HIV-related diseases of the central nervous system and hospital admissions due to opportunistic infections have plummeted Europe-wide since the advent of HAART.
However, more people are now being hospitalised with liver disease due to coinfection with hepatitis C, and because of treatment-related toxicities, according to new data presented in Warsaw at the Ninth European AIDS Conference by EuroSIDA, a 26 country collaborative cohort.
As expected, hospital admissions due to HIV-related causes dropped significantly during the period March 1995 to December 2001, when the proportion of patients admitted to hospital declined from 7.4% in 1995 to 2.6% in 2001, an estimated reduction of 0.77% per year (95%-CI 0.45-1.09, p=0.0032).
The median length of a hospital stay also declined during this period from 12 days in 1995 (range 5 - 19 days) to 6 days (range 3 - 11 days), a decline of one day per year (95%-CI 0.48-1.52, p = 0.0090).
But since the advent of HAART, individuals who made a change to their treatment-regimen due to toxicity were more likely to be admitted to hospital (odds ratio (OR) 2.44; 95%-CI 1.68-3.53, p
Additionally, in 2001, patients coinfected with hepatitis C were found to have an increased risk of admission (OR 1.78; 95% CI 1.11-2.86, p=0.018).
An analysis of the same 9,803 individuals found that incidence all diseases of the central nervous system have also dropped from 5.9 per 100 patient years in 1994 to 0.5 in 2002. The incidence of HIV-associated dementia, in particular, has decreased significantly, with an annual decrease rate of 45% between 1994 and 2002.
In 1994, HIV-associated dementia was the most commonly diagnosed opportunistic infection of the central nervous system, and during the 1990s, many film and TV portrayals of the ravages of AIDS included representations of dementia.
In 2002, as rates of mortality and morbidity have fallen in common with all opportunistic infections due to the immune restoration associated with HAART, HIV-associated dementia is now seen relatively rarely, although it is still the third most common disease of the central nervous system, although it is possible that the course of HIV dementia has been slowed by HAART, but not completely prevented.
The incidence of other diseases of the central nervous system - including cryptococcal meningitis and toxoplasmosis - decreased 37% in the same period, although an increase has been seen in the prevalence of progressive multifocal leukoencephalopathy (PML), possibly due to immune restoration inflammatory disease (IRIS); PML currently affects about 4% of people with AIDS.
In multivariate analysis, low CD4 cell count and high plasma viral load, were associated with the development of central nervous system diseases, whereas, additionally, age (p
In contrast, use of NRTIs, irrespective of use of PIs or NNRTIs, appeared to protect specifically against HIV-related dementia (RH=0.59, 95% CI: 0.39-0.90), but not against other diseases of the central nervous system (RH=1.06, 95% CI: 0.80-1.40), suggesting that the NRTIs which pass through the blood-brain barrier - including zidovudine, abacavir and stavudine - have had a direct effect on the central nervous system itself.
Professor Antonella d'Arminio Monforte, who was the lead author of both studies, made the point that since opportunistic infection-related hospital admissions have declined so remarkably and now are of a shorter duration, "a considerable saving from reductions in admission can be offset against the cost of HAART."
Further information on this website
Low CD4 count and high HIV viral load in year after HIV infection predicts future brain impairment - news story, October 2003
Rate of hospital admissions for HIV/HCV coinfected patients has increased dramatically since 1995 - news story, October 2003
HIV-positive HAART patients with PML and CD4 count below 100 at greatest risk of death - news story, April 2003
HIV-associated dementia - overview
Progressive multifocal leukoencephalopathy - overview
d'Arminio Monforte A. et al. Changing incidence of central nervous system AIDS-related diseases in the EuroSIDA cohort Ninth European AIDS Conference, Warsaw, abstract F9/6, 2003.
d'Arminio Monforte A. et al. Changes in hospital admissions across Europe in 1995-2002 Ninth European AIDS Conference, Warsaw, abstract F9/7, 2003.