Thi Thu Ha Hoang
National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
Title: Histoplasmosis- Laboratory Diagnosis In Vietnam
Biography
Biography: Thi Thu Ha Hoang
Abstract
Background
Histoplamosis, a fungal infection caused by Histoplasma capsulatum (H.capsulatum) - a severe biohazard pathogen. H.capsulatum occurs most commonly in America and Africa, but the organism exists in many diverse areas around the world. Cases have also been reported in the following Asian countries: India, Malaysia, Thailand, Singapore, and Japan. In Vietnam, histoplasmosis is still under reported because the researchers are inexperienced for detection of histoplasmosis. In addition, the clinicians do not consider histoplamosis as a possible cause of acute respiratory or influenza – like illness in travelers returning from areas in which histoplasmosis is endemic, and this may contribute to under diagnosis. Therefore, a really situation of Histosplamosis should be identified in this country.
Aims: To identify the proportion of Histoplasmosis and detect H.capsulatum in human clinical sample in Hanoi, Vietnam.
Materials: Between August 2012 to Janury 2013, 206 serum and 158 bronchial washing samples have been collected from the pulmonary infection patients in Bach Mai and Military 103 hospitals in Hanoi. Serum samples were tested by ELISA – Histoplasma Dx™Select kit (Focus – Mỹ). The bronchial washing samples were extracted DNA and identified H.capsulatum by nested PCR using primers specific to gene coding M-antigen (Msp1F/Msp2R, Msp2F/Msp3R).
Results: Serum samples from 206 patients were tested for antibody reactivity by ELISA. Positive ELSIA results were obtained in 27 (13.1%) samples. 9/158 bronchial washing samples were presented M- antigen gene by a nested PCR, and then were confirmed by sequencing.
Conclusion: Due to the proportion of Histoplasmosis in pulmonary infection patients is very high (13.1%). Also, H.capsulatum found in these patients samples by PCR which confirmed that H.capulatum has been presented in Vietnam. However, the transmission route of the disease is still a challenge and need to be demonstrated in further studies.
Key words: Histoplasmosis, ELISA, nested PCR, pulmonary infection patients, Vietnam