A Review of Blastomycosis in Indian Subcontinent

This study traces the earliest cases of blastomycosis reported from India. Four authentic cases of blastomycosis from India including one each from Arunachal Pradesh, Himachal Pradesh, Kerala, and one each from Bangladesh and Nepal, and five misdiagnosed cases have been reported in India after 2013. The clinical and diagnostic features of all cases are reviewed. The authentic cases from India originate from widespread locations in the country. The incidence of blastomycosis in dogs is known to be eight to ten times higher than that in humans. There is only one case of canine blastomycosis from India manifesting as a fatal pulmonary infection in a Mongrel dog. It is suggested additional canine cases should be looked for in different parts of India to facilitate the detection of endemic foci of B. dermatitidis for human and animal infections in the country. Mycological investigation of cases of pulmonary tuberculosis negative for culture and AFBs mear, and not responding to anti-tubercular therapy may reveal some cases of blastomycosis. A recently developed real-time PCR for identification of B. dermatitidis in culture and tissue may facilitate correct diagnosis of blastomycosis in suspected cases. Antigen testing in urine or serum is also recommended for diagnosing clinical infection and monitoring antifungal therapy in blastomycosis.

Prevalence, distribution, and risk factors for canine blastomycosis in Michigan, USA

Blastomycosis is a systemic fungal infection that most commonly affects dogs and humans. The disease is thought to be endemic in southern regions of Michigan, USA, but epidemiologic investigations have not been reported in detail for this state. The primary aims of this study were to investigate the prevalence and distribution of canine blastomycosis cases in Michigan and to identify risk factors for infection. Over 200 primary care veterinary clinics throughout the state were surveyed regarding blastomycosis prevalence, and demographic information was obtained from medical records of affected dogs that were evaluated at these clinics. A retrospective case control study was conducted for an additional 49 dogs with blastomycosis that were evaluated at specialty referral centers located in the southern mid-Michigan region. Prevalence rates were calculated for each county, and cases were mapped using geocoding software. Univariable and multivariable analyses were used to identify risk factors for infection. Prevalence rates were ≥100 cases per 100,000 dogs in five counties. Most blastomycosis cases originated from the Upper Peninsula or from a high-density area in the northern Lower Peninsula. Multivariable regression analysis identified travel or residence north of the 45th parallel as a strong risk factor for infection (P < .001). Blastomycosis was uncommon in southern counties. These results refute previous speculations and should be of value to both human and animal health. Given that many heightened risk areas are popular tourist destinations, practitioners across the USA should be mindful of the spatial distribution of blastomycosis in Michigan.

Mycotic Mastitis in Three Dogs Due to Blastomyces dermatitidis

Canine blastomycosis is a common systemic fungal infection within the Ohio and Mississippi River valleys and typically presents as pneumonia, lymphadenitis, or endophthalmitis. This report describes three cases in which mammary tissue samples were submitted to the Department of Pathobiology, University of Tennessee, College of Veterinary Medicine with clinical suspicion of neoplasia or postpartum bacterial mastitis. Pyogranulomatous to granulomatous mastitis and dermatitis with intralesional yeast consistent with Blastomyces dermatitidis were diagnosed. Two of the three dogs also had lymph node and pulmonary involvement. Mycotic mastitis due to Blastomyces dermatitidis is rarely reported and blastomycosis should be considered in the differential diagnosis of dogs with mammary lesions from endemic areas.