Demographic and clinical characteristics of people diagnosed with active sexually transmitted infections among monkeypox cases in Brazil: the 2022 outbreak.

The worldwide monkeypox (mpox) outbreak in 2022 showed a high frequency of sexually transmitted infections (STI). A cross-sectional study was carried out using secondary data from the Brazilian official mpox surveillance systems. A total of 10,169 mpox cases were identified, with a median age of 32 years. Among them, 92.3% were male at birth and 57.5% were men who have sex with other men (MSM). Approximately 11% were diagnosed with STI, including 5.8% with syphilis and 2.5% with genital herpes. Individuals aged from 25 to 34 years, MSM, individuals with HIV-positive status, and those manifesting skin eruptions or penile edema were associated with STI. Laboratory investigation for mpox must be implemented as a priority in STI clinics (especially for MSM) to mitigate neglected cases, ensure appropriate treatments, and prevent misdiagnoses.

Prevalence of Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, and Mycoplasma genitalium and risk factors among pregnant women in Brazil: Results from the national molecular diagnosis implementation project.

BACKGROUND: Sexually transmitted infections (STIs) are a public health problem. The aim of the present study was to assess the prevalence and risk factors associated with at least one STI (Chlamydia trachomatis [CT], Neisseria gonorrhoeae [NG], Trichomonas vaginalis [TV], and Mycoplasma genitalium [MG]) in Brazil. METHODS: A cross-sectional study was conducted using secondary data from the pilot implementation of the National Service for molecular diagnosis of CT, NG, TV, and MG in pregnancy. We obtained Ministry of Health surveillance data from the implementation project. Data encompassing pregnant women aged 15-49 years from public antenatal clinics in Brazil in 2022 were included. RESULTS: A total of 2728 data of pregnant women were analyzed. The prevalence of at least one infection was 21.0% (573), with the highest prevalence in the Southeast region (23.3%) and the lowest in the Center-West region (15.4%). The prevalence of CT was 9.9% (270), NG 0.6% (16), TV 6.7% (184), and MG 7.8% (212). Factors associated with any infection were from 15 to 24 years (AOR = 1.93; 95% CI: 1.58-2.35); reported family income up to US$400 (AOR = 1.79; 95% CI: 1.03-3.34); declared not living maritally with their partners (AOR = 1.90, 95% CI: 1.52-2.37) and had more than one sexual partner in their lifetime (AOR = 2.09, 95% CI: 1.55-2.86). CONCLUSION: This study showed a high prevalence of at least one STI among pregnant women in Brazil, particularly among younger women. It also provides up-to-date national data on CT, NG, TV, and MG infections in this population. These findings underscore the importance of enhancing access to STI screening for young pregnant women within the Brazilian public health system.

Demographic and clinical characteristics of people diagnosed with active sexually transmitted infections among monkeypox cases in Brazil: the 2022 outbreak

ABSTRACT The worldwide monkeypox (mpox) outbreak in 2022 showed a high frequency of sexually transmitted infections (STI). A cross-sectional study was carried out using secondary data from the Brazilian official mpox surveillance systems. A total of 10,169 mpox cases were identified, with a median age of 32 years. Among them, 92.3% were male at birth and 57.5% were men who have sex with other men (MSM). Approximately 11% were diagnosed with STI, including 5.8% with syphilis and 2.5% with genital herpes. Individuals aged from 25 to 34 years, MSM, individuals with HIV-positive status, and those manifesting skin eruptions or penile edema were associated with STI. Laboratory investigation for mpox must be implemented as a priority in STI clinics (especially for MSM) to mitigate neglected cases, ensure appropriate treatments, and prevent misdiagnoses.

Gonorrhea prevalence in adults in Brazil: Spectrum-STI trend estimation, 2000-2020.

BACKGROUND: Gonorrhea is not a notifiable disease in Brazil, and the national health information system does not collect data on reported cases or infection prevalence. METHODS: We compiled published data on gonorrhea prevalence in Brazil from cross-sectional surveys and clinical trials between 2000 and 2020. The study entry criteria included a sample size of 50 or more, and Neisseria gonorrhoeae infection detected in urine, urethral, anal, or cervicovaginal specimens using either Nucleic Acid Amplification Test or culture. Gonorrhea prevalence trends between 2000 and 2020 were generated using Spectrum-STI, a statistical trend-fitting model. RESULTS: Forty-five studies with 59 gonorrhea prevalence data points were identified. Fifty data points were for women and represented 21,815 individuals, eight for men encompassing a total of 4,587 individuals, and one for transgender people comprising 345 individuals. The Spectrum-STI estimate for the prevalence of urogenital infection with gonorrhea in women 15-49 in 2020 was 0.63% (95% confidence interval (CI): 0.13-2.23) and was lower than the 1.05% estimated value for 2000 (95% CI: 0.36-2.79). The corresponding figures for men were 0.70% (95% CI: 0.16-2.44) and 1.14% (95% CI: 0.34-3.15). Anal prevalence estimates could not be generated because of insufficient data (three data points). CONCLUSIONS: These results suggest that the overall prevalence of genitourinary gonococcal infections in Brazil is less than 1%. Data on gonorrhea prevalence in men and in populations at increased STI vulnerability are limited.

Sexual behavior and self-declaration of sexual orientation among people 18-64 years in Brazil: results from the Knowledge, Attitudes, and Practices survey, 2013 and the National Health Survey, 2019.

BACKGROUND: Population surveys involving the monitoring of high-risk sexual behavior have been recognized as important public health tools to control the HIV epidemic and other sexually transmitted infections (STIs). METHODS: Using data from the Knowledge, Attitudes, and Practices survey (PCAP-2013) and from the National Health Survey (PNS-2019), indicators of sexual behavior were compared according to sociodemographic characteristics among individuals aged 18-64 years, including size (%) estimates of men who have sex with men (MSM) and women who have sex with women (WSW). Specifically, the PNS-2019 prevalence estimates of homosexual, bisexual, heterosexual males and females were compared with those from the PCAP-2013. To compare PCAP and PNS proportional distributions, the Pearson's chi-square test, adjusted by the Rao-Scott's correction, was applied. RESULTS: Size (%) estimates of MSM and WSW obtained by direct questions from the PCAP-2013, showed higher homosexuality prevalence estimates than those resulting from the PNS-2019 self-declared sexual orientation. Significant differences were found between the MSM proportions according to the PCAP-2013 (3.7%; 95% CI 3.1-4.4%) and to the PNS-2019 (2.2%; 95% CI 1.9-2.5), and between the WSW proportions (4.6%; 95% CI 4.0-5.4%) and (2.1%; 95% CI 1.8-2.4), respectively. Results from both surveys showed MSM and WSW prevalence estimates increase with educational level, decrease with age, and is larger among people who do not live with partner, live in urban areas and in state capitals. Regarding condom use at last sexual intercourse, no differences between the PCAP-2013 and the PNS-2019 estimates were found at the national level, but significant improvements were found for MSM, people aged 18-24 and 25-34 years, and individuals not living with a partner. CONCLUSIONS: The underestimation of MSM and WSW prevalence by self-declared sexual orientation suggests that sexual minorities face many difficulties related to disclosing their sexuality and reinforces the importance of developing public health interventions for changing population attitudes and promoting sexual orientation disclosure. Moreover, the low use of condoms in both surveys (PCAP-2013 and PNS-2019) carried out 6 years apart highlights the need of public policies to expand prevention strategies for HIV infection and other STIs.

Gonorrhea prevalence in adults in Brazil: Spectrum-STI trend estimation, 2000-2020

ABSTRACT Background: Gonorrhea is not a notifiable disease in Brazil, and the national health information system does not collect data on reported cases or infection prevalence. Methods: We compiled published data on gonorrhea prevalence in Brazil from cross-sectional surveys and clinical trials between 2000 and 2020. The study entry criteria included a sample size of 50 or more, and Neisseria gonorrhoeae infection detected in urine, urethral, anal, or cervicovaginal specimens using either Nucleic Acid Amplification Test or culture. Gonorrhea prevalence trends between 2000 and 2020 were generated using Spectrum-STI, a statistical trend-fitting model. Results: Forty-five studies with 59 gonorrhea prevalence data points were identified. Fifty data points were for women and represented 21,815 individuals, eight for men encompassing a total of 4,587 individuals, and one for transgender people comprising 345 individuals. The Spectrum-STI estimate for the prevalence of urogenital infection with gonorrhea in women 15-49 in 2020 was 0.63% (95% confidence interval (CI): 0.13-2.23) and was lower than the 1.05% estimated value for 2000 (95% CI: 0.36-2.79). The corresponding figures for men were 0.70% (95% CI: 0.16-2.44) and 1.14% (95% CI: 0.34-3.15). Anal prevalence estimates could not be generated because of insufficient data (three data points). Conclusions: These results suggest that the overall prevalence of genitourinary gonococcal infections in Brazil is less than 1%. Data on gonorrhea prevalence in men and in populations at increased STI vulnerability are limited.

Epidemiological and clinical characteristics of monkeypox cases in Brazil in 2022: a cross-sectional study. / Características epidemiológicas e clínicas dos casos de monkeypox no Brasil em 2022: estudo transversal.

OBJECTIVE: to describe epidemiological and clinical characteristics of monkeypox (MPX) in Brazil, from the identification of the first case, on June 7, 2022, to Epidemiological Week (EW) 39, ending on October 1, 2022. METHODS: this was a descriptive study of cases notified to the Ministry of Health; trends were analyzed based on the number of confirmed and probable cases per EW; the cases were also described according to demographic and clinical variables. RESULTS: out of 31,513 notifications, 23.8% were confirmed; 91.8% were male; 70.6% were cis men; and median age was 32 years. Fever (58.0%), adenomegaly (42.4%), headache (39.9%) and rash (37.0%) were the most frequent symptoms; 27.5% reported being immunosuppressed, 34.6% were living with HIV and 10.5% had a sexually transmitted infection; three deaths were recorded. CONCLUSION: the MPX case profile was similar to that of other countries; surveillance actions must be strengthened to control the outbreak.

HIV incidence estimates by sex and age group in the population aged 15 years or over, Brazil, 1986-2018.

INTRODUCTION: HIV incidence estimates are essential to monitor the progress of prevention and control interventions. METHODS: Data collected by Brazilian surveillance systems were used to derive HIV incidence estimates by age group (15-24; 25+) and sex from 1986 to 2018. This study used a back-calculation method based on the first CD4 count among treatment-naïve cases. Incidence estimates for the population aged 15 years or over were compared to Global Burden of Disease Study (GBD) estimates from 2000 to 2018. RESULTS: Among young men (15-24 years), HIV incidence increased from 6,400 (95% CI: 4,900-8,400), in 2000, to 12,800 (95% CI: 10,800-15,900), in 2015, reaching incidence rates higher than 70/100,000 inhabitants and an annual growth rate of 3.7%. Among young women, HIV incidence decreased from 5,000 (95% CI: 4,200-6,100) to 3,200 (95% CI: 3,000-3,700). Men aged ≥25 years and both female groups showed significant annual decreases in incidence rates from 2000 to 2018. In 2018, the estimated number of new infections was 48,500 (95% CI: 45300-57500), 34,800 (95% CI: 32800-41500) men, 13,600 (95% CI: 12,500-16,000) women. Improvements in the time from infection to diagnosis and in the proportion of cases receiving antiretroviral therapy immediately after diagnosis were found for all groups. Comparison with GBD estimates shows similar rates for men with overlapping confidence intervals. Among women, differences are higher mainly in more recent years. CONCLUSIONS: The results indicate that efforts to control the HIV epidemic are having an impact. However, there is an urgent need to address the vulnerability of young men.

HIV incidence estimates by sex and age group in the population aged 15 years or over, Brazil, 1986-2018

Abstract INTRODUCTION HIV incidence estimates are essential to monitor the progress of prevention and control interventions. METHODS Data collected by Brazilian surveillance systems were used to derive HIV incidence estimates by age group (15-24; 25+) and sex from 1986 to 2018. This study used a back-calculation method based on the first CD4 count among treatment-naïve cases. Incidence estimates for the population aged 15 years or over were compared to Global Burden of Disease Study (GBD) estimates from 2000 to 2018. RESULTS Among young men (15-24 years), HIV incidence increased from 6,400 (95% CI: 4,900-8,400), in 2000, to 12,800 (95% CI: 10,800-15,900), in 2015, reaching incidence rates higher than 70/100,000 inhabitants and an annual growth rate of 3.7%. Among young women, HIV incidence decreased from 5,000 (95% CI: 4,200-6,100) to 3,200 (95% CI: 3,000-3,700). Men aged ≥25 years and both female groups showed significant annual decreases in incidence rates from 2000 to 2018. In 2018, the estimated number of new infections was 48,500 (95% CI: 45300-57500), 34,800 (95% CI: 32800-41500) men, 13,600 (95% CI: 12,500-16,000) women. Improvements in the time from infection to diagnosis and in the proportion of cases receiving antiretroviral therapy immediately after diagnosis were found for all groups. Comparison with GBD estimates shows similar rates for men with overlapping confidence intervals. Among women, differences are higher mainly in more recent years. CONCLUSIONS The results indicate that efforts to control the HIV epidemic are having an impact. However, there is an urgent need to address the vulnerability of young men.

Características epidemiológicas e clínicas dos casos de monkeypox no Brasil em 2022: estudo transversal / Características epidemiológicas y clínicas de los casos de viruela del mono en Brasil em 2022: un estudio transversal / Epidemiological and clinical characteristics of monkeypox cases in Brazil in 2022: a cross-sectional study

Objetivo: descrever características epidemiológicas e clínicas da monkeypox (MPX) no Brasil desde a identificação do primeiro caso, em 7 de junho de 2022, até a semana epidemiológica (SE) 39, encerrada em 1º de outubro de 2022. Métodos: estudo descritivo dos casos notificados ao Ministério da Saúde; as tendências foram analisadas sobre o número de casos confirmados e prováveis, por SE; os casos foram descritos segundo variáveis demográficas e variáveis clínicas. Resultados: das 33.513 notificações, 23,8% foram confirmadas, 91,8% eram do sexo masculino e 70,6% de homens cis com idade mediana de 32 anos; febre (58,0%), adenomegalia (42,4%), cefaleia (39,9%) e erupções (37,0%) foram os sintomas mais frequentes; 27,5% declararam ser imunossuprimidos, 34,6% viviam com HIV e 10,5% possuíam infecção sexualmente transmissível; três óbitos foram registrados. Conclusão: o perfil de casos de MPX foi semelhante ao de outros países; ações de vigilância devem ser reforçadas para o controle do surto.

Objetivo: Describir las características epidemiológicas y clínicas de la viruela del mono (MPX) en Brasil, desde la identificación del primer caso, el 7 de junio de 2022, hasta la semana epidemiológica (SE) 39, finalizando el 1° de octubre de 2022. Métodos: Las tendencias de los casos notificados al Ministerio de Salud se analizaron como el número de casos notificados confirmados y probables, por SE. Los casos se describieron según variables demográficas y clínicas. Resultados: se confirmaron 33.513 notificaciones un 23,8%; 91,8% del sexo masculino; un 70,6% de hombres cis; con edad promedio de 32 años. Fiebre (58,0%), adenomegalia (42,4%), cefalea (39,9%) y exantema (37,0%) fueron los síntomas más frecuentes. Un 27,5% declaró estar inmunodeprimido, 34,6% vivía con VIH y 10,5% tenía alguna infección de transmisión sexual. Se registraron 3 muertes. Conclusión: El perfil de los casos MPX fue similar al de otros países. Se deben reforzar las acciones de vigilancia para controlar el brote.

Objective: to describe epidemiological and clinical characteristics of monkeypox (MPX) in Brazil, from the identification of the first case, on June 7, 2022, to Epidemiological Week (EW) 39, ending on October 1, 2022. Methods: this was a descriptive study of cases notified to the Ministry of Health; trends were analyzed based on the number of confirmed and probable cases per EW; the cases were also described according to demographic and clinical variables. Results: out of 31,513 notifications, 23.8% were confirmed; 91.8% were male; 70.6% were cis men; and median age was 32 years. Fever (58.0%), adenomegaly (42.4%), headache (39.9%) and rash (37.0%) were the most frequent symptoms; 27.5% reported being immunosuppressed, 34.6% were living with HIV and 10.5% had a sexually transmitted infection; three deaths were recorded. Conclusion: the MPX case profile was similar to that of other countries; surveillance actions must be strengthened to control the outbreak.

Achieving consistency in measures of HIV-1 viral suppression across countries: derivation of an adjustment based on international antiretroviral treatment cohort data.

INTRODUCTION: The third of the Joint United Nations Programme on HIV/AIDS (UNAIDS) 90-90-90 targets is to achieve a 90% rate of viral suppression (HIV viral load <1000 HIV-1 RNA copies/ml) in patients on antiretroviral treatment (ART) by 2020. However, some countries use different thresholds when reporting viral suppression, and there is thus a need for an adjustment to standardize estimates to the <1000 threshold. We aim to propose such an adjustment, to support consistent monitoring of progress towards the "third 90" target. METHODS: We considered three possible distributions for viral loads in ART patients: Weibull, Pareto and reverse Weibull (imposing an upper limit but no lower limit on the log scale). The models were fitted to data on viral load distributions in ART patients in the International epidemiology Databases to Evaluate AIDS (IeDEA) collaboration (representing seven global regions) and the ART Cohort Collaboration (representing Europe), using separate random effects models for adults and children. The models were validated using data from the World Health Organization (WHO) HIV drug resistance report and the Brazilian national ART programme. RESULTS: Models were calibrated using 921,157 adult and 37,431 paediatric viral load measurements, over 2010-2019. The Pareto and reverse Weibull models provided the best fits to the data, but for all models, the "shape" parameters for the viral load distributions differed significantly between regions. The Weibull model performed best in the validation against the WHO drug resistance survey data, while the Pareto model produced uncertainty ranges that were too narrow, relative to the validation data. Based on these analyses, we recommend using the reverse Weibull model. For example, if a country reports an 80% rate of viral suppression at <200 copies/ml, this model estimates the proportion virally suppressed at <1000 copies/ml is 88.3% (0.800.56 ), with uncertainty range 85.5-90.6% (0.800.70 -0.800.44 ). CONCLUSIONS: Estimates of viral suppression can change substantially depending on the threshold used in defining viral suppression. It is, therefore, important that viral suppression rates are standardized to the same threshold for the purpose of assessing progress towards UNAIDS targets. We have proposed a simple adjustment that allows this, and this has been incorporated into UNAIDS modelling software.

Application of the Respondent-Driven Sampling methodology in a biological and behavioral surveillance survey among female sex workers, Brazil, 2016.

INTRODUCTION: Respondent-Driven Sampling (RDS) has been used in surveys with key populations at risk of HIV infection, such as female sex workers (FSW). This article describes the application of the RDS method among FSW in 12 Brazilian cities, during a survey carried out in 2016. METHODOLOGY: A biological and behavioral surveillance study carried out in 12 Brazilian cities, with a minimum sample of 350 FSW in each city. Tests were performed for HIV, syphilis, and hepatitis B and C infections. A social-behavioral questionnaire was also applied. RESULTS: The sample was comprised of 4,328 FSW. For data analysis, the sample was weighted according to each participant's network size (due consideration to the implications of RDS complex design and to the effects of homophilia are recommended). DISCUSSION: Although RDS methods for obtaining a statistical sample are based on strong statistical assumptions, allowing for an estimation of statistical parameters, with each new application the method has been rethought. In the analysis of whole-sample data, estimators were robust and compatible with those found in 2009. However, there were significant variations according to each city. CONCLUSION: The achieved sample size was of great relevance for assessing progress and identifying problems regarding the prevention and treatment of Sexually Transmitted Infections. New RDS studies with more time and operational resources should be envisaged. This could further network development.

Determinants of survival of people living with HIV/AIDS on antiretroviral therapy in Brazil 2006-2015.

BACKGROUND: We compared AIDS-related mortality rates in people living with HIV (PLHIV) starting antiretroviral therapy (ART) in Brazil during 2006-2015 and examined associated risk factors . METHODS: Data on ART use in PLHIV and AIDS mortality in Brazil was analysed with piecewise constant exponential models. Mortality rates and hazard ratios were estimated for 0-6, 6-12, 13-24, 25-36 and > 36 months of ART use and adjusted for region, age, sex, baseline CD4 cell count and calendar year of ART initiation. An additional analysis restricted to those with data on risk group was also performed. RESULTS: 269,076 individuals were included in the analysis, 165,643 (62%) males and 103,433 (38%) females, with 1,783,305 person-years of follow-up time. 21,749 AIDS deaths were reported and 8898 deaths occurred in the first year of ART. The risk of death in the first six months decreased with early ART initiation; those starting treatment early with CD4 > 500 cells per µL had a hazard ratio of 0.06 (95% CI 0.05-0.07) compared with CD4 < 200 cells per µL. Older age, male sex, intravenous drug use and starting treatment in earlier calendar years were associated with higher mortality rates. People living in the North, Northeast and South of Brazil experienced significantly higher AIDS mortality rates than those in the Southeast (HR 1.44, [95% CI 1.35-1.54], 1.10 [1.05-1.16] and 1.22 [1.17-1.28] respectively). CONCLUSIONS: Early treatment is likely to have contributed to the improved survival in PLHIV on ART, with the greatest benefits observed in women, younger age-groups and those living in the North.

The 12 city HIV Surveillance Survey among MSM in Brazil 2016 using respondent-driven sampling: a description of methods and RDS diagnostics.

INTRODUCTION: This paper details the methods used in the second national Biological and Behavioral Surveillance Survey (BBSS) of HIV, syphilis, and hepatitis B and C among men who have sex with men in Brazil. METHODS: Respondent-driven sampling (RDS) was used in 12 cities in 2016. The targeted sample size was initiated with five to six seeds in each city. HIV, syphilis, and Hepatitis B and C rapid tests were offered to participants. RDS Analyst with Gile's successive sampling (SS) estimator was used to adjust results as recommended and a weight for each individual was generated for further analysis. Data for the 12 cities were merged and analyzed using Stata 14.0 complex survey data tools with each city treated as its own stratum. RESULTS: Duration of data collection varied from 5.9 to 17.6 weeks. 4,176 men were recruited in the 12 cities. Two sites failed to achieve targeted sample size due to a six-month delay in local IRB approval. No city failed to reach convergence in our major outcome variable (HIV). CONCLUSION: The comprehensive BBSS was completed as planned and on budget. The description of methods here is more detailed than usual, due to new diagnostic tools and requirements of the new STROBE-RDS guidelines.

Estimating HIV incidence from surveillance data indicates a second wave of infections in Brazil.

Emerging evidence suggests that HIV incidence rates in Brazil, particularly among men, may be rising. Here we use Brazil's integrated health systems data to develop a mathematical model, reproducing the complex surveillance systems and providing estimates of HIV incidence, number of people living with HIV (PLHIV), reporting rates and ART initiation rates. An age-structured deterministic model with a flexible spline was used to describe the natural history of HIV along with reporting and treatment rates. Individual-level surveillance data for 1,077,295 cases (HIV/AIDS diagnoses, ART dispensations, CD4 counts and HIV/AIDS-related deaths) were used to calibrate the model using Bayesian inference. The results showed a second wave of infections occurring after 2001 and 56,000 (95% Credible Interval 43,000-71,000) new infections in 2015, 37,000 (95% CrI 28,000-54,000) infections in men and 16,000 (95% CrI 10,000-23,000) in women. The estimated number of PLHIV by end-2015 was 838,000 (95% CrI 675,000-1,083,000), with 80% (95% CrI 62-98%) of those individuals reported to the Ministry of Health. Women were more likely to be diagnosed and reported than men; 86.8% of infected women had been reported compared with 75.7% of men. Likewise, ART initiation rates for women were higher than those for men. The second wave contradicts previous estimates of HIV incidence trends in Brazil and there were persistent differences in the rates of accessing care between men and women. Nevertheless, the Brazilian HIV program has achieved high rates of detection and treatment, making considerable progress over the past ten years.

Application of the Respondent-Driven Sampling methodology in a biological and behavioral surveillance survey among female sex workers, Brazil, 2016 / Aplicação da metodologia Respondent-Driven Sampling em pesquisa biológica e comportamental com mulheres trabalhadoras do sexo, Brasil, 2016

ABSTRACT Introduction: Respondent-Driven Sampling (RDS) has been used in surveys with key populations at risk of HIV infection, such as female sex workers (FSW). This article describes the application of the RDS method among FSW in 12 Brazilian cities, during a survey carried out in 2016. Methodology: A biological and behavioral surveillance study carried out in 12 Brazilian cities, with a minimum sample of 350 FSW in each city. Tests were performed for HIV, syphilis, and hepatitis B and C infections. A social-behavioral questionnaire was also applied. Results: The sample was comprised of 4,328 FSW. For data analysis, the sample was weighted according to each participant's network size (due consideration to the implications of RDS complex design and to the effects of homophilia are recommended). Discussion: Although RDS methods for obtaining a statistical sample are based on strong statistical assumptions, allowing for an estimation of statistical parameters, with each new application the method has been rethought. In the analysis of whole-sample data, estimators were robust and compatible with those found in 2009. However, there were significant variations according to each city. Conclusion: The achieved sample size was of great relevance for assessing progress and identifying problems regarding the prevention and treatment of Sexually Transmitted Infections. New RDS studies with more time and operational resources should be envisaged. This could further network development.

RESUMO Introdução: O método de amostragem Respondent-Driven Sampling (RDS) tem sido utilizado em inquéritos com populações-chave sob maior risco de infecção pelo HIV, como as mulheres trabalhadoras do sexo (MTS). Este artigo tem o objetivo de descrever a implementação do RDS entre MTS em 12 cidades brasileiras em 2016. Metodologia: Trata-se de um estudo de vigilância biológica e comportamental realizado em 12 cidades brasileiras, com amostra mínima de 350 MTS em cada cidade. Foram realizados testes para infecções por HIV, sífilis, hepatites B e C, e aplicou-se questionário sociocomportamental. Resultados: Participaram 4.328 MTS. Para a análise dos dados, foi elaborada uma ponderação amostral considerando o tamanho da rede de cada participante; recomenda-se que o desenho complexo de amostragem por RDS e o efeito de homofilia sejam considerados. Discussão: Apesar de o RDS ser fundamentado em pressupostos estatísticos para obtenção de uma amostra probabilística e possibilitar estimação de parâmetros estatísticos, ele vem sendo repensado a cada nova aplicação. Na análise dos dados na totalidade da amostra, os estimadores mostraram-se robustos e coerentes aos encontrados em 2009. Entretanto, constataram-se grandes variações por cidade. Conclusão: O tamanho amostral alcançado foi de grande relevância para avaliar avanços e identificar problemas a respeito da prevenção e assistência às infecções sexualmente transmissíveis. Ressalta-se a necessidade de pensar estudos RDS com maior tempo e recursos para implementação, o que poderia permitir um melhor desenvolvimento das redes.

The 12 city HIV Surveillance Survey among MSM in Brazil 2016 using respondent-driven sampling: a description of methods and RDS diagnostics / Inquérito sobre o HIV entre HSH no Brasil em 2016 usando respondent-driven sampling (RDS): descrição dos métodos e dos diagnósticos do RDS

ABSTRACT: Introduction: This paper details the methods used in the second national Biological and Behavioral Surveillance Survey (BBSS) of HIV, syphilis, and hepatitis B and C among men who have sex with men in Brazil. Methods: Respondent-driven sampling (RDS) was used in 12 cities in 2016. The targeted sample size was initiated with five to six seeds in each city. HIV, syphilis, and Hepatitis B and C rapid tests were offered to participants. RDS Analyst with Gile's successive sampling (SS) estimator was used to adjust results as recommended and a weight for each individual was generated for further analysis. Data for the 12 cities were merged and analyzed using Stata 14.0 complex survey data tools with each city treated as its own stratum. Results: Duration of data collection varied from 5.9 to 17.6 weeks. 4,176 men were recruited in the 12 cities. Two sites failed to achieve targeted sample size due to a six-month delay in local IRB approval. No city failed to reach convergence in our major outcome variable (HIV). Conclusion: The comprehensive BBSS was completed as planned and on budget. The description of methods here is more detailed than usual, due to new diagnostic tools and requirements of the new STROBE-RDS guidelines.

RESUMO: Introdução: Este artigo detalha os métodos utilizados na segunda Pesquisa Nacional de Vigilância Biológica e Comportamental (BBSS) do HIV, sífilis e hepatite B e C entre os homens que fazem sexo com homens no Brasil. Métodos: O método Respondent-driven Sampling (RDS) foi utilizado em 12 cidades em 2016. A amostra foi iniciada com cinco a seis sementes em cada cidade. Testes rápidos para o HIV, sífilis e Hepatite B e C foram oferecidos aos participantes. O software RDS Analyst com o estimador de amostragem sucessiva (SS) de Gile foi utilizado para ajustar os resultados como recomendado, gerando um peso para cada indivíduo para análises. Osdados das 12cidades foram unidos em um único banco e analisados usando as ferramentas de dados complexos do Stata 14.0, com cada cidade sendo tratada como seu próprio estrato. Resultados: A duração da coleta de dados variou de 5,9 a 17,6 semanas e 4.176 homens foram recrutados nas 12 cidades. Dois sites não alcançaram o tamanho da amostra alvo devido a uma demora de seis meses na aprovação local do Comitê de Ética. Todas as cidades atingiram a convergência na principal variável estudada (HIV). Conclusão: O BBSS foi representativo e concluído conforme planejado e dentro do orçamento. A descrição dos métodos aqui é mais detalhada do que o habitual, devido às novas ferramentas e requisitos de diagnóstico das novas diretrizes do STROBE-RDS.

Sociodemographic determinants of attrition in the HIV continuum of care in Brazil, in 2016.

The aim of this study was to identify sociodemographic factors associated with attrition in the 3 steps of the HIV continuum of care related to the 90-90-90 targets - access to diagnosis, treatment initiation, and virologic suppression, in Brazilian adults (15 years or older), in 2016.Programmatic data were obtained from 2 information systems from the Brazilian Ministry of Health, which register all antiretroviral therapy (ART) dispensations and all CD4 and viral load counts (VL) performed within the country's public health system. The 3 attrition indicators were late presentation to care, defined as a first CD4 count <350 cells/mm among ART-naive individuals who performed a first CD4 count in 2016; not being on ART, defined as having no recorded dispensation within the last 100 days of the year, among those who were linked to care in 2016; and not being virologically suppressed, defined as having the last recorded VL >200 copies/mL in 2016, among those with a recorded VL count who were on treatment for at least 6 months. Association of sociodemographic factors with these indicators was analyzed by unconditional logistic regression analysis.Lower educational level and black/brown/indigenous race/color were associated with worse outcomes in the 3 indicators. Environmental indicators, namely the region, size, and social vulnerability index of the municipality of residence, also played an important role in the models. Younger age was strongly associated with not being on ART and not showing virological suppression.Our findings help identify the barriers in the different stages of the HIV continuum of care, which need to be addressed in order to progress toward the achievement of the 90-90-90 targets.

HIV prevalence among men who have sex with men in Brazil: results of the 2nd national survey using respondent-driven sampling.

This paper reports human immuno-deficiency virus (HIV) prevalence in the 2nd National Biological and Behavioral Surveillance Survey (BBSS) among men who have sex with men (MSM) in 12 cities in Brazil using respondent-driven sampling (RDS).Following formative research, RDS was applied in 12 cities in the 5 macroregions of Brazil between June and December 2016 to recruit MSM for BBSS. The target sample size was 350 per city. Five to 6 seeds were initially selected to initiate recruitment and coupons and interviews were managed online. On-site rapid testing was used for HIV screening, and confirmed by a 2nd test. Participants were weighted using Gile estimator. Data from all 12 cities were merged and analyzed with Stata 14.0 complex survey data analysis tools in which each city was treated as its own strata. Missing data for those who did not test were imputed HIV+ if they reported testing positive before and were taking antiretroviral therapy.A total of 4176 men were recruited in the 12 cities. The average time to completion was 10.2 weeks. The longest chain length varied from 8 to 21 waves. The sample size was achieved in all but 2 cities.A total of 3958 of the 4176 respondents agreed to test for HIV (90.2%). For results without imputation, 17.5% (95%CI: 14.7-20.7) of our sample was HIV positive. With imputation, 18.4% (95%CI: 15.4-21.7) were seropositive.HIV prevalence increased beyond expectations from the results of the 2009 survey (12.1%; 95%CI: 10.0-14.5) to 18.4%; CI95%: 15.4 to 21.7 in 2016. This increase accompanies Brazil's focus on the treatment to prevention strategy, and a decrease in support for community-based organizations and community prevention programs.

HIV Testing among men in Curitiba, Brazil.

In 2015, a community-wide intervention was launched in the city of Curitiba to evaluate the uptake of multiple HIV testing. A three-stage cluster sampling of 4800 men aged 15-64 years was selected in Curitiba. Logistic regression models were used to establish driving factors of HIV testing over the past 12 months. In the total sample, 49.5% have tested for HIV once in lifetime and 18.7% in the last 12 months. Among MSM, the proportions were much higher: 75.9% and 47.8% respectively. In the multivariate analysis, a significantly higher likelihood of HIV testing was found for young men (15-24 years), men with better educational level, those with more than 6 casual partners, and MSM compared to heterosexual men. The results indicate that the intervention to increase HIV diagnosis has substantially expanded MSM access to HIV testing.