Prevalence of Blastocystis hominis Carriage in Thai Army Personnel Based in Chonburi, Thailand

Abstract

Blastocystis hominis is one of the most common intestinal parasites found in humans. The prevalence of B. hominis carriage in personnel who worked in the First Army Support Command, Chonburi, Thailand, was determined. Forty-four percent of 616 stool samples were positive for B. hominis using both simple smear and concentration (Formalin/ethyl acetate) techniques. The usefulness of the concentration technique in the diagnosis of B. hominis has been confirmed. Of 272 positive specimens, 75% were detected by simple smear and 25% were additionally identified by the concentration technique. The prevalence of B. hominis carriage was highest among the privates who had lived longest in this command. This finding indicates that they might have acquired B. hominis during their stay at this base. The significantly high prevalence of B. hominis carriage was found in the Ordnance Ammunition Battalion. In this battalion, privates who had education lower than the secondary school level had significantly greater risk of B. hominis carriage.

The Prevalence of Blastocystis hominis and Other Protozoan Parasites in Soldiers Returning from Peacekeeping Missions

“…A similar prevalence of B. hominis infection to this study had been found in Thai soldiers (15%) in one study, 11 whereas a higher prevalence of B. hominis infection had been observed in stool samples in 37% 12 of Thai soldiers in another study and 44% 13 of military personnel as well as 36% 14 of the local population of Honduras. The difference in prevalence of B. hominis infections between these populations may be caused by the different diagnostic methods used 7 as well as the soldiers being stationed in different areas under different sanitary conditions.…”

Identification of Blastocystis Subtype 1 Variants in the Home for Girls, Bangkok, Thailand

“…5,6,19 Among these, subtype 3 is predominant, and usually found in both symptomatic and asymptomatic individuals, except those in Thailand and Brazil. 12,14,25 Studies from different communities in these two countries showed contrasting results, i.e., that subtype 1 is the most predominant. 3,14,20 The prevalence of subtype 1 is 1.1 to 26.5 times higher than those of other countries.…”

“…Previous studies have shown the evidence of person-toperson, waterborne, and zoonotic transmission of Blastocystis infection [11][12][13][14]20,26,27 ; the route of transmission of this organism could be different depending on the study population. In this study, the data concerning all routes of transmission were collected to elucidate the source of infection.…”

“…Waterborne transmission of Blastocystis infection has been indicated in a few studies [11][12][13][14] ; a survey of parasitic infections in primary school children of a rural community, central Thailand, showed a high prevalence of Blastocystis subtype 1. Blastocystis subtype 1 was also found in the drinking water.…”

“…10 In Thailand, epidemiological studies of Blastocystis infection showed the prevalence of 10-40% in different populations. 3,[11][12][13][14][15] Using molecular methods, extensive genetic diversity was detected among Blastocystis populations. [16][17][18] Recently, a consensus terminology for subtypes of Blastocystis was developed on the basis of small subunit ribosomal RNA (SSU rRNA) gene analysis for which at least 13 subtypes have been characterized from humans and animals.…”