What is the appropriate evaluation and treatment for a patient with symptoms of frequent urination and odor, who has been notified by the CDC of trichomoniasis and varicella virus, following recent unprotected sex with a new partner, and is experiencing their first STI diagnosis?

Evaluation and Treatment Following CDC Notification of Trichomoniasis and Varicella

Treat the confirmed trichomoniasis immediately with metronidazole 500 mg orally twice daily for 7 days, perform comprehensive STI screening including gonorrhea, chlamydia, syphilis, and HIV testing, and address varicella immunity status separately as this is not sexually transmitted. 1, 2, 3

Immediate Treatment for Trichomoniasis

• Begin metronidazole 500 mg orally twice daily for 7 days as this is the preferred regimen for women, demonstrating superior cure rates compared to single-dose therapy (reduced treatment failure at 1-month test of cure). 2, 3
• The 7-day regimen is specifically recommended over the 2-gram single dose for women due to better efficacy in preventing persistent infection. 2
• Instruct the patient to abstain from sexual intercourse for 7 days after completing the full treatment course. 1
• Avoid alcohol consumption during treatment and for 24 hours after completion due to disulfiram-like reactions with metronidazole. 4

Comprehensive STI Screening Panel

Given the recent unprotected sexual exposure, perform immediate testing for all common STIs:

• Gonorrhea and chlamydia NAATs from cervical/vaginal specimens or urine (NAATs have 86-100% sensitivity and 97-100% specificity). 5, 1
• Syphilis serology at baseline, with repeat testing at 6 weeks and 3 months. 6
• HIV antibody testing at baseline, with repeat testing at 6 weeks and 3 months post-exposure. 6
• Hepatitis B surface antigen and antibody if vaccination status is unknown or incomplete. 6

Presumptive Treatment Considerations

While awaiting test results, consider presumptive treatment for cervicitis given the patient's symptoms of frequent urination and odor:

• Azithromycin 1 g orally single dose OR doxycycline 100 mg orally twice daily for 7 days should be given if the patient is at high risk (new sexual partner, unprotected sex) and follow-up is uncertain. 5, 1
• Add concurrent gonorrhea treatment (ceftriaxone 500 mg IM for patients ≥150 kg or 250 mg IM for <150 kg) if local gonorrhea prevalence exceeds 5% or if the patient has risk factors. 5, 1, 3

Follow-Up Testing Schedule

• Retest for trichomoniasis at 3 months after treatment due to high reinfection rates (this is critical and often missed). 1, 2, 3
• Retest for gonorrhea and chlamydia at 3 months if initial tests are positive, as reinfection likelihood is high. 5, 1
• Repeat HIV and syphilis testing at 6 weeks and 3 months from the exposure date. 6
• Test-of-cure at 2 weeks for gonorrhea and chlamydia if initial tests were negative and no presumptive treatment was given. 6

Partner Management (Critical Component)

• All sexual partners from the past 60 days must be notified, evaluated, and treated for trichomoniasis and any other identified STIs. 5, 1
• Expedited partner therapy should be considered, allowing delivery of metronidazole prescription directly to the partner if they cannot access care promptly. 5
• Both patient and partner must abstain from sex until both have completed the full 7-day treatment course and are symptom-free. 1
• Failure to treat partners results in reinfection rates exceeding 50%. 7

Addressing the Varicella Component

The varicella virus notification requires separate evaluation as this is NOT sexually transmitted:

• Assess for history of chickenpox or varicella vaccination (2 doses).
• If no immunity documented, check varicella IgG antibody titers.
• If non-immune and recent exposure occurred, consider varicella-zoster immune globulin (VariZIG) if within 10 days of exposure.
• This is unrelated to the STI evaluation and should not delay trichomoniasis treatment.

Critical Pitfalls to Avoid

• Do not use single-dose metronidazole 2 g in women—the 7-day regimen is superior for cure rates. 2, 3
• Do not skip the 3-month retest—reinfection rates are extremely high (up to 17% at 3 months), often due to untreated partners. 1, 2
• Do not assume partners are treated—directly verify or provide expedited partner therapy. 5
• Do not overlook HIV risk—trichomoniasis increases HIV acquisition risk by 2-5 fold. 8, 9
• Do not delay treatment while awaiting test results if the patient is high-risk and follow-up is uncertain. 5

Counseling and Risk Reduction

• Educate the patient that trichomoniasis is sexually transmitted and requires partner treatment to prevent reinfection. 4, 7
• Discuss consistent condom use for future encounters to reduce STI transmission risk. 5
• Provide reassurance that trichomoniasis is highly curable (approaching 100% cure rate when partners are treated). 7
• Address the emotional distress by normalizing STI diagnosis and emphasizing treatability. 5

HIV-Specific Considerations

• If HIV status is positive or unknown, the same treatment regimen applies for trichomoniasis and other STIs. 5
• Treatment of trichomoniasis in HIV-infected women reduces cervical HIV shedding and may decrease HIV transmission to partners. 5
• Consider HIV post-exposure prophylaxis (PEP) if the exposure occurred within 72 hours and the partner's HIV status is unknown or positive. 6