Virologic response to antiretroviral therapy in people with HIV and tuberculosis in high tuberculosis burden countries.

OBJECTIVE: We sought to compare virologic outcomes on antiretroviral therapy (ART) between people with HIV (PWH) also treated for tuberculosis in the different countries who participated to two randomized trials. DESIGN: Pooled analysis of two randomized clinical trials. METHODS: In the phase II Reflate TB and phase III Reflate TB2 trials conducted in Brazil, Côte d'Ivoire, Mozambique and Vietnam, ART-naïve PWH treated for tuberculosis were randomized to receive raltegravir or efavirenz. We assessed country differences in baseline characteristic using Wilcoxon tests and chi-square, or Fisher's exact test. We used logistic regression to analyze determinants of virologic success, defined as week-48 plasma HIV-1 RNA <50 copies/ml. RESULTS: Of 550 participants (140 from Brazil, 170 from Côte d'Ivoire, 129 from Mozambique and 111 from Vietnam) with median baseline HIV-1 RNA of 5.4 log 10  copies/ml, 362 (65.8%) achieved virologic success at week 48. Virologic success rates were: 105/140 (75.0%) in Brazil, 99/170 (58.2%) in Côte d'Ivoire, 84/129 (65.1%) in Mozambique and 74/111 (66.7%) in Vietnam ( P  = 0.0233). Baseline HIV-1 RNA, but not the country, was independently associated with virologic success: baseline HIV-1 RNA ≥500 000 copies/ml (reference), HIV RNA <100 000 copies/ml odds ratio 3.12 [95% confidence interval (CI) 1.94; 5.01] and HIV-1 RNA 100 000-499 999 copies/ml odds ratio: 1.80 (95% CI 1.19; 2.73). Overall, 177/277 (63.9%) patients treated with raltegravir and 185/273 (67.9%) patients treated with efavirenz had a plasma HIV-1 RNA <50 copies/ml at week 48. CONCLUSIONS: Virologic response to antiretroviral therapy in PWH with TB varied across countries but was mainly driven by levels of pretreatment HIV-1 RNA.

Effect of Maternal Immunization With 10-Valent Pneumococcus Conjugate Vaccine (PCV-10), 23-Valent Pneumococcus Polysaccharide Vaccine, or Placebo on the Immunogenicity of PCV-10 in Human Immunodeficiency Virus-Exposed Uninfected Infants: A Randomized Clinical Trial.

BACKGROUND: The effect of pneumococcal vaccination of mothers with human immunodeficiency virus (HIV) on infant responses to childhood vaccination has not been studied. We compared the immunogenicity of 10-valent pneumococcus conjugate vaccine (PCV-10) in HIV-exposed uninfected infants born to mothers who received PCV-10, 23-valent pneumococcus polysaccharide vaccine (PPV-23), or placebo during pregnancy. METHODS: Antibody levels against 7 serotypes were measured at birth, before the first and second doses of PCV-10m and after completion of the 2-dose regimen in 347 infants, including 112 born to mothers who received PPV-23, 112 who received PCV-10, and 119 who received placebo during pregnancy. Seroprotection was defined by antibody levels ≥0.35 µg/mL. RESULTS: At birth and at 8 weeks of life, antibody levels were similar in infants born to PCV-10 or PPV-23 recipients and higher than in those born to placebo recipient. After the last dose of PCV-10, infants in the maternal PCV-10 group had significantly lower antibody levels against 5 serotypes than those in the maternal PPV-23 group and against 3 serotypes than those in the maternal placebo group, and they did not have higher antibody levels against any serotype. The seroprotection rate against 7 serotypes was 50% in infants in the maternal PCV-10 group, compared with 71% in both of the maternal PPV-23 and placebo groups (P < .001). CONCLUSIONS: Administration of PCV-10 during pregnancy was associated with decreased antibody responses to PCV-10 and seroprotection rates in infants. Considering that PCV-10 and PPV-23 had similar immunogenicity in pregnant women with HIV and that administration of PPV-23 did not affect the immunogenicity of PCV-10 in infants, PPV-23 in pregnancy may be preferred over PCV-10.

Immunogenicity of Conjugated and Polysaccharide Pneumococcal Vaccines Administered During Pregnancy or Postpartum to Women With HIV.

BACKGROUND: Pneumococcal vaccination is recommended in people with HIV, prioritizing PCV. We compared the immunogenicity of PCV-10 and PPV-23 administered antepartum or postpartum. METHODS: This double-blind study randomized 346 pregnant women with HIV on antiretrovirals to PCV-10, PPV-23, or placebo at 14-34 weeks gestational age. Women who received placebo antepartum were randomized at 24 weeks postpartum to PCV-10 or PPV-23. Antibodies against 7 serotypes common to both vaccines and 1 serotype only in PPV-23 were measured by ELISA/chemiluminescence; B- and T-cell responses to serotype 1 by FLUOROSPOT; and plasma cytokines/chemokines by chemiluminescence. RESULTS: Antibody responses were higher after postpartum versus antepartum vaccination. PCV-10 generated lower antibody levels than PPV-23 against 4 and higher against 1 of 7 common serotypes. Additional factors associated with high postvaccination antibody concentrations were high prevaccination antibody concentrations and CD4+ cells; low CD8+ cells and plasma HIV RNA; and several plasma cytokines/chemokines. Serotype 1 B- and T-cell memory did not increase after vaccination. CONCLUSIONS: Antepartum immunization generated suboptimal antibody responses, suggesting that postpartum booster doses may be beneficial and warrant further studies. Considering that PCV-10 and PPV-23 had similar immunogenicity, but PPV-23 covered more serotypes, use of PPV-23 may be prioritized in women with HIV on antiretroviral therapy. CLINICAL TRAILS REGISTRATION: NCT02717494.

Evaluation of Phylogenetic Methods for Inferring the Direction of Human Immunodeficiency Virus (HIV) Transmission: HIV Prevention Trials Network (HPTN) 052.

BACKGROUND: Phylogenetic analysis can be used to assess human immunodeficiency virus (HIV) transmission in populations. We inferred the direction of HIV transmission using whole-genome HIV sequences from couples with known linked infection and known transmission direction. METHODS: Complete next-generation sequencing (NGS) data were obtained for 105 unique index-partner sample pairs from 32 couples enrolled in the HIV Prevention Trials Network (HPTN) 052 study (up to 2 samples/person). Index samples were obtained up to 5.5 years before partner infection; partner samples were obtained near the time of seroconversion. The bioinformatics method, phyloscanner, was used to infer transmission direction. Analyses were performed using samples from individual sample pairs, samples from all couples (1 sample/person; group analysis), and all available samples (multisample group analysis). Analysis was also performed using NGS data from defined regions of the HIV genome (gag, pol, env). RESULTS: Using whole-genome NGS data, transmission direction was inferred correctly (index to partner) for 98 of 105 (93.3%) of the individual sample pairs, 99 of 105 (94.3%) sample pairs using group analysis, and 31 of the 32 couples (96.9%) using multisample group analysis. There were no cases where the incorrect transmission direction (partner to index) was inferred. The accuracy of the method was higher with greater time between index and partner sample collection. Pol region sequences performed better than env or gag sequences for inferring transmission direction. CONCLUSIONS: We demonstrate the potential of a phylogenetic method to infer the direction of HIV transmission between 2 individuals using whole-genome and pol NGS data.

Low prevalence of human gammaherpesvirus 8 (HHV-8) infection among HIV-infected pregnant women in Rio De Janeiro, Brazil.

Pregnant women coinfected with the human immunodeficiency virus (HIV) and human gammaherpesvirus 8 (HHV-8) are at higher risk of Kaposi's sarcoma development, increased viral load, and vertical transmission of these viruses. A total of 131 pregnant women infected with HIV were examined for antibodies against HHV-8 latency-associated nuclear antigen (LANA) and lytic antigens using immunofluorescence assays. The presence of HHV-8 DNA was confirmed using real-time polymerase chain reaction (qPCR) and nested PCR. Overall, 0.8% (1/131) of the patients contained antibodies to HHV-8 LANA and lytic antigens, and no HHV-8 DNA was detected. This study, including a small population of HIV-infected pregnant women in Brazil, indicates a low prevalence of HHV-8 seropositivity and absence of active infection in this group. However, a potential role of HHV-8 in the increased transmission and pathogenic activity of HIV in pregnant women is suggested. Attention should be given to the emergence of HHV-8 infection in this population group in order to avoid comorbidities and transmission of HIV.

Sexually transmitted infections among HIV-infected and HIV-uninfected women in the Tapajós region, Amazon, Brazil: Self-collected vs. clinician-collected samples.

The anogenital prevalence of sexually transmitted infections (STIs) and the use of cervico-vaginal self-collected vs. clinician-collected samples were evaluated for the diagnosis of human immunodeficiency virus (HIV)-infected and HIV-uninfected women in the Tapajós region, Amazon, Brazil. We recruited 153 women for a cross-sectional study (112 HIV-uninfected and 41 HIV-infected) who sought health services. Anal and cervical scrapings and cervico-vaginal self-collection samples were collected. Real-time polymerase chain reaction methods were used for Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis and Mycoplasma genitalium. A syphilis test was also performed. Risk factors for STIs were identified by multivariate analysis. The overall prevalence of STIs was 30.4% (34/112) in HIV-uninfected women and 24.4% (10/41) in HIV-infected women. Anogenital Chlamydia trachomatis infection was the most prevalent in both groups of women (20.5% vs 19.5%). There was significant agreement for each STI between self-collected and clinician-collected samples: 91.7%, kappa 0.67, 95% confidence interval (CI) 0.49-0.85 for Chlamydia trachomatis; 99.2%, kappa 0.85, 95% CI 0.57-1.00 for Neisseria gonorrhoeae; 97.7%, kappa 0.39, 95% CI -0.16-0.94 for Trichomonas vaginalis; and 94.7%, kappa 0.51, 95% CI 0.20-0.82 for Mycoplasma genitalium. Women with human papillomavirus had coinfection or multiple infections with other STIs. Risk factors for STIs were being ≤ 25 years old, being employed or a student, reporting a history of STI and having a positive HPV test. A high prevalence of STIs in women in the Tapajós region was found. Cervico-vaginal self-collection is a useful tool for STI screening and can be used in prevention control programs in low-resource settings, such as in northern Brazil.

Adverse Pregnancy Outcomes Among Women Who Conceive on Antiretroviral Therapy.

Background: Adverse pregnancy outcomes for women who conceive on antiretroviral therapy (ART) may be increased, but data are conflicting. Methods: Human immunodeficiency virus-infected, nonbreastfeeding women with pre-ART CD4 counts ≥400 cells/µL who started ART during pregnancy were randomized after delivery to continue ART (CTART) or discontinue ART (DCART). Women randomized to DCART were recommended to restart if a subsequent pregnancy occurred or for clinical indications. Using both intent-to-treat and as-treated approaches, we performed Fisher exact tests to compare subsequent pregnancy outcomes by randomized arm. Results: Subsequent pregnancies occurred in 277 of 1652 (17%) women (CTART: 144/827; DCART: 133/825). A pregnancy outcome was recorded for 266 (96%) women with a median age of 27 years (interquartile range [IQR], 24-31 years) and median CD4+ T-cell count 638 cells/µL (IQR, 492-833 cells/µL). When spontaneous abortions and stillbirths were combined, there was a significant difference in events, with 33 of 140 (23.6%) in the CTART arm and 15 of 126 (11.9%) in the DCART arm (relative risk [RR], 2.0 [95% confidence interval {CI}, 1.1-3.5]; P = .02). In the as-treated analysis, the RR was reduced and no longer statistically significant (RR, 1.4 [95% CI, .8-2.4]). Conclusions: Women randomized to continue ART who subsequently conceived were more likely to have spontaneous abortion or stillbirth, compared with women randomized to stop ART; however, the findings did not remain significant in the as-treated analysis. More data are needed on pregnancy outcomes among women conceiving on ART, particularly with newer regimens.

Phylogenetic Methods Inconsistently Predict the Direction of HIV Transmission Among Heterosexual Pairs in the HPTN 052 Cohort.

BACKGROUND: We evaluated use of phylogenetic methods to predict the direction of human immunodeficiency virus (HIV) transmission. METHODS: For 33 pairs of HIV-infected patients (hereafter, "index patients") and their partners who acquired genetically linked HIV infection during the study, samples were collected from partners and index patients close to the time when the partner seroconverted (hereafter, "SC samples"); for 31 pairs, samples collected from the index patient at an earlier time point (hereafter, "early index samples") were also available. Phylogenies were inferred using env next-generation sequences (1 tree per pair/subtype). The direction of transmission (DoT) predicted from each tree was classified as correct or incorrect on the basis of which sequences (those from the index patient or the partner) were closest to the root. DoT was also assessed using maximum parsimony to infer ancestral node states for 100 bootstrap trees. RESULTS: DoT was predicted correctly for both single-pair and subtype-specific trees in 22 pairs (67%) by using SC samples and in 23 pairs (74%) by using early index samples. DoT was predicted incorrectly for 4 pairs (15%) by using SC or early index samples. In the bootstrap analysis, DoT was predicted correctly for 18 pairs (55%) by using SC samples and for 24 pairs (73%) by using early index samples. DoT was predicted incorrectly for 7 pairs (21%) by using SC samples and for 4 pairs (13%) by using early index samples. CONCLUSIONS: Phylogenetic methods based solely on the tree topology of HIV env sequences, particularly without consideration of phylogenetic uncertainty, may be insufficient for determining DoT.

Cervico-vaginal self-collection in HIV-infected and uninfected women from Tapajós region, Amazon, Brazil: High acceptability, hrHPV diversity and risk factors.

OBJECTIVE: We evaluated acceptability of cervico-vaginal self-collection (CVSC) and prevalence of human papillomavirus (HPV) in Human immunodeficiency virus (HIV)-infected and HIV-uninfected women living in the Tapajós region, Amazon, Brazil. METHODS: Cross-sectional study recruited 153 non-indigenous women (HIV-uninfected, n = 112 and HIV-infected, n = 41) who voluntarily sought assistance in health services. Peripheral blood for HIV screening and cervical scraping (CS) for HPV detection were collected. Women who accepted to perform CVSC received instructions and individual collection kits. Risk factors for high-risk HPV genotypes (hrHPV) were identified by uni- and multivariate analyses. RESULTS: The overall acceptability of CVSC was 87%. Only HIV-infected women had cytological abnormalities (12.2%). Prevalence of any HPV and hrHPV infection was 42.9% and 47.9% for HIV-uninfected and 97.6% and 77.5% for HIV-infected women, respectively. There was significant agreement in the detection of HPV (88%, 0.76, 95% confidence interval [CI], 0.65-0.87) and hrHPV (79.7%, 0.56, 95% CI, 0.41-0.71) between self-collected and clinician-collected samples. The most prevalent hrHPV types were HPV16 and HPV18 in HIV-uninfected and HPV16, HPV51 and HPV59 in HIV-infected women. HIV-infected women with hrHPV infection had multiple hrHPV infections (p = 0.005) and lower CD4 count (p = 0.018). Risk factors for hrHPV infection included being HIV-infected and having five or more sexual partners. CONCLUSIONS: CVSC had high acceptability and high prevalence of hrHPV types in women living in the Tapajós region, Amazon, Brazil.

HIV Drug Resistance in Adults Receiving Early vs. Delayed Antiretroviral Therapy: HPTN 052.

INTRODUCTION: We evaluated HIV drug resistance in adults who received early vs. delayed antiretroviral therapy (ART) in a multinational trial [HIV Prevention Trials Network (HPTN) 052, enrollment 2005-2010]. In HPTN 052, 1763 index participants were randomized to start ART at a CD4 cell count of 350-550 cells/mm (early ART arm) or <250 cells/mm (delayed ART arm). In May 2011, interim study results showed benefit of early ART, and all participants were offered ART regardless of CD4 cell count; the study ended in 2015. METHODS: Virologic failure was defined as 2 consecutive viral loads >1000 copies/mL >24 weeks after ART initiation. Drug resistance testing was performed for pretreatment (baseline) and failure samples from participants with virologic failure. RESULTS: HIV genotyping results were obtained for 211/249 participants (128 early ART arm and 83 delayed ART arm) with virologic failure. Drug resistance was detected in 4.7% of participants at baseline; 35.5% had new resistance at failure. In univariate analysis, the frequency of new resistance at failure was lower among participants in the early ART arm (compared with delayed ART arm, P = 0.06; compared with delayed ART arm with ART initiation before May 2011, P = 0.032). In multivariate analysis, higher baseline viral load (P = 0.0008) and ART regimen (efavirenz/lamivudine/zidovudine compared with other regimens, P = 0.024) were independently associated with higher risk of new resistance at failure. CONCLUSIONS: In HPTN 052, the frequency of new drug resistance at virologic failure was lower in adults with early ART initiation. The main factor associated with reduced drug resistance with early ART was lower baseline viral load.

Association of HIV diversity and virologic outcomes in early antiretroviral treatment: HPTN 052.

Higher HIV diversity has been associated with virologic outcomes in children on antiretroviral treatment (ART). We examined the association of HIV diversity with virologic outcomes in adults from the HPTN 052 trial who initiated ART at CD4 cell counts of 350-550 cells/mm3. A high resolution melting (HRM) assay was used to analyze baseline (pre-treatment) HIV diversity in six regions in the HIV genome (two in gag, one in pol, and three in env) from 95 participants who failed ART. We analyzed the association of HIV diversity in each genomic region with baseline (pre-treatment) factors and three clinical outcomes: time to virologic suppression after ART initiation, time to ART failure, and emergence of HIV drug resistance at ART failure. After correcting for multiple comparisons, we did not find any association of baseline HIV diversity with demographic, laboratory, or clinical characteristics. For the 18 analyses performed for clinical outcomes evaluated, there was only one significant association: higher baseline HIV diversity in one of the three HIV env regions was associated with longer time to ART failure (p = 0.008). The HRM diversity assay may be useful in future studies exploring the relationship between HIV diversity and clinical outcomes in individuals with HIV infection.

Virologic outcomes in early antiretroviral treatment: HPTN 052.

INTRODUCTION: The HIV Prevention Trials Network (HPTN) 052 trial demonstrated that early antiretroviral therapy (ART) prevented 93% of HIV transmission events in serodiscordant couples. Some linked infections were observed shortly after ART initiation or after virologic failure. OBJECTIVE: To evaluate factors associated with time to viral suppression and virologic failure in participants who initiated ART in HPTN 052. METHODS: 1566 participants who had a viral load (VL) > 400 copies/mL at enrollment were included in the analyses. This included 832 in the early ART arm (CD4 350-550 cells/mm3 at ART initiation) and 734 in the delayed ART arm (204 with a CD4 < 250 cells/mm3 at ART initiation; 530 with any CD4 at ART initiation). Viral suppression was defined as two consecutive VLs ≤ 400 copies/mL after ART initiation; virologic failure was defined as two consecutive VLs > 1000 copies/mL > 24 weeks after ART initiation. RESULTS: Overall, 93% of participants achieved viral suppression by 12 months. The annual incidence of virologic failure was 3.6%. Virologic outcomes were similar in the two study arms. Longer time to viral suppression was associated with younger age, higher VL at ART initiation, and region (Africa vs. Asia). Virologic failure was strongly associated with younger age, lower educational level, and lack of suppression by three months; lower VL and higher CD4 at ART initiation were also associated with virologic failure. CONCLUSIONS: Several clinical and demographic factors were identified that were associated with longer time to viral suppression and virologic failure. Recognition of these factors may help optimize ART for HIV treatment and prevention.

High HIV-1 Diversity and Prevalence of Transmitted Drug Resistance Among Antiretroviral-Naive HIV-Infected Pregnant Women from Rio de Janeiro, Brazil.

Antiretroviral (ARV) resistance mutations in human immunodeficiency virus type 1 (HIV-1) infection may reduce the efficacy of prophylactic therapy to prevent mother-to-child transmission (PMTCT) and future treatment options. This study evaluated the diversity and the prevalence of transmitted drug resistance (TDR) in protease (PR) and reverse transcriptase (RT) regions of HIV-1 pol gene among 87 ARV-naive HIV-1-infected pregnant women from Rio de Janeiro, Brazil, between 2012 and 2015. The viral diversity comprised HIV-1 subtypes B (67.8%), F1 (17.2%), and C (4.6%); the circulating recombinant forms 12_BF (2.3%), 28/29_BF, 39_BF, 02_AG (1.1% each) and unique recombinants forms (4.5%). The overall prevalence of any TDR was 17.2%, of which 5.7% for nucleoside RT inhibitors, 5.7% for non-nucleoside RT inhibitors, and 8% for PR inhibitors. The TDR prevalence found in this population may affect the virological outcome of the standard PMTCT ARV-regimens, reinforcing the importance of continuous monitoring.

Antiretroviral Therapy for the Prevention of HIV-1 Transmission.

BACKGROUND: An interim analysis of data from the HIV Prevention Trials Network (HPTN) 052 trial showed that antiretroviral therapy (ART) prevented more than 96% of genetically linked infections caused by human immunodeficiency virus type 1 (HIV-1) in serodiscordant couples. ART was then offered to all patients with HIV-1 infection (index participants). The study included more than 5 years of follow-up to assess the durability of such therapy for the prevention of HIV-1 transmission. METHODS: We randomly assigned 1763 index participants to receive either early or delayed ART. In the early-ART group, 886 participants started therapy at enrollment (CD4+ count, 350 to 550 cells per cubic millimeter). In the delayed-ART group, 877 participants started therapy after two consecutive CD4+ counts fell below 250 cells per cubic millimeter or if an illness indicative of the acquired immunodeficiency syndrome (i.e., an AIDS-defining illness) developed. The primary study end point was the diagnosis of genetically linked HIV-1 infection in the previously HIV-1-negative partner in an intention-to-treat analysis. RESULTS: Index participants were followed for 10,031 person-years; partners were followed for 8509 person-years. Among partners, 78 HIV-1 infections were observed during the trial (annual incidence, 0.9%; 95% confidence interval [CI], 0.7 to 1.1). Viral-linkage status was determined for 72 (92%) of the partner infections. Of these infections, 46 were linked (3 in the early-ART group and 43 in the delayed-ART group; incidence, 0.5%; 95% CI, 0.4 to 0.7) and 26 were unlinked (14 in the early-ART group and 12 in the delayed-ART group; incidence, 0.3%; 95% CI, 0.2 to 0.4). Early ART was associated with a 93% lower risk of linked partner infection than was delayed ART (hazard ratio, 0.07; 95% CI, 0.02 to 0.22). No linked infections were observed when HIV-1 infection was stably suppressed by ART in the index participant. CONCLUSIONS: The early initiation of ART led to a sustained decrease in genetically linked HIV-1 infections in sexual partners. (Funded by the National Institute of Allergy and Infectious Diseases; HPTN 052 ClinicalTrials.gov number, NCT00074581 .).

Tracing the origin of a singular HIV-1 CRF45_cpx clade identified in Brazil.

The HIV-1 epidemiology has changed over the past decade toward a marked increase in the circulation of strains previously restricted to local epidemics. Recent molecular epidemiological surveys identified some HIV-1 strains of probable African origin circulating in Brazil, including the Circulating Recombinant Form (CRF) 45_cpx, a complex A1/K/U recombinant that circulates in Central Africa. Here, we characterize partial genomic sequences and reconstruct the evolutionary history of HIV-1 CRF45_cpx-related recombinant samples identified in independent studies carried out with HIV+ individuals in Brazil. The sequences were obtained by overlapping PCR amplifications followed by direct sequencing. Recombination profiles were determined by phylogenetic and bootscaning analyses. The evolutionary history was estimated by a Bayesian coalescent-based method using datasets representing the gag, pol and env gene fragments. Six of the 10 samples isolated in Rio de Janeiro showed a CRF45_cpx-like pattern throughout the sequenced genome. The remaining were classified as second-generation recombinants, showing the mosaic patterns: CRF45_cpx/B/D/F1/U, CRF45_cpx/B/F1/U, CRF45_cpx/B/U and CRF45_cpx/F1. All Brazilian CRF45_cpx sequences, except one, formed a monophyletic clade (CRF45-BR), which seems to be the result of a single introduction event that has spread to the Rio de Janeiro, São Paulo and Minas Gerais states and is related to sequences from Argentina, Italy and Belgium. The Bayesian analyses pointed out quite consistent onset dates for CRF45-BR clade (~1984: 1976-1996) in the three gene datasets. These results indicate that the CRF45-BR clade has been circulating in the Southeastern Brazilian region for about 30years, although its presence was not detected until recently due to its very low prevalence. This reinforces the relevance of large-scale molecular surveillance data to identify the emergence of new HIV variants and their impact on local epidemics.

Zika Virus Infection in Pregnant Women in Rio de Janeiro.

BACKGROUND: Zika virus (ZIKV) has been linked to central nervous system malformations in fetuses. To characterize the spectrum of ZIKV disease in pregnant women and infants, we followed patients in Rio de Janeiro to describe clinical manifestations in mothers and repercussions of acute ZIKV infection in infants. METHODS: We enrolled pregnant women in whom a rash had developed within the previous 5 days and tested blood and urine specimens for ZIKV by reverse-transcriptase-polymerase-chain-reaction assays. We followed women prospectively to obtain data on pregnancy and infant outcomes. RESULTS: A total of 345 women were enrolled from September 2015 through May 2016; of these, 182 women (53%) tested positive for ZIKV in blood, urine, or both. The timing of acute ZIKV infection ranged from 6 to 39 weeks of gestation. Predominant maternal clinical features included a pruritic descending macular or maculopapular rash, arthralgias, conjunctival injection, and headache; 27% had fever (short-term and low-grade). By July 2016, a total of 134 ZIKV-affected pregnancies and 73 ZIKV-unaffected pregnancies had reached completion, with outcomes known for 125 ZIKV-affected and 61 ZIKV-unaffected pregnancies. Infection with chikungunya virus was identified in 42% of women without ZIKV infection versus 3% of women with ZIKV infection (P<0.001). Rates of fetal death were 7% in both groups; overall adverse outcomes were 46% among offspring of ZIKV-positive women versus 11.5% among offspring of ZIKV-negative women (P<0.001). Among 117 live infants born to 116 ZIKV-positive women, 42% were found to have grossly abnormal clinical or brain imaging findings or both, including 4 infants with microcephaly. Adverse outcomes were noted regardless of the trimester during which the women were infected with ZIKV (55% of pregnancies had adverse outcomes after maternal infection in the first trimester, 52% after infection in the second trimester, and 29% after infection in the third trimester). CONCLUSIONS: Despite mild clinical symptoms in the mother, ZIKV infection during pregnancy is deleterious to the fetus and is associated with fetal death, fetal growth restriction, and a spectrum of central nervous system abnormalities. (Funded by Ministério da Saúde do Brasil and others.).