Estimation of HIV incidence in two Brazilian municipalities, 2013 / Estimação da incidência de HIV em dois municípios brasileiros, 2013

ABSTRACT OBJECTIVE To estimate HIV incidence in two Brazilian municipalities, Recife and Curitiba, in the year of 2013. METHODS The method for estimating incidence was based on primary information, resulting from the Lag-Avidity laboratory test for detection of recent HIV infections, applied in a sample of the cases diagnosed in the two cities in 2013. For the estimation of the HIV incidence for the total population of the cities, the recent infections detected in the research were annualized and weighted by the inverse of the probability of HIV testing in 2013 among the infected and not diagnosed cases. After estimating HIV incidence for the total population, the incidence rates were estimated by sex, age group, and exposure category. RESULTS In Recife, 902 individuals aged 13 years and older were diagnosed with HIV infection. From these, 528 were included in the study, and the estimated proportion of recent infections was 13.1%. In Curitiba, 1,013 people aged 13 years and older were diagnosed, 497 participated in the study, and the proportion of recent infections was 10.5%. In Recife, the estimated incidence rate was 53.1/100,000 inhabitants of 13 years and older, while in Curitiba, it was 41.1/100,000, with male-to-female ratio of 3.5 and 2.4, respectively. We observed high rates of HIV incidence among men who have sex with men, of 1.47% in Recife and 0.92% in Curitiba. CONCLUSIONS The results obtained in the two cities showed that the group of men who have sex with men are disproportionately subject to a greater risk of new infections, and indicate that strategies to control the spread of the epidemic in this population subgroup are essential and urgent.

RESUMO OBJETIVO Estimar a incidência de HIV em dois municípios brasileiros, Recife e Curitiba, no ano de 2013. MÉTODOS O método de estimação da incidência foi baseado em informações primárias, resultantes do ensaio laboratorial Lag-Avidity para detecção de infecções recentes do HIV, aplicado em uma amostra dos casos diagnosticados nas duas cidades em 2013. Para a estimação da incidência de HIV para a população total das cidades, as infecções recentes detectadas na pesquisa foram anualizadas e ponderadas pelo inverso da probabilidade de teste de HIV no ano de 2013 entre os casos infectados e não diagnosticados. Após a estimação da incidência de HIV para a população total, foram estimadas as taxas de incidência por sexo, faixa de idade e categoria de exposição. RESULTADOS Em Recife, foram diagnosticados 902 indivíduos de 13 anos e mais com infecção de HIV. Desses, 528 foram incluídos no estudo, e a proporção estimada de infecções recentes foi de 13,1%. Em Curitiba, foram diagnosticadas 1.013 pessoas de 13 anos e mais, 497 participaram do estudo, e a proporção de infecções recentes foi de 10,5%. Em Recife, a taxa de incidência estimada foi de 53,1 por 100 mil habitantes de 13 anos e mais, enquanto em Curitiba, de 41,1 por 100 mil, com razão do sexo masculino para o feminino de 3,5 e 2,4, respectivamente. Foram evidenciadas elevadas taxas de incidência de HIV entre homens que fazem sexo com homens, de 1,47% em Recife e 0,92% em Curitiba. CONCLUSÕES Os resultados obtidos nas duas cidades mostraram que o grupo dos homens que fazem sexo com homens está desproporcionalmente sujeito ao maior risco de novas infecções, e indicam que estratégias para controle da disseminação da epidemia nesse subgrupo populacional são essenciais e urgentes.

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

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.

Recent HIV infection rates among HIV positive patients seeking voluntary counseling and testing centers in the metropolitan region of Recife - Pe, Brazil

The BED capture enzyme immunoassay test makes it possible to determine whether individuals were recently infected with HIV. OBJECTIVE: In this study, the overall HIV and recent infections prevalences were determined at five Voluntary Counseling and Testing (VCT) centers, in the Metropolitan Region of Recife, Northeastern of Brazil. MATERIAL AND METHODS: A cross-sectional study was conducted among users of five VCTs in the metropolitan region of Recife between July 2007 and April 2009. Out of the individuals who tested positive for HIV, 169 were analyzed to assess the prevalence of recent infection by means of the BED-CEIA (BED-Calypte®). RESULTS: Out of 46,696 individuals tested 916 (1.96%) turned out positive for HIV infection The highest prevalence was in Recife (3.9%). The prevalence was higher among males (3.93%), and men who have sex with men (MSM) (12.4%). The frequency of recent infections among the 169 subjects evaluated was 23.7%. Recent infections were more common among individuals under 25 years of age. There was slight predominance of men and higher frequency of heterosexuals in both groups, but still a significant portion of MSM (33%). Subtype B predominated, followed by a high proportion of subtype F. CONCLUSIONS: Recent infection occurs mainly among young individuals and heterosexuals, despite a significant proportion of recent infection among MSM. These results suggest that preventive actions aimed at the MSM community remains a challenge and efforts focusing this group should continue to be a priority.

Antiretroviral resistance in individuals presenting therapeutic failure and subtypes of the human immunodeficiency virus type 1 in the Northeast Region of Brazil

This study aimed to analyze human immunodeficiency virus (HIV) mutation profiles related to antiretroviral resistance following therapeutic failure, and the distribution of hiv subtypes in the Northeast Region of Brazil. A total of 576 blood samples from AIDS patients presenting therapeutic failure between 2002 and 2004 were analyzed. The genotyping kit viroSeq® was used to perform viral amplification in order to identify mutations related to hiv pol gene resistance. An index of 91.1 percent of the patients presented mutations for nucleoside reverse transcriptase inhibitors (nrti), 58.7 percent for non-nucleoside reverse transcriptase inhibitors (nnrti), and 94.8 percent for protease inhibitors (pi). The most prevalent mutations were 184V and 215E for nrti, 103N and 190A for nnrti. Most mutations associated with PIs were secondary, but significant frequencies were observed in codons 90 (25.2 percent), 82 (21.1 percent), and 30 (16.2 percent). The resistance index to one class of antiretrovirals was 14 percent, to two classes of antiretrovirals 61 percent, and to three classes 18.9 percent. Subtype B was the most prevalent (82.4 percent) followed by subtype F (11.8 percent). The prevalence of mutations related to nrti and nnrti was the same in the two subtypes, but codon analysis related to PI showed a higher frequency of mutations in codon 63 in subtype B and in codon 36 in subtype F. The present study showed that there was a high frequency of primary mutations, which offered resistance to nrti and nnrti. Monitoring patients with treatment failure is an important tool for aiding physicians in rescue therapy.

Comparison of the epidemiology, profile of mutations, and clinical response to antiretrovirals among subtypes B and F of the human immunodeficiency virus type 1

The authors compared demographic aspects and profile of mutations in 80 patients with subtypes B and F of human immunodeficiency type 1 (HIV-1). Genotyping of the pol region of the reverse transcriptase was performed using the ViroSeqTM Genotyping System. A total of 61 (76.2 percent) patients had subtype B and 19 (23.8 percent) subtype F of the HIV-1. Subtype F tended to be more frequent in heterosexuals and women with a low educational level, but without statistical significance. The frequency of mutations related to nucleoside reverse transcriptase inhibitors and protease inhibitors (PI) was the same in the two subtypes, but mutations related to PI at the codons 63, 77, and 71 were more frequent in subtype B, while mutations at the codons 36 and 20 predominated in subtype F. Sixty-two of the 80 patients infected with subtypes B and F were submitted to antiretroviral therapy for an average of 18-22 months. Undetectable viral loads at the end of follow-up were similar in the two groups, representing 63.8 percent of subtype B and 73.3 percent of subtype F (p = 0.715). CD4 lymphocyte counts before and after treatment were similar in the two groups. This study, despite pointing to possible epidemiological and genetic differences among subtypes B and F of HIV-1, suggests that the use of highly active antiretroviral therapy is equally effective against these subtypes.

Primary resistance of human immunodeficiency virus type 1 in a reference center in Recife, Pernambuco, Brazil

To assess the prevalence of primary resistance of human immunodeficiency virus type 1 (HIV-1) to antiretrovirals, 84 patients chronically infected with HIV without prior antiretroviral treatment from Northeast Brazil were studied. Genotyping was performed using the ViroSeqTM Genotyping System. Thimidine analog mutations occurred in 3 (3.6 percent) patients. Accessory mutations related to NRTI occurred in 6 (7.1 percent) and related to PI in 67 (79.8 percent). Subtypes B (72.6 percent), F (22.6 percent), B/F 3 (3.6 percent), and C (1.2 percent) were detected. A low prevalence of major mutations related to NRTI in patients chronically infected by HIV was observed.