Donald G. McNeil Jr. / New York Times News Service

People infected with HIV should be put on antiretroviral therapy even sooner than they are now, the World Health Organization said Sunday as it released new treatment guidelines.

While the new guidelines, issued at an international AIDS conference in Malaysia, were an aggressive step forward, they also represent a compromise between how much the world could do to suppress the epidemic if money were no object and how much donor countries are willing to pay for.

Dr. Margaret Chan, the WHO’s director general, called the guidelines “a leap ahead in a trend of ever-higher goals and ever-greater achievements,” while Michel Sidibé, the executive director of the United Nations AIDS agency, who several years ago called for universal treatment, said the step-by-step rise of the guidelines “gets most of the people we want on treatment, but not all – so it shows that you have limits to the system.”

The new guidelines recommend that drugs be initiated as soon as a patient’s CD4 count falls below 500 cells per cubic millimeter of blood. CD4s are the white blood cells that the virus first attacks. The count is an index for how much of the immune system has been destroyed; 500 is the bottom of the normal range while a patient below 200 is at high risk of fatal infections. The previous cutoff point, recommended in 2010, was a count of 350; a decade ago, when donors first began buying drugs, it was 200.

For some subgroups, the new guidelines recommend starting treatment immediately upon a positive HIV test, regardless of CD4 count. Those include people with active tuberculosis or hepatitis B liver disease, those whose regular sex partners are not infected, women who are pregnant or breast-feeding, and children under 5.

Many scientists now recommend that all patients start treatment immediately regardless of CD4 levels. The evidence is overwhelming that they are far less likely to infect anyone else if they do so. They also may live longer, healthier lives because their immune systems are not allowed to sink before being revived. In rare cases when the infection is caught very early, some may even be able to safely stop treatment after a year or two.

WHO guidelines, however, are used mostly by the health ministries of poor countries that depend on donors.

The new guidelines mean that about 26 million people in poor and middle-income countries will be eligible for the drugs, up from 17 million under the previous guidelines. Almost 10 million people are on the drugs now. Globally, more than 34 million people are infected.