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Types of infections


Bacteria are easy to treat as they’re killed by antibiotics. When this happens the infection’s gone from your body. It will only come back if you get infected again. Bacterial STIs are ones like gonorrhoea, syphilis, and chlamydia.

Parasites, fungal and gut infections

Parasites are small creatures that live on or inside your body. Some, such as crabs, are big enough to see. Others, like the ones that cause gut infections, can’t be seen.

Some, such as threadworm or crabs, don’t harm you but can be a nuisance. Other parasites, such as ones that cause gut infections, can do serious damage if they are left untreated. Some gut infections are caused by bacteria.

Fungal infections, such as thrush, are caused by a sort of mould that lives on warm, moist skin in the mouth or on the cock.


Viruses can’t usually be cured by medicines. They’re tricky to treat as antibiotics have no effect and it’s very hard to make drugs or vaccines against them.

Eventually your body’s own immune system will deal with a virus, either killing it off or keeping it under control. Some viruses may stay in your body for years (like warts) or even a lifetime (like HIV or herpes).

A virus is more likely to cause symptoms when your immune system isn’t managing to keep it under control.

Effective HIV treatment now means that levels of the virus can become undetectable in the blood and it cannot be passed on.

Hep C can now be cured with new treatments.

Last review: 2/11/2018
Next review: 2/11/2021