Geneva/Bangkok - Failure to diagnose and treat cytomegalovirus retinitis (CMV) in people with AIDS is leading to unnecessary blindness, according to a paper published today in the journal PLoS Medicine.
The authors found in pilot studies that CMV retinitis, which has been dramatically reduced in wealthy countries since the advent of antiretroviral therapy, occurred in 23, 27 and 32 percent of patients with advanced AIDS in Cambodia, Myanmar and Thailand respectively. By training clinicians to screen and taking steps to make the best treatment affordable, the authors argue that CMV diagnosis and treatment can easily be integrated into existing AIDS treatment programmes.
"We can diagnose CMV retinitis fairly easily and reliably in less than two minutes, and there is an effective, practical treatment," said one of the authors, Dr. David Wilson, a former MSF Medical Coordinator, Thailand. "Instead of addressing the problem, it's like the world is pretending the death and the blindness CMV causes are not happening, or worse, we're just accepting them."
Detecting and treating CMV retinitis early enough would stop the slow, but relentless progress of a disease that leads to blindness within three to six months in patients whose immune systems are severely weakened with HIV. But because there are often no symptoms in the early stage of the disease, CMV can only be diagnosed through systematic screening of all at-risk patients.
"Routine retinal examination of high-risk HIV patients in Myanmar has allowed us to save patients from CMV-related blindness," said Dr. Kalpana Sabapathy, HIV/AIDS advisor at MSF, citing recent studies in the Myanmar programme by an ophthalmologist and CMV specialist from SEVA Foundation, Dr. David Heiden. But in many countries the best treatment option, oral valganciclovir, costs more than US$10,000 for a four-month treatment course. An alternative treatment using intravenous ganciclovir is cumbersome, requiring infusions twice a day for two or three weeks, and then daily infusions for another two or three months.
A third method to treat CMV retinitis, with intraocular injections of ganciclovir - doctors have to repeatedly jab patients in one or both eyes - is all the more unsatisfactory. This invasive technique requires special training and does nothing to treat potentially fatal forms of CMV that occur outside the eye.
Integration of CMV retinitis into HIV programmes is therefore feasible, but dependent on systematic screening of at-risk patients and securing access to affordable oral valganciclovir, the authors argue. Until then, CMV retinitis will continue to be the neglected disease of the AIDS epidemic.
"This is a classic case of the vicious circle," said Dr. Tido von Schoen-Angerer, Director of the MSF Campaign for Access to Essential Medicines. "Because the price of the drug is so high, HIV programmes aren't screening and therefore are not reporting large numbers of CMV patients. But since on paper there are so few patients, bringing down the price of this treatment and ensuring its availability has never been a priority."
CMV retinitis is not mentioned in the current and pending WHO guidelines for HIV treatment in resource-poor settings.
While there has been some progress on the accessibility of valganciclovir, it remains limited. NGOs have been proposed a discounted price from Roche of ââ?š¬1,281 (US$1,899) for a four-month course of therapy but this offer remains expensive and excludes many countries where the CMV retinitis problem is most acute.
This has forced difficult compromises. In Thailand, along with local partners, MSF has decided to use the sub-optimal intravenous formulation of ganciclovir as well as intraocular injections. In China, MSF pays the full price for oral valganciclovir, which is 6,930 (US$10,273). This is higher than the price of a Chinese economy car.
There is an urgent need for Roche to both extend their discounted prices to all developing countries and to lower this price further. Current prices in China and Thailand mimic wealthy country prices where the drug is almost exclusively used to prevent CMV for patients undergoing organ transplants. Roche is targeting a small but lucrative market, and protecting its position through patents, including in India which is a significant source of generic drugs for developing countries.
The PLoS paper was authored by an international team of eye doctors and HIV specialists and is based the clinical experience from Médecins Sans Frontières and other programmes assessed by the lead author, Dr. David Heiden, a consultant from SEVA Foundation, based at the California Pacific Medical Center, San Francisco. The article Cytomegalovirus Retinitis: The Neglected Disease of the AIDS Pandemic is freely available from the open access journal PLoS Medicine at here