The worldwide incidence of trichomoniasis was estimated to be 276.4 million new cases per year in 2008 .In Egypt, the reported prevalence rate ranges from 5% to 79.16% we aim to study genetic variability of Trichomonas vaginalis using PCR

In women, trichomoniasis has a wide range of presentations, from asymptomatic to acute or chronic inflammatory disease they include urethral discharge and dysuria. Among women, common sites of infection include the vagina, urethra and endocervix. Symptoms include vaginal discharge (which is often diffuse, malodorous, yellow-green), dysuria, itching, vulvar irritation and abdominal pain. The normal vaginal pH is 4.5, but with TV infection this increases markedly, often to >5 Colpitis macularis or strawberry cervix is seen in about 5 % of women, though with colposcopy this rises to nearly 50 % .Other complications include infection of the adnexa, endometrium, and Skene and Bartholin glands. In men, it can cause epididymitis, prostatitis, and decreased sperm cell motility .

A lot of risk factors of infection are related to age, educational level, residence, race/ethnicity, marital status, number of sex partners, use of condom/IUD, history of sexually transmitted diseases and presence of vaginal discharge .

Traditionally physicians make the diagnosis based on clinical grounds, but in women, the characteristics of the vaginal discharge, including color and odor, are poor predictors of T. vaginalis. Since no symptom alone or in combination is sufficient to diagnose T. vaginalis infection reliably, laboratory diagnosis is necessary ,Diagnosis of T. vaginalis infection is established by the traditional method wet mount test, in which "corkscrew" motility observed . Anyhow, culture has long been the gold standard for diagnosing T. vaginalis infection , with a sensitivity range from 85-95 % . Other used methods for diagnosis include enzyme-linked immunosorbent assay , staining methods latex agglutination , immunochromatography and nucleic acid amplification tests .In order to develop protocol for the diagnosis of trichomoniasis, ideal test should have high sensitivity and specificity and be easily available, simple to perform, and inexpensive Knowledge of the genetic characteristics of T. vaginalis populations is valuable for the prevention and control of trichomoniasis in humans .

The lengths of specific regions in the small subunit of nuclear ribosomal RNA (SSU nrRNA, also known as 18S rRNA) are not conserved among different groups, and these differences can be significant. Thus, 18S rRNA is suitable to study genetic variations and genotypes of organisms.

The use of reliable classification and genetic characterization methods can help to clarify the ambiguities in this field.

Multiple approaches to typing Trichomonas isolates have been described; antigenic characterization, ribosomal gene and intergenic region sequence polymorphisms, random amplified polymorphic DNA analysis, and restriction fragment length polymorphism .These studies produced differing results, even when using similar techniques, in attempting to demonstrate concordance between parasite genotypes and phenotypic expressions during infection, such as virulence and metronidazole resistance. The T. vaginalis genome composition provides a potential explanation for this difficulty in correlating genotype with phenotype.

Inclusion Criteria:

• females ,non virgins,complain from vaginitis ,at reproductive age and attending to sohag general hospital outpatient clinic of gynecology and obstetric

Exclusion Criteria:

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non virgins females

one group from 20 patients