HIV update - 20th August 2014

Pneumococcal disease

People living with HIV continue to be at increased risk of invasive pneumococcal disease, according to a study in Denmark. Even in the era of modern combination HIV treatment, the risk of infection was 19-fold higher among people living with HIV than in the general population.

Infection with Streptococcus pneumoniae can cause a range of bacterial diseases, from relatively mild illness to much more serious conditions. Non-invasive pneumococcal infections include ear and sinus infections, and bronchitis. Invasive pneumococcal infections include infections of the joints, bones, lungs, and blood.

People who have a weakened immune system are most at risk from infection with pneumococcal bacteria. Investigators in Denmark wanted to find out whether the availability of effective HIV treatment and the introduction of a childhood vaccine in 2007 had reduced rates of invasive pneumococcal disease in people living with HIV.

They compared rates of the disease between people living with HIV and people in the general population (controls) at different time periods – 1995-96; 1997-99 and 2000-12. Each person living with HIV was matched with 19 controls.

The research found that overall risk of invasive pneumococcal disease was around 24-fold higher among people living with HIV. Risk became lower as HIV treatment improved, but even in the latest time period the risk was significantly higher for people living with HIV.

Smoking and injecting drugs were associated with an increased risk of pneumococcal disease. Detectable viral load and low CD4 count also increased risk.

Moreover, the risk of the disease remained unchanged throughout the study for people living with HIV who inject drugs. The researchers comment that people who inject drugs, “have a remarkably high risk of invasive pneumococcal disease that hasn’t declined over time, and remain an obvious group for targeted immunization”.

HIV superinfection

New research has shown that HIV superinfection accelerates viral load increases, but has no impact on HIV disease progression.

HIV superinfection involves someone living with HIV acquiring another strain of HIV at a later time. It had been thought to be rare, but research in Kenya found an annual superinfection incidence of 3% among a group of women at high risk.

The impact of superinfection on HIV disease progression is not clear. The team of researchers in Kenya therefore followed-up women in the group and compared changes in viral load, CD4 count, and clinical disease progression between women with superinfection and women with a single virus.

They found that there was a significantly faster increase in viral load among the women with superinfection, but only a modest impact on CD4 cell loss and this did not translate into faster disease progression.


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