There are rarely any extra precautions to be taken by carers and health care workers looking after people with HIV with specific opportunistic infections.

This is because, by the nature of the disease, the organisms that cause opportunistic infections such as candida, PCP, toxoplasmosis, MAI, CMV are prevalent everywhere and standard universal precautions are adequate to deal with them.

Some specific extra precautions for immunocompetent carers are probably only required in a few situations:

Herpes zoster (shingles)

If there's an attack, until the blisters or lesions settle down and dry out, people who have never had chicken pox (and especially pregnant women) should keep away. If contact has taken place protection is available in the form of immunoglobulin.

Herpes simplex

If there's an attack around the mouth kissing would be infectious at the time; if round the genitals touching could be infective, so wear gloves.

Salmonella

Cryptosporidiosis

The epidemiology isn't wholly understood: it could cause an acute diarrhoea–type illness in people with a normal immune system, or much more severe life–threatening illness in people with immune deficiency. The same precautions as for salmonella are advised.

`Active TB'

i.e. when coughing up TB organisms.

The chance of becoming infected with Mycobacterium tuberculosis if you have been in prolonged contact with someone who has active TB is approximately 50%. Prolonged contact means sharing a home, a ward or being in other close proximity for many hours. In other circumstances the chances of infection are very much lower – probably around 8–10% if you encounter TB organisms in the air. It is important to note that these risk estimates are derived from the USA, where the BCG vaccination is not given routinely at puberty, so the chances of infection in the UK are much lower for individuals who have received the BCG vaccination (it is believed to provide approximately 70% protection in immunocompetent people).  M.TB can linger on droplets in the air for several hours, so if you are caring for someone with TB and you haven't received the BCG vaccination, it is best to wear a mask.

Once treatment has begun, TB ceases to become infectious within a few weeks, and individuals can often be treated at home provided they can be relied upon to take the full course of medication. If the full course of medication is not taken the TB may relapse, with the additional danger that it will be multi–drug resistant: that is, insensitive to the commonly used cocktail of anti–TB drugs. If multi–drug resistant TB emerges it is frequently lethal, but it is not any more infectious than other strains of TB.

Unfortunately, active multi–drug resistant TB can persist for many months, and it is often difficult to determine if a patient has ceased to be infectious. For this reason people with MDR–TB are usually isolated in hospital until they are pronounced non–infectious, and the hospital will have infection control procedures to protect visitors.