'Better screening needed' for AIDS-related blindness
Diagnosis and treatment of cytomegalovirus (CMV) retinitis must become part of HIV primary care in developing countries, says an article published in PLoS Medicine this week (1 December).
The researchers found that CMV retinitis — which causes blindness and death in patients with AIDS — is underdiagnosed and undertreated in resource-poor nations.
Their observations are based on retinal screening examinations of 325 patients with AIDS who attended clinics of Médicins Sans Frontieres, the independent humanitarian medical aid agency, in Cambodia, Myanmar, South Africa, Thailand and Uganda.
About 20 per cent of patients were found to have CMV retinitis, while additional studies revealed that 37 per cent of individual eyes were blind because of the disease.
CMV retinitis is common in developing countries. The infection can remain latent for life or until a factor, such as the immunosuppression caused by HIV, brings about clinical disease.
Healthcare systems for HIV in developing countries rarely include systematic screening for the disease — a necessary step because symptoms aren't always present. In addition, the 'gold standard' treatment, an oral antibiotic called valganciclovir, costs over US$10,000 in some countries.
The authors point out that the WHO has not included CMV retinitis in either its guidelines for management of HIV in resource-limited settings, or its 'Vision 2020' blindness programme.
"CMV has been ignored in resource-poor settings but must be in the list," says lead researcher David Heiden, ophthalmologist at the US-based California Pacific Medical Center.
The first step is training HIV/AIDS doctors to use an instrument called an indirect ophthalmoscope, a fast, cheap method that eliminates the need for special eye tests. The second step is treatment. "There is an effective treatment for CMV retinitis, in pill form, but it's a single-source monopoly product priced at a level that is absurdly unrealistic. The medication needs to made available and affordable."
Nimit Tienudom, director of the AIDS Access Foundation, promoting better understanding of AIDS in Thailand, says that current treatments — such as antiretroviral drugs — could help suppress infectious diseases like CMV retinitis.
Kumnuan Ungchusak, director of the Thai Bureau of Epidemiology, under the Department of Disease Control, said the government would not yet adjust its current treatment programme since it has already embraced the international standard to care for HIV/AIDS patients.
"But in the future, if there are more studies backing up more advanced treatment, we will not hesitate to consider and follow."
Reference: PLoS Medicine 4, e334 (2007) doi 10.1371/journal.pmed.0040334