STIs and HIV: Understanding the Overlap

Educators who work in HIV services often meet two opposite attitudes: some people worry far more than the facts support, and others far less. A column written by two staff members of a Vancouver AIDS service organization set out to explain how ordinary sexually transmitted infections connect to HIV. This article gathers its main points as general background.

Arousal and decision-making

The column discussed a behavioural study of male college students. Participants answered questions about sexual situations either in a neutral state or after self-stimulation. Arousal left their ability to name the risks of unprotected sex unchanged, yet it lowered their stated likelihood of using a condom across several related questions.

The sample was small and drawn from one group, so the results cannot be applied to everyone without more research. Findings like these are sometimes used to explain why intentions formed in a calm moment do not always match behaviour in the heat of one.

Counts, cures and lifelong conditions

Provincial surveillance reports in British Columbia, as elsewhere, track yearly counts of reportable infections. A drop in one year reflects only that year and predicts nothing about the next.

The column noted that many bacterial infections can be cured when found early, while HIV remains a lifelong condition. HIV spreads less easily than herpes or HPV, is not passed on through saliva and survives only briefly outside the body.

How one infection raises vulnerability to another

A central point is that gonorrhea, herpes, HPV and similar infections can make HIV transmission more likely. Sores or irritated tissue around the genitals give the virus an easier way in for an HIV-negative person. For a person living with HIV, a second infection can push viral load higher, which raises the chance of passing the virus on. The effect runs in both directions, whichever partner carries the other infection.

Condoms and barrier methods

Research cited in the column found that external and internal condoms, used consistently and correctly, are highly effective against HIV and cut the chance of other infections considerably. Genital herpes, syphilis and HPV can spread by skin contact, so a barrier protects only the areas it covers.

Internal condoms are typically made of nitrile or polyurethane, which suits people with latex allergies. Part of the design rests against the skin around the vagina or anus, which is described as a way to widen coverage.

When protection fails or is absent

Condoms occasionally tear or slip, and in some encounters none is used at all because of intoxication, lack of access or distraction. Certain infections cause no symptoms for months or years, so a partner can sincerely report good health and still carry one.

Testing and post-exposure treatment

Herpes symptoms, when they occur, often appear within a few weeks, while HPV and chlamydia may cause no symptoms for months, and HIV can stay symptom-free for long stretches. Early HIV symptoms, when they occur, resemble flu, with fatigue and swollen lymph nodes in the first weeks after infection. Untreated chlamydia and gonorrhea can lead to infertility, and HPV is linked to cervical cancer, which is why Pap testing is part of routine care in Canada.

Post-exposure prophylaxis, or PEP, is a course of antiretroviral medication prescribed after a possible HIV exposure and assessed by a physician or clinic. It is generally described as time-sensitive, with the window measured in days. Health authorities across Canada publish their own criteria.