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Approximately one-third of people with chronic Trypanosoma cruzi infection develop Chagas cardiomyopathy, which carries a poor prognosis. Accurate prediction of which individuals will go on to develop Chagas cardiomyopathy remains elusive. We performed a systematic review of literature comparing characteristics of individuals with chronic Chagas disease with or without evidence of cardiomyopathy. Studies were not excluded on the basis of language or publication date. Our review yielded a total of 311 relevant publications. We further examined the subset of 170 studies with data regarding individual age, sex, or parasite load. A meta-analysis of 106 eligible studies indicated that male sex was associated with having Chagas cardiomyopathy (Hedge’s g: 1.56, 95% CI: 1.07–2.04), and a meta-analysis of 91 eligible studies indicated that older age was associated with having Chagas cardiomyopathy (Hedge’s g: 0.66, 95% CI: 0.41–0.91). A meta-analysis of four eligible studies did not find an association between parasite load and disease state. This study provides the first systematic review to assess whether age, sex, and parasite load are associated with Chagas cardiomyopathy. Our findings suggest that older and male patients with Chagas disease are more likely to have cardiomyopathy, although we are unable to identify causal relationships due to the high heterogeneity and predominantly retrospective study designs in the current literature. Prospective, multidecade studies are needed to better characterize the clinical course of Chagas disease and identify risk factors for progression to Chagas cardiomyopathy.

BackgroundThe natural history of SARS-CoV-2 infection and transmission dynamics may have changed as SARS-CoV-2 has evolved and population immunity has shifted.MethodsHousehold contacts, enrolled from two multi-site case-ascertained household transmission studies (April 2020–April 2021 and September 2021–September 2022), were followed for 10–14 days after enrollment with daily collection of nasal swabs and/or saliva for SARS-CoV-2 testing and symptom diaries. SARS-CoV-2 virus lineage was determined by whole genome sequencing, with multiple imputation where sequences could not be recovered. Adjusted infection risks were estimated using modified Poisson regression.Findings858 primary cases with 1473 household contacts were examined. Among unvaccinated household contacts, the infection risk adjusted for presence of prior infection and age was 58% (95% confidence interval [CI]: 49–68%) in households currently exposed to pre-Delta lineages and 90% (95% CI: 74–100%) among those exposed to Omicron BA.5 (detected May – September 2022). The fraction of infected household contacts reporting any symptom was similarly high between pre-Delta (86%, 95% CI: 81–91%) and Omicron lineages (77%, 70–85%). Among Omicron BA.5-infected contacts, 48% (41–56%) reported fever, 63% (56–71%) cough, 22% (17–28%) shortness of breath, and 20% (15–27%) loss of/change in taste/smell.InterpretationThe risk of infection among household contacts exposed to SARS-CoV-2 is high and increasing with more recent SARS-CoV-2 lineages. This high infection risk highlights the importance of vaccination to prevent severe disease.FundingFunded by the Centers for Disease Control and Prevention and the Food and Drug Administration.Key points-Monitoring the transmissibility and symptomatology of SARS-CoV-2 lineages is important for informing public health practice and understanding the epidemiology of COVID-19; household transmission studies contribute to our understanding of the natural history of SARS-CoV-2 infections and the transmissibility of SARS-CoV-2 variants.-The Omicron BA.5 sub-lineage is highly transmissible, similar to previous Omicron sub-lineages.-Over 80% of infected household contacts reported at least 1 symptom during their infection and the proportion of household contacts with asymptomatic infection did not differ by SARS-CoV-2 variant. The most common symptom was cough. Change in taste or smell was more common in Omicron BA.5 infections, compared to previous Omicron sub-lineages, but less common compared to pre-Delta lineages.-The high infection risk among household contacts supports the recommendations that individuals maintain up-to-date and lineage-specific vaccinations to mitigate further risks of severe disease.

Background Racial and ethnic minorities have borne a disproportionate burden from COVID-19. Certain essential occupations, including food processing and farm work, employ large numbers of Hispanic migrant workers and have been shown to carry an especially high risk of infection. Methods We conducted an observational cohort study measuring the seroprevalence of SARS-CoV-2 and assessing risk factors for seropositivity among North Carolina food processing and farm workers and members of their households. Participants completed questionnaires and we collected blood samples and used an enzyme-linked immunosorbent assay to assess SARS-CoV-2 seropositivity. Univariate and multivariate analyses were carried out to identify risk factors associated with seropositivity, using generalized estimating equations to account for household clustering. Findings Among the 218 participants, 94.5% were Hispanic, and SARS-CoV-2 seropositivity was 50.0%. Most seropositive individuals did not report a history of illness compatible with COVID-19. Attending church, having a prior history of COVID-19, having a seropositive household member, and speaking Spanish as one's primary language were associated with SARS-CoV-2 seropositivity, while preventive behaviors were not. Interpretation These findings underscore the substantial burden of COVID-19 among a population of mostly Hispanic essential workers and their households in rural North Carolina. Our study contributes to a large body of evidence showing that Hispanic Americans have suffered a disproportionate COVID-19 burden. We also highlight the epidemiologic importance of viral transmission within the household.

Knowledge regarding the frequency of ocular abnormalities and abnormal visual function in children exposed to Zika virus (ZIKV) in utero but born without congenital Zika syndrome (CZS) is limited. We hypothesized that children exposed to ZIKV in utero born without CZS may have visual impairments in early childhood. We performed ophthalmic examination between 16 and 21 months of age and neurodevelopment assessment at 24 months of age with the Mullen Scales of Early Learning test (MSEL) on children enrolled in a cohort born to women pregnant during and shortly after the ZIKV epidemic in Nicaragua (2016–2017). ZIKV exposure status was defined based on maternal and infant serological testing. Visual impairment was defined as abnormal if the child had an abnormal ophthalmic exam and/or low visual reception score in the MSEL assessment. Of 124 children included in the analysis, 24 (19.4%) were classified as ZIKV-exposed and 100 (80.6%) unexposed according to maternal or cord blood serology. Ophthalmic examination showed that visual acuity did not differ significantly between groups, thus, 17.4% of ZIKV-exposed and 5.2% of unexposed had abnormal visual function (p = 0.07) and 12.5% of the ZIKV-exposed and 2% of the unexposed had abnormal contrast testing (p = 0.05). Low MSEL visual reception score was 3.2-fold higher in ZIKV-exposed than unexposed children, but not statistically significant (OR 3.2, CI: 0.8–14.0; p = 0.10). Visual impairment (a composite measure of visual function or low MESL visual reception score) was present in more ZIKV-exposed than in unexposed children (OR 3.7, CI: 1.2, 11.0; p = 0.02). However, the limited sample size warrants future investigations to fully assess the impact of in utero ZIKV exposure on ocular structures and visual function in early childhood, even in apparently healthy children.

The mechanism of vertical transmission of Trypanosoma cruzi is poorly understood. In this study, we evaluated the role of IgG subclasses in the congenital transmission of Chagas disease. We conducted a case-control study in a public maternity hospital in Santa Cruz, Bolivia, enrolling women at delivery. Thirty women who transmitted T. cruzi to their newborns (cases), and 51 women who did not (controls) were randomly selected from 676 total seropositive women. Trypanosoma cruzi–specific IgG1, IgG2, and IgG3 levels were measured by in-house ELISA. The IgG4 levels were unmeasurable as a result of low levels in all participants. Quantitative polymerase chain reaction results and demographic factors were also analyzed. One-unit increases in normalized absorbance ratio of IgG1 or IgG2 levels increased the odds of congenital T. cruzi transmission in Chagas-seropositive women by 2.0 (95% CI: 1.1–3.6) and 2.27 (95% CI: 0.9–5.7), adjusted for age and previous blood transfusion. Odds of congenital transmission were 7.0 times higher in parasitemic mothers (95% CI: 2.3–21.3, P < 0.01) compared with nonparasitemic mothers. We observed that all mothers with IgG1 ≥ 4 were transmitters (sensitivity = 20%, specificity = 100%). Additionally, no mothers with IgG2 < 1.13 were transmitters (sensitivity = 100%, specificity = 21.6%). We demonstrated that IgG subclasses and parasite presence in blood are associated with vertical transmission of T. cruzi and could identify women at increased risk for congenital transmission by measuring IgG subclasses. These measures have potential as objective screening tests to predict the congenital transmission of Chagas.

The American Zika virus (ZIKV) epidemic has highlighted the need to gain a better understanding of this emerging virus. The goal of this study was to describe the clinical symptoms, laboratory findings, and risk factors for symptomatic ZIKV infection in an area with ongoing transmission of other arboviral infections. We recruited patients at least 2 years of age seeking care at public health centers in León, Nicaragua, between January 2016 and August 2017, for fever, maculopapular rash, and/or nonsuppurative conjunctivitis with a duration of less than 1 week. A laboratory diagnosis of ZIKV was established using a combination of molecular and serological tests. Clinical and laboratory findings and potential risk factors were compared between participants with and without acute ZIKV infection. Fifty-eight (26%) of the 225 participants included in the analysis were found to have acute ZIKV infection. Pregnancy and reports of previous arboviral infection were associated with a higher risk of ZIKV infection. Rash, conjunctivitis, sore throat, and lower absolute neutrophil counts were associated with acute ZIKV infection. The clinical characteristics and risk factors identified were consistent with those identified by previous studies; however, we found sore throat to be a feature of ZIKV infection. We also found that neutrophil counts were lower in ZIKV-infected subjects. These clinical symptoms and laboratory data may help clinicians suspect ZIKV infection during future outbreaks.

Background After initiation of antiviral therapy (ART), plasma HIV-1 RNA is usually undetectable after one month. In rare cases, viral suppression may not be achieved despite good adherence and with virus susceptible to ART. We used ultra-deep Primer ID next gen sequencing (NGS) to study the viral population and evolution of HIV-1 in two patients with persistent viremia on intensive ART. Methods We extracted viral RNA from plasma samples collected at multiple timepoints over the duration of the treatment from two patients (VEX1 and VEX2). We constructed Primer ID NGS libraries covering part of the pol gene and the env V1/V3 region and sequenced them on the Illumina MiSeq platform. We used the ‘tcs’ pipeline to construct template consensus sequences (TCS) for each region, and searched for drug resistance mutations (DRMs). The Geno2pheno pipeline was used to predict co-receptor tropisms. Results Patient VEX1 was followed for two years on ART. VEX2 restarted ART in the hospital and received directly observed therapy for nearly 6 months. Both had over 1 million viral copies/mL at the initiation of ART, and the CD4 cell counts were extremely low. Their viral loads slowly declined to approx. 10,000 copies/mL at the end of follow-up but complete viral suppression was not achieved for either patient despite appropriate ART. DRMs were not detected in either patient throughout the treatment with detection sensitivity as low as 0.1%. The sequencing results for VEX1 showed that there were both X4- and R5-tropic viruses at all timepoints and R5 viruses decayed much more slowly than X4 viruses, up to 35-fold more slowly in the initial 3 months of ART. Phylogenetic analysis revealed that the persistent R5 viruses were largely clonal while little clonality was found in the persistent X4 virus. In VEX2, all viruses were R5-tropic. There were three major distinct lineages in the viral population, and two of them completely disappeared after the initiation of ART while the other lineage persisted throughout therapy (Fig 1). The persistent lineage in VEX2 was highly clonal. Pooled maximum likelihood tree at env V1V3 region of 3 time points from patient VEX2. Sequences in red were from 2018 when we obtained the initial specimen from the patient. Sequences in blue were from Sept 2021 when the patient restarted ART. Sequences in green were from Oct 2021 when the patient were on ART for 3 weeks. The patient had 3 major viral lineages, L1, L2, and L3. From 2018 to Sept 2021, we could see the viral evolution of the three lineages (blue arrows). After 3 weeks of ART, L1 and L2 disappeared, while the L3 persisted. We could also see that L3 had several clonal populations which did not respond to ART nor evolve from 2018 to 2021. The additional sequences from Nov 2021 to Feb 2022 were identical to the sequences obtained on Oct 2021 (not shown on this figure). Conclusion Our study shows that persistent viremia on ART can come from clonal viral lineages that carry no DRMs. Clonally expanded and infected host cells might contribute to the phenomenon. Further study is needed to explore the origin of these clonal viral genomes. Disclosures Jonathan Parr, MD, Abbott Laboratories: Donation of laboratory testing and reagents|Gilead Sciences: Grant/Research Support|Virology Education: Honoraria|World Health Organization: Advisor/Consultant|World Health Organization: Grant/Research Support David A. Wohl, M.D., Gilead: Advisor/Consultant|Gilead: Grant/Research Support|Janssen: Advisor/Consultant|Lilly: Grant/Research Support|Merck: Grant/Research Support|ViiV: Advisor/Consultant|ViiV: Grant/Research Support Joseph J. Eron, MD, Adagio Therapeutics: data safety monitoring committee|Gilead Sciences: Advisor/Consultant|Gilead Sciences: Grant/Research Support|Glaxo Smith Kline: Advisor/Consultant|Merck: Advisor/Consultant|ViiV Healthcare: Advisor/Consultant|ViiV Healthcare: Grant/Research Support.

To characterize the timing and genotype distribution of symptomatic and asymptomatic sapovirus infections and re-infections in a Nicaraguan birth cohort.Infants (N = 444) were enrolled at 10-14 days of life and observed weekly until 2 years of age. Stool samples were collected for each acute gastroenteritis (AGE) episode, and routine stool samples were collected monthly. Stool samples were tested for sapovirus using RT-qPCR, and positive samples were genotyped.A total of 348 children completed 2 years of AGE weekly surveillance; 93 (26.7%) of them experienced sapovirus AGE. Most infections occurred after 5 months of age and mainly during the second year of life (62.4%, 58/93) and early in the rainy season. Sapovirus screening in all stools from a subset of 67 children who consistently provided samples showed sapovirus infections in 91 of 330 (27.6%) AGE episodes and in 39 of 1350 (2.9%) routine stools. In this subset, the median age at the first sapovirus AGE was 11.2 months (95% CI, 9.3-15.9 months); 38 of 67 (57%) children experienced re-infections, 19 symptomatic and 19 asymptomatic. On average, sapovirus re-infections were reported 7.2 months after symptomatic and 5.3 months after asymptomatic infections. Genogroup GI (64%, 69/108) was the most common detected. Sapovirus GI.1 was more frequently detected in AGE stool samples than in routine stool samples (47.2%, 43/91 vs. 25.6%, 10/39; p 0.005), and re-infection with the same genotype was uncommon.The first sapovirus infections occurred at approximately 11 months of age, whereas the median time to symptomatic re-infection was 7.2 months. Re-infections with the same sapovirus genotype were rare during 2 years of life suggesting genotype-specific protection after natural infection.

Background Vertical transmission of Trypanosoma cruzi infection from mother to infant accounts for a growing proportion of new cases of Chagas disease. However, no systematic reviews of risk factors for T. cruzi vertical transmission have been performed. Methods We performed a systematic review of the literature in PubMed, LILACS, and Embase databases, following PRISMA guidelines. Studies were not excluded based on language, country of origin, or date of publication. Results Our literature review yielded 27 relevant studies examining a wide variety of risk factors, including maternal age, parasitic load, immunologic factors, vector exposure, and more. Several studies suggested that mothers with higher parasitic loads may have a greater risk of vertical transmission, and a meta-analysis of two studies found a significantly higher parasitic load among transmitting than non-transmitting mothers with T. cruzi infection. A second meta-analysis of ten studies demonstrated that maternal age was not significantly associated with vertical transmission risk. Conclusions The current literature suggests that high maternal parasitic load may be a risk factor for congenital Chagas disease among infants of T. cruzi seropositive mothers. Given the considerable heterogeneity and risk of bias among current literature, additional studies are warranted to assess potential risk factors for vertical transmission of T. cruzi infection.

Background: Sapovirus is increasingly recognized as an important cause of acute gastroenteritis (AGE) in children. We identified risk factors and characterized the clinical profile of sapovirus AGE in a birth cohort in León, Nicaragua. Methods: We conducted a case-control study nested within a birth cohort (n = 444). Fieldworkers conducted weekly household AGE surveillance. AGE stools were tested for sapovirus by reverse transcriptase quantitative polymerase chain reaction. For each first sapovirus episode, we selected 2 healthy age-matched controls and estimated independent risk factors of sapovirus AGE using conditional logistic regression. We compared clinical characteristics of sapovirus AGE episodes with episodes associated with other etiologies and identified co-infections with other enteric pathogens. Results: From June 2017 to July 2019, we identified 63 first sapovirus AGE episodes and selected 126 controls. Having contact with an individual with AGE symptoms and vaginal delivery were independent risk factors for sapovirus AGE. All cases experienced diarrhea, lasting a median 6 days; 23% experienced vomiting. Compared with children with AGE due to another etiology, sapovirus AGE was similar in severity, with less reported fever. Most cases experienced co-infections and were more likely than controls to be infected with diarrheagenic Escherichia coli or astrovirus. Conclusions: Sapovirus was a commonly identified AGE etiology in this Central American setting, and symptoms were similar to AGE associated with other etiologies. The association between vaginal delivery and sapovirus is a novel finding. Gut microbiome composition might mediate this relationship, or vaginal delivery might be a proxy for other risk factors. Further investigation into more specific biological mechanisms is warranted.

Background Neurodevelopmental outcomes of asymptomatic children exposed to Zika virus (ZIKV) in utero are not well characterized. Methods We prospectively followed 129 newborns without evidence of congenital Zika syndrome (CZS) up to 24 months of age. Participants were classified as ZIKV exposed or ZIKV unexposed. The Mullen Scales of Early Learning (MSEL) was administered in the participants’ homes at 6, 12, 15, 18, 21, and 24 months of age by trained psychologists. Sociodemographic data, medical history, and infant anthropometry at birth were collected at each home visit. Our primary outcome was the Mullen Early Learning Composite Score (ECL) at 24 months of age between our 2 exposure groups. Secondary outcomes were differences in MSEL subscales over time and at 24 months. Results Of 129 infants in whom exposure status could be ascertained, 32 (24.8%) met criteria for in utero ZIKV exposure and 97 (75.2%) did not. There were no differences in maternal age, maternal educational attainment, birthweight, or gestational age at birth between the 2 exposure groups. The adjusted means and standard errors (SEs) for the ELC score between the ZIKV-exposed children compared to ZIKV-unexposed children were 91.4 (SE, 3.1) vs 96.8 (SE, 2.4) at 12 months and 93.3 (SE, 2.9) vs 95.9 (SE, 2.3) at 24 months. In a longitudinal mixed model, infants born to mothers with an incident ZIKV infection (P = .01) and low-birthweight infants (, Children with in utero Zika virus exposure and without congenital Zika syndrome in Nicaragua had lower neurocognitive scores at 24 months. Our study includes multiple evaluations over time and a contemporary nonexposed comparator group of children, which is currently lacking in the literature.

Background Global efforts are needed to elucidate the epidemiology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the underlying cause of coronavirus disease 2019 (COVID-19), including seroprevalence, risk factors, and long-term sequelae, as well as immune responses after vaccination across populations and the social dimensions of prevention and treatment strategies. Methods In the United States, the National Cancer Institute in partnership with the National Institute of Allergy and Infectious Diseases, established the SARS-CoV-2 Serological Sciences Network (SeroNet) as the nation’s largest coordinated effort to study coronavirus disease 2019. The network comprises multidisciplinary researchers bridging gaps and fostering collaborations among immunologists, epidemiologists, virologists, clinicians and clinical laboratories, social and behavioral scientists, policymakers, data scientists, and community members. In total, 49 institutions form the SeroNet consortium to study individuals with cancer, autoimmune disease, inflammatory bowel diseases, cardiovascular diseases, human immunodeficiency virus, transplant recipients, as well as otherwise healthy pregnant women, children, college students, and high-risk occupational workers (including healthcare workers and first responders). Results Several studies focus on underrepresented populations, including ethnic minorities and rural communities. To support integrative data analyses across SeroNet studies, efforts are underway to define common data elements for standardized serology measurements, cellular and molecular assays, self-reported data, treatment, and clinical outcomes. Conclusions In this paper, we discuss the overarching framework for SeroNet epidemiology studies, critical research questions under investigation, and data accessibility for the worldwide scientific community. Lessons learned will help inform preparedness and responsiveness to future emerging diseases.

BackgroundKnock-down resistance (kdr) mutations in the voltage gated sodium channel gene of Aedes species mosquitoes are biomarkers for resistance to pyrethroid insecticides. In the United States, few studies have reported kdr mutations among Aedes albopictus(family: Culicidae, order: Diptera, Skuse, 1895) populations. In this study we sought to explore the potential for permethrin-impregnated uniforms worn by military servicemembers to drive kdr emergence.Methods and ResultsWe collected 538 Aedes albopictus mosquitoes, including 156 from 4 sites at Fort Bragg (exposed), North Carolina and 382 from 15 sites in Wake County (control), North Carolina to compare the prevalence of kdr mutations. Of those successfully sequenced, we identified 12 (3.0%) mosquitoes with kdr mutations, all of which were attributed to variants at position 1534 within domain 3. All mutations were found in mosquitoes collected at Wake County sites; no mutations were identified at Fort Bragg. There was a focus of mutations observed at the Wake County sites with approximately 92% (11 of 12) of the mosquitoes with the mutation coming from one site, where kdr mutations represented 24.4% (11 of 45) of all mosquitoes collected.ConclusionsOur study did not show any evidence that universal implementation of permethrin-impregnated uniforms drives the development of resistance. In contrast, we observed highly focal resistance in a suburban area of Raleigh, which may be attributable to peri-domestic mosquito control activities that involve area dispersal of pyrethroid insecticides. More robust surveillance is needed to monitor the emergence and spread of resistance.AUTHOR SUMMARYResistance to commonly employed insecticides among Aedes albopictus(family: Culicidae, order: Diptera, Skuse, 1895) mosquitoes poses as a substantial public health threat. In this study we sought to explore the potential for permethrin-impregnated uniforms worn by military servicemembers to drive emergence of resistance to pyrethroid insecticides by collecting and testing mosquitoes from both military and civilian sites. Overall, we did not identify mosquitoes harboring resistance at Ft. Bragg, but did find a focus of resistance in sub-urban Raleigh, which may be driven by commercial, peri-domestic mosquito control activities. These results suggest that resistance to pyrethroid insecticides may be more prevalent in the United States than previously known, but highly heterogenous. More robust surveillance is needed to monitor the emergence and spread of resistance.

Knock-down resistance (kdr) mutations in the voltage-gated sodium channel gene of Aedes species mosquitoes are biomarkers for resistance to pyrethroid insecticides. In the United States, few studies have reported kdr mutations among Aedes albopictus (Skuse) (Diptera: Culicidae) populations. In this study, we sought to compare the presence of kdr alleles among Ae. albopictus mosquitoes collected from Fort Bragg and Wake County, North Carolina. We collected 538 Ae. albopictus mosquitoes, including 156 from 4 sites at Fort Bragg, North Carolina and 382 from 15 sites in Wake County, North Carolina to compare the prevalence of kdr mutations. Of those successfully sequenced, we identified 12 (3.0%) mosquitoes with kdr mutations, all of which were attributed to variants at position 1534 within domain 3. All mutations were found in mosquitoes collected at Wake County sites; no mutations were identified in collections from Fort Bragg. There was a focus of mutations observed at the Wake County sites with approximately 92% (11 of 12) of the mosquitoes with the mutation coming from one site, where kdr mutations represented 24.4% (11 of 45) of all mosquitoes collected. We observed highly focal resistance in a suburban area of Raleigh, which may be attributable to peri-domestic mosquito control activities that involve area dispersal of pyrethroid insecticides. More robust surveillance is needed to monitor the emergence and spread of resistance.

ImportanceInfluenza virus infections declined globally during the COVID-19 pandemic. Loss of natural immunity from lower rates of influenza infection and documented antigenic changes in circulating viruses may have resulted in increased susceptibility to influenza virus infection during the 2021-2022 influenza season.ObjectiveTo compare the risk of influenza virus infection among household contacts of patients with influenza during the 2021-2022 influenza season with risk of influenza virus infection among household contacts during influenza seasons before the COVID-19 pandemic in the US.Design, Setting, and ParticipantsThis prospective study of influenza transmission enrolled households in 2 states before the COVID-19 pandemic (2017-2020) and in 4 US states during the 2021-2022 influenza season. Primary cases were individuals with the earliest laboratory-confirmed influenza A(H3N2) virus infection in a household. Household contacts were people living with the primary cases who self-collected nasal swabs daily for influenza molecular testing and completed symptom diaries daily for 5 to 10 days after enrollment.ExposuresHousehold contacts living with a primary case.Main Outcomes and MeasuresRelative risk of laboratory-confirmed influenza A(H3N2) virus infection in household contacts during the 2021-2022 season compared with prepandemic seasons. Risk estimates were adjusted for age, vaccination status, frequency of interaction with the primary case, and household density. Subgroup analyses by age, vaccination status, and frequency of interaction with the primary case were also conducted.ResultsDuring the prepandemic seasons, 152 primary cases (median age, 13 years; 3.9% Black; 52.0% female) and 353 household contacts (median age, 33 years; 2.8% Black; 54.1% female) were included and during the 2021-2022 influenza season, 84 primary cases (median age, 10 years; 13.1% Black; 52.4% female) and 186 household contacts (median age, 28.5 years; 14.0% Black; 63.4% female) were included in the analysis. During the prepandemic influenza seasons, 20.1% (71/353) of household contacts were infected with influenza A(H3N2) viruses compared with 50.0% (93/186) of household contacts in 2021-2022. The adjusted relative risk of A(H3N2) virus infection in 2021-2022 was 2.31 (95% CI, 1.86-2.86) compared with prepandemic seasons.Conclusions and RelevanceAmong cohorts in 5 US states, there was a significantly increased risk of household transmission of influenza A(H3N2) in 2021-2022 compared with prepandemic seasons. Additional research is needed to understand reasons for this association.

In a Nicaraguan population-based cohort, SARS-CoV-2 seroprevalence reached 28% in the first 6 months of the country's epidemic and reached 35% 6 months later. Immune waning was uncommon. Individuals with a seropositive household member were over three times as likely to be seropositive themselves, suggesting the importance of household transmission.

To describe the presence and persistence of neurological and neuropsychological sequelae among children with acquired Zika virus infection and assess whether those sequelae were more common in children infected with Zika virus compared to uninfected children.We conducted a prospective cohort study of children with and without Zika virus infection in León, Nicaragua, using a standard clinical assessment tool and questionnaire to collect data on symptoms at three visits, about 6 months apart, and a battery of standardized instruments to evaluate neurocognitive function, behavior, depression, and anxiety at the last two visits.Sixty-two children were enrolled, with no significant differences in demographics by infection group. Children infected with Zika virus had a range of neurological symptoms, some of which persisted for 6 to 12 months; however, no consistent pattern of symptoms was observed. At baseline a small percentage of children infected with Zika virus had an abnormal finger-to-nose test (13%), cold touch response (13%), and vibration response (15%) versus 0% in the uninfected group. Neurocognitive deficits and behavioral problems were common in both groups, with no significant differences between the groups. Children infected with Zika virus had lower cognitive efficiency scores at the 6-month visit. Anxiety and depression were infrequent in both groups.Larger studies are needed to definitively investigate the relationship between Zika virus infection and neurological symptoms and neurocognitive problems, with adjustment for factors affecting cognition and behavior, including mood and sleep disorders, home learning environment, history of neuroinvasive infections, and detailed family history of neuropsychological problems.Describir la presencia y persistencia de secuelas neurológicas y neuropsicológicas en pacientes pediátricos que contrajeron la infección por el virus del Zika y evaluar si dichas secuelas fueron más comunes en los infectados con el virus del Zika en comparación con los no infectados.Se realizó un estudio de cohorte prospectivo en pacientes pediátricos con y sin infección por el virus del Zika en León (Nicaragua), con una herramienta de evaluación clínica estándar y un cuestionario para recopilar datos sobre los síntomas en tres visitas, con aproximadamente seis meses de diferencia, y un conjunto de instrumentos estandarizados para evaluar la función neurocognitiva, el comportamiento, la depresión y la ansiedad en las últimas dos visitas.Participaron 62 niños y niñas sin diferencias significativas en la demografía por grupo de infección. Los participantes infectados con el virus del Zika mostraron una variedad de síntomas neurológicos, algunos de los cuales persistieron entre 6 y 12 meses; no obstante, no se observó un patrón sistemático en los síntomas. Al inicio del estudio, un pequeño porcentaje de participantes infectados con el virus del Zika mostró resultados anormales a las pruebas dedo-nariz (13%), respuesta al tacto (frío) (13%) y respuesta a la vibración (15%), frente a un 0% en el grupo no infectado. Los déficits neurocognitivos y los problemas de comportamiento fueron comunes en ambos grupos, sin diferencias significativas entre los grupos. Los participantes infectados con el virus del Zika mostraron puntuaciones de eficiencia cognitiva más bajas en la visita a los 6 meses. La ansiedad y la depresión fueron poco frecuentes en ambos grupos.Son necesarios estudios más amplios para investigar definitivamente la relación entre la infección por el virus del Zika y los síntomas neurológicos y los problemas neurocognitivos, haciendo ajustes para los factores relacionados con la cognición y el comportamiento, incluidos los trastornos del estado de ánimo y el sueño, el entorno de aprendizaje en el hogar, los antecedentes de infecciones neuroinvasivas y los antecedentes familiares detallados de problemas neuropsicológicos.Descrever a presença e a persistência de sequelas neurológicas e neuropsicológicas em crianças com infecção pelo vírus zika e avaliar se essas sequelas foram mais comuns em crianças infectadas pelo vírus zika em comparação com crianças não infectadas.Realizamos um estudo de coorte prospectivo em crianças com e sem infecção pelo vírus zika em León, Nicarágua, usando uma ferramenta de avaliação clínica padrão e um questionário para coletar dados de sintomas em três consultas, com cerca de 6 meses de intervalo, além de um conjunto de ferramentas padronizadas para avaliar função neurocognitiva, comportamento, depressão e ansiedade nas duas últimas consultas.Foram incluídas 62 crianças, sem diferenças significativas nas características demográficas por grupo de infecção. As crianças infectadas pelo vírus zika tinham uma gama de sintomas neurológicos, alguns dos quais persistiram por 6 a 12 meses. Entretanto, não se observou nenhum padrão consistente de sintomas. No início do estudo, uma pequena porcentagem de crianças infectadas com o vírus zika apresentou resultado anormal na prova índex-nariz (13%), resposta ao toque frio (13%) e sensibilidade vibratória (15%), em comparação a 0% no grupo não infectado. Déficits neurocognitivos e problemas comportamentais foram frequentes em ambos os grupos, mas sem diferenças significativas entre eles. As crianças infectadas com o vírus zika tiveram resultados mais baixos de eficiência cognitiva na consulta de 6 meses. Ansiedade e depressão não foram observadas com frequência em ambos os grupos.São necessários estudos mais amplos para investigar a relação exata entre a infecção pelo vírus zika e sintomas neurológicos e problemas neurocognitivos, com ajuste para fatores que afetam a cognição e o comportamento, incluindo distúrbios do humor e do sono, ambiente de aprendizagem em casa, história de infecções neuroinvasivas e história familiar detalhada de problemas neuropsicológicos.

MicroRNAs (miRNAs) are small non-coding RNAs involved in post-transcriptional gene regulation that have a major impact on many diseases and provide an exciting avenue toward antiviral therapeutics. From patient transcriptomic data, we determined that a circulating miRNA, miR-2392, is directly involved with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) machinery during host infection. Specifically, we show that miR-2392 is key in driving downstream suppression of mitochondrial gene expression, increasing inflammation, glycolysis, and hypoxia, as well as promoting many symptoms associated with coronavirus disease 2019 (COVID-19) infection. We demonstrate that miR-2392 is present in the blood and urine of patients positive for COVID-19 but is not present in patients negative for COVID-19. These findings indicate the potential for developing a minimally invasive COVID-19 detection method. Lastly, using in vitro human and in vivo hamster models, we design a miRNA-based antiviral therapeutic that targets miR-2392, significantly reduces SARS-CoV-2 viability in hamsters, and may potentially inhibit a COVID-19 disease state in humans., Graphical abstract, McDonald et al. uncover a role of a circulating microRNA, miR-2392, as a potential biomarker for COVID-19 and begin development of a potential COVID-19 therapeutic and antiviral to inhibit miR-2392.

Chagas disease, caused by Trypanosoma cruzi, can reactivate and cause severe acute disease in immunocompromised patients such as those infected with human immunodeficiency virus (HIV). We conducted amplicon deep sequencing of a 327-bp fragment of the tcscd5 gene using an Ion Torrent PGM directly from clinical samples from HIV patients with high parasitemia. We describe the within-host diversity, both characterizing the discrete typing unit of the infections and confirming the presence of multistrain infections, directly from clinical samples. This method can rapidly provide information on the genetic diversity of T. cruzi infection, which can have direct impacts on clinical disease.

In a Nicaraguan population-based cohort, SARS-CoV-2 seroprevalence was 34%, with higher prevalence in children compared to adults. Having a seropositive household member was associated with a two-fold probability of individual seropositivity, suggesting a role for household transmission. Co-morbidities and preventive behaviors were not associated with SARS-CoV-2 seroprevalence.

Background Diagnosis of toxoplasmic encephalitis (TE) is challenging under the best clinical circumstances. The poor clinical sensitivity of quantitative polymerase chain reaction (qPCR) for Toxoplasma in blood and CSF and the limited availability of molecular diagnostics and imaging technology leaves clinicians in resource-limited settings with few options other than empiric treatment. Methology/principle findings Here we describe proof of concept for a novel urine diagnostics for TE using Poly-N-Isopropylacrylamide nanoparticles dyed with Reactive Blue-221 to concentrate antigens, substantially increasing the limit of detection. After nanoparticle-concentration, a standard western blotting technique with a monoclonal antibody was used for antigen detection. Limit of detection was 7.8pg/ml and 31.3pg/ml of T. gondii antigens GRA1 and SAG1, respectively. To characterize this diagnostic approach, 164 hospitalized HIV-infected patients with neurological symptoms compatible with TE were tested for 1) T. gondii serology (121/147, positive samples/total samples tested), 2) qPCR in cerebrospinal fluid (11/41), 3) qPCR in blood (10/112), and 4) urinary GRA1 (30/164) and SAG1 (12/164). GRA1 appears to be superior to SAG1 for detection of TE antigens in urine. Fifty-one HIV-infected, T. gondii seropositive but asymptomatic persons all tested negative by nanoparticle western blot and blood qPCR, suggesting the test has good specificity for TE for both GRA1 and SAG1. In a subgroup of 44 patients, urine samples were assayed with mass spectrometry parallel-reaction-monitoring (PRM) for the presence of T. gondii antigens. PRM identified antigens in 8 samples, 6 of which were concordant with the urine diagnostic. Conclusion/significances Our results demonstrate nanoparticle technology’s potential for a noninvasive diagnostic test for TE. Moving forward, GRA1 is a promising target for antigen based diagnostics for TE., Author summary Toxoplasmic Encephalitis is a debilitating, yet highly treatable illness, classically seen in person living with HIV lacking treatment. Prompt diagnosis ensures the best outcome possible for patients, but remains a challenge: requiring invasive specimen collection, lacking necessary clinical sensitivity, demanding significant technical skills, and substantial infrastructure. Here we offer proof of concept of a diagnostic approach that is minimally invasive, using a urine-based approach that concentrates T. gondii antigens with hydrogel mesh nanoparticles to improve analytical sensitivity for detection by western blot.

Zika virus (ZIKV) RNA has been found to remain in human semen for up to one year after infection, but the presence of Flavivirus antigens in the different compartments of semen has been largely unexplored. Following the introduction of ZIKV in Nicaragua (2016), a prospective study of patients with clinical symptoms consistent with ZIKV was conducted in Le&oacute, n to investigate virus shedding in different fluids. ZIKV infection was confirmed in 16 male subjects (&ge, 18 years of age) by RT-qPCR in either blood, saliva or urine. Of these, three provided semen samples at 7, 14, 21, 28, 60 and 180 days postsymptom onset (DPSO) for Flavivirus antigens and RNA studies. These cases were compared with 19 asymptomatic controls. Flavivirus antigens were examined by immunofluorescence (IF) using the 4G2 Mabs, and confocal microscopy was used to explore fluorescence patterns. The three (100%) symptomatic subjects and 3 (16%) of the 19 asymptomatic subjects had Flavivirus antigens and viral RNA in the spermatozoa fraction. The percentage of IF Flavivirus-positive spermatozoa cells ranged from 1.9% to 25% in specimens from symptomatic subjects, as compared with 0.8% to 3.8% in specimens from asymptomatic controls. A marked IF-pattern in the cytoplasmic droplets and tail of the spermatozoa was observed. The sperm concentrations (45 &times, 106/mL vs. 63.5 &times, 106/mL, p = 0.041) and the total motility percentage (54% vs. 75%, p = 0.009) were significantly lower in specimens from ZIKV-positive than in those of ZIKV-negative. In conclusion, this study demonstrated the presence of Flavivirus antigens and RNA within a time frame of 28 DPSO in sperm cells of symptomatic and asymptomatic subjects during the ZIKV epidemic. These findings have implications for public health, in terms of nonarthropod-born, silent transmission facilitated by sperm cells and potential transmission from asymptomatic males to pregnant women, with consequences to the fetus.

Despite signs of infection, the involvement of the oral cavity in COVID-19 is poorly understood. To address this, single-cell RNA sequencing data-sets were integrated from human minor salivary glands and gingiva to identify 11 epithelial, 7 mesenchymal, and 15 immune cell clusters. Analysis of SARS-CoV-2 viral entry factor expression showed enrichment in epithelia including the ducts and acini of the salivary glands and the suprabasal cells of the mucosae. COVID-19 autopsy tissues confirmed in vivo SARS-CoV-2 infection in the salivary glands and mucosa. Saliva from SARS-CoV-2-infected individuals harbored epithelial cells exhibitingACE2expression and SARS-CoV-2 RNA. Matched nasopharyngeal and saliva samples found distinct viral shedding dynamics and viral burden in saliva correlated with COVID-19 symptoms including taste loss. Upon recovery, this cohort exhibited salivary antibodies against SARS-CoV-2 proteins. Collectively, the oral cavity represents a robust site for COVID-19 infection and implicates saliva in viral transmission.

Campylobacteriosis is an important contributor to the global burden of acute gastroenteritis (AGE). In Nicaragua, the burden, risk factors, and species diversity for infant campylobacteriosis are unknown. Between June 2017 and December 2018, we enrolled 444 infants from León, Nicaragua, in a population-based birth cohort, conducting weekly household AGE surveillance. First, we described clinical characteristics of symptomatic Campylobacter infections, and then compared clinical characteristics between Campylobacter jejuni/coli and non-jejuni/coli infections. Next, we conducted a nested case–control analysis to examine campylobacteriosis risk factors. Finally, we estimated the population attributable fraction of campylobacteriosis among infants experiencing AGE. Of 296 AGE episodes in the first year of life, Campylobacter was detected in 59 (20%), 39 were C. jejuni/coli, and 20 were non-jejuni/coli species, including the first report of Campylobacter vulpis infection in humans. Acute gastroenteritis symptoms associated with C. jejuni/coli lasted longer than those attributed to other Campylobacter species. In a conditional logistic regression model, chickens in the home (odds ratio [OR]: 3.8, 95% CI: 1.4–9.8), a prior AGE episode (OR: 3.3; 95% CI: 1.4–7.8), and poverty (OR: 0.4; 95% CI: 0.2–0.9) were independently associated with campylobacteriosis. Comparing 90 infants experiencing AGE with 90 healthy controls, 22.4% (95% CI: 11.2–32.1) of AGE episodes in the first year of life could be attributed to Campylobacter infection. Campylobacter infections contribute substantially to infant AGE in León, Nicaragua, with non-jejuni/coli species frequently detected. Reducing contact with poultry in the home and interventions to prevent all-cause AGE may reduce campylobacteriosis in this setting.

Acute Chagas disease reactivation (CDR) after cardiac transplantation is a well-known phenomenon in endemic countries of Central and South America and Mexico, but is rare outside of those countries. In this report, we describe a case of a 49 year old male who presented 25 weeks after heart transplant with clinical features concerning for acute rejection, including malaise, anorexia, weight loss, and fever. His immunosuppression therapy included tacrolimus, mycophenolate, and prednisone. An endomyocardial biopsy revealed lymphocytic and eosinophilic inflammation, myocyte damage, and rare foci of intracellular organisms consistent with Trypanosoma cruzi amastigotes. The patient had no known history of Chagas disease. Upon additional questioning, the patient endorsed bites from reduviid bugs during childhood in El Salvador. Follow-up serum PCR testing was positive for T. cruzi DNA. Tests for other infectious organisms and donor specific antibodies were negative. This case illustrates the striking clinical and histologic similarities between acute cellular rejection and acute CDR with cardiac involvement in heart transplant patients, and thus emphasizes the importance of pre-transplant testing for Chagas in patients with epidemiologic risk factors.

Background Human immunodeficiency virus type 1 (HIV-1) populations are detected in cerebrospinal fluid (CSF) of some people on suppressive antiretroviral therapy (ART). Detailed analysis of these populations may reveal whether they are produced by central nervous system (CNS) reservoirs. Methods We performed a study of 101 asymptomatic participants on stable ART. HIV-1 RNA concentrations were cross-sectionally measured in CSF and plasma. In participants with CSF HIV-1 RNA concentrations sufficient for analysis, viral populations were genetically and phenotypically characterized over multiple time points. Results For 6% of participants (6 of 101), the concentration of HIV-1 RNA in their CSF was ≥0.5 log copies/mL above that of plasma (ie, CSF escape). We generated viral envelope sequences from CSF of 3 participants. One had a persistent CSF escape population that was macrophage-tropic, partially drug resistant, genetically diverse, and closely related to a minor macrophage-tropic lineage present in the blood prior to viral suppression and enriched for after ART. Two participants (1 suppressed and 1 not) had transient CSF escape populations that were R5 T cell-tropic with little genetic diversity. Conclusions Extensive analysis of viral populations in 1 participant revealed that CSF escape was from a persistently replicating population, likely in macrophages/microglia, present in the CNS over 3 years of ART. CSF escape in 2 other participants was likely produced by trafficking and transient expansion of infected T cells in the CNS. Our results show that CNS reservoirs can persist during ART and that CSF escape is not exclusively produced by replicating CNS reservoirs.

Zika virus, an arthropod-borne flavivirus pathogen in humans, is unusual because it can be sexually transmitted and can be shed for prolonged periods in semen. We report viral shedding in vaginal secretions for up to 6 months, indicating the potential for sexual and vertical transmission by infected women.

Norovirus is a leading cause of pediatric gastroenteritis. Understanding norovirus epidemiology is essential for reducing disease burden. We conducted a case–control study to describe the distribution, clinical features, and risk factors of norovirus gastroenteritis among children < 5 years of age in León, Nicaragua. Cases were children testing positive for norovirus and controls were children living in the cases’ communities. Study staff interviewed mothers of enrolled cases and controls to obtain detailed exposure information including food, water, and sanitation sources; recent exposures; household characteristics; and handwashing practices. In addition, study staff requested stool samples to be tested for norovirus from select household members. We used descriptive statistics to understand the epidemiologic and clinical features of gastroenteritis episodes. To analyze potential risk factors, we used Firth’s penalized logistic regression to estimate crude and adjusted odds ratios (ORs) and corresponding 95% confidence intervals (CIs). There were 102 children with gastroenteritis, 18 cases of norovirus and 31 controls. Norovirus cases occurred later in the year, corresponding to a delay in the rainy season. Cases were more likely to have a household member with norovirus in their stool as compared with controls [crude OR: 13.3 (95% CI: 2.5, 136.2) and adjusted OR: 11.5 (95% CI: 1.6, 223.2)]. In addition, alcohol-based hand sanitizer use among household members was reported for 10 (32%) of controls and but never for cases. Further research is needed to understand household transmission of norovirus in low- and middle-income countries and the potential impact of hand sanitizer use.

Tick-borne diseases are a growing threat to public health in the United States, especially among outdoor workers who experience high occupational exposure to ticks. Long-lasting permethrin-impregnated clothing has demonstrated high initial protection against bites from blacklegged ticks, Ixodes scapularis Say (Acari: Ixodidae), in laboratory settings, and sustained protection against bites from the lone star tick, Amblyomma americanum (L.) (Acari: Ixodidae), in field tests. However, long-lasting permethrin impregnation of clothing has not been field tested among outdoor workers who are frequently exposed to blacklegged ticks. We conducted a 2-yr randomized, placebo-controlled, double-blinded trial among 82 outdoor workers in Rhode Island and southern Massachusetts. Participants in the treatment arm wore factory-impregnated permethrin clothing, and the control group wore sham-treated clothing. Outdoor working hours, tick encounters, and bites were recorded weekly to assess protective effectiveness of long-lasting permethrin-impregnated garments. Factory-impregnated clothing significantly reduced tick bites by 65% in the first study year and by 50% in the second year for a 2-yr protective effect of 58%. No significant difference in other tick bite prevention method utilization occurred between treatment and control groups, and no treatment-related adverse outcomes were reported. Factory permethrin impregnation of clothing is safe and effective for the prevention of tick bites among outdoor workers whose primary exposure is to blacklegged ticks in the northeastern United States.

Background Several health agencies define microcephaly for surveillance purposes using a single criterion, a percentile or Z-score cut-off for newborn head circumference. This definition, however, conflicts with the reported prevalence of microcephaly even in populations with endemic Zika virus. Objective We explored possible reasons for this conflict, hypothesising that the definition of microcephaly used in some studies may be incompletely described, lacking the additional clinical criteria that clinicians use to make a formal diagnosis. We also explored the potential for misclassification that can result from differences in these definitions, especially when applying a percentile cut-off definition in the presence of the much lower observed prevalence estimates that we believe to be valid. Methods We conducted simulations under a theoretical bimodal distribution of head circumference. For different definitions of microcephaly, we calculated the sensitivity and specificity using varying cut-offs of head circumference. We then calculated and plotted the positive predictive value for each of these definitions by prevalence of microcephaly. Results Simple simulations suggest that if the true prevalence of microcephaly is approximately what is reported in peer-reviewed literature, then relying on cut-off-based definitions may lead to very poor positive predictive value under realistic conditions. Conclusions While a simple head circumference criterion may be used in practice as a screening or surveillance tool, the definition lacks clarification as to what constitutes true pathological microcephaly and may lead to confusion about the true prevalence of microcephaly in Zika-endemic areas, as well as bias in aetiologic studies.

The recent Zika virus (ZIKV) epidemic in the Americas has revealed rare but serious manifestations of infection. ZIKV has emerged in regions endemic for dengue virus (DENV), a closely related mosquito-borne flavivirus. Cross-reactive antibodies confound studies of ZIKV epidemiology and pathogenesis. The immune responses to ZIKV may be different in people, depending on their DENV immune status. Here, we focus on the human B cell and antibody response to ZIKV as a primary flavivirus infection to define the properties of neutralizing and protective antibodies generated in the absence of preexisting immunity to DENV. The plasma antibody and memory B cell response is highly ZIKV type–specific, and ZIKV-neutralizing antibodies mainly target quaternary structure epitopes on the viral envelope. To map viral epitopes targeted by protective antibodies, we isolated 2 type-specific monoclonal antibodies (mAbs) from a ZIKV case. Both mAbs were strongly neutralizing in vitro and protective in vivo. The mAbs recognize distinct epitopes centered on domains I and II of the envelope protein. We also demonstrate that the epitopes of these mAbs define antigenic regions commonly targeted by plasma antibodies in individuals from endemic and nonendemic regions who have recovered from ZIKV infections.

Autonomic dysfunction is common in Chagas disease and diabetes. Patients with either condition complicated by cardiac autonomic dysfunction face increased mortality, but no clinical predictors of autonomic dysfunction exist. Pupillary light reflexes (PLRs) may identify such patients early, allowing for intensified treatment. To evaluate the significance of PLRs, adults were recruited from the outpatient endocrine, cardiology, and surgical clinics at a Bolivian teaching hospital. After testing for Chagas disease and diabetes, participants completed conventional autonomic testing (CAT) evaluating their cardiovascular responses to Valsalva, deep breathing, and orthostatic changes. PLRs were measured using specially designed goggles, then CAT and PLRs were compared as measures of autonomic dysfunction. This study analyzed 163 adults, including 96 with Chagas disease, 35 patients with diabetes, and 32 controls. PLRs were not significantly different between Chagas disease patients and controls. Patients with diabetes had longer latency to onset of pupil constriction, slower maximum constriction velocities, and smaller orthostatic ratios than nonpatients with diabetes. PLRs correlated poorly with CAT results. A PLR-based clinical risk score demonstrated a 2.27-fold increased likelihood of diabetes complicated by autonomic dysfunction compared with the combination of blood tests, CAT, and PLRs (sensitivity 87.9%, specificity 61.3%). PLRs represent a promising tool for evaluating subclinical neuropathy in patients with diabetes without symptomatic autonomic dysfunction. Pupillometry does not have a role in the evaluation of Chagas disease patients.

Members of the Chagas Disease Working Group in Peru and Bolivia include Edith Hinojosa, Clariza Chavez, Jean Karla Velarde, Carla Chavarria, Victoria Serrudo, Roberto Araya, Alcides Buitron, Rita Mendieta, Holger Mayta, Maritza Calderon, Holger Mayta and Yagahira Castro. Background Vertical transmission of Trypanosoma cruzi infection accounts for a growing proportion of new cases of Chagas disease. Congenital infection is curable if treated promptly, but the majority of infected infants do not receive timely diagnosis or treatment. Better risk stratification is needed to predict which women are more likely to transmit the infection. Methods This study enrolled women who presented for delivery and their infants at the Percy Boland Women’s Hospital in Santa Cruz, Bolivia. Pregnant women were screened for Chagas disease by rapid test. The infants of seropositive mothers underwent diagnostic testing with microscopy (“micromethod”) and quantitative polymerase chain reaction (qPCR) as newborns and at one- and nine-month follow-up. Mothers completed surveys about demographics and medical history. Results Among 5,828 enrolled women, 1,271 (21.8%) screened positive for Chagas disease. Of the 1,325 infants of seropositive mothers, 113 (8.5%) were diagnosed with congenital Chagas disease by microscopy or qPCR. Cesarean delivery was significantly associated with lower odds of vertical transmission (adjusted OR: 0.63, 95% CI: 0.41–0.98, p=0.040). Congenital infection was more common in twins (adjusted OR: 3.30, 95% CI: 1.97–5.54, p< 0.001) and male infants (adjusted OR: 1.50, 95% CI: 1.01–1.22, p=0.045). Conclusion Our findings suggest that Cesarean delivery may be protective against vertical transmission of T. cruzi, while twins and male infants may have an increased risk. A better understanding of risk stratification for congenital Chagas disease may help improve regional initiatives to reduce disease burden. Disclosures All Authors: No reported disclosures

Pyrethroid-treated clothing is commonly worn for protection against mosquitoes; pyrethroids are both insecticides and repellents. Pyrethroid resistance has become increasingly common in Aedes aegypti, the vector of dengue, Zika, and other arboviruses, but it is not clear whether resistance is associated with reductions in repellency. In order to determine whether long-lasting permethrin impregnated (LLPI) clothing is protective, we used Aedes aegypti from New Orleans, LA (pyrethroid-sensitive) and San Juan, PR (resistant) to measure both lethality and repellency. PCR and Sanger sequencing were used to confirm resistance status by detecting mutations in the kdr gene at positions 1016 and 1534. Arm-in-cage trials of 100 Aedes aegypti females from both populations were performed for 10 minutes to bare arm or an arm clothed in untreated military camouflage or military camouflage impregnated with deltamethrin, permethrin, or etofenprox. Trials were repeated 4-5 times on different days. Number of landings, number of blood meals, and immediate and 24-hour mortality were recorded. Mortality was extremely low in all trials. Compared to untreated cloth, mosquitoes demonstrated a trend towards a 2%-63% reduction in landings and a statistically significant 78-100% reduction in blood feeding on pyrethroid-treated cloth for most insecticides. Effects were observed in both pyrethroid-sensitive and pyrethroid-resistant mosquito populations. Our data show that kdr mutations are associated with pyrethroid resistance but are likely not the only contributors. Pyrethroids appear to maintain repellent effect against resistant mosquitoes. This finding suggests that even in places where pyrethroid resistance is widespread, permethrin still has a role for use as a repellent on clothing to protect against mosquito bites.