Very high level of late diagnosis in US: 38% develop AIDS within one year

A substantial proportion of HIV-positive people in the US are diagnosed late, according to an article in the June 26^th edition of Morbidity and Mortality Weekly Report. An analysis of data from 34 US states revealed that 38% of patients progressed to AIDS within a year of their HIV diagnosis.

The report was published ahead of the US National HIV Testing Day on June 27^th. “To reduce late testing for HIV infection, health-care providers should fully implement both routine and risk-based HIV testing,” comment the investigators.

It is estimated that 21% of HIV-positive people in the US remain undiagnosed. People who are undiagnosed are unable to benefit from highly effective HIV treatment, which not only reduces the risk of illness and death, but also has a substantial impact on infectiousness.

There is now significant research indicating that late diagnosis of HIV is the reason underlying much of the HIV-related illness and death still seen in industrialised countries. Furthermore, epidemiological studies suggest that individuals with undiagnosed HIV infection are a major driver of the continued spread of the infection.

Routine HIV testing is now recommended in the US for all individuals aged between 13 and 64 years of age. People with high-risk behaviours for HIV are also encouraged to test regularly.

To gain a better understanding of the reasons for late diagnosis, investigators from the US Centers for Disease Control and Prevention analysed reports of HIV testing between 1996 and 2005 from 34 states that have confidential names-based HIV reporting. Late HIV testing was defined as progression to AIDS within three years of HIV diagnosis.

This analysis showed that 38% of patients progressed to AIDS (an AIDS-defining illness or a CD4 cell count below 200 cells/mm³) within a year of their diagnosis, with a further 7% developing an AIDS-defining condition in the second or third year after finding out they had HIV.

“These findings underscore the need for both routine screening of persons aged 13-64 years and more frequent testing for persons at increased risk, and therefore, in greater need of periodic HIV testing,” write the study’s authors.

A total of 281,000 people were included in the study. An especially high level of early progression to AIDS (63%) was observed in individual aged over 60 at the time of their HIV diagnosis.

Higher rates of AIDS within three years were observed in people from minority racial groups (50%, Asian; 48%, indigenous; 47%, Hispanic; 46% black) than amongst whites (43%).

Men who acquired HIV as a consequence of injecting drug use or heterosexual sex were more likely to be diagnosed late than women who were infected with the virus through the same activities.

Despite being the focus of the HIV epidemic in the US for over a quarter of a century, a very high rate of late diagnosis was observed amongst gay and other men who have sex with men. A total of 48% of this group progressed to AIDS within three years of their HIV diagnosis.

Encouragingly, however, the data suggested that the proportion of patients diagnosed late had fallen in recent years. Between 1996 and the end of 2002, 50% of patients progressed to AIDS within three years of their HIV diagnosis. After 2003, this fell to 45%. Moreover, there was a reduction in the proportion of individuals developing AIDS within one year, down from 43% in 1996 to 36% in 2005.

“Because the probability of progression to AIDS following HIV infection in the absence of therapy is approximately 2% in the first two years and increases to approximately 50% at ten years, a diagnosis of AIDS within one year of the initial HIV diagnosis suggests late testing for HIV infection and not more rapid advancement to AIDS,” comment the investigators.

However, they acknowledge that an AIDS diagnosis within three years of diagnosis could also be a consequence of poor HIV care or treatment.

“Achieving earlier diagnosis and reducing HIV transmission will require providers, health departments, and community organizations to promote screening in healthcare settings and periodically retest persons with ongoing risk behaviors,” conclude the investigators. They add, “expansion of efforts within the social network of persons who receive an HIV diagnosis can result in testing others who are likely infected.”