Reinfection (superinfection) with HIV

Reinfection, or ‘superinfection’ as it is sometimes known, means someone contracting a new or secondary infection from a virus [1]A small infective organism which is incapable of reproducing outside a host cell. with which they have already been infected. In some viral diseases such as measles or mumps, reinfection does not occur because the original infection creates immunity. In other viral infections such as colds and flu [2]A highly contagious and relatively common viral infection of the respiratory system, transmitted by infected droplets of moisture which may be spread through coughing and sneezing. Most people with flu recover but some go on to develop secondary infections such as pneumonia which may be fatal., reinfection occurs frequently, due to different strains of the virus.

While rare, we now know that reinfection with HIV happens through unsafe sex or injecting with other people with HIV. One study has shown it is most likely to occur within the first three years of HIV infection in people who have not previously taken HIV treatments or who have taken structured treatment interruptions. However, recently there was a documented case where reinfection occurred between two HIV positive gay men who had been in a long term relationship practicing unsafe sex and having a history of non-adherence to HIV treatments.

We do know that adherence to treatments may impact and provide protection against the possibility of re-infection occurring (e.g. it may be less likely to occur if both HIV positive partners are currently on treatments with a low or undetectable viral load [3]A measurement of the quantity of HIV RNA in the blood. Viral load blood test results are expressed as the number of copies (of HIV) per milliliter of blood plasma.). However, we do not know whether exposure to different viral strains during early infection provides protective immunity against later reinfection.

Studies among dually infected (more than one strain of HIV virus) people have shown that having more than one HIV strain or being reinfected is likely to lead to a poorer long-term prognosis and more rapid disease progression.

The rise of sexually transmissible infections (STIs [4][Sexually Transmissible (or Transmitted) Infection] Infections spread by the transfer of organisms from person to person during sexual contact. Also called venereal disease (VD) (an older public health term) or sexually transmitted diseases (STDs). ) such as syphilis among HIV positive gay men can cause serious damage to the immune system and make HIV more difficult to treat. It may increase the chance of reinfection with an STI or with a different strain of HIV. It is important to test regularly for syphilis and other STIs such as herpes, and to seek early treatment to reduce the risk of further damage to your immune system or reinfection.