Evidence of Waterborne Transmission of Blastocystis Hominis

Abstract

A cross-sectional study was performed in February 2001 to evaluate the prevalence and risk factors of Blastocystis hominis infection in army personnel who resided in an army base in Chonburi, Thailand. A total of 904 army personnel were enrolled in this study. Short-term in vitro cultivation was used to detect B. hominis in stool samples. In this population, B. hominis was the parasite most frequently found, and was identified in 334 of 904 stool specimens (36.9%). A significant association between B. hominis infection and symptoms was identified that might emphasize the role of B. hominis as a human pathogen. After adjustment for potential confounders, significantly increased risk of being infection with B. hominis was associated with being a private, working in a specific unit, and consuming unboiled drinking water. Thus, waterborne transmission of B. hominis infection was indicated at this army base. However, other modes of transmission cannot be ruled out.

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.…”

Frecuencia y fuentes de Blastocystis sp. en niños urbanos de 0 a 5 años de hogares infantiles del estado del municipio de Calarcá, Colombia

“…en heces y la sintomatología en los niños, ya que en diferentes estudios se han documentado síntomas gastrointestinales de todo tipo, sin resultados concluyentes sobre esa posible asociación (3,23,25).…”

Direct characterization of Blastocystis from faeces by PCR and evidence of zoonotic potential

“…In previous studies using Jones' medium supplemented with 10 % horse serum (Salim et al 1999 ;Leelayoova et al 2002 ;Suresh and Smith, 2004 ;Termmathurapoj et al 2004 ;Yakoob et al 2004 ;Yoshikawa et al 2004 c), only human faecal samples were screened for Blastocystis. However, several different types of media to cultivate Blastocystis have been reported, and it has been suggested that the usefulness of cultivation may depend on the reagents and protocols employed (Zaman and Khan, 1994 ;Leelayoova et al 2002).…”

“…However, several different types of media to cultivate Blastocystis have been reported, and it has been suggested that the usefulness of cultivation may depend on the reagents and protocols employed (Zaman and Khan, 1994 ;Leelayoova et al 2002). Perhaps an alternative to Jones' medium should be evaluated for the detection of Blastocystis in nonhuman hosts, since Blastocystis is susceptible to changes in environmental conditions (Stenzel and Boreham, 1996 ;Leelayoova et al 2002 ;Tan, 2004).…”

“…There are several methods used to detect Blastocystis infections, which include wet smears, concentration methods and in vitro amplification which was recently shown to be the most sensitive method to detect Blastocystis from faecal samples (Zaman and Khan, 1994 ;Leelayoova et al 2002 ;Suresh and Smith, 2004 ;Termmathurapoj et al 2004). However, due to the variable morphological forms that Blastocystis exhibits, it is impossible to distinguish among different species and subspecies of Blastocystis solely based on morphology without the use of molecular techniques (Yoshikawa et al 2004 b).…”