Risk factors for late HIV diagnosis in French Guiana

Risk factors for delayed HIV diagnosis in French Guiana were studied in 1952 patients between 1992 and 2003. At the time of diagnosis, 30% of patients had less than 200 CD4 lymphocytes/mm³; age, male sex, and foreign nationality were independently associated with a low CD4 cell count. The availability of highly active antiretroviral therapy was not associated with an earlier HIV diagnosis. Promoting HIV information and testing should be done in several languages to reach minorities.

With 48 new AIDS cases per 100 000 inhabitants per year and 1.6% of pregnant women infected with HIV, French Guiana is the French overseas department in which the HIV epidemic is most worrying ^[1]. Transmission occurs through heterosexual sex in over 90% of cases. Approximately two-thirds of HIV patients are foreign citizens ^[2]. The standards of healthcare are close to those of metropolitan France. Free and anonymous HIV testing is available for all. However, many immigrants have little contact with the healthcare and information systems. In French Guiana, 40% of patients diagnosed with AIDS ignored their HIV status at the time of diagnosis ^[3]. An early diagnosis of HIV infection is important in order to reduce the risk of HIV transmission to other partners and to reduce morbidity and mortality rates ^[4]. Our objective was to determine the risk factors for a late diagnosis of HIV infection in order to optimize HIV screening strategies.

Between 1 January 1992 and 31 December 2003, 1952 HIV-positive patients were enrolled in the French Hospital Database for HIV. Patients were classified into three groups according to their CD4 cell counts at the time of diagnosis of the HIV infection: less than 200 cells/mm³ (n = 594, 30%), 200 or more but less than 500 cells/mm³ (n = 561, 29%), and 500 or more CD4 lymphocytes/mm³ (n = 797, 41%). An ordinal logit model with the CD4 cell category at the time of diagnosis as a dependent variable was used to determine which independent variables were related to the outcome.

There was no relationship between the transmission mode and late HIV diagnosis (chi square 10.8, P = 0.55). After controlling for confounding using ordinal logit regression, age, male sex, and foreign nationality were independently associated with a low CD4 cell count at the time of diagnosis (Table 1). The availability of highly active antiretroviral therapy (HAART) did not seem to be associated with an earlier HIV diagnosis. In the past 12 years there was no improvement in the early detection of HIV infections (data not shown).

Table 1

Using a Cox regression model adjusting for age, sex, nationality, and antiretroviral treatment, the hazard ratio of dying was 4.5 [95% confidence interval (CI) 3.2-6.2] for patients with CD4 cell counts at the time of diagnosis of less than 200 cells/mm³ compared with those with more than 500 CD4 cells/mm³ (P < 0.0001), the hazard ratio of dying was 1.4 (95% CI 0.98-2) for patients with CD4 cell counts less than 500 and 200 cells/mm³ or greater at the time of HIV diagnosis compared with those with more than 500 CD4 cells/mm³ (P = 0.06). Similarly, adjusting for age, sex, nationality, and antiretroviral treatment, the hazard ratio of developing AIDS was 3.4 (95% CI 2.4-4.8) for patients with CD4 cell counts at the time of diagnosis of less than 200 cells/mm³ compared with those with more than 500 CD4 cells/mm³ (P < 0.0001), the hazard ratio of dying was 1.4 (95% CI 1.04-1.9) for patients with CD4 cell counts less than 500 and 200 cells/mm³ or greater at the time of HIV diagnosis compared with those with more than 500 CD4 cells/mm³ (P = 0.02).

Despite the availability of HAART, an early diagnosis of HIV is still important to avoid immunosuppression, severe morbidity and death, and to prevent the unwilling infection of sex partners. Age, sex, and nationality influence the CD4 cell count at the time of diagnosis, possibly because they are related to health-seeking behaviours. The influence of age here seemed to be linear rather than bimodal (younger and older age groups having been found to be more at risk of a late diagnosis elsewhere than intermediate ages ^[5,6]). This supports findings suggesting that HIV awareness in younger age groups is greater than in older age groups in French Guiana ^[1]. Older men in French Guiana have longer sex lives during which they cumulate the risk of getting infected. Their higher socioeconomic status often facilitates access to sex partners. They are also more often reluctant to use condoms, and are usually not as forthcoming regarding HIV testing as younger men ^[7]. Many HIV infections are diagnosed during pregnancy screening, which leads to earlier diagnoses in women in their reproductive age compared with men. The influence of male sex on late HIV testing has been consistently observed on several continents ^[5,6,8-12]. The HIV transmission mode was not associated with any particular trend here, whereas it has been repeatedly observed elsewhere, including in metropolitan France ^[9], that heterosexual transmission was more likely to be associated with late diagnosis ^[8,10,13]. This may be due to the fact that transmission in French Guiana occurs predominantly through heterosexual sex and that homosexuality in the area is mostly hidden.

Legal and illegal foreign nationals were globally more likely to have a later HIV diagnosis than French citizens for several possible reasons. First, a simple explanation is that they may have recently arrived in French Guiana (maybe seeking medical care), which could have delayed diagnosis. A majority of foreign nationals does not speak French and is not reached by information campaigns that are mostly conducted in French. For illegal citizens the fear of being arrested by the police and expelled from French Guiana may also reduce their presence in hospitals or dispensaries, which they perceive as too risky. Finally, widespread cultural beliefs in witchcraft or voodoo and illiteracy often make the viral explanation of AIDS quite difficult to believe, therefore making HIV testing illogical for those who hold such beliefs.

As observed elsewhere ^[10], the advent of HAART and its spectacular impact on the evolution of HIV has not had any noticeable impact on the CD4 cell counts at the time of diagnosis, suggesting that behaviours regarding HIV testing were not affected by the prospect of effective antiretroviral treatments. There is indeed a need to strengthen HIV information and screening in order to diagnose HIV infections earlier.