Over half of all new HIV diagnoses in Barcelona are late

Over half of all new HIV diagnosis in the Spanish city of Barcelona are late, according to research published in the online journal AIDS Research and Therapy.

Between 2001 and 2009 approximately 56% of patients at the time of their diagnosis had a CD4 cell count below 350 cells/mm³ or AIDS.

European HIV treatment guidelines recommend that antiretroviral therapy should be started if a patients is ill because of HIV or when their CD4 cell count falls to around 350 cells/mm.³

“Thus”, write the investigators, “50% of new diagnoses of HIV infection occur when the subject needs treatment…the negative impact of late presentation is a likely increase in morbidity and mortality and potential transmission at the community level and further treatment costs.”

With the right treatment and care many patients with HIV have an excellent prognosis. There is also evidence that treatment with antiretroviral drugs reduces the risk of an HIV-positive individual transmitting the virus to sex partners by around 96%.

However, many HIV-positive individuals are unable to benefit from antiretroviral therapy because their infection is undiagnosed. Late diagnosis of HIV is a major factor in much of the AIDS-related mortality that still occurs. Studies have also suggested that a large proportion of new HIV transmissions originate in undiagnosed patients.

Investigators in Barcelona therefore wished to establish the prevalence and risk factors for late HIV diagnosis in their city.

They designed a retrospective study, analysing the records of 2938 individuals who were newly diagnosed with HIV in the city between 2001 and 2009.

Most of the patients were men (83%), and their median age was 35 years. A fifth of patients had an AIDS-defining illness at the time of their diagnosis.

Overall, 52% of the patients were gay men. However, the proportion of new diagnoses involving gay men increased from 40% in 2001-2002 to 62% in 2008-2009 (p < 0.001). At the same time, there was a fall in the number of male injecting drug users diagnosed with HIV (p < 0.001).

Approximately 23% of new diagnoses were in migrants in 2001-2002, but this had increased to 46% by 2009 (p < 0.0001).

Analysis was restricted to the 2507 patients who had a CD4 cell count or information on an AIDS diagnosis available at the time of their diagnosis.

Overall, 56% of these patients were diagnosed late, and 39% had advanced HIV infection (CD4 cell count below 200 cells/mm³ or AIDS).

In 2001-2002, 63% of patients presented late. This fell to 52% in 2004-2005, but then remained steady for the rest of the study.

Late diagnosis differed according to HIV risk group. Gay men were the group least likely to be diagnosed late (48%), but two-thirds of male injecting drug users and 70% of heterosexual men were diagnosed late.

Statistical analysis showed that a number of factors were significantly associated with an increased risk of late diagnosis. These included:

• Older age. Each five-year increase in age increased the odds of late diagnosis by 38%.

• Region of birth.  Compared to Spanish-born individuals, patients from sub-Saharan Africa were (OR = 2.43; 95% CI, 1.14-4.17) and South America (OR = 1.48; 95% CI, 1.20-1.83) were more likely to be diagnosed late.

• Exposure category. The risk of late diagnosis was higher for injecting drug users (OR = 2.12; 95% CI, 1.57-2.87) and male heterosexuals (OR = 1.79; 95% CI, 1.38-2.34) compared to gay men.

“Late presentation of HIV is common in spite of a strong commitment to universal access to HIV infection, prevention, diagnosis and treatment in our city,” comment the investigators.

They conclude, “this study reveals a need to develop interventions that increase HIV testing and facilitate earlier entry into care.” The researchers recommend “routine screening in healthcare and non-clinical settings for patients at risk of HIV.”

de Olalla PG et al. Epidemiological characteristics and predictors of late presentation of HIV infection in Barcelona (Spain) during the period 2001-2009. AIDS Research and Therapy, 8: 22, 2011 (click here for the open-access article).