Prevalence of Trichomonas vaginalis using parasitological methods in Tehran

Trichomonas vaginalis is a parasitic protozoan with a predilection for human urogenital tract and causative agent for vaginitis, cervicitis and urethritis in females. T. vaginalis is known as a cofactor in transmission of human immunodeficiency virus and may lead to adverse outcomes in pregnant women. The goal of this study was to determine the prevalence of T. vaginalis infection in females attending Mirzakuchak Khan Hospital, Tehran, Iran. During May 2008 to March 2009, 500 vaginal discharges samples were obtained from women attending sexual transmitted disease [STD] clinic of Mirzakuchak Khan Hospital in Tehran, Iran. The samples were examined by Dorsse culture medium and wet-mount methods. The prevalence of T.vaginalis was determined using culture based method and wet-mount examinations. Sixteen positive [3.2%] and 484 negative [96.8%] samples for T. vaginalis were detected by culture based methods. The wet mount examination revealed 13 positive [2.6%] and 487 negative [97.4%] samples. In the above population, prevalence of trichomoniasis was estimated as 3.2% based on culturing method. Due to adverse outcomes of vaginal trichomoniasis and its correlation with HIV transmission, there is a great need for public education regarding implementation of personal hygienic measures and prevention of inappropriate sexual contacts

Comparison of a PCR-based method with culture and direct examination for diagnosis of Acanthamoeba keratitis

The aim was to compare three different methods [direct examination, culture and PCR methods] for the diagnosis of Acanthamoeba keratitis [AK] in corneal scrapes. Twenty eight corneal scrapes and contact lenses were collected from keratitis patients and referred to the Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences. Corneal scrapes were divided in three parts for direct examination, culture on non-nutrient agar and PCR analysis. PCR analysis was also performed using a 18S rRNA gene primer pair [DF3 region]. DF3 [Diagnostic fragment 3] is a region of the nuclear small subunit ribosomal RNA gene which is specific for detecting Acanthamoeba strains. Acanthamoeba was the causative agent of keratitis in 50% of the patients. Direct smear of all prepared corneal scrapes in AK patients was negative and culture was positive in only 14.3% of the isolates. PCR analysis was positive in 71.4% of AK patients. These three methods were negative in corneal scrapes of non-AK patients. The sensitivity and specificity of PCR technique for the detection of Acanthamoeba sp. were calculated as 71.4% and 100%, respectively. According to high sensitivity and specificity of PCR-based method, this study confirmed that PCR using 18S rRNA gene primers [DF3 region] is more useful for detecting AK cases compare to culture and direct microscopy methods

field study of the distribution of entamoeba histolytica / dispar cyst passers in northern, central, and southern Iran

Amoebiasis is one of the most important human diseases in many countries especially in tropical and sub-tropical regions. This study was carried out from August 1999 to February 2002 in order to determine the ratio of Entamoeba histolytica / Entamoeba dispar in some regions of Iran. A total of 16, 592 stool samples were randomly collected from different agegroups in central, northern and southern Iran both from urban and rural areas. The samples were examined by direct and formalin-ether concentration methods. Two hundred and twenty six samples [1.36%] were positive for E. histolytica/E. dispar cyst [C.I = 1.18-1.54%]. The prevalence of infection with E. histolytica/E. dispar was 0.78%, 3.9% and 4.6% for central, northern and southern part of Iran, respectively. The minimum rate of prevalence was 0.6% in Tehran, Yazd and Ardekan [central Iran], while the highest rate [8.3%] was seen in rural areas of Ahwaz [southern Iran].The study showed that ratio of E. histolytica /E. dispar was higher in southern regions [tropical and subtropical] than other regions. It seems that more sanitary facilities and health trainings are needed in different parts of the country, especially in southern Iran, where the rate of infection is high