Risk for Coccidioidomycosis among Hispanic Farm Workers, California, USA, 2018.

To determine occupational risk factors for coccidioidomycosis among adult Hispanic outdoor agricultural workers in California, USA, we conducted a case-control study of workers seen at the Kern County medical facility and referred to the public health laboratory for coccidioidomycosis serologic testing. Participants completed an interviewer-administered health and work questionnaire. Among 203 participants (110 case-patients with positive and 93 controls with negative serologic results), approximately half were women, and more than three quarters were born in Mexico. Associated with coccidioidomycosis were self-reported dust exposure and work with root and bulb vegetable crops. A protective factor was leaf removal, an activity associated with grape cultivation. We conclude that subjective dust exposure and work with root and bulb vegetable crops are associated with increased risk for coccidioidomycosis among Hispanic farm workers. The agricultural industry should evaluate and promote dust-reduction measures, including wetting soil and freshly harvested products.

Prevalence of Bordetella pertussis and Bordetella parapertussis in infants presenting to the emergency department with bronchiolitis.

BACKGROUND: The clinical presentation of Bordetella pertussis can overlap with that of respiratory syncytial virus (RSV), and coinfection does occur, but management differs. HYPOTHESIS: The prevalence of B. pertussis is < 2% among Emergency Department (ED) patients with bronchiolitis. Our secondary hypothesis was that the prevalence of Bordetella parapertussis is also < 2% among these patients. METHODS: Nasal washings were obtained from children up to 18 months of age (inclusive) who presented to a county hospital ED with a clinical diagnosis of bronchiolitis. These washings were frozen to -70°C before testing for B. pertussis and B. parapertussis using species-specific real-time polymerase chain reaction (PCR) assays. The assays were optimized to target conserved regions within a complement gene and the CarB gene, respectively. A Bordetella spp. genus-specific real-time PCR assay was designed to detect the Bhur gene of B. pertussis, B. parapertussis, and B. bronchiseptica. RSV antigen detection was also performed. RESULTS: There were 227 patients enrolled. After exclusions, 204 remained in the analysis. RSV antigen testing was positive in 109/186 (59%) of the patients in whom it was performed. All samples were tested for B. pertussis. B. parapertussis testing could not be completed on 23 samples. No cases (0/204; 95% confidence interval [CI] 0-1.8%) tested positive for B. pertussis or B. parapertussis (0/181; 95% CI 0-2%). CONCLUSION: The prevalence of B. pertussis in children presenting to the ED with bronchiolitis was < 2%.

Outcomes among inmates treated for coccidioidomycosis at a correctional institution during a community outbreak, Kern County, California, 2004.

BACKGROUND: Treatment of pulmonary coccidioidomycosis is typically limited to patients with severe disease or those with increased risk of dissemination. In response to an increase of coccidioidomycosis at a correctional institution in an endemic area, physicians initiated an enhanced diagnosis and treatment program. METHODS: Case patients were inmates with laboratory-confirmed coccidioidomycosis during January 1, 2003, through October 31, 2004. We abstracted medical record data, including demographics, IgG complement fixation (CF) titers, treatment, and clinical outcome for initial and follow-up visits. Case patients receiving antifungal treatment were categorized into early (4 weeks after symptom onset). We evaluated clinical outcome, median IgG CF titer, and time to clinical improvement. RESULTS: Eighty-seven persons were diagnosed with coccidioidomycosis; 79 (91%) records were available. Median age was 36 years (range, 21-71 years), 34 (43%) were black, and all were male. Median time from symptom onset to diagnosis was 3 weeks (range, <1-36 weeks). Most (95%) received antifungal therapy; 32 were in the early treatment and 43 were in the late treatment group. Good clinical outcome was equally likely. In both groups, median peak IgG CF titers were 1:64. Titers in patients with early treatment did not decrease more rapidly. Median time to improvement was similar in early and late treatment groups (7 and 6 months, respectively; P = .6). CONCLUSIONS: Persons incarcerated in endemic areas constitute a susceptible population that should be considered at risk for coccidioidomycosis. Further studies are needed to identify populations that may benefit from early antifungal treatment for pulmonary coccidioidomycosis.

Combining forces--the use of Landsat TM satellite imagery, soil parameter information, and multiplex PCR to detect Coccidioides immitis growth sites in Kern County, California.

Coccidioidomycosis is a fungal disease acquired through the inhalation of spores of Coccidioides spp., which afflicts primarily humans and other mammals. It is endemic to areas in the southwestern United States, including the San Joaquin Valley portion of Kern County, California, our region of interest (ROI). Recently, incidence of coccidioidomycosis, also known as valley fever, has increased significantly, and several factors including climate change have been suggested as possible drivers for this observation. Up to date details about the ecological niche of C. immitis have escaped full characterization. In our project, we chose a three-step approach to investigate this niche: 1) We examined Landsat-5-Thematic-Mapper multispectral images of our ROI by using training pixels at a 750 m × 750 m section of Sharktooth Hill, a site confirmed to be a C. immitis growth site, to implement a Maximum Likelihood Classification scheme to map out the locations that could be suitable to support the growth of the pathogen; 2) We used the websoilsurvey database of the US Department of Agriculture to obtain soil parameter data; and 3) We investigated soil samples from 23 sites around Bakersfield, California using a multiplex Polymerase Chain Reaction (PCR) based method to detect the pathogen. Our results indicated that a combination of satellite imagery, soil type information, and multiplex PCR are powerful tools to predict and identify growth sites of C. immitis. This approach can be used as a basis for systematic sampling and investigation of soils to detect Coccidioides spp.

Prevalence of Bordetella pertussis and Bordetella parapertussis in Samples Submitted for RSV Screening.

BACKGROUND: The clinical presentation of Bordetella pertussis can overlap with that of respiratory syncytial virus (RSV); however, management differs. HYPOTHESIS: First, the prevalence of B. pertussis is less than 2% among patients screened for RSV, and second the prevalence of B. parapertussis is also less than 2% among these patients. METHODS: Nasal washings submitted to a clinical laboratory for RSV screening were tested for B. pertussis and B. parapertussis, using species-specific real-time polymerase chain reaction (PCR) assays. These were optimized to target conserved regions within a complement gene and the CarB gene, respectively. A Bordetella spp. genus-specific real-time PCR assay was designed to detect the Bhur gene of B. pertussis, B. parapertussis, and B. bronchiseptica. RSV A and B subtypes were tested by reverse transcription-PCR. RESULTS: Four hundred and eighty-nine clinical samples were tested. There was insufficient material to complete testing for one B. pertussis, 10 RSV subtype A, and four RSV subtype B assays. Bordetella pertussis was detected in 3/488 (0.6%) (95% CI 0.1% to 1.8%), while B. parapertussis was detected in 5/489 (1.0%) (95% CI 0.3% to 2.4%). Dual infection of B. pertussis with RSV and of B. parapertussis with RSV occurred in two and in three cases respectively. RSV was detected by PCR in 127 (26.5%). CONCLUSION: The prevalence of B. pertussis in nasal washings submitted for RSV screening was less than 2%. The prevalence of parapertussis may be higher than 2%. RSV with B. pertussis and RSV with B. parapertussis coinfection do occur.