CLINICAL CHARACTERISTICS OF HISTOPLASMOSIS PATIENTS TREATED AT MAHARAJ NAKORN CHIANG MAI HOSPITAL, THAILAND

Abstract

Histoplasmosis, caused by Histoplasma capsulatum, is not endemic in Thailand. In this study we aimed to describe the characteristics of patients with histoplasmosis in northern Thailand, treated at Maharaj Nakorn Chiang Mai Hospital, in order to better understand the epidemiology of this disease in this patient population. We retrospectively reviewed the medical records of patients treated at Maharaj Nakorn Chiang Mai Hospital, Chiang Mai, Thailand for histoplasmosis during January 2009-February 2019 and recorded the following data: patient demographics, clinical characteristics, microbiological data and treatment outcomes. A total of 49 subjects were included in the study; 34 (69%) males. The mean (±standard deviation) age of study subjects was 51 (±16) (range: 16-87) years. The most common underlying disease was human immunodeficiency virus (HIV) infection (n = 16, 33%), followed by adult-onset immunodeficiency due to anti-interferon-γ autoantibodies (anti-IFN- γAAb) (n = 9, 18%) and diabetes mellitus (n = 4, 8%). The median (interquartile range; IQR) CD4 cell count among HIV-infected patients was 21 (15-39) cells/mm3. The most common presenting symptoms were fever (n = 28, 57%), weight loss (n = 14, 29%), anemia (n = 14, 29%), cough (n = 9, 18%) and lymphadenopathy (n = 9, 18%). Patients with HIV-infection were younger, more likely to have lymphadenopathy, less likely to have pulmonary, bone or joint infections and more likely to have disseminated infection than patients without HIV-infection. The most common clinical presentation among those with HIV infection was disseminated histoplasmosis (n = 11, 69%) and among those without HIV infection was pulmonary histoplasmosis (n = 9, 28%). Fifty-five patients (93%) received treatment. The median (IQR) duration of treatment was 16 (12-52) weeks. The mortality rate was 6% (n = 3). In summary, most of the histoplasmosis patients in our study were male, middle to older aged, had HIV infection and had disseminated histoplasmosis. Among those without HIV the most common clinical presentation was pulmonary histoplasmosis and the most common underlying condition was anti-IFN- γAAb. We conclude given the uncommon incidence of histoplasmosis in Thailand, physicians caring for patients with these associated factors in the study area should keep a strong index of suspicion for histoplasmosis if they present with these symptoms. Further studies are needed to determine what the incidence of histoplasmosis is in other parts of Thailand and Southeast Asia.