Blastocystis spp. is one of the most common intestinal protozoa found in the human intestinal tract. Blastocystis infection is widely distributed throughout the world with a high prevalence in developing countries in the tropics and subtropics. Human infection is associated with poor personal hygiene, lack of sanitation, exposure to animals, and consumption of contaminated food or water. Although its role in human disease has been widely debated in the literature during the two last decades, numerous recent in-vivo and in-vitro studies strongly suggest that Blastocystis hominis is pathogenic. However, its pathogenic role is still regarded as controversial by some authors. Also, studies have been in progress for years to evaluate the role of blastocystosis in irritable bowel syndrome.
It is believed that Blastocystis hominis can be a pathogen under some conditions such as immunosuppression, malnutrition, transplantation or co-infections. Many studies demonstrated it as a causative agent of diarrhea especially chronic diarrhea.
The recognized forms of Blastocystis spp. are vacuolar, granular, multi vacuolar, amoeboid and cystic forms. As other intestinal parasites, transmission occurs by fecal oral route, although this has not been confirmed experimentally.
Direct microscopic examination of fecal material, with or without addition of Lugol's iodine solution, has been suggested for diagnostic purposes. Permanent smear stained with trichrome has also been recommended for the diagnosis of B. hominis infection. Techniques for concentration using formalin-ether may be suitable because preservative liquids are used for storage and dilution of the feces. Previous epidemiological study of B. hominis suggested that B. hominis rapidly multiplies in culture medium supplemented with serum after 24-48 hours of cultivation and considered it the most sensitive method available for diagnosis.
The present work aimed to determine the prevalence of B. hominis in diarrheic patients in Qualyobia Governorate using different direct diagnostic methods and to determine the associated risk factors and investigate the relation between the parasite and the socioeconomic status of the overall population studied, determine the best direct method in the diagnosis of the parasite and to study different morphological forms of the parasite. To reach these objectives the study was carried out on one thousand and two hundred patients suffered from diarrhea inhabiting Qualyobia Governorate. Samples were collected from six centers and six related villages representing urban and rural areas of the Governorate as follows:
Benha and one related village (Gamgara).
Kafr shokr and one related village (Asnite).
Tookh and one related village (Beltan).
Qualyob and one related village (Mitnama).
Kaha and one related village (Senhera).
Shobra and on related village (Mostorod).
From each center and village two hundred random samples were collected with aid of health units.
All studied cases were subjected to:
1- History taking
2-Stool examination by:
Direct smear method
Iodine stained smear
Formol ether concentration technique
Trichrome stained smear
In vitro cultivation using Jone’s medium
All the results obtained were analyzed statistically, and the following results were obtained:
- Among one thousand and two hundred diarrheic patients who recruited into the present study, B.hominis was found in stool of 274 individuals (22.8%).
- B. hominis infection was higher in males (175 +ve cases(25.2%) out of 694 cases) than females (99 +ve cases (19.6%) out of 506 cases).
- The highest rate of infection occurred in the age group ranged from 14-35 years old (38.1%)
- Blastocystosis was more prevalent in cases from rural areas (31.7%) than those from urban areas (14%).
- Regarding the socioeconomic status of the participants, B. hominis infection was higher among non educated patients, patients were working , in patients their Monthly household income |
