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

Stephen A Mccurdy,Heejung Bang,Kirt W Emery,Carol L Sipan,Catherine Portillo-Silva

doi:10.3201/eid2607.200024

Abstract

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.

Highlights

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
Study Sample and Demographic Characteristics: We screened 1,803 (51%) of 3,509 persons selected from the Kern County Public Health Services Department periodic lists of coccidioidomycosis testing referrals
Reasons for not screening were wrong numbers or failure to connect after 10 attempts (≈75%), language or communication difficulty (≈15%), or the person declining to be screened (≈10%)

Summary

Introduction

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. Associated with coccidioidomycosis were self-reported dust exposure and work with root and bulb vegetable crops. 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. Coccidioidomycosis (Valley fever or San Joaquin Valley fever) is a pulmonary and systemic infection that results from respiratory exposure to aerosolized arthroconidia spores of soil-dwelling species of Coccidioides fungi [1]. Because most cases are subclinical, public health surveillance substantially underestimates infection risk. McCotter et al estimated that the true number of cases is ≈4–6-fold greater than that captured by public health surveillance [2]

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