Monitoring the epidemic of Human Immunodeficiency Virus (HIV) infection plays a vital role in tracking the leading edge of HIV transmission and designing intervention programs both at individual and population level. At individual level, it is imperative to identify newly infected individuals to reduce onwards transmission. At population level, knowledge on the HIV incidence is essential to monitor the spread of the epidemic and plan/evaluate HIV prevention programs. This dissertation will examine the way in which biomarker data can be used to monitor the HIV epidemic. There are two primary aims of this thesis: a) to investigate the use of biomarkers in quantifying the recency of HIV infection at individual level and b) to estimate quantities such as mean window period and testing rate that are the building blocks for estimating HIV incidence at population level. We apply and further develop existing statistical methods to answer the research questions of interest. At individual level, we investigate the use of one or more biomarkers to quantify the recency of HIV infection. We propose a novel approach to make probabilistic statements on the recency of HIV infection by combining the knowledge on the growth of such biomarkers with observations from a newly diagnosed individual. Univariate and bivariate non-linear mixed-effects models are implemented in a fully Bayesian framework. A simulation study is conducted to investigate the biomarkers’ features that affect the accuracy of the estimation of recency. The research findings suggest that rapidly evolving biomarkers of antibody response, such as LAg Avidity, provide reliable estimates of the probability of recency. The proposed methods are applied to a panel of individuals for whom information on various biomarkers is given along with an estimated date of detectable infection. At population level, we focus on estimating two fundamental ingredients, the mean window period and the HIV testing rate, required for estimating HIV incidence using biomarker data. We compare commonly used statistical methods and explore the use of multi-state models in estimating the mean window period of the fourth generation Architect Avidity. We further investigate the factors that are associated with the probability of having an HIV test and the HIV testing rate using surveillance data. Logistic and count regression models using the Generalized Estimating Equations (GEE) approach are employed to make inference at population level about the probability of testing and HIV testing rate respectively.

Background: HIV was added to the British Columbia list of reportable diseases on 1 May 2003 which included enhanced contact tracing by public health. A sensitive/less-sensitive (S/LS) algorithm using a modified EIA anti-HIV assay was employed to evaluate enhanced partner notification by comparing the proportion of newly diagnosed cases of HIV presenting within 6 months of becoming infected before and after HIV Reporting. Methods: Banked HIV positive samples, collected between 1 Jan 2000– 30 Apr 2003 (pre-reporting group) and 1 May 2003 – 23 Aug 2006 (post-reporting group) were re-tested using the bioMérieux Vironostika HIV-1-S/LS tests. Samples were classified by the S/LS EIA (detuned test) as a recent seroconversion (RSC) (infected for <170 days) or established infection (>170 days). Data was linked to the BC HIV Surveillance and AIDS databases. The proportion of RSC in the pre-reporting group was compared to the proportion of RSC in the post-reporting group using a 2-sided z-test of independent proportions. Similarly, the proportion of new cases of HIV presenting with AIDS was compared between groups. A Kappa statistic was calculated to determine the level of agreement between clinical assessment of HIV staging was compared and the detuned test results. Finally, characteristics of RSC were examined. Results: Serum was available for 1111 newly positive HIV cases in the pre-reporting group and 470 in the post-reporting group. RSC in the pre and post reporting group were 311 (28%; CI: 25.36%, 30.73%) and 136 (29%; CI: 24.87%, 33.27%) respectively (p= 0.70). There was no significant difference in the proportion of cases presenting with AIDS between groups (pre-reporting: 6.7% [CI: 5.4%, 8.1%]; post-reporting: 7.6% [CI: 6.3%, 9.1%]) (p=0.31). Sex work is independently associated with being RSC (AOR 1.78 [CI:1.09, 2.91]). There is an inverse association between being 41-60 yrs old, Asian and/or mixed ethnicity and RSC. Conclusions: The bioMérieux Vironostika HIV-1-S/LS test is an effective tool to objectively evaluate public health interventions and in identifying sub-populations likely to be RSC. This underpowered study demonstrated a slight increase in RSC post reporting which was not statistically significant. Similarly there was no difference in the proportion of cases presenting with AIDS.

Background: HIV was added to the British Columbia list of reportable diseases on 1 May 2003 which included enhanced contact tracing by public health. A sensitive/less-sensitive (S/LS) algorithm using a modified EIA anti-HIV assay was employed to evaluate enhanced partner notification by comparing the proportion of newly diagnosed cases of HIV presenting within 6 months of becoming infected before and after HIV Reporting. Methods: Banked HIV positive samples, collected between 1 Jan 2000– 30 Apr 2003 (pre-reporting group) and 1 May 2003 – 23 Aug 2006 (post-reporting group) were re-tested using the bioMérieux Vironostika HIV-1-S/LS tests. Samples were classified by the S/LS EIA (detuned test) as a recent seroconversion (RSC) (infected for <170 days) or established infection (>170 days). Data was linked to the BC HIV Surveillance and AIDS databases. The proportion of RSC in the pre-reporting group was compared to the proportion of RSC in the post-reporting group using a 2-sided z-test of independent proportions. Similarly, the proportion of new cases of HIV presenting with AIDS was compared between groups. A Kappa statistic was calculated to determine the level of agreement between clinical assessment of HIV staging was compared and the detuned test results. Finally, characteristics of RSC were examined. Results: Serum was available for 1111 newly positive HIV cases in the pre-reporting group and 470 in the post-reporting group. RSC in the pre and post reporting group were 311 (28%; CI: 25.36%, 30.73%) and 136 (29%; CI: 24.87%, 33.27%) respectively (p= 0.70). There was no significant difference in the proportion of cases presenting with AIDS between groups (pre-reporting: 6.7% [CI: 5.4%, 8.1%]; post-reporting: 7.6% [CI: 6.3%, 9.1%]) (p=0.31). Sex work is independently associated with being RSC (AOR 1.78 [CI:1.09, 2.91]). There is an inverse association between being 41-60 yrs old, Asian and/or mixed ethnicity and RSC. Conclusions: The bioMérieux Vironostika HIV-1-S/LS test is an effective tool to objectively evaluate public health interventions and in identifying sub-populations likely to be RSC. This underpowered study demonstrated a slight increase in RSC post reporting which was not statistically significant. Similarly there was no difference in the proportion of cases presenting with AIDS.

Background: HIV was added to the British Columbia list of reportable diseases on 1 May 2003 which included enhanced contact tracing by public health. A sensitive/less-sensitive (S/LS) algorithm using a modified EIA anti-HIV assay was employed to evaluate enhanced partner notification by comparing the proportion of newly diagnosed cases of HIV presenting within 6 months of becoming infected before and after HIV Reporting. Methods: Banked HIV positive samples, collected between 1 Jan 2000– 30 Apr 2003 (pre-reporting group) and 1 May 2003 – 23 Aug 2006 (post-reporting group) were re-tested using the bioMérieux Vironostika HIV-1-S/LS tests. Samples were classified by the S/LS EIA (detuned test) as a recent seroconversion (RSC) (infected for <170 days) or established infection (>170 days). Data was linked to the BC HIV Surveillance and AIDS databases. The proportion of RSC in the pre-reporting group was compared to the proportion of RSC in the post-reporting group using a 2-sided z-test of independent proportions. Similarly, the proportion of new cases of HIV presenting with AIDS was compared between groups. A Kappa statistic was calculated to determine the level of agreement between clinical assessment of HIV staging was compared and the detuned test results. Finally, characteristics of RSC were examined. Results: Serum was available for 1111 newly positive HIV cases in the pre-reporting group and 470 in the post-reporting group. RSC in the pre and post reporting group were 311 (28%; CI: 25.36%, 30.73%) and 136 (29%; CI: 24.87%, 33.27%) respectively (p= 0.70). There was no significant difference in the proportion of cases presenting with AIDS between groups (pre-reporting: 6.7% [CI: 5.4%, 8.1%]; post-reporting: 7.6% [CI: 6.3%, 9.1%]) (p=0.31). Sex work is independently associated with being RSC (AOR 1.78 [CI:1.09, 2.91]). There is an inverse association between being 41-60 yrs old, Asian and/or mixed ethnicity and RSC. Conclusions: The bioMérieux Vironostika HIV-1-S/LS test is an effective tool to objectively evaluate public health interventions and in identifying sub-populations likely to be RSC. This underpowered study demonstrated a slight increase in RSC post reporting which was not statistically significant. Similarly there was no difference in the proportion of cases presenting with AIDS. / Medicine, Faculty of / Population and Public Health (SPPH), School of / Graduate

Abstract Previous scientific data suggest that beta-cell destruction in type 1 diabetes is mediated by an autoimmune process. This work was aimed at expanding existing knowledge of humoral autoimmunity by analysing antibodies against the intracellular part of the IA-2 protein (IA-2A) in 1200 patients with the disease, 750 siblings and more than 370 non-diabetic controls. IA-2A were present at the time of diagnosis in the overwhelming majority of patients with type 1 diabetes, and were associated with human leucocyte antigen (HLA) DR4 and DQB1*0302, but not with gender. Humoral autoimmunity was more marked in patients diagnosed when younger than 20 years of age than in older ones, but no noticeable association was observed between IA-2A and age under the age of 20 years. IA-2A in combination with antibodies to GAD65 (GADA) identified a higher proportion of patients younger than 15 years of age at the time of diagnosis than did islet cell antibodies (ICA) alone. The levels of IA-2A and the proportions of antibody-positive patients decreased with increasing duration of type 1 diabetes, although more than half of the patients still tested positive for IA-2A after 10 years of clinical disease. IA-2A, GADA, insulin autoantibodies (IAA) and ICA were detected with individual fluctuations in 8-14% of the siblings of children with type 1 diabetes monitored from the time of diagnosis of the proband, and the fluctuations were modified by HLA-defined genetic susceptibility, age of the siblings, family size and total number of detectable autoantibodies. IA-2A positivity detected at the time of diagnosis of the proband increased the risk of future disease in the siblings. The positive predictive value increased with increasing IA-2A levels, although individual risk assessment appeared to be a complex matter. In conclusion, IA-2 appears to be an important autoantigen in type 1 diabetes, since IA-2A is associated with the HLA haplotype that most strongly predisposes subjects to the disease and have the highest positive predictive value for future disease out of the four autoantibodies used for risk assessment purposes.

Thesis (Ph.D.(Public Health))--University of the Witwatersrand, Faculty of Health Sciences, 2012. / Measuring HIV incidence has proved challenging over the years. A number of serological HIV assays have been proposed, and among these, the BED Capture Enzyme Immunoassay (CEIA) is one of the more widely used. Although the assay performs well among known seroconverting panels, it has been shown to classify some long term infected patients as being recently infected. Information on the performance of the BED assay among low CD4 cell count patients and those on antiretroviral therapy is limited. The risk of onwards transmission of HIV has been reported to be elevated around the seroconversion period compared to the chronic stage of infection. RNA viral load has been reported as the strongest predictor of HIV transmission compared to other HIV markers. Understanding how these markers influence the relationship between the likelihood of being recently infected and the BED assay might help in understanding some of the shortcomings of the BED assay. The main aim of this study was to understand the properties of the BED assay. The performance of the BED assay among advanced HIV disease patients and the influence of ART on BED levels once patients started treatment was investigated. The BED assay and CD4 cell count were used to quantify the risk of in utero and intrapartum transmission to their infants among women believed to have seroconverted during pregnancy. The influence of viral load, haemoglobin and mid-upper arm circumference was investigated on the relationship between the probability of being recently infected and BED ODn levels. Methods Cryopreserved plasma samples from HIV patients on the national antiretroviral treatment (ART) rollout programme at Tygerberg Hospital HIV clinic, South Africa, iv were used to investigate the effect of ART on BED ODn levels once patients commenced treatment. Mixed effect logistic regression models accounting for multiple readings per patient were used. To investigate the risk associated with seroconversion during pregnancy HIV seropositive women who had just given birth were classified into mutually exclusive groups according to their likelihood of having recently seroconverted using BED and CD4 cell count levels. Multinomial logistic regression models adjusting for other factors were used to assess the risk of MTCT in utero and intra-partum infection comparing these groups. To investigate the relationship between BED ODn levels and the probability of being recently infected, BED data from known HIV infected women and women who seroconverted over a 2 year period was used. Fractional polynomial regression models that allow for non-linear functions to be fitted were used, and the influence of viral load, haemoglobin and mid-upper arm circumference was assessed through multi-variable models. Data from the Zimbabwe Vitamin A for Mothers and Babies (ZVITAMBO) project, a double blinded treatment-placebo trial was used for these last two objectives. Results Patients with very low CD4 cell counts were more likely to test false recently infected according to the BED assay than other patients. ART changed BED ODn kinetics among HIV patients on treatment. Over half of advanced disease stage patients were likely to be classified as being recently infected according to the BED assay 2 years into ART treatment. v Women who seemed to have seroconverted during pregnancy had elevated risk of transmitting HIV in-utero compared to chronic HIV patients. BED and CD4 cell count were not predictive of risk of intra-partum infections attributed to seroconversion during pregnancy. The relationship between the probability of being recently infected with HIV and BED ODn levels was described better using Fractional Polynomial regression models than using a linear model in BED ODn or a model in which the BED ODn was categorised. Viral load and haemoglobin were important independent predictors of incident infections. Conclusions If the BED assay is to be used for HIV incidence estimations patients on ART should be accounted for. The BED assay together with other HIV serological markers can be used as prognostic tools to assess the risk of HIV transmission. The risk of in-utero transmission of HIV is higher among women who seroconvert during pregnancy. Repeat HIV testing among pregnant women may help in identifying women who seroconvert during pregnancy, and these women will benefit from Prevention of Mother-to-Child transmission (PMTCT) programmes. It was found that additional markers such as viral load and haemoglobin did not alter the relationship between the probability of having been recently infected and BED ODn.

Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-06-14T19:01:30Z No. of bitstreams: 1 MarinildeSouza.pdf: 1783855 bytes, checksum: bc20000b025261af153ffc4f6418fad7 (MD5) / Made available in DSpace on 2017-06-14T19:01:30Z (GMT). No. of bitstreams: 1 MarinildeSouza.pdf: 1783855 bytes, checksum: bc20000b025261af153ffc4f6418fad7 (MD5) Previous issue date: 2016-05-20 / Introduction: The hepatitis B virus (HBV) present diversity of its genome, which is to be classified in different genotypes and subgenotypes (A-J). It has been demonstrated that different genotypes are related to the natural history of infection. The maintenance of viral replication could be one of the factors related to genotypes. Objectives: To identify the viral replication status of HBV carriers among the subgenótipos A1 and D4. Materials and methods: HBV carriers identified have been studied in two studies involving individuals from the state of Maranhão, northeast,Brazil, which had genotyping and subgenotypes, serology for HBeAg and anti-HBe and certain viral loads. Serological tests were performed by ELISA, HBV – DNA quantification real time PCR and genotyping performed by sequencing. Results: We identified 146 patients. Among these, 136 were subgenotype A1 or D4. It is 85 - A1 (62.5%) and 51 - D4 (37.5%). No difference was found between groups when age was evaluated (42 ± 12 vs 38 ± 17 p=0.11) or gender (male 48.5% vs 51.5% p=00.18). Among the D4 subgenotype carriers had more patients with HBeAg positive (23.5% vs 9.4%, p=0.02) and a higher proportion of patients with viral loads above 20.000 IU / ml (43.1% vs 12.9 % p <0.0001), even when only those with negative HBeAg (25.6% vs 6.5%, p=0.007) when compared with the A1 subgenotype. Conclusion: HBV carriers, subgenotype D4, compared to A1 subgenotype have delayed HBeAg seroconversion and higher levels of HBV – DNA, suggesting that this subgenotype is possibly related to / Introdução: O vírus da hepatite B (VHB) apresenta diversidade do seu genoma, o que o faz ser classificado em diferentes genótipos e subgenótipos (A-J). Tem sido demonstrado que os diversos genótipos estão relacionados com a história natural da infecção. A manutenção da replicação viral pode ser um dos fatores relacionado aos genótipos. Objetivos: Identificar o estado de replicação viral do VHB entre portadores dos subgenótipos A1 e D4. Materiais e métodos: Foram estudados portadores do VHB identificados em dois estudos que envolveram indivíduos provenientes do estado do Maranhão, nordeste do Brasil, que tinham determinação de genótipos e subgenótipos, sorologias para o HBeAg e anti-HBe e cargas virais determinadas. Sorologias foram realizadas por ELISA, VHB–DNA quantificado por PCR em tempo real e genotipagem realizada por sequenciamento. Resultados: Foram identificados 146 portadores. Dentre estes, 136 eram subgenótipo A1 ou D4. Sendo 85 - A1 (62,5%) e 51 - D4 (37,5%). Não houve diferença entre os grupos quando foi avaliado idade (42±12 vs 38±17 p=0,11) ou gênero (masculino 48,5% vs 51,5% p=0,18). Entre os portadores do subgenótipo D4 havia mais indivíduos com HBeAg positivo (23,5% vs 9,4%, p=0.02) e maior proporção de portadores de cargas virais acima de 20.000 UI/ml (43,1% vs 12,9% p<0,0001), mesmo quando avaliados apenas aqueles com HBeAg negativos (25,6% vs 6,5% p=0,007), quando comparados com os de subgenótipo A1. Conclusão: Portadores do VHB, subgenótipo D4, quando comparados com subgenótipo A1 apresentam soroconversão mais tardia do HBeAg e maiores níveis de VHB–DNA, sugerindo que esse subgenótipo possivelmente está relacionado com potencial para doença mais grave e maior facilidade de transmissão da infecção.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22144号 / 医博第4535号 / 新制||医||1039(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 松田 秀一, 教授 生田 宏一, 教授 杉田 昌彦 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / OBJECTIVE: Determine the impact of HIV-1 seroconversion on inflammatory cytokines in the rectal mucosa. SETTING: Secondary analysis of data from men who have sex with men and transgender women who participated in a HIV prevention trial Lima, Peru. METHODS: From July to December 2017, 605 men who have sex with men and transgender women were screened for rectal gonorrhea/chlamydia (GC/CT). Fifty GC/CT-positive cases were randomly selected and matched with 52 GC/CT-negative controls by age and number of receptive anal intercourse partners in the last month. All participants were HIV-negative at baseline and those with GC/CT at baseline and/or follow-up received appropriate antibiotic therapy. Participants underwent sponge collection of rectal secretions for the measurement of inflammatory cytokines (IL-1β, IL-6, IL-8, and TNF-α) and were screened for rectal GC/CT and HIV at baseline, 3 months, and 6 months. Wilcoxon rank-sum tests compared inflammatory cytokine levels between participants diagnosed with HIV during follow-up and persons who remained HIV-negative. RESULTS: Eight participants were diagnosed with HIV at the 3-month (n = 6) or 6-month (n = 2) visit. The median number of receptive anal intercourse partners in the month before HIV diagnosis was the same for those who acquired HIV and those who did not. There were no significant differences in inflammatory cytokine levels in rectal mucosa between participants who did and did not experience HIV seroconversion at any time point. CONCLUSIONS: Despite a surge in viral replication during acute infection, findings from this study suggest that there is no prolonged effect of HIV-1 seroconversion on inflammatory cytokine levels in the rectal mucosa. Copyright / National Institute of Allergy and Infectious Diseases / Revisión por pares

Submitted by Cláudia Bueno (claudiamoura18@gmail.com) on 2016-05-19T17:45:53Z No. of bitstreams: 2 Tese - Yanna Andressa Ramos de Lima - 2014.pdf: 3948681 bytes, checksum: 03820f7151617bba515baa141492f753 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-05-20T13:41:52Z (GMT) No. of bitstreams: 2 Tese - Yanna Andressa Ramos de Lima - 2014.pdf: 3948681 bytes, checksum: 03820f7151617bba515baa141492f753 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-05-20T13:41:52Z (GMT). No. of bitstreams: 2 Tese - Yanna Andressa Ramos de Lima - 2014.pdf: 3948681 bytes, checksum: 03820f7151617bba515baa141492f753 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-07-02 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / HIV-1 mother-to-child-transmission (MTCT) is a multifactorial event associated mainly with maternal viral load. Thus, the molecular epidemiology of HIV-1 and the evaluation of factors associated with MTCT in pregnant women are crucial for epidemic understanding and monitoring in this population. Objectives: To assess the frequency of recent seroconversion cases among newly diagnosed, antiretroviral (ARV) naïve pregnant women and evaluation of pregnancy outcomes and transmitted drug resistance (TDR) in this group; to compare sociodemographical, clinical, genetic diversity of the virus and resistance among young and adult pregnant women. Methods: HIV-1-infected pregnant women (n = 250) were recruited during antenatal care conducted by the Program for the Protection of Pregnant Women from Goias State (PPPW/GO). Recent cases of seroconversion were identified by BED-CEIA among naïve pregnant women and confirmed by ambiguous nucleotide calls. Pol gene (protease/PR and 2/3 of the reverse transcriptase/RT) was sequenced from plasma samples. Resistance mutations were evaluated by Calibrated Population Resistance tool and Stanford HIV-1 and International AIDS Society-USA (IAS-USA) databases. Viral subtypes were assigned by REGA software and phylogenetic analyzes with reference sequences. Results: Cases of recent seroconversion (RS) were identified in 16.6% of 95 newly diagnosed, ARV-naïve pregnant women. Medians of CD4+ cell count and viral load were 530 cells/μL and 8,796.5 copies/mL, respectively. Nine patients with RS probably seroconverted during pregnancy. One case of MTCT was observed among pregnant women with RS. Incident cases presented a predominance of isolates assigned as subtype B. There was no difference regarding the distribution of non-B subtypes. The amont of 250 pregnant women recruited were divided into two distinct age groups: adolescents and young (96/250, 38%) and adult women (154/250, 62%). When compared with the adult group, young women had fewer previous pregnancies and they were diagnosed mainly in the current pregnancy. One case of MTCT was identified in both groups (2/250, 0.8%). The CD4+ cell counts were similar between both groups. Viral load was significantly higher among ARV-naïve pregnant adolescents (15-19 years) when compared with the group of ARV-naïve pregnant adults (>24 years). Young pregnant women previously exposed to ARVs were less likely to have viral load <1,500 copies / mL. The distribution of HIV-1 subtypes was similar in both groups and recombinant subtypes with similar recombination points were identified among both groups. The frequency of transmitted resistance was similar between young and adult women (9.5% and 7.1%, respectively). The frequency of secondary resistance was higher among adult pregnant women compared with younger women (21.8% and 12.8%, respectively). Conclusions: Recent seroconversion during pregnancy associated with moderate levels of transmitted resistance may contribute to vertical transmission of HIV-1. Preventive measures should include adolescents and young women as an attempt to control the vertical transmission of HIV-1 in Central Western region, Brazil. / A transmissão vertical do HIV-1 é um evento multifatorial em que a carga viral materna desempenha importante papel. Assim, a epidemiologia molecular do HIV-1 em gestantes e a avaliação de fatores associados com a transmissão vertical são cruciais para a compreensão e monitoramento da epidemia nessa população. Objetivos: Avaliação da frequência de casos de soroconversão recente entre gestantes recém-diagnosticadas, virgens de tratamento e avaliação dos desfechos da gestação nesse grupo e da frequência de resistência transmitida. Comparação entre os fatores sociodemográficos, clínicos, de diversidade genética do vírus e perfil de resistência entre gestantes jovens e adultas. Métodos: Gestantes infectadas por HIV-1 (n=250) foram recrutadas durante o pré-natal realizado pelo Programa de Proteção à Gestante/GO. Os casos de soroconversão recente em pacientes virgens de tratamento com diagnóstico recente foram identificados pelo teste imunoenzimático BED-CEIA e confirmados pela análise molecular de bases ambíguas em pol. O gene pol (protease/PR e 2/3 da transcriptase reversa/RT) foi sequenciado a partir de amostras de plasma. As mutações de resistência foram avaliadas pela ferramenta Calibrated Population Resistance tool e pelos bancos de dados Stanford HIV-1 Database e International AIDS Society-USA (IAS-USA). Os subtipos virais foram definidos pelo software REGA e análises filogenéticas com sequências de referência. Resultados: Casos de soroconversão recente (SR) foram identificados em 16,6% das 95 gestantes recém-diagnosticadas e virgens de tratamento. A mediana da contagem de células CD4+ foi 530 células/μL e da carga viral foi 8796,5 cópias/mL. Nove pacientes com SR (82%) provavelmente soroconverteram durante a gestação. Um caso de transmissão vertical foi observado entre as gestantes com SR. Os casos incidentes apresentaram predomínio de isolados com subtipo B. Não houve diferença com relação à distribuição dos outros subtipos. As 250 gestantes recrutadas foram divididas em dois grupos etários distintos: adolescentes e jovens (96/250, 38%) e adultas (154/250, 62%). Quando comparadas com as adultas, as gestantes jovens apresentaram menor número de gestações prévias e foram diagnosticadas principalmente na gestação atual. Um caso de transmissão vertical da infecção foi identificado em cada um dos grupos (2/250, 0,8%). A contagem de células CD4+ foi similar entre ambos os grupos. O grupo de gestantes adolescentes (15-19 anos), virgens de tratamento, apresentou carga viral significativamente mais alta que o grupo de gestantes adultas. As gestantes jovens previamente expostas aos ARVs tinham menor probabilidade de apresentar carga viral <1500 cópias/mL. A distribuição de subtipos do HIV-1 foi similar em ambos os grupos e foram identificados subtipos recombinantes com ponto de recombinação similar entre os dois grupos. A frequência de resistência transmitida foi similar entre as gestantes jovens e adultas (9,5% e 7,1%, respectivamente). A frequência de resistência secundária foi maior entre as gestantes adultas quando comparadas com as gestantes jovens (21,8% e 12.8%, respectivamente). Conclusões: A soroconversão recente na gestação associada com níveis moderados de resistência transmitida pode contribuir para a transmissão vertical do HIV-1. Políticas preventivas devem incluir a população de adolescentes e jovens como tentativa de controlar a transmissão vertical do HIV-1, na região Centro-Oeste do Brasil.