What can be transmitted from a woman to a man during sexual intercourse and what are the potential effects on him?

From the Guidelines

During sexual intercourse, women can transmit various infections to men, including bacterial infections like chlamydia, gonorrhea, and syphilis; viral infections such as HIV, herpes, HPV, and hepatitis; and other conditions like trichomoniasis and pubic lice. These infections can cause symptoms ranging from discharge, pain during urination, and genital sores to more serious complications like infertility, systemic illness, and certain cancers if left untreated 1. For protection, consistent condom use is highly recommended, along with regular STI testing, especially with new partners. Many STIs can be effectively treated with antibiotics if bacterial (like azithromycin 1g single dose for chlamydia) or managed with antiviral medications if viral (like acyclovir 400mg twice daily for herpes) 1. Transmission occurs through exchange of bodily fluids or skin-to-skin contact, with risk factors including unprotected sex, multiple partners, and previous STI history 1. Some infections may be asymptomatic in men but can still cause complications or be transmitted to future partners, making regular screening essential for sexually active individuals 1. Key points to consider include:

• The risk of HIV transmission from female to male is estimated to be between 1 in 700 and 1 in 3000 per act of vaginal intercourse 1
• Chlamydia and gonorrhea are common bacterial STIs that can be transmitted from women to men, with estimated annual costs of $516.7 million and $162.1 million, respectively 1
• Regular screening for STIs, including chlamydia and gonorrhea, is recommended for sexually active individuals, especially those with new partners or a history of STIs 1
• Hepatitis B vaccination is recommended for all susceptible HIV-infected patients, and hepatitis A vaccination is recommended for men who have sex with men and others with indications for hepatitis A virus vaccine 1

From the FDA Drug Label

Urethritis and cervicitis due to Chlamydia trachomatis or Neisseria gonorrhoeae. Genital ulcer disease in men due to Haemophilus ducreyi (chancroid). All patients with sexually-transmitted urethritis or cervicitis should have a serologic test for syphilis and appropriate cultures for gonorrhea performed at the time of diagnosis.

The potential effects on a man from a woman during sexual intercourse include the transmission of:

• Chlamydia trachomatis: causing urethritis
• Neisseria gonorrhoeae: causing urethritis and cervicitis
• Haemophilus ducreyi: causing genital ulcer disease (chancroid)
• Syphilis: which may be masked or delayed in symptoms if antimicrobial agents are used to treat non-gonococcal urethritis 2 These infections can cause symptoms such as discharge, pain, and ulcers in the genital area. It is essential to practice safe sex and get tested for sexually transmitted infections (STIs) to prevent transmission and ensure prompt treatment if an infection occurs.

From the Research

Transmission of Infections from Woman to Man

During sexual intercourse, several infections can be transmitted from a woman to a man, including:

• Bacterial infections such as gonorrhoea, chlamydiasis, syphilis, chancroid, lymphogranuloma venereum, and granuloma inguinale 3
• Protozoan infections such as trichomoniasis 3, 4
• Viral infections such as genital herpes, genital warts, and HIV 3, 5
• Parasitic infections such as pediculosis pubis and scabies 4

Potential Effects on Men

These infections can cause a range of symptoms and health problems in men, including:

• Genital ulcers or erosion 3
• Urethral or vaginal discharge 3
• Pelvic inflammatory disease 3, 6
• Proctitis, particularly in men who have sex with men 7
• Infertility, ectopic pregnancy, cervical cancer, premature mortality, or miscarriage 3
• Acute or chronic diarrhea, and other abdominal symptoms in the case of parasitic infections such as amebiasis and giardiasis 4

Prevention and Protection

Using condoms and diaphragms can provide some protection against bacterial and viral infections 6. Spermicides have been reported to kill a wide range of bacteria and viruses, including HIV, in vitro, and may provide some protection against infection 6. However, the most effective way to avoid the risk of becoming infected with STIs is through monogamous sex with a stable, uninfected partner or sexual abstinence 3.