In countries where monitoring of viral load and CD4 counts may be impossible, researchers have proposed the use of clinical markers for starting prophylaxis and anti-HIV treatment, where available.
However, research published this week by a UK Medical Research Council team suggests that some of these markers may be just as common in the HIV-negative population, and by inference, are not necessarily a reliable marker of disease progression. Indeed, disease progression rates in Uganda and other countries may have been over-estimated as a result of the use of some of these symptoms in the World Health Organisation staging system for patients with HIV.
Whilst tuberculosis, herpes zoster and oral candidiasis were significantly more common in people with HIV, prolonged fever, oral hairy leucoplakia and weight loss of less than 10% were no more frequent.
WHO stage 2 symptoms are weight loss of 5-10%, minor mucocutaneous disease, herpes zoster and recurrent respiratory tract infection. Using this definition of disease progression, the median time from seroconversion to stage 2 was 25.4 months. Thirty eight of the 63 patients in this category who were classified as having `progressed’ were diagnosed with weight loss (a condition that was just as common in the HIV-negative population).
WHO stage 3 symptoms are weight loss of greater than 10%, chronic diarrhoea, prolonged fever, oral candidiasis, oral hairy leucoplakia, pulmonary tuberculosis and severe bacterial infection. Using this definition of disease progression, the median time from seroconversion to stage 3 was 45 months. In this category, only 15% of the 72 patients who progressed had been diagnosed with a condition that was just as frequent among the HIV-negative population.
The authors noted that “Most of the population in Uganda lives in poverty; food is often in limited supply…malaria is endemic, and infections other than HIV, especially bacterial infections, are common. The shorter interval from seroconversion to symptomatic disease in African populations probably reflects the high background level of these conditions, rather than rapid disease progression.”
Nevertheless, the study does indicate that diseases reliably associated with HIV do appear within four years in the majority of people infected with HIV in rural Uganda, suggesting the urgency of improving treatment access for people becoming infected with HIV today.
Morgan D et al. Progression to symptomatic disease in people infected with HIV-1 in rural Uganda: prospective cohort study. British Medical Journal 324: 193-197, 2002.