Estimates of annual infections

Coccidioidomycosis is a reportable disease at the national level and in certain states. Reported infections number in the thousands in Arizona and California. In Arizona (1999), coccidioidomycosis is the third most common reportable infectious disease (Arizona Department of Health Services). However, an alternative analysis suggests that unreported infections far outweigh those that are reported. In Arizona, approximately 3.3 million people reside in Maricopa and Pima counties (Table 1). Of these, approximately two-thirds (2.2 million) appear susceptible as judged by non-reactive skin tests to coccidioidal antigens. If the average risk of annual infection in southern Arizona is 3%, then the predicted number of infections would be 100,000, nearly fifty times the number actually reported to the state.

Reasons for under reporting of

Valley Fever

The striking discrepancy between the expected number of infections and those actually reported is predominately related to two factors. First, in some states, reporting of new coccidioidal infections is the responsibility of the treating physician, many of whom may not be aware of this obligation and others may be unable to find the time to comply. This was the case for Arizona until April 1997, when its Department of Health Services expanded reporting responsibility to laboratories that identify serologic or cultural evidence of coccidioidal infections. If all states were to follow this approach, reporting deficiencies would be greatly diminished.

A second factor contributing to under reporting of coccidioidal infections is related to the lack of recognition of coccidioidal infections by health care professionals. The diagnosis of Valley Fever depends upon specific laboratory testing (see Section 4). If health care professionals do not consider the diagnosis of Valley Fever and diagnostic tests are not performed, many patients with coccidioidomycosis will go undiagnosed and consequently, unreported. This source of under reporting cannot be rectified simply by a change in reporting requirements. It will require a reexamination of the importance of identifying early infections and a change in the practice patterns of primary care medicine.

The value of identifying patients with early coccidioidal infections

At a superficial level, there are seemingly reasonable arguments for primary care physicians not being concerned with identifying most early infections of C. immitis. Frequently, primary care givers feel that because most patients do not require antifungal therapy, why bother with establishing a diagnosis. Instead, simply wait for complications to develop in the few patients that become more serious and then treat those. Closely related to this argument is another consideration; the pursuit of a diagnosis of Valley Fever requires laboratory testing (see below) that comes with a cost. This cost will vary widely depending upon a variety of local circumstances.

At the University of Arizona Student Health Center and the Southern Arizona Veterans Administration Health Care System, approximately one in six patients who are tested for Valley Fever are found to be positive. If the cost of the serologic test averages $40, then the cost to identify an infected patient would only be approximately $240. Although ignoring most coccidioidal infections is one approach, it may not be the best strategy for optimal patient care.

One important reason for diagnosing early coccidioidal infections is that an accurate diagnosis is beneficial to the patient, even if it does not always lead to initiating drug therapy. Giving an illness a specific name is beneficial to patients because it removes the fear of the unknown. Early in this century, diagnosis used to be the major contribution of physicians. Today, even though we have many interventions at our disposal, the value of diagnosis should not be overlooked. This is especially true for patients over the age of 30, where the concern that undiagnosed respiratory illness may represent cancer. A myriad of physical, mental, and emotional consequences are associated with an incorrect or suspected diagnosis of cancer. For all ages, an accurate diagnosis allows for reassurance in most cases and appropriate prognostic patient education.

Additionally, early diagnosis of Valley Fever reduces or eliminates the need to search for another diagnosis. The symptoms associated with Valley Fever often resolve only after a period of weeks to even months. Patients with symptoms that persist this long may be subjected to diagnostic blood tests, chest X-rays, CT scans, MRIs, bronchoscopy, percutaneous fine needle aspiration, and even thoracotomies. All of these procedures carry attendant costs and cause patient discomfort and morbidity which may be avoided if coccidioidomycosis were known to have been responsible.

A third benefit of diagnosing coccidioidal infections early is the reduction or elimination of empiric therapy for bacterial infection. Patients with persistent respiratory complaints often receive empiric antibiotics in an ambulatory practice. In one study, 21% of antibiotic use in ambulatory care was prescribed for "upper respiratory infections" or "bronchitis." If symptoms persist despite an initial course of empiric therapy, there is a temptation to try a second or even third course of therapy to manage the problem. In addition to the cost of antibiotics, this strategy has the potential to cause adverse events for the patient and increase antibiotic resistance in the community. A less frequent but potentially more serious problem is the use of corticosteroids for the cutaneous or rheumatologic complaints that may accompany primary coccidioidal infection. The anti-inflammatory effects of corticosteroids may impede host defenses, and their use in patients with early coccidioidal infections may cause adverse effects.

Finally, by establishing a diagnosis of coccidioidomycosis early, complications (should they arise) may be more quickly recognized and treated. As discussed in Section 6, complications of coccidioidal infection usually manifest within months of the initial infection. For this reason, symptoms which develop in the weeks following a new infection may indicate extrapulmonary spread (back pain may indicate vertebral osteomyelitis, etc.). A more detailed evaluation of new symptoms at this stage might identify a need for treatment and reduce complications.

In summary, the posture health care professionals take with respect to early diagnosis of coccidioidal infections is critical to all further discussion about the proper management of this infection in the primary care setting. Historically, the approach in general, has been passive, leaving diagnosis and treatment to only the most severely ill. Providing an accurate, early diagnosis can decrease patient anxiety, eliminate unwarranted diagnostic testing, and unnecessary exposure to antibiotics. It also allows for faster identification and treatment of complications. Thus, the point of view in this manual is that there are major advantages of seeking an early diagnosis of Valley Fever. The following sections describe general strategies for primary care professionals to identify and manage this important disease.

Primary management of coccidioidomycosis

The following sections will outline an approach to recognizing new infections, assessing their impact on the patient, and subsequent management. We have developed an acronym (COCCI) for this approach. These five topics will be discussed in greater detail in the following sections.