Mapping histoplasmosis in South East Asia – implications for diagnosis in AIDS

Abstract

Histoplasmosis caused by the fungus Histoplasma capsulatum is often lethal in patients with AIDS. Urine antigen testing is highly sensitive and much quicker for diagnosis than culture. Histoplasmosis has a patchy and incompletely appreciated distribution around the world especially in South East Asia. We conducted a systematic literature review of cases of all disease forms of histoplasmosis in SE Asia, not including the Indian sub-continent. We also reviewed all histoplasmin skin test mapping studies to determine localities of exposure. We found a total of 407 cases contracted or likely to have been contracted in SE Asia. Numbers of cases by country varied: Thailand (233), Malaysia (76), Indonesia (48) and Singapore (21), with few or no cases reported in other countries. Most cases (255 (63%)) were disseminated histoplasmosis and 177 (43%) cases were HIV associated. Areas of high histoplasmin skin test sensitivity prevalence were found in Myanmar, the Philippines, Indonesia, Thailand and Vietnam - 86.4%, 26.0%, 63.6%, 36.0% and 33.7%, respectively. We have drawn maps of these data. Further study is required to ascertain the extent of histoplasmosis within SE Asia. Diagnostic capability for patients with HIV infection is urgently required in SE Asia, to reduce mortality and mis-diagnosis as tuberculosis.

Re-drawing the Maps for Endemic Mycoses

“…Within Asia, Histoplasma has been known to be present in certain areas for many years [ 60 ]. Histoplasma was first isolated from soil in Malaysia in 1963, and Randhawa reviewed 30 possible autochthonous cases from India, Malaysia, Indonesia, Singapore, Thailand, Vietnam, and Japan in 1970 [ 61 , 62 ].…”

“…Histoplasmin sensitivity in adults ranged from 9 to 12% in Indonesia and Malaysia and as high as 26% in the Philippines with cases reported in each of these countries [ 74 – 79 ]. Additional data suggest histoplasmin positivity of greater than 50% in parts of Myanmar and additional cases of histoplasmosis from Laos, Cambodia, Vietnam, Indonesia, Malaysia, Myanmar, the Philippines, and Singapore [ 60 , 80 – 96 ]. Scattered cases of autochthonous histoplasmosis have been reported in Australia dating back to 1948, and H. capsulatum has been isolated from fowl yards and caves within the country [ 97 , 98 ].…”

Introductory Chapter: The Global Distribution of Human Histoplasmosis - An Overview

“…Excluding the Indian sub-continent, 407 cases of histoplasmosis in South East Asia have been reported [34]. Most cases (255 (63%)) were disseminated histoplasmosis and 177 (43%) cases were HIV associated [34].…”

Infectious sources of Histoplasmosis and molecular techniques for its identification

“…In many rural settings, cases of some diseases are often identified only through their clinical signs and symptoms. Lack of proper public health awareness and treatment of infectious diseases made people prone to several fungal infections, including Histoplasmosis, which may be a severe issue [40]. As the pervasiveness of HIV/AIDS and Tuberculosis are budding swiftly, the infection from the Histoplasma may lead to a significant effect [41].…”