Valley Fever epidemic

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COCCIDIOIDOMYCOSIS - USA (CALIFORNIA)

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[see also:

Coccidioidomycosis - USA (Arizona) 20000503.0676]

Date: 5 Oct 2001 9:14 PM

Source: The Bakersfield Channel [edited]

<http://www.thebakersfieldchannel.com/news/1006077/detail.html>

BAKERSFIELD, 9:14 p.m. PDT 5 Oct 2001 -- Valley Fever is primarily a

disease of the lungs that is common in the southwestern United States

and

northwestern Mexico. [Patients] contract it from breathing in fungal

spores, which grow during spring rains. When summer hits and the

winds pick

up, the spores are carried through the air. That's when people get

infected.

Researchers said that this year the Bakersfield area is in the midst

of a

Valley Fever epidemic. Last year at this time, 300 new cases had been

diagnosed. So far this year, that number is well above 500. Experts

said

that a monsoon-like rain that came through parts of the valley in

July

could be part of the reason behind the sharp increases in cases.

Gov. Gray has until 15 Oct 2001 to sign legislation that would

continue

state support of the efforts to eradicate Valley Fever. Otherwise, it

will

be vetoed, [TV station] KERO 23 reports.

--

ProMED-mail

<promed@...>

[Valley fever is another name for coccidioidomycosis, which is caused

by

_Coccidioides immitis_, a fungus found in soil. The disease is

endemic to

the western USA and periodic outbreaks are seen. The clinical picture

includes cough, chest pain, myalgias, and headaches. Erythema nodosum

is

seen in approximately 20 percent of cases. Disseminated disease can

result

in diffuse granulomatous abscess formation in skin and other tissues,

and

can be fatal. Renal failure can result from granulomatous disease of

the

kidneys.

According to GIDEON (Global Infectious Disease and Epidemiology Net

<http://www.cyinfo.com/> ) Coccidioidomycosis was first reported in

the

United States in 1893 - as fatal infection acquired in California's

San

Joaquin Valley, one of the areas where the disease is most common.

Other

areas include Arizona, Texas, New Mexico, southern Nevada, and Utah.

The

highest incidence occurs in late summer and early fall - large

outbreaks

frequently follow dust storms. An estimated 100 000 infections occur

in the

United States annually, and 1 in 200 infections progresses to

disseminated

disease. The mean incidence in California during 1986 to 1990 was 450

per

year. Kern County accounted for 52% of California cases during 1981

to 1990

and 70% during 1991 to 1993. In all, 1208 cases were reported

nationwide in

1991; 4516 in 1992; 4137 in 1993. - Mod.MPP]

[Fisher et al. (J Clin Microbiol. 2000 Feb;38(2):807-13) have shown

that

" epidemics " of coccidioidomycosis in the southwestern USA are related

to

environmental factors such as periods of drought followed by periods

of

increased rainfall. It is noteworthy that southern California was

greener

than normal this spring and summer due to rainfall patterns, so

perhaps

this increased incidence should be expected in the context of

climatic

patterns. - Mod.ES]

COCCIDIOIDOMYCOSIS ­ US (AZ): BACKGROUND

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International Society for Infectious Diseases

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Date: Sat, 15 Feb 2003 08:33:20 -0500 (EST)

From: ProMED-mail <promed@...>

Source: MMWR 2003 Vol 52, No 06;109 [Fri 14 Feb 2003] [edited]

Increase in Coccidioidomycosis --- Arizona, 1998-2001

--------------------------------------------

Coccidioidomycosis is a systemic infection caused by inhalation of

airborne

spores from _Coccidioides immitis_, a fungus found in soil in the

southwestern United States and in parts of Mexico and Central and

South

America (1). Infection occurs usually following activities or natural

events that disrupt the soil, resulting in aerosolization of the

fungal

arthrospores (2). Clinical manifestations occur in 40 percent of

infected

persons and range from an influenza-like illness (ILI) to severe

pneumonia

and, rarely, extrapulmonary disseminated disease (3).

Persons at higher risk for disseminated disease include blacks,

Filipinos,

pregnant women in their third trimester, and immunocompromised

persons (4).

During 2001, the Arizona Department of Health Services (ADHS)

reported a

coccidioidomycosis incidence of 43 cases per 100 000 population,

representing an increase of 186 percent since 1995 (3). To

characterize

this increase, CDC analyzed data from the National Electronic

Telecommunications System for Surveillance (NETSS) and the Arizona

Hospital

Discharge Database (AHDD), and environmental and climatic data, and

conducted a cohort study of a random sample of patients with

coccidioidomycosis. This report summarizes the findings of this

investigation, which indicate that the recent Arizona

coccidioidomycosis

epidemic is attributed to seasonal peaks in incidence that probably

are

related to climate. Healthcare providers in Arizona should be aware

that

peak periods of coccidioidomycosis incidence occur during the winter

and

should consider testing patients with ILI.

Surveillance and Hospitalizations:

Coccidioidomycosis became a nationally reportable disease at the

southwest

regional level through NETSS in 1995, at which time a case definition

was

adopted that required laboratory confirmation*. During 1997,

laboratory

reporting of coccidioidomycosis became mandatory in Arizona, after

which a

marked increase was noted in the number of reported cases. However,

incidence continued to increase in subsequent years. NETSS data for

1998-2001 were analyzed to calculate incidence by using U.S. Census

2000

data for denominators.

During 2001, a total of 2203 cases were reported to ADHS (rate: 43

cases

per 100 000 population), compared with 1551 cases in 1998 (rate: 33).

Persons aged >65 years had the highest incidence (79 during 2001),

although

incidence in all age groups increased. The youngest age groups

experienced

the largest increase in incidence during the surveillance period:

during

2001, incidence of coccidioidomycosis among patients aged <20 years

increased 121 percent, from approximately 5 in 1998 to 11 in 2001.

Analysis by season demonstrated peak periods of disease incidence

during

the winter months (November-February) (Figure 1). The baseline rate

between

peak periods was stable, indicating that the seasonal periods were

responsible for the overall annual increase in reported cases. AHDD

was

reviewed to identify patients with a primary or secondary discharge

diagnosis of coccidioidomycosis (International Classification of

Diseases,

Ninth Revision codes 114.0-114.3 and 114.5-114.9).

Hospitalizations caused by coccidioidomycosis increased substantially

during the study period. During 2001, a total of 598 persons were

discharged with a primary or secondary diagnosis of

coccidioidomycosis,

compared with 69 persons during 1998; 154 (26 percent) of the 598

hospitalized patients had disseminated coccidioidomycosis. Persons

aged >65

years comprised 34 percent of all hospitalized patients during the

study

period and had the highest rate of hospitalization (29 per 100 000

population during 2001).

Cohort Study:

To explain peak periods and to further characterize the epidemic, CDC

conducted a cohort study of patients from NETSS who had

coccidioidomycosis

to evaluate host factors, exposures, and outcomes.

Patients reported with coccidioidomycosis were divided into 4 groups

based

on inclusion in peak or nonpeak periods and year of disease. Of 208

randomly selected persons contacted by telephone, 196 (94 percent)

completed a questionnaire (range per group: 43-56 persons). No

statistically significant differences were found between groups

related to

host risk factors or exposures that could explain the large peak

seasons.

Geographic Information Systems:

Geographic Information Systems (GIS) software was used to identify

areas of

high incidence in Maricopa County, the most populous county in

Arizona.

Locations of patients identified in NETSS and AHDD were plotted by

postal

code by using Arc View v3.2, and incidence was calculated by using

U.S.

Census 2000 data. The highest incidence of coccidioidomycosis for

both

NETSS cases and hospitalizations occurred in areas surrounding

metropolitan

Phoenix (Figure 2). These areas have experienced substantial

construction

activity according to building permit data provided by the Maricopa

County

Association of Governments. Seasonal variations in construction

activity

approximated by building permits were not significantly associated

with

cases (Table).

Environment and Climate:

Arizona has been experiencing dry weather conditions recently.

Environmental and climatic data were analyzed in relation to

incidence of

disease, and Poisson regression was performed to construct a model

that

might predict seasonal peaks. Many climatic variables were

significantly

associated with increased incidence of disease, including drought

indices

(Palmer Z Index and Palmer Drought Severity Index), wind velocity,

mean

temperature, dust (measured by concentration of suspended particulate

matter <10 microns), and rain (Table). Poisson regression analysis

indicated a high correlation (R-squared = 0.75) between incidence of

disease and 1) cumulative rain during the preceding 7 months, 2) the

average temperature during the preceding 3 months, 3) dust during the

preceding month, and 4) the amount of rain during the preceding 2

months in

proportion to the preceding 7 months. The projected cases based on

the

model were compared with the actual cases in Maricopa County (Figure

1).

The model accurately mirrored peak seasonal periods during 1998-1999,

in

particular the large peak beginning in November 2001. In addition,

the

model accurately described the absence of a seasonal peak during

winter

2000-01.

Reported by: K Komatsu, V Vaz, C McRill, T Colman, Arizona Dept of

Health

Svcs; A Comrie, Univ of Arizona Dept of Geography, Tucson. K Sigel, T

, M Phelan, R Hajjeh, Div of Bacterial and Mycotic Diseases,

National

Center for Infectious Diseases; B Park, MD, EIS Officer, CDC.

Editorial Note:

Coccidioidomycosis is the fourth most common infectious disease

reported to

ADHS; only gonorrhea, chlamydia, and chronic hepatitis C are more

frequent

(ADHS, unpublished data, 2002). The findings in this report indicate

that

the incidence of coccidioidomycosis in Arizona has increased

substantially

since 1998, affecting all age groups. In addition, hospitalizations

for

coccidioidomycosis have increased, indicating an increase in the

numbers of

persons with severe disease. Although seasonality of

coccidioidomycosis in

Arizona has been suggested previously, this study is the first to

confirm

the pattern (5,6). In addition, this study documents peak incidence

periods

during November-February; improved timeliness and completeness of

reporting

because of mandatory laboratory reporting since 1997 might have

helped

reveal the seasonal pattern. Seasonal fluctuations could not be

explained

by differences in the prevalence of the various host risk factors or

exposures but were significantly associated with climatic and

environmental

factors. A climate model incorporating some of these factors

recreated the

seasonal outbreaks in Maricopa county and predicted that large

outbreak

seasons might occur during winter seasons following prolonged drought

periods, especially in conjunction with hot and dusty conditions.

These

conditions, which might facilitate aerosolization of arthrospores,

have

been described in studies of coccidioidomycosis epidemics in

California

(7). Dry and dusty conditions continue in Arizona, suggesting that

another

large peak season might occur this winter. Preliminary data for 2002

indicate that the number of total cases already exceeds 3000,

considerably

surpassing 2001 levels (ADHS, unpublished data, 2002). Although

coccidioidomycosis is not readily preventable, a better understanding

of

its epidemiology can assist in developing more effective prevention

and

education strategies and help with earlier diagnosis and appropriate

medical management. Healthcare providers should consider testing for

coccidioidomycosis in any patient who has moved or traveled recently

to

Arizona and who has ILI, especially during the winter months. Dust

reduction measures, such as paving roads or wetting soil at

construction

sites, are currently in place and might be useful in preventing

further

cases. Persons at risk for severe disease should avoid activities

that

might increase their exposure to dust. These persons might benefit

from

development of a vaccine that confers long-term immunity (6).

References

Galgiani JN. Coccidioidomycosis: a regional disease of national

importance:

rethinking approaches for control. Ann Intern Med 1999;130:293-300.

Schneider E, Hajjeh RA, Spiegel RA, et al. A coccidioidomycosis

outbreak

following the Northridge, California, earthquake. JAMA 1997;277:904-

8.

Ampel NM, Mosley DG, England B, Vertz PD, Komatsu K, Hajjeh RA.

Coccidioidomycosis in Arizona: increase in incidence from 1990 to

1995.

Clin Infect Dis 1998;27:1528-30.

Rosenstein NE, Emery KW, Werner SB, et al. Risk factors for severe

pulmonary and disseminated coccidioidomycosis: Kern County,

California,

1995-1996. Clin Infect Dis 2001;32:708-15.

Kerrick SS, Lundergan LL, Galgiani JN. Coccidioidomycosis at a

university

health service. American Review of Respiratory Disease 1985;131:100-

2.

Kirkland TN, Fierer J. Coccidioidomycosis: a reemerging infectious

disease.

Emerg Infect Dis 1996;2:192-9.

Koenig G, White TJ, JW, Fisher MC. Pathogenic clones versus

environmentally driven population increase: analysis of an epidemic

of the

human fungal pathogen Coccidioides immitis. Mol Biol Evol

2000;17:1164-74.

* The laboratory criteria for diagnosis are cultural,

histopathologic, or

molecular evidence of the presence of Coccidioides spp; a positive

serologic test for coccidioidal antibodies in serum or cerebrospinal

fluid

by 1) detection of coccidioidal IgM by immunodiffusion, enzyme

immunoassay

(EIA) latex agglutination, or tube precipitin or 2) detection of

rising

titer of coccidioidal IgM by immunodiffusion, EIA, or complement

fixation;

or a coccidioidal skin test conversion from negative to positive

after the

onset of clinical signs and symptoms.