments to the California Department of Public Health as of May 9, 2017, incidence rates were calculated by estimated year of illness onset as the number of confirmed coccidioidomycosis cases per 100,000 population (3). Estimated year of illness onset was extracted from the closest date to the time when symptoms first appeared for each patient. From 1995, when coccidioidomycosis became an individually reportable disease in California, to 2009, annual incidence rates ranged from 1.9 to 8.4 per 100,000, followed by a substantial increase to 11.9 per 100,000 in 2010 and a peak of 13.8 per 100,000 in 2011 (Figure). Annual rates decreased during 2012-2014, but increased in 2016 to 13.7 per 100,000, with 5,372 reported cases, the highest annual number of cases in California recorded to date.