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Background: Rapid IgM/IgG antibody tests were largely used in lieu of RT-PCR tests as part of COVID-19 public health response activities in Lima, Peru. To assess their utility, we explored the relationship between the time since onset of several COVID-19-related symptoms and the sensitivity of a rapid combined IgM/IgG antibody test. Methods: We collected data from a community sample of individuals (n = 492) who received concurrent RT-PCR and rapid IgM/IgG antibody testing between May 2020 and March 2021. We estimated the sensitivity of the antibody test, against the RT-PCR test, by weeks since symptom onset via segmented regression analysis. Results: The overall sensitivity of the rapid IgM/IgG antibody test was 46.7% (95% CI, 42.4–51.2%). Among 372 (75.6%) participants who reported COVID-19-related symptoms, sensitivity increased from 30.4% (95% CI, 24.7–36.6%) in week 1 after symptom onset to 83.3% (95% CI, 41.6–98.4%) in week 4. The test sensitivity increased by 31.9% (95% CI, 24.8–39.0%) per week until week 2 to 3, then decreased by − 6.0% (95% CI, − 25.7–13.7%) per week thereafter. Conclusion: Rapid antibody tests are a poor substitute for RT-PCR testing, regardless of presenting symptoms. This highlights the need for future pandemic planning to include timely and equitable access to gold-standard diagnostics, treatment, and vaccination. [ABSTRACT FROM AUTHOR]

Background: The enteric string test can be used to obtain a specimen for microbiological confirmation of tuberculosis in children, but it is not widely used for this. The aim of this analysis to evaluate this approach in children with tuberculosis symptoms.Methods: We conducted a cross-sectional study to assess children's ability to complete the test (feasibility), and self-reported pain (tolerability). We examined caregivers' and children's willingness to repeat the procedure (acceptability) and described the diagnostic yield of cultures for diagnostic tools. We stratified estimates by age and compared metrics to those derived for gastric aspirate (GA).Results: Among 148 children who attempted the string test, 34% successfully swallowed the capsule. Feasibility was higher among children aged 11-14 than in children 4-10 years (83% vs 22% respectively, p < 0.0001). The string test was better tolerated than GA in both age groups; however, guardians and older children reported higher rates of willingness to repeat GA than the string test (86% vs. 58% in children; 100% vs. 83% in guardians). In 9 children with a positive sputum culture, 6 had a positive string culture. The one children with a positive gastric aspirate culture also had a positive string culture.Conclusion: Although the string test was generally tolerable and accepted by children and caregivers; feasibility in young children was low. Reducing the capsule size may improve test success rates in younger children. [ABSTRACT FROM AUTHOR]

Background: Identifying hotspots of tuberculosis transmission can inform spatially targeted active case-finding interventions. While national tuberculosis programs maintain notification registers which represent a potential source of data to investigate transmission patterns, high local tuberculosis incidence may not provide a reliable signal for transmission because the population distribution of covariates affecting susceptibility and disease progression may confound the relationship between tuberculosis incidence and transmission. Child cases of tuberculosis and other endemic infectious disease have been observed to provide a signal of their transmission intensity. We assessed whether local overrepresentation of child cases in tuberculosis notification data corresponds to areas where recent transmission events are concentrated.Methods: We visualized spatial clustering of children < 5 years old notified to Peru's National Tuberculosis Program from two districts of Lima, Peru, from 2005 to 2007 using a log-Gaussian Cox process to model the intensity of the point-referenced child cases. To identify where clustering of child cases was more extreme than expected by chance alone, we mapped all cases from the notification data onto a grid and used a hierarchical Bayesian spatial model to identify grid cells where the proportion of cases among children < 5 years old is greater than expected. Modeling the proportion of child cases allowed us to use the spatial distribution of adult cases to control for unobserved factors that may explain the spatial variability in the distribution of child cases. We compare where young children are overrepresented in case notification data to areas identified as transmission hotspots using molecular epidemiological methods during a prospective study of tuberculosis transmission conducted from 2009 to 2012 in the same setting.Results: Areas in which childhood tuberculosis cases are overrepresented align with areas of spatial concentration of transmission revealed by molecular epidemiologic methods.Conclusions: Age-disaggregated notification data can be used to identify hotspots of tuberculosis transmission and suggest local force of infection, providing an easily accessible source of data to target active case-finding intervention. [ABSTRACT FROM AUTHOR]

Background: Rapid and accurate diagnosis of childhood tuberculosis (TB) is challenging because children are often unable to produce the sputum sample required for conventional tests. Stool is an alternative sample type that is easy to collect from children, and studies investigating the use of stool for molecular detection of Mycobacterium tuberculosis (Mtb) have led to promising results. Our objective was to evaluate stool as an alternative specimen to sputum for Mtb detection in children. We did so using the TruTip workstation (Akonni Biosystems), a novel automated lysis and extraction platform.Methods: We tested stool samples from 259 children aged 0-14 years old, in Lima, Peru who presented with TB symptoms. Following extraction with TruTip, we detected the presence of Mtb DNA by IS6110 real-time PCR. We calculated assay sensitivity in two groups: (1) children with culture confirmed TB (N = 22); and (2) children with clinically-diagnosed unconfirmed TB (N = 84). We calculated specificity among children in whom TB was ruled out (N = 153). Among children who were diagnosed with TB, we examined factors associated with a positive stool test.Results: Assay sensitivity was 59% (95% confidence interval [CI]: 39-80%) and 1.2% (95% CI: 0.0-6.5%) in children with culture-confirmed and clinically-diagnosed unconfirmed TB, respectively, and specificity was 97% (95% CI: 93-99%). The assay detected Mtb in stool of 7/7 children with smear-positive TB (100% sensitivity; 95% CI: 59-100%), and in 6/15 of children with smear-negative, culture-confirmed TB (40% sensitivity; 95% CI: 16-68%). Older age, smear positivity, culture positivity, ability to produce sputum and cavitary disease were associated with a positive stool result.Conclusion: Testing of stool samples with the TruTip workstation and IS6110 amplification yielded sensitivity and specificity estimates comparable to other tests such as Xpert. Future work should include detection of resistance using the TruTip closed amplification system and assay optimization to improve sensitivity in children with low bacillary loads. [ABSTRACT FROM AUTHOR]

Objective: Diagnostic testing for tuberculosis depends on microbiological detection of Mycobacterium tuberculosis (Mtb) in sputum. For patients unable to expectorate sputum, such as children and individuals living with HIV, this poses barriers to rapid diagnosis and treatment initiation. Therefore, this study aimed to use oral swabs as an alternative sample type for Mtb detection via molecular testing. Results: In a pilot study, we aimed to evaluate sensitivity of Mtb detection via oral swabs using Xpert MTB/RIF ULTRA. We enrolled 33 TB cases and 30 controls from Lima, Peru, and detected Mtb from oral swabs with a sensitivity of 45% (95% confidence interval (CI) 29–62%) and specificity of 100% (95% CI 89–100%) using liquid culture of sputum as reference test. Our current protocol will need optimization, but these results support future exploration of the use of oral swabs for Mtb detection. [ABSTRACT FROM AUTHOR]

Background: The global HIV burden among adolescents ages 10-19 is growing. This population concurrently confronts the multifaceted challenges of adolescence and living with HIV. With the goal of informing future interventions tailored to this group, we assessed sexual activity, HIV diagnosis disclosure, combination antiretroviral therapy (cART) adherence, and drug use among adolescents living with HIV (ALHIV) in Lima, Peru., Methods: Adolescents at risk or with a history of suboptimal cART adherence completed a self-administered, health behaviors survey and participated in support group sessions, which were audio recorded and used as a qualitative data source. Additionally, we conducted in-depth interviews with caregivers and care providers of ALHIV. Thematic content analysis was performed on the group transcripts and in-depth interviews and integrated with data from the survey to describe adolescents' health related behaviors., Results: We enrolled 34 ALHIV, of which 32 (14 male, 18 female, median age 14.5 years) completed the health behavior survey. Nine (28%) adolescents reported prior sexual intercourse, a minority of whom (44%) reported using a condom. cART adherence was highest in the 10-12 age group with 89% reporting ≤2 missed doses in the last month, compared to 36% in adolescents 13 years or older. Over 80% of adolescents had never disclosed their HIV status to a friend or romantic partner. Adolescents, caregivers, and health service providers described sexual health misinformation and difficulty having conversations about sexual health and HIV., Conclusions: In this group of ALHIV, adherence to cART declined with age and condom use among sexually active adolescents was low. Multifactorial interventions addressing sexual health, gaps in HIV-related knowledge, and management of disclosure and romantic relationships are urgently needed for this population.