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AFHSB Surveillance Case Definitions
FINAL November 2017
Case Definition and Incidence Rules
For surveillance purposes, a case of vaginal candidiasis is defined as:
One hospitalization or outpatient medical encounter with any of the defining diagnoses
of a vaginal candidiasis (see ICD9 and ICD10 code lists below) in the primary diagnostic
position.
Incidence rules:
For individuals who meet the case definition:
The incidence date is considered the date of the first hospitalization or outpatient medical
encounter that includes a defining diagnosis of a vaginal candidiasis.
An individual may be considered a new incident case if at least 30 days have passed
since the last medical encounter with a case defining diagnosis of a vaginal candidiasis
(see explanation of “gap” rule below).
For “first occurrence” incident rate calculations an individual may be considered an
incident case only once per surveillance period.
For recurrent case calculations, an individual is considered a recurrent case if they meet
the case defining criteria for a “new incident case” one or more times during the
surveillance period.
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VAGINAL CANDIDIASIS
Background
This case definition was developed by the Armed Forces Health Surveillance Branch (AFHSB) for the
purpose of epidemiological surveillance of a common type of genitourinary tract infection among
women.
Clinical Description
Vaginal candidiasis, commonly referred to as a yeast infection, is an inflammation of the vagina and
vulva caused by the fungus Candida. Infection is often caused by changes in the normal bacterial flora
or vaginal pH due to antibiotic use, high estrogen levels, tight fitting clothing, douches, and conditions
that alter normal immune functions. Symptoms include redness, swelling, itching, and soreness of the
vaginal area sometimes accompanied by a thick white vaginal discharge. Treatments include antifungal
creams, suppositories, and oral medication, many which are available over the counter.
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Armed Forces Health Surveillance Center. Vaginal Yeast Infections While Deployed in
Southwest/Central Asia, Active Component Females, U.S. Armed Forces, 2008-2013. Medical
Surveillance Monthly Report (MSMR). 2014 Aug; 21(8): 13-15.
