The number of coccidioidomycosis-associated deaths in the United States is appreciable. Mortality rates were highest in persons >65 years of age, men, Native Americans, and Hispanics. Since 1997, however, coccidioidomycosis-related mortality rates have been relatively stable.
The increased risk for coccidioidomycosis-associated death among older persons might reflect decreasing immune function and increased prevalence of concurrent diseases. Increasing age has been identified as a potential risk factor for infection with Coccidioides
). The increased rate of coccidioidomycosis-associated deaths observed among men might reflect their higher risk for severe pulmonary and disseminated coccidioidomycosis (17
). The occupations associated with coccidioidomycosis (agricultural work, construction work, military service, and work at archeological sites) might also play an additional role (10
) in the high numbers of coccidioidomycosis-associated deaths among men.
Age-adjusted, race-specific, coccidioidomycosis-associated mortality rates were highest for Native Americans and Hispanics; these rates probably reflect the higher density of American Indian and Hispanic populations living in areas that are arid and where coccidioidomycosis is endemic. All the coccidioidomycosis-associated deaths of Native Americans occurred in the western region of the United States. Some literature sources have suggested that Native Americans are at increased risk for exposure to Coccidioides
spp. because of cultural practices and exposure to contaminated dust (11
). Poor access to health care services might delay diagnosis, resulting in more severe disease. The high rates observed among Native Americans must be interpreted with caution, given the relatively small number of deaths.
Coccidioidomycosis-associated mortality rates were also higher among blacks and Asians than among whites but lower than rates among Native Americans and Hispanics. Black race and Filipino ancestry are recognized risk factors for disseminated disease (2
). We were unable to ascertain coccidioidomycosis-associated mortality rates for Filipino Americans. These higher mortality rates might reflect an increased risk for severe disease, greater risk for exposure, or both.
That coccidioidomycosis-associated mortality rates are highest in Arizona and California is expected, given that Coccidioides
spp. are endemic to these regions. These 2 regions are also classic retirement magnets; they attract elderly persons to migrate and settle down (29
), thereby introducing new, unexposed populations to Coccidioides
spp. Every state recorded coccidioidomycosis-associated deaths, which probably reflects population mobility and movement in and out of coccidioidomycosis-endemic areas after exposure.
Chronic illnesses have changed the way opportunistic mycoses affect the population. The conditions that were associated with coccidioidomycosis were all inherently associated with immunosuppression: HIV, tuberculosis, diabetes mellitus, autoimmune diseases, organ transplant, and cancers of lymphatic cells (30
). Despite relatively low numbers of cases, an association was found between coccidioidomycosis-associated deaths and lupus erythematosus, vasculitis, and rheumatoid arthritis.
Several limitations are inherent when multiple-cause-of-death data are used. Although these data are population based and contain large numbers of observations, death certificates probably underreport causes of death and can contain errors, which have been attributed to a variety of factors (39
). Mortality rates can be distorted because of errors in population estimates, particularly for race/ethnicity. Because estimates of the at-risk population factor into the denominator for rate calculations, such errors can lead to biased estimates. Although inferential statistics are not designed for use with population-based data, 95% CIs demonstrate that error does exist in the mortality rates and rate ratios reported here. We urge caution in the strict interpretation of our values.
Coccidioidomycosis remains a major cause of death in the United States. Given the growing US population of elderly and immunosuppressed persons, the number of coccidioidomycosis-related deaths will probably increase, resulting in higher costs to the health care system (38
). Effects of increasing health care costs associated with coccidioidomycosis have been observed in coccidioidomycosis-endemic states; almost half of the reported case-patients are hospitalized and make multiple visits to emergency rooms and outpatient facilities during the course of the illness (15
). Physicians should be aware of the increased risk for coccidioidomycosis-associated death among those who are immunosuppressed, elderly, male, Hispanic, and/or Native American. For identifying suspected cases, an accurate travel exposure and occupational history are crucial, especially in persons from non–coccidioidomycosis-endemic areas. Further investigation into measures that will effectively decrease coccidioidomycosis exposure risk to the general public is needed, as are more studies of health disparities that surround coccidioidomycosis-associated deaths.