Microbiota in vaginal health and pathogenesis of recurrent vulvovaginal infections: a critical review.

Recurrent vulvovaginal infections (RVVI) has not only become an epidemiological and clinical problem but also include large social and psychological consequences. Understanding the mechanisms of both commensalism and pathogenesis are necessary for the development of efficient diagnosis and treatment strategies for these enigmatic vaginal infections. Through this review, an attempt has been made to analyze vaginal microbiota (VMB) from scratch and to provide an update on its current understanding in relation to health and common RVVI i.e. bacterial vaginosis, vulvovaginal candidiaisis and Trichomoniasis, making the present review first of its kind. For this, potentially relevant studies were retrieved from data sources and critical analysis of the literature was made. Though, culture-independent methods have greatly unfolded the mystery regarding vaginal bacterial microbiome, there are only a few studies regarding the composition and diversity of vaginal mycobiome and different Trichomonas vaginalis strains. This scenario suggests a need of further studies based on comparative genomics of RVVI pathogens to improve our perceptive of RVVI pathogenesis that is still not clear (Fig. 5). Besides this, the review details the rationale for Lactobacilli dominance and changes that occur in healthy VMB throughout a women's life. Moreover, the list of possible agents continues to expand and new species recognised in both health and VVI are updated in this review. The review concludes with the controversies challenging the widely accepted dogma i.e. "VMB dominated with Lactobacilli is healthier than a diverse VMB". These controversies, over the past decade, have complicated the definition of vaginal health and vaginal infections with no definite conclusion. Thus, further studies on newly recognised microbial agents may reveal answers to these controversies. Conversely, VMB of women could be an answer but it is not enough to just look at the microbiology. We have to look at the woman itself, as VMB which is fine for one woman may be troublesome for others. These differences in women's response to the same VMB may be determined by a permutation of behavioural, cultural, genetic and various other anonymous factors, exploration of which may lead to proper definition of vaginal health and disease.

Association between Trichomonas vaginalis and prostate cancer mortality.

We previously observed a positive association between seropositivity for the parasite Trichomonas vaginalis and risk of clinically significant prostate cancer at diagnosis. Here, we examined whether T. vaginalis seropositivity was associated with increased prostate cancer-specific or all-cause mortality among prostate cancer patients. We studied 736 men with prostate cancer from the Physicians' Health Study (PHS) and 749 men with prostate cancer from the Health Professionals Follow-Up Study (HPFS). We used Cox proportional hazards regression models to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of the association between T. vaginalis serostatus and progression to death from prostate cancer and from all causes. In PHS, 423 men died of any cause during a median follow-up of 13.8 years from the date of cancer diagnosis, among whom 131 died of prostate cancer. In HPFS, there were 287 deaths, including 77 deaths from prostate cancer, during a median follow-up of 12.8 years. We found no association between T. vaginalis serostatus and either prostate cancer mortality or all-cause mortality in either the PHS or HPFS. While previous studies suggest a possible role for T. vaginalis in the development of clinically significant prostate cancer, our findings do not support the hypothesis that T. vaginalis serostatus is associated with mortality among prostate cancer patients.

Epigenetics regulates transcription and pathogenesis in the parasite Trichomonas vaginalis.

Trichomonas vaginalis is a common sexually transmitted parasite that colonizes the human urogenital tract. Infections range from asymptomatic to highly inflammatory, depending on the host and the parasite strain. Different T. vaginalis strains vary greatly in their adherence and cytolytic capacities. These phenotypic differences might be attributed to differentially expressed genes as a consequence of extra-genetic variation, such as epigenetic modifications. In this study, we explored the role of histone acetylation in regulating gene transcription and pathogenesis in T. vaginalis. Here, we show that histone 3 lysine acetylation (H3KAc) is enriched in nucleosomes positioned around the transcription start site of active genes (BAP1 and BAP2) in a highly adherent parasite strain; compared with the low acetylation abundance in contrast to that observed in a less-adherent strain that expresses these genes at low levels. Additionally, exposition of less-adherent strain with a specific histone deacetylases inhibitor, trichostatin A, upregulated the transcription of BAP1 and BAP2 genes in concomitance with an increase in H3KAc abundance and chromatin accessibility around their transcription start sites. Moreover, we demonstrated that the binding of initiator binding protein, the transcription factor responsible for the initiation of transcription of ~75% of known T. vaginalis genes, depends on the histone acetylation state around the metazoan-like initiator to which initiator binding protein binds. Finally, we found that trichostatin A treatment increased parasite aggregation and adherence to host cells. Our data demonstrated for the first time that H3KAc is a permissive histone modification that functions to mediate both transcription and pathogenesis of the parasite T. vaginalis.

Higher vaginal pH in Trichomonas vaginalis infection with intermediate Nugent score in reproductive-age women-a hospital-based cross-sectional study in Odisha, India.

A close association between Trichomonas vaginalis (TV) infection and bacterial vaginosis (BV) has been reported. Some other studies have found association is stronger with intermediate Nugent score than BV. Most studies have used wet mount microscopy, a relatively insensitive method, to detect TV infection. We wanted to study the association of TV infection with BV and with intermediate Nugent score. We undertook a cross-sectional hospital-based study of 1110 non-pregnant women from Odisha state, India, aged between 18 and 45 years, collecting vaginal swabs for diagnosis of BV by Nugent score (NS) criteria and TV by PCR analysis. TV infection was found in 13.3% of women with intermediate Nugent score (NS 4-6) and 13.6% with BV (NS 7-10). Before adjustment, TV infection was associated with BV, intermediate Nugent, vaginal pH ≥ 4.5, and age group between 26 and 35 years. Multivariate analysis confirmed that TV infection was more likely to have raised vaginal pH, either BV or intermediate Nugent. Proportion of TV cases increased sequentially with the increase in Nugent score up to NS 6, after which a decline was observed. Vaginal pH was higher in the TV-infected group than the uninfected group in women with intermediate Nugent, but no difference was noticed in women with BV. TV infection was equally prevalent in women with intermediate Nugent as well as BV. In the intermediate Nugent group women, TV infection was found only when vaginal pH was raised, indicating a crucial role of vaginal pH in determining TV infection.

Prevalence of human papillomavirus, Chlamydia trachomatis, and Trichomonas vaginalis infections in Amazonian women with normal and abnormal cytology.

Sexually transmitted infections are an important cause of morbidity among sexually active women worldwide, and have been implicated as cofactors in the pathogenesis of cervical cancer. We investigated the prevalence of human papillomavirus (HPV), Chlamydia trachomatis (CT), and Trichomonas vaginalis (TV), and accessed the diversity of HPV in women with normal and abnormal cytology in Manaus, Brazil. We used polymerase chain reaction and HPV genotyping by direct sequencing. The chi-square test was used to calculate the absolute and relative frequencies of the categorical variables, and Fisher's test was used when P < 0.05. The level of significance was set at 5%. All statistical analyses were performed using R 2.9.0. There were statistically significant differences in age (P = 0.0395), education level (P = 0.0131), sexual partners (P = 0.0211), condom use (P = 0.0039), marital status (P < 0.0001), and pregnancy (P = 0.0003) between the normal and abnormal groups. HPV DNA was found in 36.56 and 93.88% of subjects in the normal and abnormal groups, respectively. A total of 19 genotypes were detected; HPV16 was the most common, followed by HPV58. The percentages of TV and CT DNA were 18.04 and 9.02% in the normal group, respectively. The percentages of HPV/TV and HPV/CT coinfection were 12.5% each in women with normal cytology. These findings improve our understanding of HPV, CT, and TV, and the distribution of HPV types, which may be relevant to vaccination strategies for protecting women from the north of Brazil from cervical cancers and precancerous lesions.

Molecular characterization of double-stranded RNA virus in Trichomonas vaginalis Egyptian isolates and its association with pathogenicity.

Trichomoniasis is a common human sexually transmitted infection caused by Trichomonas vaginalis. The parasite can be infected with double-stranded RNA viruses (TVV). This viral infection may have important implications on trichomonal virulence and disease pathogenesis. This study aimed to determine the prevalence of T. vaginalis virus among isolates obtained from infected (symptomatic and asymptomatic) women in Ismailia City, Egypt, and to correlate the virus-infected isolates with the clinical manifestations of patients. In addition, the pathogenicity of TVV infected isolates on mice was also evaluated. T. vaginalis isolates were obtained from symptomatic and asymptomatic female patients followed by axenic cultivation in Diamond's TYM medium. The presence of T. vaginalis virus was determined from total extraction of nucleic acids (DNA-RNA) followed by reverse transcriptase-PCR. Representative samples were inoculated intraperitoneally in female albino/BALB mice to assess the pathogenicity of different isolates. A total of 110 women were examined; 40 (36.3 %) samples were positive for T. vaginalis infection. Of these 40 isolates, 8 (20 %) were infected by TVV. Five isolates contained TVV-2 virus species, and the remaining three isolates were infected withTVV-4 variant. A significant association was found between the presence of TVV and particular clinical manifestations of trichomoniasis. Experimental mice infection showed varying degrees of pathogenicity. This is the first report on T. vaginalis infection by TVV in Egypt. The strong association detected between TVV and particular clinical features of trichomoniasis and also the degree of pathogenicity in experimentally infected mice may indicate a possible clinical significance of TVV infection of T. vaginalis isolates.

Correlation of leukorrhea and Trichomonas vaginalis infection.

Trichomonas vaginalis is a common sexually transmitted infection (STI) causing vaginitis. Microscopy has poor sensitivity but is used for diagnosis of trichomoniasis in resource-poor settings. We aimed to provide a more reliable diagnosis of trichomoniasis by investigating an association with leukorrhea. Women presenting for evaluation of vaginal discharge, STI exposure, or preventative gynecologic examination were evaluated for Trichomonas infection. Vaginal pH was determined and microscopy was performed by the provider, who recorded the number of polymorphonuclear leukocytes (PMNLs) per epithelial cell and the presence of clue cells, yeast, and/or motile trichomonads. Leukorrhea was defined as greater than one PMNL per epithelial cell. Culture and a nucleic acid amplification test (NAAT) were used to detect T. vaginalis. Patients were evaluated for Chlamydia trachomatis and Neisseria gonorrhoeae using NAATs and bacterial vaginosis using Gram stains. Two hundred ninety-four women were enrolled, and 16% were found to have Trichomonas (46/294). Trichomonas infection was more common in parous non-Hispanic, black women, who reported low rates of contraceptive use (33% versus 17%; P = 0.02) and a STI history (85% versus 55%; P = 0.002). These women were more likely to report vaginal discharge (76% versus 59%; P = 0.02) and have an elevated vaginal pH (87% versus 48%; P < 0.001) and gonorrhea infection (15% versus 4%; P = 0.002). Leukorrhea was associated with a 4-fold-increased risk of Trichomonas infection. Leukorrhea on microscopy was associated with Trichomonas vaginitis. Patients with leukorrhea should be evaluated with more-sensitive tests for T. vaginalis, preferably NAATs, if microscopy is negative.

The role of physical examination in diagnosing common causes of vaginitis: a prospective study.

OBJECTIVE: We evaluated agreement in diagnoses for bacterial vaginosis (BV), Trichomonas vaginalis (TV) and vulvovaginal candidiasis (VVC) between clinicians examining the patient and performing diagnostic tests versus a clinician with access only to the patient's history and diagnostic findings from self-obtained vaginal swabs (SOVS). DESIGN: Women presenting with vaginal discharge to a sexually transmitted infections clinic provided SOVS for evaluation and completed the study and qualitative questionnaires. A clinician then obtained a history and performed speculum and bimanual examinations. Participants' history and diagnostic test results from SOVS were provided to a masked non-examining clinician who rendered independent diagnoses. Overall agreement in diagnoses and κ statistics was calculated. RESULTS: The prevalence of infections among the 197 participants was 63.4% (BV), 19% (TV) and 14% (VVC). The per cent agreement between the examining and non-examining clinician for the diagnoses of BV was 68.5%, 90.9% for TV and 91.9% for VVC. Of the 105 women diagnosed with BV by the examining clinician, 34 (32%) were missed by the non-examining clinician. The non-examining clinician missed 13 (48%) of 27 women and 12 (34%) of 35 women treated for VVC and TV, respectively. Four women who all presented with abdominal pain were diagnosed with pelvic inflammatory disease. CONCLUSIONS: Tests from SOVS and history alone cannot be used to adequately diagnose BV, TV and VVC in women presenting with symptomatic vaginal discharge. Cost benefits from eliminating the speculum examination and using only tests from SOVS may be negated by long-term costs of mistreatment.

Involvement of mast cells in inflammation induced by Trichomonas vaginalis via crosstalk with vaginal epithelial cells.

Vaginal epithelial cells (VECs) are thought to function as immune-responsive cells in trichomoniasis, and mast cells have been detected in vaginal smears and the vaginal wall in trichomoniasis. It therefore seemed possible that the VEC-trichomonad reaction might affect the activity of mast cells present in the lamina propria of the vaginal mucosa. In this study, we tested whether culture supernatants of VEC incubated with Trichomonas vaginalis (TCM) could stimulate mast cells. When VECs (MS74) were incubated with live trichomonads, IL-8, IL-6 and MCP-1 expressions increased in the TCM, and mast cells (HMC-1) and human neutrophils migrated more actively towards the TCM. Also, when the TCM was added to mast cells, ß-hexosaminidase and cytokines (IL-8 and TNF-α) expressions were increased. Moreover, the culture supernatant of mast cells incubated with TCM (M-TCM) had more increased chemotactic activity for neutrophils than that of TCM. We conclude that inflammatory mediators made by VECs in response to activation by T. vaginalis activate and attract mast cells and then stimulate them to induce neutrophil migration. Our results indicate, for the first time, that VECs play a role in the infiltration of mast cells and neutrophils early in T. vaginalis infection.

Gardnerella, Trichomonas and Candida in cervical smears of 58,904 immigrants participating in the Dutch national cervical screening program.

OBJECTIVE: To report the prevalence of Gardnerella, Trichomonas and Candida in the cervical smears of 9 immigrant groups participating in the Dutch national cervical screening program. STUDY DESIGN: Cervical smears were taken from 58,904 immigrant participants and 498,405 Dutch participants. As part of the routine screening process, all smears were screened for the overgrowth of Gardnerella (i.e. smears with an abundance of clue cells) and for the presence of Trichomonas and Candida. The smears were screened by 6 laboratories, all of which use the Dutch KOPAC coding system. The odds ratio and confidence interval were calculated for the 9 immigrant groups and compared to Dutch participants. RESULTS: Immigrants from Suriname, Turkey and the Dutch Antilles have a 2-5 times higher prevalence of Gardnerella and Trichomonas when compared to native Dutch women. Interestingly, the prevalence of Trichomonas in cervical smears of Moroccan immigrants is twice as high, yet the prevalence of Gardnerella is 3 times lower than in native Dutch women. CONCLUSIONS: Immigrants with a high prevalence of Gardnerella also have a high prevalence of Trichomonas. In the context of the increased risk of squamous abnormalities in smears with Gardnerella, such slides should be screened with extra care.

Development of a pigtail macaque model of sexually transmitted infection/HIV coinfection using Chlamydia trachomatis, Trichomonas vaginalis, and SHIV(SF162P3).

BACKGROUND: Sexually transmitted infections (STIs) are associated with an increased risk of HIV infection. To model the interaction between STIs and HIV infection, we evaluated the capacity of the pigtail macaque model to sustain triple infection with Trichomonas vaginalis, Chlamydia trachomatis, and SHIV(SF162P3). METHODS: Seven SHIV(SF162P3) -infected pigtail macaques were inoculated with T. vaginalis only (n = 2), C. trachomatis only (n = 1), both T. vaginalis and C. trachomatis (n = 2), or control media (no STI; n = 2). Infections were confirmed by culture and/or nucleic acid testing. Genital mucosa was visualized by colposcopy. RESULTS: Characteristic gynecologic signs were observed for both STIs, but not in control animals. Manifestations were most prominent at days 7-10 post-infection. STIs persisted between 4 and 6 weeks and were cleared with antibiotics. CONCLUSIONS: These pilot studies demonstrate the first successful STI-SHIV triple infection of pigtail macaques, with clinical presentation of genital STI symptoms similar to those observed in humans.

Trichomonas vaginalis 62 kDa proteinase as a possible virulence factor.

The aim of this study was to analyze the presence of 62 kDa proteinase and anti-62 kDa proteinase antibody in clinical samples of symptomatic and asymptomatic infected women. Proteinase was detected in all the swabs vaginal of infected women. Significantly, amounts of antigen (mean optical density (OD) values) were detected in swabs vaginal of symptomatic as compared to asymptomatic women. This protein was not detected in the group of patients with Trichomonas vaginalis-culture-negative results and in the groups of samples infected with other agents. Antibody to 62 kDa was detected in the swabs vaginal the only 66.6% of the symptomatic and 55.5% of the asymptomatic infected women. Antibody to 62 kDa was also detected in 7/30 of the swabs vaginal from uninfected women. No significant difference was observed in mean OD values of vaginal swabs of T. vaginalis-infected symptomatic as compared to asymptomatic women. The presence of proteinase in 100% of T. vaginalis-infected women suggested that 62 kDa proteinase could be a virulence factor.

Trichomonas vaginalis is highly prevalent in adolescent girls, pregnant women, and commercial sex workers in Ndola, Zambia.

OBJECTIVES: The aim of the study was to assess the prevalence of Trichomonas sp. infection among adolescent girls, pregnant women, and commercial sex workers in Ndola, Zambia. METHODS: A cross-sectional study was conducted among 460 girls attending school, 307 pregnant women, and 197 commercial sex workers. Self-collected specimens from the vagina, rectum, and mouth were tested by polymerase chain amplification assays for the presence of Trichomonas vaginalis, Pentatrichomonas hominis, and Trichomonas tenax. Genotyping was performed on specimens that tested positive for T. vaginalis. RESULTS: The prevalence of vaginal infection with T. vaginalis was 24.6% among the adolescents, 32.2% among the pregnant women, and 33.2% among the commercial sex workers. Trichomonads other than T. vaginalis were rarely found in the vagina, rectum, and mouth. The presence of T. vaginalis in the rectum was associated with T. vaginalis in the vagina. T. tenax was also detected in the vagina. A total of 9 actin genotypes of T. vaginalis were identified. The distribution of the actin genotypes of T. vaginalis was similar in the 3 study groups. CONCLUSION: We detected high prevalence rates of trichomoniasis among women in Ndola, Zambia. Prevalence among adolescent girls was lower than among pregnant women and commercial sex workers but was still high. We were not able to detect differences in T. vaginalis actin genotypes among the 3 study groups.

Morphologic criteria associated with Trichomonas vaginalis in liquid-based cytology.

OBJECTIVE: To evaluate the morphologic criteria associated with Trichomonas vaginalis on Cytyc (Marlborough, Massachusetts, U.S.A.) liquid-based cytology and to compare results between 2 types of liquid-based cytology-Cytyc and SurePath (BD Diagnostics-TriPath, Burlington, Vermont, U.S.A). STUDY DESIGN: Forty thousand Cytyc liquid-based cytology cases were tested between January 2005 and 2008. Among these, 80 cases (0.2%) had aT vaginalis infection without intraepithelial lesions or other associated infectious organism. The 80 ThinPrep (Cytyc) slides were reexamined, and for each case, morphologic characteristics associated with the parasite were listed. Concerning the SurePath technique, only 1 paper has been found in the literature based on 60,104 cases with 88 cases of T vaginalis (0.17%). RESULTS: Among the 80 T vaginalis patients, the most frequent features associated with the infection were the presence of cannonballs (93%), perinuclear halo (90%), reactive nuclear changes (88%) and attachment of T vaginalis to squamous cells (86%). Moreover, the presence of ghost cells was significantly more frequent in SurePath than Cytyc liquid-based cytology (p = 0.00001), and the presence of neutrophils, reactive nuclear changes, dirty background and karyorrhexis and the predominance of coccobacilli were significantly more frequent in Cytyc than SurePath liquid-based cytology (p < 0.05). CONCLUSION: On the basis of these results, we conclude that SurePath and Cytyc, which are the both commonly used liquid-based cytologic techniques, are useful and have the same efficacy in the detection of T vaginalis infection (p = 0.99).

Trichomonas vaginalis-induced neutrophil apoptosis causes anti-inflammatory cytokine production by human monocyte-derived macrophages.

Neutrophils are the predominant inflammatory cells found in the vaginal discharge of patients with a Trichomonas vaginalis infection. Neutrophils have a shorter life span than other leucocytes. Our previous study indicated that live T. vaginalis alters Mcl-1 expression and caspase-3 activation, thereby inducing apoptosis of human neutrophils. However, it was previously unknown that the apoptotic neutrophils brought about by T. vaginalis can influence vaginal inflammation. Thus, human monocyte-derived macrophages (HMDM) were incubated with T. vaginalis-induced apoptotic neutrophils. Cytokine production and phagocytosis by HMDM were evaluated by ELISA and myeloperoxidase stain, respectively. HMDM showed increased anti-inflammatory cytokine production (IL-10) and decreased levels of pro-inflammatory cytokines, such as TNF-α and IL-6, compared with macrophages alone.

Atypical Squamous Cells in Liquid-Based Cervical Cytology: Microbiology, Inflammatory Infiltrate, and Human Papillomavirus-DNA Testing.

OBJECTIVE: The aim of this study was to assess the correlation between atypical squamous cells (ASC) and inflammatory infiltrate and vaginal microbiota using cervical liquid-based cytological (SurePath®) and high-risk human papillomavirus (HR-HPV) tests. STUDY DESIGN: A cross-sectional study was conducted using a 6-year database from a laboratory in Fortaleza (Brazil). Files from 1,346 ASC cases were divided into subgroups and results concerning inflammation and vaginal microorganisms diagnosed by cytology were compared with HR-HPV test results. RESULTS: An absence of specific microorganisms (ASM) was the most frequent finding (ASC of undetermined significance, ASC-US = 74%; ASC - cannot exclude high-grade squamous intraepithelial lesion, ASC-H = 68%), followed by bacterial vaginosis (ASC-US = 20%; ASC- H = 25%) and Candida spp. (ASC-US = 6%; ASC-H = 5%). Leukocyte infiltrate was present in 71% of ASC-US and 85% of ASC-H (p = 0.0040), and in these specific cases HR-HPV tests were positive for 65 and 64%, respectively. A positive HR-HPV test was relatively more frequent when a specific microorganism was present, and Candida spp. was associated with HR-HPV-positive results (p = 0.0156), while an ASM was associated with negative HR-HPV results (p = 0.0370). CONCLUSION: ASC-US is associated with an absence of inflammation or vaginosis, while ASC-H smears are associated with Trichomonas vaginalis and inflammatory infiltrate. A positive HR-HPV is associated with Candida spp. in ASC cytology.

Results of longterm hospital based cytological screening in asymptomatic women.

Routine cytological screening has been carried out in 27,062 asymptomatic women attending Gynaec and Family Planning O.P.D. of Queen Mary's Hospital, Lucknow, India (April 1971-December 2004). Incidence of squamous intraepithelial lesion (SIL) was found to be 5.9% in the series, while cervical malignancy was seen in 0.6% of cases. The study highlighted the immense utility of cytological screening in minimizing the incidence of carcinoma cervix in the segment of the urban population screened, as the incidence dropped down to 0.5% in the second half from 1.1% noticed in the first half of the screening period. The study also emphasized the utility of clinically downstaging the cervical cancer as 7,316 women showing clinical lesions of cervix were found to harbor SIL in 15.3% and carcinoma cervix in 1.3% of cases as against the incidence of 2.5% for SIL and 0.6% for frank cancer in women with normal cervix. The investigation into different risk factors involved in cervical carcinogenesis revealed that the incidence of SIL and cancer cervix showed a rise with increasing age and parity and prolonged sexual period. The incidences of both cervical cytopathologies were also higher in women of low socio-economic status while religion was found to have no bearing on the occurrence of the disease. Among the four sexually transmitted diseases (STDs) diagnosed in the cervical smears, Trichomonas vaginalis was found to be more prevalent (2.6%), while human papillomavirus (HPV) and Herpes simplex was seen in 0.4 and 0.2% of cases, respectively Herpes simplex was found to have strong affinity with both SIL and carcinoma cervix, while only SIL incidence was high with HPV infection. The study emphasizes need of proper education to women of low socio-economic class for creating awareness regarding hazards and risk factors of cervical cancer as well as management and cure of the disease.

[Molecular and chemical mechanism of Trichomonas vaginalis-induced contact-dependent cytotoxicity].

Trichomonas vaginalis parasitizes in human genitourinary tract. The protozoon adhering to target cell plays a critical role in its contact-dependent cytotoxicity. The enzymes synthesized by T.voginalis can hurt vaginalis epithelial cells (VECs) directly. The focal immune reaction in the location parasitized by the parasite may provide an immunologic protection. Meanwhile, inflammatory factors and immune cells may aggravate the situation. In general, the T. vaginalis-induced contact-dependent cytotoxicity is a result of the involvement of some molecular and chemical factors.

Antibiotics for bacterial vaginosis or Trichomonas vaginalis in pregnancy: a systematic review.

OBJECTIVE: To determine whether antibiotic treatment for bacterial vaginosis or Trichomonas vaginalis during pregnancy decreases the risk of preterm birth and associated adverse outcomes. DATA SOURCES: Pre-MEDLINE and MEDLINE (1966-2003), EMBASE (1980-2003), and the Cochrane Library were searched using the keywords "bacterial vaginosis", "Trichomonas", "Trichomonas vaginalis", "Trichomonas vaginitis", "Trichomonas infections", "pregnancy", "pregnant", "antibiotics", and "antibiotic prophylaxis". METHODS OF STUDY SELECTION: The search produced 1,888 titles, of which 1,256 abstracts were reviewed further. Of these, 1,217 were ineligible. Inclusion criteria were the following: randomized controlled trials in which antibiotics were compared with no antibiotic or placebo, for women in the second or third trimester of pregnancy with symptomatic or asymptomatic bacterial vaginosis or Trichomonas vaginalis, intact membranes, and not in labor. Exclusion criteria were as follows: published in a language other than English, dropout rate of more than 20% of women in either group, and lack of usable outcomes. Of the 39 papers reviewed in detail, 14 studies were included in the meta-analysis. TABULATION, INTEGRATION, AND RESULTS: One of the authors reviewed titles obtained from the searches, and 2 reviewers independently reviewed the abstracts, excluded those that were ineligible, identified eligible papers, and abstracted the data. For women with bacterial vaginosis, antibiotics reduced the risk of persistent infection but did not reduce the risk of preterm birth or the incidence of associated adverse outcomes for the general population or for any subgroup analyzed. For women with Trichomonas vaginalis, metronidazole reduced the risk of persistent infection but increased the incidence of preterm birth. CONCLUSION: Contrary to the conclusions of 3 recent systematic reviews, we found no evidence to support the use of antibiotic treatment for bacterial vaginosis or Trichomonas vaginalis in pregnancy to reduce the risk of preterm birth or its associated morbidities in low- or high-risk women.