Primary resistance of HIV to antiretrovirals among individuals recently diagnosed at voluntary counselling and testing centres in the metropolitan region of Recife, Pernambuco

Ana Maria Salustiano Cavalcanti,Heloisa Ramos Lacerda,Ana Maria De Brito,Ricardo Sobhie Diaz,Kledoaldo Oliveira De Lima,Sirleide Pereira Da Silva,Daniela Medeiros Salustiano

doi:10.1590/s0074-02762012000400002

Abstract

Determining the prevalence and type of antiretroviral (ARV) resistance among ARV-naïve individuals is important to assess the potential responses of these individuals to first-line regimens. The prevalence of primary resistance and the occurrence of recent infections among individuals with human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) were identified among recently diagnosed patients at five sexually transmitted disease/AIDS testing and counselling centres in the metropolitan region of Recife (RMR), Pernambuco, Brazil, between 2007-2009. One-hundred and eight samples were analysed using the Calypte® BED assay. Males predominated (56%), as did patients aged 31-50 years. Twenty-three percent presented evidence of a recent HIV infection. The median CD4+ T lymphocyte count was 408 cells/mm³ and the median viral load was 3.683 copies/mL. The prevalence of primary resistance was 4.6% (confidence interval 95% = 1-8.2%) based on criteria that excluded common polymorphisms in accordance with the surveillance drug resistance mutation criteria. The prevalence of resistance to non-nucleoside reverse transcriptase, nucleoside/nucleotide reverse transcriptase and protease inhibitors were 3.8%, 1.5% and 0.8%, respectively. Fifty-seven percent of strains were from clade B, 37.7% were clade F and 3.1% were clade C; there were no statistically significant differences with respect to resistance between clades. Recent infection tended to be more common in men (p = 0.06) and in municipalities in the south of the RMR (Jaboatão dos Guararapes and Cabo de Santo Agostinho) (p = 0.046). The high prevalence of recent infection and the high prevalence of non-B strains in this poor Brazilian region merit further attention.

Highlights

In Brazil, antiretroviral (ARV) therapy has been offered universally and free of charge to human immunodeficiency virus (HIV)-positive individuals since 1997
There are nine voluntary counselling and testing (VCT) centres located at strategic points throughout the metropolitan region of Recife (RMR); these VCT centres are located at selected clinics where there is a high demand for HIV testing
The mutations associated with resistance to reverse transcriptase inhibitors and protease inhibitors (PIs) that were found among eight patients in the study are detailed in Table II, which presents the socio-demographic and laboratory data of these patients

Summary

Results

Subtype B was the most prevalent (56.9%) in the study population, followed by F (37.7%), C (3.1%) and B/F (2.3%). The mutations associated with resistance to reverse transcriptase inhibitors and PIs that were found among eight patients in the study are detailed, which presents the socio-demographic and laboratory data of these patients. The prevalence of recent infection was greater among patients from the city. 452 Mem Inst Oswaldo Cruz, Rio de Janeiro, Vol 107(4), June 2012 of Recife and the southern region of the RMR (Jaboatão dos Guararapes and Cabo de Santo Agostinho), whereas the prevalence of chronic infection was greater among those patients from the northern region of the RMR (Olinda and Paulista). There were no statistically significant differences with respect to socio-demographic and laboratory characteristics between individuals with and without resistance or between individuals infected by the B and F subtypes of HIV-1 (Table IV)

Discussion

Sex worker

Mutations NNRTI

Primary resistance IAS SDRM