Double-blind comparison of a single dose and a five-day course of metronidazole in the treatment of trichomoniasis

A Resistant Case of Familial Nonsexual Transmission of Trichomonas

Trichomonas vaginalis is a protozoan responsible for the most prevalent sexually transmitted nonviral disease worldwide. This is a case report of probable grandmother to granddaughter nonsexual transmission of trichomonas. The granddaughter had no prior sexual contact for the last 11 years.

The patient presented for a follow-up of urinary tract infection diagnosed at her neurologist’s office. On review, it was noticed that the urinalysis microscopy revealed trichomonas. History-taking revealed no usual sexual exposure, but subsequent investigation revealed probable exposure from her grandmother. Furthermore, typical single-dose treatment followed by typical seven-day treatment was ineffective. High-dose metronidazole for seven days was required for treatment.

 While nonsexual transmission of trichomonas is rare, there have been numerous case reports and studies showing that it does occur. The subsequent presented case highlights the need to broaden the search for contacts beyond sexual transmission. Also, resistance to usual treatment, as seen in this case, is seldom encountered, but it could have been caused by repeated treatment and re-exposure to the unusual source.

Recent advances in the epidemiology, diagnosis, and management of Trichomonas vaginalis infection

Trichomonas vaginalis is the most common, curable non-viral sexually transmitted infection (STI) worldwide. Despite this burden of disease, it is not currently a reportable disease in the United States. Recent advances in the epidemiology, diagnosis, and management of T. vaginalis infection are described in this article. This includes updated global and U.S. prevalence data in women and men as well as recent epidemiological data in HIV-infected individuals and pregnant women. Advances in molecular diagnostics are also reviewed, as are data from recent clinical trials regarding the treatment of trichomonas in women.

Single-dose versus 7-day-dose metronidazole for the treatment of trichomoniasis in women: an open-label, randomised controlled trial

BACKGROUND

Among women, trichomoniasis is the most common non-viral sexually transmitted infection worldwide, and is associated with serious reproductive morbidity, poor birth outcomes, and amplified HIV transmission. Single-dose metronidazole is the first-line treatment for trichomoniasis. However, bacterial vaginosis can alter treatment efficacy in HIV-infected women, and single-dose metronidazole treatment might not always clear infection. We compared single-dose metronidazole with a 7-day dose for the treatment of trichomoniasis among HIV-uninfected, non-pregnant women and tested whether efficacy was modified by bacterial vaginosis.

METHODS

In this multicentre, open-label, randomised controlled trial, participants were recruited at three sexual health clinics in the USA. We included women positive for Trichomonas vaginalis infection according to clinical screening. Participants were randomly assigned (1:1) to receive either a single dose of 2 g of metronidazole (single-dose group) or 500 mg of metronidazole twice daily for 7 days (7-day-dose group). The randomisation was done by blocks of four or six for each site. Patients and investigators were aware of treatment assignment. The primary outcome was T vaginalis infection by intention to treat, at test-of-cure 4 weeks after completion of treatment. The analysis of the primary outcome per nucleic acid amplification test or culture was also stratified by bacterial vaginosis status. This trial is registered with ClinicalTrials.gov, number NCT01018095, and with the US Food and Drug Administration, number IND118276, and is closed to accrual.

FINDINGS

Participants were recruited from Oct 6, 2014, to April 26, 2017. Of the 1028 patients assessed for eligibility, 623 women were randomly assigned to treatment groups (311 women in the single-dose group and 312 women in the 7-day-dose group; intention-to-treat population). Although planned enrolment had been 1664 women, the study was stopped early because of funding limitations. Patients in the 7-day-dose group were less likely to be T vaginalis positive at test-of-cure than those in the single-dose group (34 [11%] of 312 vs 58 [19%] of 311, relative risk 0·55, 95% CI 0·34-0·70; p<0·0001). Bacterial vaginosis status had no significant effect on relative risk (p=0·17). Self-reported adherence was 96% in the 7-day-dose group and 99% in the single-dose group. Side-effects were similar by group; the most common side-effect was nausea (124 [23%]), followed by headache (38 [7%]) and vomiting (19 [4%]).

INTERPRETATION

The 7-day-dose metronidazole should be the preferred treatment for trichomoniasis among women.

FUNDING

National Institutes of Health.

In Vitro Study of the Susceptibility of Clinical Isolates of Trichomonas vaginalis to Metronidazole and Secnidazole

Nitroimidazoles (metronidazole [MTZ] and tinidazole [TNZ]) are the only drugs recommended for treatment of Trichomonas vaginalis infections. MTZ resistance occurs in 4% to 10% of cases of vaginal trichomoniasis (R. D. Kirkcaldy et al., Emerg Infect Dis 18:939-943, 2012; J. R. Schwebke and F. J. Barrientes, Antimicrob Agents Chemother 50:4209-4210, 2006) and TNZ resistance in 1% of cases (J. R. Schwebke and F. J. Barrientes, Antimicrob Agents Chemother 50:4209-4210, 2006). Emerging nitroimidazole-resistant trichomoniasis is concerning, because few alternatives to standard therapy exist. We assessed the prevalence of in vitro aerobic MTZ and secnidazole resistance among T. vaginalis isolates collected in 2015 to 2016 from 100 women in Birmingham, Alabama, with positive cultures. Archived specimens were treated with secnidazole or MTZ (0.2 to 400 μg/ml) for 48 h, according to U.S. Centers for Disease Control and Prevention protocols. Ninety-six (96%) of the 100 clinical Trichomonas isolates tested demonstrated lower minimum lethal concentrations for secnidazole than for MTZ, suggesting that secnidazole has better in vitro activity than MTZ.

Single-Dose Compared With Multidose Metronidazole for the Treatment of Trichomoniasis in Women: A Meta-Analysis

BACKGROUND

Trichomonas vaginalis is the most common curable sexually transmitted infection worldwide. Although the Centers for Disease Control and Prevention and the World Health Organization recommend a single 2-g dose of metronidazole for the first line of treatment for T. vaginalis among human immunodeficiency virus (HIV) negative women, high rates of repeat infections are found. The purpose of this meta-analysis was to compare treatment failure between single versus multidose metronidazole for the treatment of T. vaginalis.

METHODS

A systematic literature search was performed using search terms including metronidazole AND trichomoniasis AND women. Embase, MEDLINE, and Clinicaltrials.gov were used to search for relevant studies as well as hand searching relevant articles. These databases were last searched on January 25, 2016. To be included in this meta-analysis, the study had to be a clinical trial, evaluate T. vaginalis, use oral metronidazole, and compare single dose metronidazole to multidose metronidazole.

RESULTS

There were 487 articles that were assessed for relevance and quality. Of these articles, 6 met the eligibility criteria and were included in the final results. The pooled risk ratio indicated higher treatment failure for single dose compared to multidose 1.87 (95% confidence interval, 1.23-2.82; P < 0.01). When the one study that included HIV+ women was excluded from analysis, the findings were similar with a pooled risk ratio of 1.80 (95% confidence interval, 1.07-3.02; P < 0.03).

CONCLUSIONS

Centers for Disease Control and Prevention recently changed treatment recommendations for HIV+ women to multidose rather than single-dose. These data suggest that those recommendations should be considered for all women.

Sexually transmitted diseases treatment guidelines, 2015

These guidelines for the treatment of persons who have or are at risk for sexually transmitted diseases (STDs) were updated by CDC after consultation with a group of professionals knowledgeable in the field of STDs who met in Atlanta on April 30-May 2, 2013. The information in this report updates the Sexually Transmitted Diseases Treatment Guidelines, 2010 (MMWR Recomm Rep 2010;59 [No. RR-12]). These updated guidelines discuss 1) alternative treatment regimens for Neisseria gonorrhoeae; 2) the use of nucleic acid amplification tests for the diagnosis of trichomoniasis; 3) alternative treatment options for genital warts; 4) the role of Mycoplasma genitalium in urethritis/cervicitis and treatment-related implications; 5) updated HPV vaccine recommendations and counseling messages; 6) the management of persons who are transgender; 7) annual testing for hepatitis C in persons with HIV infection; 8) updated recommendations for diagnostic evaluation of urethritis; and 9) retesting to detect repeat infection. Physicians and other health-care providers can use these guidelines to assist in the prevention and treatment of STDs.

A randomized treatment trial: single versus 7-day dose of metronidazole for the treatment of Trichomonas vaginalis among HIV-infected women

OBJECTIVE

To determine if the metronidazole (MTZ) 2-gm single dose (recommended) is as effective as the 7-day 500 mg twice a day dose (alternative) for treatment of Trichomonas vaginalis (TV) among HIV+ women.

METHODS

Phase IV randomized clinical trial; HIV+ women with culture confirmed TV were randomized to treatment arm: MTZ 2-gm single dose or MTZ 500 mg twice a day 7-day dose. All women were given 2-gm MTZ doses to deliver to their sex partners. Women were recultured for TV at a test-of-cure (TOC) visit occurring 6-12 days after treatment completion. TV-negative women at TOC were again recultured at a 3-month visit. Repeat TV infection rates were compared between arms.

RESULTS

Two hundred seventy HIV+/TV+ women were enrolled (mean age = 40 years, ±9.4; 92.2% African American). Treatment arms were similar with respect to age, race, CD4 count, viral load, antiretroviral therapy status, site, and loss-to-follow up. Women in the 7-day arm had lower repeat TV infection rates at TOC [8.5% (11 of 130) versus 16.8% (21 of 125) (relative risk: 0.50, 95% confidence interval = 0.25, 1.00; P < 0.05)] and at 3 months [11.0% (8 of 73) versus 24.1% (19 of 79) (relative risk: 0.46, 95% confidence interval = 0.21, 0.98; P = 0.03)] compared with the single-dose arm.

CONCLUSIONS

The 7-day MTZ dose was more effective than the single dose for the treatment of TV among HIV+ women.

Persistent urethritis and prostatitis due to Trichomonas vaginalis: A case report

The present report describes a case of persistent urethritis accompanied by prostatitis due to Trichomonas vaginalis in a young male patient. The importance of the laboratory diagnosis of trichomoniasis in persistent or recurrent urethritis (ie, testing samples from multiple sites) is highlighted, with the aim of improving the clinical recognition of this pathogen.

Metronidazole in a single dose for the treatment of trichomoniasis. Failure of a 1-g single dose

To determine the minimum effective dose of metronidazole in the treatment of vaginal trichomoniasis, a randomised clinical trial comparing single 1-g and 2-g doses was carried out on 163 patients attending sexually transmitted diseases and family planning clinics. Seventy-two of 86 (84%) patients receiving a single 2-g dose of metronidazole were cured compared with only 42 of 77 (55%) receiving a 1-g dose. The body weight of the patient was a significant variable affecting treatment outcome only in the latter group; 69% of patients weighing more than 57 kg or less when cured compared with only 43% of those weighing more. Patients who failed after either dose regimen were retreated with a single 2-g dose. Eighteen of 21 (86%) and seven of 10 (70%) failures with the initial 1-g and 2-g doses respectively were cured. A single 1-g dose of metronidazole is not recommended as routine treatment for vaginal trichomoniasis.