Bacterial infections in the gut and mouth can cause diarrhoea or stomach pains. Symptoms depend on the type of bacterium present:

• Shigella tends to stay in the gut, causing symptoms such as abdominal pain and tenderness and bloody diarrhoea. These usually get gradually worse over a period of weeks. Recently, an outbreak of shigellosis has been reported amongst gay men in London, following similar outbreaks in San Francisco, Amsterdam, Sydney and Berlin.

• Campylobacter jejuni infection causes fever, diarrhoea and weight loss.

• Salmonellaorganisms can invade the bloodstream from the gut and cause septicaemia.

• Clostridium bacteria, which are normal inhabitants of the gut, sometimes grow out of control among people who are taking antibiotics, and release a toxin which causes diarrhoea.

When these infections are only causing diarrhoea, anti-diarrhoeal drugs and precautions against spreading the infections may be sufficient to allow recovery. However, antibiotics may be used to clear some infections, especially Clostridium difficile. If the infections have spread into the blood, then antibiotics are certainly needed.

Clostridium difficile was the most common cause of diarrhoea in people with HIV in a large US study looking at the period 1992-2000, but became much less frequent with the adoption of potent antiretroviral therapy^[1].

There is a separate entry on salmonellosis below, which contains more information on this infection. Information on avoiding the bacterial infections that cause food poisoning, such as Listeria, Salmonella and Campylobacter, is contained in NAM's publication Living with HIV.

A condition called lingual bacteriosis is an oral infection which may be mistaken for oral thrush (candidiasis)^[2]. It causes a white coating of the tongue and interferes with sense of taste. If lingual bacteriosis is established through testing, treatment with amoxicillin and clavulanate (co-amoxiclav, Augmentin / Augmentin-Duo / Amiclav) for 14 days has been suggested.

Recently, an outbreak of the rare sexually-transmitted infection Lymphogranuloma venereum (LGV) has been reported across Europe, mostly in HIV-positive gay men. Three cases have also been reported in the United States. Symptoms include  proctitis (inflammation of the rectum or anus), rectal pain and discharge and tender lymph nodes in the groin. It seems to be associated with unprotected anal sex, fisting and the use of sex toys, but can be treated with a 21-day course of doxycycline (Vibramycin / Vibramycin-D / Doxylar; ^[3]).

By March 2005, most cases had appeared in Amsterdam, with the majority of cases in the United Kingdom being found in London^[4]. Despite the trend for the number of cases to increase, the total number of cases is small, with 341 cases reported in the United Kingdom up to March 2006, with most in gay, HIV-positive men^[5]. Eleven per cent of these men also had hepatitis C, and most had met sexual partners at sex parties and in sex clubs.