January 22, 1993 / Vol. 42 / No. 2

Morbidity and Mortality Weekly Report
Epidemiologic Notes and Reports

Coccidioidomycosis — United States, 1991–1992

During 1991, reported cases of Coccidioidomycosis (i.e., valley fever) in California
increased more than three-fold over the annual number of cases reported since 1986;
during 1992, the number of reported cases increased 10-fold. Coccidioidomycosis, a
fungal disease caused by Coccidioides immitis, is endemic in certain parts of Arizona,
California, Nevada, New Mexico, Texas, and Utah. Sporadic cases occur each year in
parts of the United States in which the disease is not endemic and may present diagnostic
difficulties and laboratory hazards because health-care workers may be
unfamiliar with coccidioidomycosis. Recent increases in California and reports of isolated
cases in areas without endemic disease suggest that physicians and laboratory
personnel should be alert to the possible role of C. immitis. This report summarizes
the occurrence of coccidioidomycosis in California during 1991 and 1992 and highlights
three cases that occurred in areas in which the disease is not endemic.
Outbreak in California

In 1991, 1208 new cases of coccidioidomycosis were reported to the California Department
of Health Services (CDHS), compared with an average of 450 cases per year
during the previous 5 years. Of these cases, 959 (80%) were reported from Kern
County, where coccidioidomycosis is known to be endemic and where the county
health department serves as a referral laboratory for coccidioidomycosis serologic
tests. Of all cases reported to CDHS in 1991, 765 (63%) were reported from October
through December. In 1992, 4541 cases of coccidioidomycosis were reported to CDHS
(Figure 1). Of these, 4198 (92%) were reported from the central valley and southern
California, including 3027 (67%) from Kern County. Reports from the Coccidioidomycosis
Serology Laboratory of the University of California at Davis, a reference
laboratory that receives specimens from areas of California other than Kern County,
also documented an increased incidence in 1991 and 1992.

Nonendemic Coccidioidomycosis

Although no national surveillance system exists for coccidioidomycosis, each year
several cases are reported to CDC that occur outside of the southwestern United
States, where the disease is endemic. Three such case-reports follow.
Case 1. In September 1992, a 24-year-old black man from Virginia developed pulmonary
coccidioidomycosis 2 weeks after driving through California. He was admitted
to a hospital after a chest radiograph indicated bilateral lower lobe infiltrates with extensive
mediastinal and hilar lymphadenopathy. He was presumed to have bacterial
pneumonia and was treated with antibiotics. Efforts to diagnose the pneumonia,
which included bronchoalveolar lavage and transbronchial biopsy, were unsuccessful
until an open-lung biopsy was performed. Culture of the biopsy specimen grew
C. immitis. The patient was treated with an intravenous antifungal agent and was discharged
after 12 days.

Case 2. In August 1992, a 13-year-old black male from Georgia developed symptoms
that included hoarseness, noisy breathing, and difficult breathing 2 months after
visiting southern California, Nevada, and northern Mexico. During initial evaluation, a
laryngeal mass was detected; a laryngeal papilloma was suspected. Treatment with
steroids and bronchodilaters resulted in symptomatic improvement. In October 1992,
a subsequent laryngoscopy detected diffuse granular tissue on the larynx. His-

FIGURE 1. Reported cases of coccidioidomycosis, by year — California, 1986–1992







0        Year       1986   1987  1988  1989  1990  1991  1992

topathologic examination of the biopsy revealed spherules of C. immitis and culture
of the biopsy specimen grew C. immitis. The patient was treated with an intravenous
antifungal agent and, after 5 days, was discharged on an oral antifungal agent.

Case 3. In October 1992, a 30-year-old black woman, who had previously resided in
Arizona, was hospitalized in Florida because of chronic disseminated coccidioidomycosis.
A slant of C. immitis culture isolated from her blood was inadvertently broken
in the hospital’s microbiology laboratory. The fungus had not been handled in a biological
cabinet. The spill was promptly cleaned and disinfected. No subsequent
evidence of clinical infection was found in potentially exposed laboratory personnel.

Reported by: D Pappagianis, MD, Univ of California, Davis; RK Sun, MD, SB Werner, MD, Disease
Investigation Section, GW Rutherford, III, MD, State Epidemiologist, California Dept of Health
Svcs. RW Elsea, MD, Lynchburg Family Practice, Univ of Virginia; GB Miller, Jr, MD, State
Epidemiologist, Virginia Dept of Health. N Bootwala, MD, Egleston Children’s Hospital, Emory
Univ, Atlanta. RS Hopkins, MD, State Epidemiologist, Florida Dept of Health and Rehabilitative
Svcs. Div of Field Epidemiology, Epidemiology Program Office; Div of Bacterial and Mycotic
Diseases, National Center for Infectious Diseases, CDC.

Editorial Note: C. immitis resides in the soil in certain parts of the southwestern
United States, northern Mexico, and a few other areas in the Western Hemisphere.
Infection is caused by inhalation of airborne, infective arthroconidia, one stage in the
organism’s life cycle. In the host, these conidia convert into endosporulating
spherules, the organism’s other morphologic form. The disease is not transmitted
from person to person (1–3 ).

A substantial proportion of adults who are long-time residents of areas where the
disease is endemic have evidence of prior infection with C. immitis by positive coccidioidin
or spherulin skin tests. However, in addition to sporadic disease, these areas
also experience outbreaks, demonstrated by the recent sharp increase in disease incidence
in California. The current outbreak in California may be associated with weather
conditions, especially a recent protracted drought followed by occasional heavy rains.
The magnitude of the outbreak may be partially explained by recent migration of persons
previously unexposed to C. immitis into areas of California where
coccidioidomycosis is endemic. This outbreak illustrates how factors such as weather
and demographic changes can affect the emergence of public health problems from
infectious diseases (4 ).

Approximately 60% of persons infected with C. immitis remain asymptomatic.
Symptomatic coccidioidomycosis has a wide clinical spectrum, ranging from mild influenza-
like illness to serious pneumonia to widespread dissemination. Dissemination
outside the lungs occurs in approximately 0.5% of infections. Coccidioidal meningitis
is a particularly serious manifestation of disseminated coccidioidomycosis. Among
persons who become infected, blacks, Filipinos and other Asians, Hispanics, and
women who acquire the primary infection during the later stages of pregnancy are at
increased risk for disseminated coccidioidomycosis (2,3,5 ). Extrapulmonary coccidioidomycosis
is an acquired immunodeficiency syndrome-defining illness when it
occurs in a person with evidence of infection with human immunodeficiency virus
(6 ).

Infection with C. immitis in persons residing outside coccidioidomycosis-endemic
areas may occur as a result of travel in these areas, laboratory exposure, or inhalation
of contaminated fomites (e.g., soil, cotton, packing material, or museum artifacts)
taken from areas with endemic coccidioidomycosis (7,8 ).

In laboratory cultures, C. immitis develops the highly infectious mycelial form and
may pose a hazard to laboratory workers if arthroconidia from cultures are inadvertently
aerosolized. When clinical laboratories handle C. immitis, laboratory activities
should be performed at biosafety level 3. Subculturing or harvesting of arthroconidia
and opening tubes containing cultures of C. immitis should be performed only in an
appropriate biological cabinet (9 ). Agar slants or bottles should be used, instead of
petri dishes, for the isolation of C. immitis (10 ). If a plate culture is prepared, the plate
should be sealed with adhesive tape once growth is evident, and the culture plate
should be destroyed after 10–14 days. Cultures sent through the mail should be packaged
and labeled in accordance with regulations concerning the interstate shipment of
etiologic agents.*

Clinicians should consider the diagnosis of coccidioidomycosis in persons with undiagnosed
respiratory illnesses or syndromes that could represent disseminated
coccidioidomycosis for those who reside in, or have traveled to, areas where the disease
is endemic, or who have had occupational exposure to C. immitis. Laboratory
personnel should be reminded of necessary safety precautions when handling C. immitis.

1. Drutz D, Catanzaro A. State of the art: coccidioidomycosis (Part I). Am Rev Respir Dis
2. Drutz D, Catanzaro A. State of the art: coccidioidomycosis (Part II). Am Rev Respir Dis
3. Pappagianis D. Epidemiology of coccidioidomycosis. Curr Top Med Mycol 1988;2:199–238.
4. Institute of Medicine. Factors in emergence. In: Lederberg J, Shope RE, Oaks SC, eds. Emerging
infections—microbial threats to health in the United States. Washington, DC: National Academy
Press, 1992:34–112.
5. Smale LE, Waechter KG. Dissemination of coccidioidomycosis in pregnancy. Amer J Obstet
Gynec 1970;107:356–61.
6. CDC. Revision of the CDC surveillance case definition for acquired immunodeficiency syndrome.
MMWR 1987;36(no. S-1):1S–15S.
7. Symmers W St C. Cases of coccidioidomycosis seen in Britain. In: Ajello L, ed. Coccidioidomyosis.
Tucson: University of Arizona Press, 1965:301–5.
8. Gelhlbach SH, Hamilton JD, Connant NF. Coccidioidomycosis—an occupational disease in
cotton-mill workers. Arch Intern Med 1973;131:254–5.
9. CDC, National Institutes of Health. Biosafety in microbiological and biomedical laboratories.
2nd ed. Atlanta: US Department of Health and Human Services, Public Health Service, CDC,
1988:11–30; DHHS publication no. (CDC)88-8395.
10. CDC. General techniques used in medical mycology. In: Ajello L, Georg LK, Kaplan W, Kaufman
L, eds. Laboratory manual for medical mycology. Atlanta: US Department of Health,
Education, and Welfare, Public Health Service, 1963: A14–A22; DHEW publication no. (PHS)994.
Coccidioidomycosis — Continued
*42 CFR Part 72.