What is co-infection?

Someone is said to be co-infected if they have contracted two or more infections at the same time. Some infections which are often referred to with people living with HIV include tuberculosis (TB), hepatitis B and hepatitis C virus (HBV/HBC).

If you are living with HIV co-infection may be more serious as your defence system (immune system) is already compromised. However, most infections are manageable with the correct treatment and support. For more information speak to your doctor or visit our service finder to find help.

What are hepatitis B and hepatitis C?

Hepatitis B and hepatitis C are viral infections that cause inflammation of the liver and can cause liver disease if not treated.

Hepatitis B can be transmitted similarly to HIV through unprotected sex and sharing injecting drugs equipment. Hepatitis C is only transmitted from blood to blood so most commonly is passed on through injecting equipment.

Co-infection with hepatitis B or hepatitis C can be problematic as your liver is the main organ which processes HIV medication. As the hepatitis virus affects the liver, this means the anti-HIV medication doesn’t work as well as it should. Hepatitis infections can be treated and managed, visit for more information and advice.

What is Tuberculosis?

Tuberculosis (TB) is a bacterial infection usually of the lungs which is spread through the air when someone with active TB sneezes or coughs. Symptoms include a chronic cough that may produce bloody mucous, fever and weight loss.

Someone with active TB usually becomes ill very soon after becoming infected with the bacteria. This type of TB can be easily passed onto other people and can be dangerous if not treated. Latent or dormant TB is a form which is not infectious, shows no symptoms and the person does not become ill. However latent TB can develop into active TB.

The prevalence of tuberculosis in Scotland is generally very stable and low with around 8-9 cases per 100,000 population per year. TB is recorded as the underlying cause of death for around 40 people per year in Scotland. However, TB is more common in people living with HIV as the immune system is compromised.

Tuberculosis usually affects the lungs but can also infect other parts of the body such as the kidneys and bones.

As HIV weakens the immune system, it is easy for latent TB to multiply and become active and infectious. It is more difficult for the body to control the infection and in an HIV positive person tuberculosis is defined as an AIDS-defining-illness. TB can be treated and if you have tuberculosis you should start treatment as soon as possible.

How do I know if I am co-infected?

If you are living with HIV you should have been tested for hepatitis B and C and tuberculosis at your first hospital appointment. People living with HIV may be offered the HBV vaccine to prevent co-infection. You should not be offered the tuberculosis vaccine (BCG) as this vaccine contains a weakened form of tuberculosis-causing bacteria, which could cause you to become unwell with a TB-like illness.

If you start to feel unwell or have any unusual symptoms and are worried about co-infection, speak to your GP, HIV specialist or use our service finder to find services and support near you.