Episode 143: Pulmonary Cocci Basics

Episode 143: Pulmonary Cocci BasicsDr. Lovedip Kooner explains the history, diagnosis, and treatment of pulmonary coccidioidomycosis (cocci for short.) Disseminated cocci infection was also discussed. Dr. Arreaza added some anecdotes of patients seen with this infection.  Written by Lovedip Kooner, MD. Comments by Hector Arreaza, MD. You are listening to Rio Bravo qWeek Podcast, your weekly dose of knowledge brought to you by the Rio Bravo Family Medicine Residency Program from Bakersfield, California, a UCLA-affiliated program sponsored by Clinica Sierra Vista, Let Us Be Your Healthcare Home. This podcast was created for educational purposes only. Visit your primary care provider for additional medical advice.Definition:Coccidioidomycosis, also known as Valley Fever, is an infection caused by the fungi Coccidioides immitis and Coccidioides posadasii. Coccidioides is also referred to as cocci. Generally speaking, C. immitis is found in California and C. posadasii is found in Arizona, and Central and South America. More recently Cocci has also been found as far north as Washington and British Columbia. History:The fungal infection was first reported by Wernicke and Posadas in Argentina in 1892 where they described a case where a man had cutaneous cocci of the head, arm, and trunk. To this day, the head is preserved in Argentina. 4 For many years, only disseminated cases were recognized and described as “coccidioidal granulomas.” The work of Dixon and Gifford in 1935 elucidated that a pneumonic disease of unknown cause termed “San Joaquin Valley Fever” was, in fact, the primary coccidioidal infection and the port of entry of almost all coccidioidal disease. Initial infection occurs predominantly by inhalation of aerosolized arthroconidia and rarely by direct cutaneous inoculation.1,2Coccidioides spp. survive best in areas with low rainfall (12–50 cm per year), limited winter freezes, and alkaline soils. With climate change models, predicting the geographical range expansion.These dimorphic fungi exist in a mycelial form in the soil. Coccidioides species have been found in animal burrows near the Kern River and in Armadillo burrows in South American countries like Brazil. The mycelia produce arthroconidia (spores) that are ultimately airborne and inhaled.The inoculum required for infection is low and in animal models as few as a single arthroconidium may cause infection.3 Infection:Once arthroconidia are inhaled into the lung, there is typically a 1-3-week incubation period. The arthroconidia undergo morphologic changes into spherules, which are large structures that contain endospores.4 As spherules mature, they rupture and release endospores. Endospores can be spread hematogenous or through lymphatics to essentially any organ, leading to the development of new spherules and potentially disseminated disease.5 Not everyone who inhales the arthroconidia gets the infection. Clinical Manifestations.About 60% of patients who inhale arthroconidia are asymptomatic. 30% have a mild respiratory illness, like the flu. 10% have a more serious disease course and are diagnosed. Other symptoms may include fever, drenching night sweats, and weight loss. Extreme fatigue that limits baseline activity may also raise concerns. Symptom onset up to 2 months after endemic exposure should lead to coccidioidomycosis on the differential. Coccidioidomycosis cases have been documented in Michigan, Europe, and China. These cases were of people who traveled to endemic areas for as little as a few days and then were later diagnosed. 1-3% of all coccidioidomycosis cases are disseminated, severe, or chronic pulmonary infections. If undiagnosed, coccidioidomycosis may lead to significant morbidity and mortality. Dissemination sites inclu