Evidence of Zika Virus Reinfection by Genome Diversity and Antibody Response Analysis, Brazil.

We generated 238 Zika virus (ZIKV) genomes from 135 persons in Brazil who had samples collected over 1 year to evaluate virus persistence. Phylogenetic inference clustered the genomes together with previously reported ZIKV strains from northern Brazil, showing that ZIKV has been remained relatively stable over time. Temporal phylogenetic analysis revealed limited within-host diversity among most ZIKV-persistent infected associated samples. However, we detected unusual virus temporal diversity from >5 persons, uncovering the existence of divergent genomes within the same patient. All those patients showed an increase in neutralizing antibody levels, followed by a decline at the convalescent phase of ZIKV infection. Of interest, in 3 of those patients, titers of neutralizing antibodies increased again after 6 months of ZIKV infection, concomitantly with real-time reverse transcription PCR re-positivity, supporting ZIKV reinfection events. Altogether, our findings provide evidence for the existence of ZIKV reinfection events.

Long COVID-19 syndrome associated with Omicron XBB.1.5 infection: a case report.

BACKGROUND: There is interest in lingering non-specific symptoms after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, referred to as Long coronavirus disease 2019 (Long COVID-19). It remains unknown whether the risk of Long COVID-19 is associated with pre-existing comorbidities or initial COVID-19 severity, including infections due to new Omicron lineages which predominated in 2023. OBJECTIVES: The aim of this case report was to characterize the clinical features of acute XBB.1.5 infection followed by Long COVID-19. METHODS: We followed a 73-year old female resident of Rio de Janeiro with laboratory-confirmed SARS-CoV-2 during acute infection and subsequent months. The SARS-CoV-2 lineage was determined by genome sequencing. FINDINGS: The participant denied comorbidities and had completed a two-dose vaccination schedule followed by two booster doses eight months prior to SARS-CoV-2 infection. Primary infection by viral lineage XBB.1.5. was clinically mild, but the participant subsequently reported persistent fatigue. MAIN CONCLUSIONS: This case demonstrates that Long COVID-19 may develop even after mild disease due to SARS-CoV-2 in fully vaccinated and boosted individuals without comorbidities. Continued monitoring of new SARS-CoV-2 lineages and associated clinical outcomes is warranted. Measures to prevent infection should continue to be implemented including development of new vaccines and antivirals effective against novel variants.

Oral manifestations of COVID-19 in unvaccinated patients: a cross-sectional study.

BACKGROUND: Early studies have highlighted the possible development of dysgeusia and anosmia in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, and these manifestations should be considered a potential indication of coronavirus disease 19 (COVID-19). As potential contributors to these symptoms, dentists should perform careful oral and oropharyngeal examinations and document suspicious oral lesions in patients with COVID-19, especially in those who complain of loss of taste and smell. The study's objective was to assess the prevalence of oral manifestations among ambulatory unvaccinated symptomatic patients with suspected COVID-19 during the acute phase of the disease. METHODS: This cross-sectional study evaluated oral manifestations in adults (aged ≥ 18 years) with suspected and confirmed SARS-CoV-2 infection. Chi-square and Fisher's exact tests were used to compare data between the groups (rRT-PCR-positive and rRT-PCR-negative patients). RESULTS: One hundred thirty-six participants were included. Most were female (n = 79; 58.1%), with a mean age of 39.53 (± 14.17) years. Of these, 54 (39.7%) had a positive rRT-PCR test, and 82 (60.3%) had negative rRT-PCR results. Oral manifestations were observed in 40 participants (74.1%) in the rRT-PCR-positive group and 67 participants (81.7%) in the rRT-PCR-negative group. The most common oral manifestations were xerostomia (n = 85; 62.5%) and dysgeusia/ageusia (n = 57; 41.9%). Different rates of gingivitis (n = 12; 22.2% vs. n = 5; 6.1%; p = 0.005) and halitosis (n = 7; 13.0% vs. n = 1; 1.2%; p = 0.007) were observed between the rRT-PCR-positive and -negative groups, respectively. Mouth ulcers, glossitis, tongue coating, and petechiae were reported in both groups without significant differences. CONCLUSIONS: A high prevalence of oral manifestations was observed in symptomatic patients with suspected or confirmed COVID-19. CLINICAL RELEVANCE: This study highlights the importance of routine oral examinations by dentists as part of the multidisciplinary care of COVID-19 patients.

Myopericarditis associated with acute Zika virus infection: a case report.

BACKGROUND: Zika virus infection is commonly described as a mild and self-limiting illness. However, cardiac complications were associated with acute Zika virus infection. CASE PRESENTATION: A 46-year-old woman without previous comorbidities with a 1-day history of symptoms tested positive for ZIKV by real time reverse transcriptase polymerase chain reaction (rRT-PCR). She was admitted two days after with clinical worsening, cardiac enzymes elevated, and cardiac imaging findings, and the diagnosis of myopericarditis was made. The patient was treated and presented significant clinical improvement after one year. CONCLUSIONS: Cardiac complication following ZIKV infection appears to be infrequent. Here, we report a rare case of viral myopericarditis caused by ZIKV infection.

An initiative of cooperation in Zika virus research: the experience of the ZIKABRA study in Brazil.

BACKGROUND: The Zika virus outbreak has triggered a set of local and global actions for a rapid, effective, and timely public health response. A World Health Organization (WHO) initiative, supported by the Department of Chronic Condition Diseases and Sexually Transmitted Infections (DCCI) of the Health Surveillance Secretariat (SVS), Brazil Ministry of Health (MoH) and other public health funders, resulted in the start of the "Study on the persistence of Zika virus in body fluids of patients with ZIKV infection in Brazil - ZIKABRA study". The ZIKABRA study was designed to increase understanding of how long ZIKV persists in bodily fluids and informing best measures to prevent its transmission. Data collection began in July 2017 and the last follow up visit occurred in 06/26/2020. METHODS: A framework for the ZIKABRA Cooperation initiative is provided through a description and analysis of the mechanisms, strategies and the ethos that have guided the models of international governance and technical cooperation in health for scientific exchange in the context of a public health emergency. Among the methodological strategies, we included a review of the legal documents that supported the ZIKABRA Cooperation; weekly documents produced in the meetings and working sessions; technical reports; memorandum of understanding and the research protocol. CONCLUSION: We highlight the importance of working in cooperation between different institutional actors to achieve more significant results than that obtained by each group working in isolation. In addition, we point out the advantages of training activities, ongoing supervision, the construction of local installed research capacity, training academic and non-academic human resources, improvement of laboratory equipment, knowledge transfer and the availability of the ZIKABRA study protocol for development of similar studies, favoring the collective construction of knowledge to provide public health emergency responses. Strategy harmonization; human resources and health services; timing and recruiting particularities and processing institutional clearance in the different sites can be mentioned as challenges in this type of initiative.

Zika virus RNA excretion in sweat with concomitant detection in other body fluid specimens.

We evaluated sweat, blood and urine specimens obtained from an ongoing cohort study in Brazil. Samples were collected at pre-established intervals after the initial rash presentation and tested for Zika virus (ZIKV) RNA presence by real-time reverse transcriptase polymerase chain reaction (rRT-PCR). From 254 participants with confirmed infection, ZIKV RNA was detected in the sweat of 46 individuals (18.1%). Sweat presented a median cycle threshold (Ct) of 34.74 [interquartile range (IQR) 33.44-36.04], comparable to plasma (Ct 35.96 - IQR 33.29-36.69) and higher than urine (Ct 30.78 - IQR 28.72-33.22). Concomitant detection with other specimens was observed in 33 (72%) of 46 participants who had a positive result in sweat. These findings represent an unusual and not yet investigated virus shedding through eccrine glands.

Zika Virus in Rectal Swab Samples.

We detected Zika virus RNA in rectal swab samples from 10 patients by using real-time reverse transcription PCR, and we isolated the virus from 1 patient. The longest interval from symptom onset to detection was 14 days. These findings are applicable to diagnosis and infection prevention recommendations.

Study on the persistence of Zika virus (ZIKV) in body fluids of patients with ZIKV infection in Brazil.

BACKGROUND: Zika virus (ZIKV) has been identified in several body fluids of infected individuals. In most cases, it remained detected in blood from few days to 1 week after the onset of symptoms, and can persist longer in urine and in semen. ZIKV infection can have dramatic consequences such as microcephaly and Guillain-Barré syndrome. ZIKV sexual transmission has been documented. A better understanding of ZIKV presence and persistence across biologic compartments is needed to devise rational measures to prevent its transmission. METHODS: This observational cohort study will recruit non-pregnant participants aged 18 years and above with confirmed ZIKV infection [positive reverse transcriptase-polymerase chain reaction (RT-PCR) test in blood and/or urine]: symptomatic men and women in ZIKV infection acute phase, and their symptomatic or asymptomatic household/sexual infected contacts. Specimens of blood, urine, semen, vaginal secretion/menstrual blood, rectal swab, oral fluids, tears, sweat, urine and breast milk (if applicable) will be collected at pre-established intervals and tested for ZIKV RNA presence by RT-PCR, other co-infection (dengue, Chikungunya, HIV, hepatitis B and C, syphilis), antibody response (including immunoglobulins M and G), plaque reduction neutralization test (if simultaneously positive for ZIKV and dengue), and ZIKV culture and RNA sequencing. Data on socio-demographic characteristics and comorbidities will be collected in parallel. Participants will be followed up for 12 months. DISCUSSION: This prolonged longitudinal follow-up of ZIKV infected persons with regular biologic testing and data collection will offer a unique opportunity to investigate the presence and persistence of ZIKV in various biologic compartments, their clinical and immunological correlates as well as the possibility of ZIKV reactivation/reinfection over time. This valuable information will substantially contribute to the body of knowledge on ZIKV infection and serve as a base for the development of more effective recommendation on the prevention of ZIKV transmission. TRIAL REGISTRATION: NCT03106714 . Registration Date: April, 7, 2017.

Zika virus infection: epidemiology, clinical manifestations and diagnosis.

PURPOSE OF REVIEW: Zika virus (ZIKV) is an arbovirus previously believed to cause only a mild and self-limiting illness. Recently, it has emerged as a new public health threat that caused a large outbreak in French Polynesia in 2013-2014 and since 2015 an explosive outbreak in Brazil, with an increase in severe congenital malformations (microcephaly) and neurological complications, mainly Guillain-Barré syndrome (GBS). Since then, it has spread through the Americas. On 1 February 2016, the WHO declared the ZIKV epidemic in Brazil a Public Health Emergency of International Concern. We reviewed the epidemiology of ZIKV infection, clinical presentations and diagnosis. We highlighted the clinical features and nonvector borne transmission of the virus. RECENT FINDINGS: Association between ZIKV infection and severe foetal outcomes, including microcephaly and other birth defects; increased rate of GBS and other neurological complications due to the ongoing ZIKV outbreak; increased evidence to date of ZIKV being the only arbovirus linked to sexual transmission; the challenge of ZIKV diagnosis; and the need for a specific point-of care test in epidemic scenarios. SUMMARY: The findings illustrate the emergence of a viral disease with the identification of new associated disorders, new modes of transmission, including maternal-foetal and sexual transmission.

Predictors of early menopause in HIV-infected women: a prospective cohort study.

OBJECTIVE: This study sought to investigate the age at natural menopause and its predictors in a cohort of human immunodeficiency virus (HIV)-infected women in Rio de Janeiro, Brazil. STUDY DESIGN: HIV-infected women ≥30 years of age were included. Menopause was defined as having ≥1 year since the last menstrual period. Early age at natural menopause was defined as the onset of menopause at ≤45 years of age. Multivariate Cox proportional hazards analysis was applied. RESULTS: A total of 667 women were included, and the median age at baseline was 34.9 years (interquartile range, 30.9-40.5 years). In all, 507 (76%) women were premenopausal, and 160 (24%) reached menopause during the observational period; of these, 36 of 160 (27%) had early menopause. The median age at natural menopause was 48 years (interquartile range, 45-50 years). Menarche at <11 years of age (hazard ratio [HR], 2.03; 95% confidence interval [CI], 1.23-3.37), cigarette smoking during the observational period (HR, 1.59; 95% CI, 1.08-2.33), chronic hepatitis C virus (HCV) infection (HR, 2.53; 95% CI, 1.27-5.07), and CD4 count <50 cells/mm(3) (HR, 3.07; 95% CI, 1.07-8.80) were significantly associated with an earlier age at natural menopause. The magnitudes of the effects of menarche at <11 years of age (HR, 2.7; 95% CI, 1.23-5.94), cigarette smoking during the observational period (HR, 3.00; 95% CI, 1.39-6.45), chronic HCV infection (HR, 6.26; 95% CI, 2.12-18.52), and CD4 count <50 cells/mm(3) (HR, 6.64; 95% CI, 1.91-23.20) were much higher and significantly associated with early natural menopause. CONCLUSION: Early natural menopause was frequent among the HIV-infected women. In addition to menarche and cigarette smoking, which are menopausal factors among women in general, HIV-related immunodeficiency and chronic HCV were additional predictors for an earlier age at natural menopause. Adequate management of HIV in women is critical, as early onset of menopause has been associated with increased morbidity and mortality.

Viral shedding of SARS-CoV-2 in body fluids associated with sexual activity: a systematic review and meta-analysis.

OBJECTIVE: To identify and summarise the evidence on the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA detection and persistence in body fluids associated with sexual activity (saliva, semen, vaginal secretion, urine and faeces/rectal secretion). ELIGIBILITY: All studies that reported detection of SARS-CoV-2 in saliva, semen, vaginal secretion, urine and faeces/rectal swabs. INFORMATION SOURCES: The WHO COVID-19 database from inception to 20 April 2022. RISK OF BIAS ASSESSMENT: The National Institutes of Health tools. SYNTHESIS OF RESULTS: The proportion of patients with positive results for SARS-CoV-2 and the proportion of patients with a viral duration/persistence of at least 14 days in each fluid was calculated using fixed or random effects models. INCLUDED STUDIES: A total of 182 studies with 10 023 participants. RESULTS: The combined proportion of individuals with detection of SARS-CoV-2 was 82.6% (95% CI: 68.8% to 91.0%) in saliva, 1.6% (95% CI: 0.9% to 2.6%) in semen, 2.7% (95% CI: 1.8% to 4.0%) in vaginal secretion, 3.8% (95% CI: 1.9% to 7.6%) in urine and 31.8% (95% CI: 26.4% to 37.7%) in faeces/rectal swabs. The maximum viral persistence for faeces/rectal secretions was 210 days, followed by semen 121 days, saliva 112 days, urine 77 days and vaginal secretions 13 days. Culturable SARS-CoV-2 was positive for saliva and faeces. LIMITATIONS: Scarcity of longitudinal studies with follow-up until negative results. INTERPRETATION: SARS-CoV-2 RNA was detected in all fluids associated with sexual activity but was rare in semen and vaginal secretions. Ongoing droplet precautions and awareness of the potential risk of contact with faecal matter/rectal mucosa are needed. PROSPERO REGISTRATION NUMBER: CRD42020204741.

Paracoccidioidomycosis and pregnancy: A 40-year single-center cohort study in the endemic area of Rio de Janeiro, Brazil.

The occurrence of acute paracoccidioidomycosis (PCM) in urban areas of the Rio de Janeiro state, Brazil, has emerged in recent years. Therefore, young populations, including pregnant women, are at a higher risk of infection. Furthermore, young women undergoing itraconazole treatment for PCM have increased chances to get pregnant because this medication may reduce the effectiveness of contraceptives. Acute PCM is invasive, reaching abdominal organs, posing a maternal-fetal risk. PCM treatment in pregnant women is also challenging due to the teratogenicity associated with the currently available oral drugs. There are scarce studies on PCM and pregnancy, mainly consisting of case reports and experimental murine models that highlight the severity of this association. We conducted a database research at a PCM reference center in Rio de Janeiro state from 1980 to 2020. We included patients diagnosed with PCM who were pregnant shortly before, at admission, or at any moment of their PCM follow-up care. Data related to pregnancy, childbirth, and the newborn were obtained from the Brazilian official public databases. We also reviewed the epidemiological and clinical features of these patients. During the study period, we identified 18 pregnant patients, with a median age of 26 years (range: 16-38). Among these cases, six (33.3%) were detected in the last 5 years, and 14 (77.8%) presented acute PCM, supporting the recent shift in the epidemiological profile towards acute PCM. Most pregnancies occurred during PCM treatment (n = 11, 61.1%), which led to challenges in the therapeutic management. Maternal-fetal complications occurred in some of these cases, including vaginal bleeding (n = 1), preeclampsia (n = 1), prematurity (n = 2), low birth weight (n = 4), and fetal deaths (n = 2). PCM during pregnancy presents a significant public health concern in the context of the emergence of acute PCM in urban areas.

Challenges of acute febrile illness diagnosis in a national infectious diseases center in Rio de Janeiro: 16-year experience of syndromic surveillance.

INTRODUCTION: Acute febrile illnesses (AFI) are a frequent chief complaint in outpatients. Because the capacity to investigate the causative pathogen of AFIs is limited in low- and middle-income countries, patient management may be suboptimal. Understanding the distribution of causes of AFI can improve patient outcomes. This study aims to describe the most common etiologies diagnosed over a 16-years period in a national reference center for tropical diseases in a large urban center in Rio de Janeiro, Brazil. METHODS: From August 2004-December 2019, 3591 patients > 12 years old, with AFI and/or rash were eligible. Complementary exams for etiological investigation were requested using syndromic classification as a decision guide. Results. Among the 3591 patients included, endemic arboviruses such as chikungunya (21%), dengue (15%) and zika (6%) were the most common laboratory-confirmed diagnosis, together with travel-related malaria (11%). Clinical presumptive diagnosis lacked sensitivity for emerging diseases such as zika (31%). Rickettsia disease and leptospirosis were rarely investigated and an infrequent finding when based purely on clinical features. Respiratory symptoms increased the odds for the diagnostic remaining inconclusive. CONCLUSIONS: Numerous patients did not have a conclusive etiologic diagnosis. Since syndromic classification used for standardization of etiological investigation and presumptive clinical diagnosis had moderate accuracy, it is necessary to incorporate new diagnostic technologies to improve diagnostic accuracy and surveillance capacity.

Detection and persistence of Zika virus in body fluids and associated factors: a prospective cohort study.

This study aimed to analyze the detection and duration of the Zika virus (ZIKV) in plasma, urine, saliva, sweat, rectal swabs, vaginal secretions, breast milk, and semen and to explore risk factors associated with prolonged viral persistence. A prospective cohort study of symptomatic patients and their household contacts was conducted in Brazil from July 2017 to June 2019. A total of 260 individuals (184 women and 76 men) with confirmed ZIKV infection were enrolled and followed up for 12 months. ZIKV RNA was present in all body fluid specimens and detectable for extended periods in urine, sweat, rectal swabs, and semen. The longest detection duration was found in semen, with high viral loads in the specimens. ZIKV RNA clearance was associated with several factors, including age, sex, education level, body mass index, non-purulent conjunctivitis, joint pain, and whether the participant had a history of yellow fever vaccination. The influence of each of these factors on the low or fast viral clearance varied according to the specific body fluid under investigation. Recurrent ZIKV detection events after total viral clearance were observed in the cohort. Our findings provide valuable insights into the persistence and potential recurrence of ZIKV infection, highlighting the need for continued monitoring and follow-up of individuals infected with ZIKV and for effective prevention measures to reduce the risk of transmission.

Zika-specific neutralizing antibodies targeting inter-dimer envelope epitopes.

Zika virus (ZIKV) is an emerging pathogen that causes devastating congenital defects. The overlapping epidemiology and immunologic cross-reactivity between ZIKV and dengue virus (DENV) pose complex challenges to vaccine design, given the potential for antibody-dependent enhancement of disease. Therefore, classification of ZIKV-specific antibody targets is of notable value. From a ZIKV-infected rhesus macaque, we identify ZIKV-reactive B cells and isolate potent neutralizing monoclonal antibodies (mAbs) with no cross-reactivity to DENV. We group these mAbs into four distinct antigenic groups targeting ZIKV-specific cross-protomer epitopes on the envelope glycoprotein. Co-crystal structures of representative mAbs in complex with ZIKV envelope glycoprotein reveal envelope-dimer epitope and unique dimer-dimer epitope targeting. All four specificities are serologically identified in convalescent humans following ZIKV infection, and representative mAbs from all four groups protect against ZIKV replication in mice. These results provide key insights into ZIKV-specific antigenicity and have implications for ZIKV vaccine, diagnostic, and therapeutic development.

Cohort-profile: Household transmission of SARS-CoV-2 in a low-resource community in Rio de Janeiro, Brazil.

PURPOSE: To better understand the household transmission of SARS-COV-2 in a low-resource community in Rio de Janeiro during the COVID-19 pandemic (2020-2022). PARTICIPANTS: This is an open prospective cohort study of children ≤12 years old and their household contacts. During home visits over 24 months, we collected data on sociodemographic characteristics, behavioural data, clinical manifestations of SARS-CoV-2, vaccination status, SARS-CoV-2 (reverse transcription-polymerase chain reaction) RT-PCR and anti-S antibody tests. Among adults, the majority of participants were women (62%). FINDINGS TO DATE: We enrolled 845 families from May 2020 to May 2022. The median number of residents per household was four. The median household density, defined as the number of persons per room, was 0.95. The risk of SARS-CoV-2 occurrence was higher in households with a high number of persons per room. Children were not the principal source of SARS-CoV-2 infections in their households during the first wave of the pandemic. FUTURE PLANS: Future studies will investigate cellular and humoral immune responses to locally circulating SARS-CoV-2 variants, which is relevant for the design of vaccines, antivirals and monoclonal antibodies. We will also engage in outreach to encourage vaccination as a means of limiting the transmission of novel SARS-CoV-2 variants and other emerging pathogens.

Beyond arboviruses: A multicenter study to evaluate differential diagnosis of rash diseases and acute febrile illness cases in Rio de Janeiro, Brazil.

INTRODUCTION: A wide variety of viruses can cause rash diseases (RDs) or acute febrile illness (AFIs) in children, adolescents and adults; however, approximately 19% of RD cases and 40% of AFI cases remain without a defined etiology. Parvovirus B19 (B19V) and herpesvirus infection can also cause RD and/or AFI, and in some risk groups, these infections can become persistent (or latent) and may require hospital treatment. Since these infections do not have mandatory reporting, they can be hidden by other diseases, such as those caused by arboviruses (e.g., dengue virus). In this context, the aim of this study was to pursue the differential laboratory diagnoses of B19V and herpesvirus infections in patients with RD and AFI, without a defined etiology, seen in hospitals and/or reference centers for infectious diseases in Rio de Janeiro. METHODS: A total of 114 participants were enrolled in the study, including 54 children and 60 adults. B19V infection was assessed by real-time PCR (qPCR) and ELISA (anti-B19V IgM and IgG). EBV was assessed through qPCR, and betaherpesviruses (HCMV, HHV-6 and HHV-7) were assessed through multiplex qPCR. Sociodemographic and clinical data were obtained from the medical record data of these participants. RESULTS: The median age of children with RD was 2 years (interquartile range (IQR): 5), and 55.6% were male. Among adults with AFI, the median age was 38 years (IQR: 21), and 56.7% were female. Regarding RD patients, viral prevalence (and load) were 5.5%(104IU/mL), 3.4%(104IU/mL), 5.5%(104IU/mL) and 11.1%(105IU/mL) for B19V, EBV, HCMV and HHV-6 infection, respectively, and in AFI patients they were 6.6%(105IU/mL), 1.6%(103IU/mL), 3.3%(104IU/mL) for B19V, HCMV and HHV-6, respectively. HHV-7 was not detected in RD or AFI patients. CONCLUSION: These results suggest the importance of including B19V and herpesviruses in the differential laboratory diagnoses for patients with RD and AFI, not only for epidemiological purposes but also for the proper management of the patient.

Fatal Brazilian spotted fever in a healthy military man during field training in Rio de Janeiro city, southeastern Brazil.

Brazilian spotted fever, a zoonotic disease transmitted by ticks, is caused by Rickettsia rickettsii. We report a fulminant case of this zoonosis in a healthy 46-year-old military man in the urban region of Rio de Janeiro city, in October, 2021. Ticks and capybaras (Amblyomma sculptum, Hydrochoerus hydrochaeris, respectively) were identified in the military fields, pointing to the participation of this large synanthropic rodent, recognized as an efficient amplifier host of Rickettsia rickettsii in Brazil. As the military population is considered a risk group for spotted fever, it is necessary to alert health professionals to the importance of the early detection of the disease and its adequate management, mainly in populations that are particularly at risk of exposure to ticks, in order to avoid fatal outcomes.

Cohort profile: Study on Zika virus infection in Brazil (ZIKABRA study).

Zika virus (ZIKV) has been detected in blood, urine, semen, cerebral spinal fluid, saliva, amniotic fluid, and breast milk. In most ZIKV infected individuals, the virus is detected in the blood to one week after the onset of symptoms and has been found to persist longer in urine and semen. To better understand virus dynamics, a prospective cohort study was conducted in Brazil to assess the presence and duration of ZIKV and related markers (viral RNA, antibodies, T cell response, and innate immunity) in blood, semen, saliva, urine, vaginal secretions/menstrual blood, rectal swab and sweat. The objective of the current manuscript is to describe the cohort, including an overview of the collected data and a description of the baseline characteristics of the participants. Men and women ≥ 18 years with acute illness and their symptomatic and asymptomatic household contacts with positive reverse transcriptase-polymerase chain reaction test for ZIKV in blood and/or urine were included. All participants were followed up for 12 months. From July 2017 to June 2019, a total of 786 participants (284 men, 502 women) were screened. Of these, 260 (33.1%) were enrolled in the study; index cases: 64 men (24.6%), 162 (62.3%) women; household contacts: 12 men (4.6%), 22 (8.5%) women. There was a statistically significant difference in age and sex between enrolled and not enrolled participants (p<0.005). Baseline sociodemographic and medical data were collected at enrollment from all participants. The median and interquartile range (IQR) age was 35 (IQR; 25.3, 43) for men and 36.5 years (IQR; 28, 47) for women. Following rash, which was one of the inclusion criteria for index cases, the most reported symptoms in the enrollment visit since the onset of the disease were fever, itching, arthralgia with or without edema, non-purulent conjunctivitis, headache, and myalgia. Ten hospitalizations were reported by eight patients (two patients were hospitalized twice) during follow up, after a median of 108 days following symptom onset (range 7 to 266 days) and with a median of 1.5 days (range 1 to 20 days) of hospital stay. A total of 4,137 visits were performed, 223 (85.8%) participants have attended all visits and 37 (14.2%) patients were discontinued.