Seroprevalence of Histoplasmosis in Somali, Burmese, and Hmong Refugees Residing in Thailand and Kenya

Abstract

Histoplasmosis is known to be endemic to the Midwestern United States, but cases have been reported throughout much of the world. Somali, Hmong, and Burmese (ethnically Karen) persons make up some of the largest refugee populations coming the United States in recent years. Yet, information about risk of Histoplasma capsulatum infection amongst these populations is limited. This study used the CDC Migrant Serum Bank to test ~100 samples from each of Somali, Burmese, and Hmong U.S.-bound refugees. Samples were tested by enzyme immunoassay for Histoplasma capsulatum IgG. Overall 1% (2/299) of refugee serum samples were positive for H. capsulatum IgG. One of 99 samples obtained from Hmong refugees was positive, and the other positive sample came from among 100 Burmese refugee samples. H capsulatum IgG positivity was detected at low levels in Hmong and Burmese refugees. No IgG positivity was detected among 100 Somali refugees.

Re-drawing the Maps for Endemic Mycoses

“…Additional studies of histoplasmin sensitivity in Uganda showed a positivity rate ranging from 0.4%–10% in separate Ugandan districts, while a study in Somalia found a total positivity rate of only 0.3% [ 52 , 53 ]. More recently, Histoplasma antigen and anti– Histoplasma antibody studies have been performed, with zero of 100 Somali refugees residing in Kenya exhibiting seropositivity for anti- Histoplasma IgG and 1.3% of Ugandan persons living with HIV/AIDS exhibiting anti- Histoplasma IgG seropositivity (with no positive anti- Histoplasma IgM or Histoplasma serum, urine, or cerebrospinal fluid antigens among 151 subjects) [ 54 , 55 ]. One striking study from Maputo, Mozambique, found that 58% of HIV-infected patients hospitalized with respiratory infections or Kaposi’s sarcoma were diagnosed with histoplasmosis via nested PCR [ 56 ].…”

“…The majority of cases of histoplasmosis in Southeast Asia have been reported from Thailand, where 1253 cases of disseminated histoplasmosis among HIV-infected persons were reported to the Ministry of Public Health from 1984 to 2010 [ 72 ]. Histoplasmin sensitivity in Thailand is as high as 34.4% in south and central Thailand and as low as 4.8% in north and northeast Thailand, although it is hypothesized that this may be an over-estimation of true exposure due to cross-reactivity with Talaromyces marneffei antigen, which is also present in the region [ 54 , 73 ]. A study of Burmese and Hmong refugees residing in Thailand found only 2/199 with seropositivity for anti- Histoplasma IgG [ 54 ].…”

“…Histoplasmin sensitivity in Thailand is as high as 34.4% in south and central Thailand and as low as 4.8% in north and northeast Thailand, although it is hypothesized that this may be an over-estimation of true exposure due to cross-reactivity with Talaromyces marneffei antigen, which is also present in the region [ 54 , 73 ]. A study of Burmese and Hmong refugees residing in Thailand found only 2/199 with seropositivity for anti- Histoplasma IgG [ 54 ]. 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 ].…”

Cryptococcal and Histoplasma Antigen Screening Among People With Human Immunodeficiency Virus in Ghana and Comparative Analysis of OIDx Histoplasma Lateral Flow Assay and IMMY Histoplasma Enzyme Immunoassay

“…Several antigen detection assays exist for CM and DH, and they have been exploited in screening programs or studies in some countries in the Americas and Africa [ 23–29 ]. These assays have been evaluated in previous studies [ 22 , 23 , 26 , 28 , 29 , 30–32 ]. In Guatemala, an implemented screening for CM, DH, and TB reduced HIV deaths by 7% [ 24 ].…”

Actual problems of mycoses caused by dimorphic pathogens

“…Наличие гистоплазмоза в некоторых регионах Азии, с превалированием в Таиланде, зафиксировано давно [13]. Чувствительность к гистоплазмину населения Южного и Центрального Таиланда выше 30%, хотя не исключено, что у части исследованных она обусловлена перекрестной реактивностью к Talaromyces marneffei -возбудителю эндемического пенициллиоза (таларомикоза), существующего в этом регионе [14]. В Европе заболеваемость гистоплазмозом связана преимущественно с посещением эндемичных регионов, однако в Италии, Германии и Турции зафиксированы автохтонные случаи [15,16].…”