Implementation of a Rapid RT-LAMP Saliva-based SARS-CoV-2 Testing Program in the Workplace

Rising SARS-CoV-2 cases, testing delays and the risk of pre-symptomatic and asymptomatic transmission provided the impetus for an in-house rapid testing pro-gram. Employees and their household contacts were encouraged to self-collect saliva samples which were pooled for routine testing using an established colorimetric reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay. In brief, individual or a maximum of four saliva samples were pooled, heat-inactivated to render microorganisms, especially SARS-CoV-2, non-infectious prior to being added to RT-LAMP assay tubes containing either human sample control gene, RNase P or a region of the SARS-CoV-2 gene, ORF1ab. During the second wave of SARS-CoV-2 infections in November 2020, two samples from an employee and a member of their household tested positive via RT-LAMP within two days of each other. A delayed clinical qRT-PCR test confirmation of both individuals 5 days later underscores the power of routine rapid testing with within-the-hour turnaround times. Workplace rapid testing programs using RT-LAMP are flexible in their design, have a reduced cost compared to qRT-PCR, may involve non-invasive self-saliva collection for increased safety for the testing personnel, and can be performed with minimal training.

Point-of-Care Ultrasound by Nonexpert Operators Demonstrates High Sensitivity and Specificity in Detecting Gallstones: Data from the Samoa Typhoid Fever Control Program

Approximately 90% of chronic typhoid carriers with persistent Salmonella enterica serovar Typhi (S. Typhi) gallbladder infection have gallstones. In Samoa, where typhoid fever has been endemic for many decades, risk factors predisposing to the development of gallstones are increasing among adults. The Samoa Typhoid Fever Control Program dispatches a “Typhoid Epidemiologic SWAT Team” to perform a household investigation of every blood culture-confirmed case of acute typhoid fever. Investigations include screening household contacts to detect chronic carriers. Following limited training, two nonexpert ultrasound operators performed point-of-care ultrasound (POCUS) on 120 Samoan adults from August to September 2019 to explore the feasibility of POCUS to detect individuals with gallstones during household investigations and community screenings. POCUS scans from 120 Samoan adults in three cohorts (28 food handlers, two typhoid cases and their 18 household contacts, and 72 attendees at an ambulatory clinic) were reviewed by a board-certified radiologist who deemed 96/120 scans (80%) to be interpretable. Compared with the radiologist (gold standard), the nonexpert operators successfully detected 6/7 Samoans with gallstones (85.7% sensitivity) and correctly identified 85/89 without gallstones (95.5% specificity). The proportion (24/120) of uninterpretable scans from this pilot that used minimally trained clinicians (who are neither radiologists nor ultrasound technicians) indicates the need for additional training of POCUS operators. Nevertheless, this pilot feasibility study engenders optimism that in the Samoan setting nonexperts can be trained to use POCUS to diagnose cholelithiasis, thereby helping (along with stool cultures and Vi serology) to identify possible chronic S. Typhi carriers.

Cross-reactive memory T cells associate with protection against SARS-CoV-2 infection in COVID-19 contacts

Cross-reactive immune responses to SARS-CoV-2 have been observed in pre-pandemic cohorts and proposed to contribute to host protection. Here we assess 52 COVID-19 household contacts to capture immune responses at the earliest timepoints after SARS-CoV-2 exposure. Using a dual cytokine FLISpot assay on peripheral blood mononuclear cells, we enumerate the frequency of T cells specific for spike, nucleocapsid, membrane, envelope and ORF1 SARS-CoV-2 epitopes that cross-react with human endemic coronaviruses. We observe higher frequencies of cross-reactive (p = 0.0139), and nucleocapsid-specific (p = 0.0355) IL-2-secreting memory T cells in contacts who remained PCR-negative despite exposure (n = 26), when compared with those who convert to PCR-positive (n = 26); no significant difference in the frequency of responses to spike is observed, hinting at a limited protective function of spike-cross-reactive T cells. Our results are thus consistent with pre-existing non-spike cross-reactive memory T cells protecting SARS-CoV-2-naïve contacts from infection, thereby supporting the inclusion of non-spike antigens in second-generation vaccines.

Profile of Tuberculosis in Children and Adolescent at Dr. Soetomo General Hospital Surabaya

Introduction: Tuberculosis is one of ten leading causes of death worldwide, including Indonesia. Indonesia is one of seven countries that causes 64% deaths due to tuberculosis. Tuberculosis is caused by Mycobacterium tuberculosis through droplet nuclei in the air. It can occur to any group age, including children and adolescent, if there is a contact history of people with tuberculosis infection. In 2016, one million children had tuberculosis and around 250,000 children died because of tuberculosis. This study aimed to know the profile of tuberculosis in children and adolescent at Dr. Soetomo General Hospital Surabaya.Methods: This was a descriptive study using retrospective approach. Sample of this study was collected from electronic medical record provided by Dr. Soetomo General Hospital Surabaya using statistic formula of single sample for estimated population proportions of children and adolescent with tuberculosis from 2013-2017, with total samples of 149 people.Results: There were 149 samples of children and adolescent patients with tuberculosis. Most of the children were mostly 0-4 years old and 57% were female. 84% of the children had been immunized with BCG and classified as moderate, and 35% were under nutritional status. This study showed that 67% of the children in household contacts of adult tuberculosis patients also had tuberculosis. The most frequent symptoms of tuberculosis in children and adolescent were fever (72%) and cough (80%).Conclusion: Tuberculosis in children and adolescent is more likely to occur in children than adolescent, especially children within group age of 0-4 years old. The number of pulmonary tuberculosis in children and adolescent are higher than extrapulmonary tuberculosis.

Asymptomatic Scalp Carriage among Household Contacts of Children Affected by Tinea Capitis: A Prospective Study in the Metropolitan Area of Brussels, Belgium

<b><i>Introduction:</i></b> Tinea capitis (TC) is a superficial fungal infection affecting the scalp. The existence of asymptomatic carriers (ACs) could represent a potential reservoir responsible of (re)contamination and failure of treatment. No prospective studies on ACs in household contacts of TC patients in Europe have been published to date. <b><i>Objectives:</i></b> The aim of this study was to assess the prevalence of ACs in a cohort of household contacts of children who were diagnosed with TC in the metropolitan area of Bruxelles, Belgium. <b><i>Methods:</i></b> This prospective observational study was conducted from October 2015 to April 2016 at the Dermatology Department of the University Hospitals Brugmann, Saint-Pierre, Queen Fabiola Children Hospital. <b><i>Results:</i></b> Ninety-nine cases of TC from 95 different family circles were included. The main infectious agent identified was <i>Microsporum audouinii</i> in 53 cases. The mean age of TC patients was 5.8 years. Male/female ratio was 2.8. Eighty-one household contacts of TC patients were enrolled in the study. Two cases of ACs (5%) were identified. <b><i>Conclusions:</i></b> <i>M. audouinii</i> was the most common pathogen identified. The prevalence of ACs we report is on average higher compared to other European large cities. Larger prospective studies including all close contacts of affected patients are required in order to establish guidelines regarding identification and management of ACs.

Risk of Secondary Household Transmission of COVID-19 from Health Care Workers in a Hospital in Spain

Background: Hospital health care workers are at high risk of developing COVID-19 and transmitting the disease to their family upon returning home; the aim here is to estimate the secondary attack rate of COVID-19 in household contacts of health care workers and their transmission risk factors. Material and Methods: COVID-19 cases in the health care workers of an academic hospital in Pamplona, Spain, from 2 March to 26 May 2020, were followed up. The secondary attack rate (SAR) was estimated from cases in household contacts of index cases and their risk factors by Poisson regression. Results: 89 index cases were studied from 99 notified cases in health care workers (89.0%), excluding secondary cases or those who lived alone. Forty-six secondary cases confirmed by the laboratory were found among 326 household contacts, a secondary attack rate of 14.11% (95% CI 10.75–18.31), and 33 household contacts with acute infection symptoms without microbiologic confirmation 10.12% (95% CI 7.30–13.87). Considering all the cases, the secondary attack rate was 27.3 (95% CI 22.75–32.38). Risk factors were the gender and profession of the index case, the number of people living in the household, and the number of persons per bedroom. When the index case health worker used a single room, it had a protective effect, with an incidence rate ratio (IRR) of 0.493 (95% CI 0.246–0.985); Conclusions: The secondary attack rate found among household contacts of health care workers is high. The preventive isolation of health care workers in individual rooms in their house may reduce the transmission in their families.

Isoniazid preventive therapy in child household contacts of adults with active TB in Bamako, Mali

BACKGROUND and OBJECTIVE: Isoniazid preventive therapy (IPT) is known to reduce the risk of developing active TB in about 59% in children aged 15 years. We assessed adherence, completion and adverse events among children who were household contacts of a newly diagnosed adult with smear-positive TB in Bamako, Mali.METHODS: Children aged <15 years living in the same house with an adult smear-positive index case were enrolled in the study in the Bamako Region after consent was obtained from the parent or legal guardian. Adherence was assessed based on the number of tablets consumed during 6 months.RESULTS: A total of 260 children aged <15 years were identified as household contacts of 207 adult patients with smear-positive TB during the study period. Among all child contacts, 130/260 (50.0%) were aged 0–4 years and were eligible for IPT; 128/130 (98.5%) were started on IPT and 83/128 (64.8%) completed with good adherence at the end of the 6 months, and without any significant adverse events.CONCLUSION: We successfully implemented IPT with good acceptance, but low completion rate. The Mali National TB Program and partners should expand this strategy to reach more children in Bamako and the whole country and create greater awareness in the population.

Increased Transmissibility of SARS-CoV-2 Alpha Variant (B.1.1.7) in Children: Three Large Primary School Outbreaks Revealed by Whole Genome Sequencing in the Netherlands

BackgroundVariant of concern (VOC) SARS-CoV-2 alpha variant (B.1.1.7) was the dominant strain in the Netherlands between March 2021 – June 2021. We describe three primary school outbreaks due to the alpha variant using whole genome sequencing with evidence of large-scale transmission among children, teachers and their household contacts. MethodAll outbreaks described were investigated by the South Limburg Public Health Service, the Netherlands. A case was defined as an individual with a real-time polymerase chain reaction test or antigen test positive for SARS-CoV-2. Whole genome sequencing was performed on random samples from at least one child and one teacher of each affected class.ResultsPeak attack rates in classes were 53%, 33% and 39%, respectively. Specific genotypes were identified for each school across a majority of affected classes. Attack rates were high among staff members, likely to promote staff-to-children transmission. Cases in some classes were limited to children, indicating child-to-child transmission. At 39%, the secondary attack rate (SAR) in household contacts of infected children was remarkably high, similar to SAR in household contacts of staff members (42%). SAR of household contacts of asymptomatic children was only 9%. Conclusion Our findings suggest increased transmissibility of the alpha variant in children compared to preceding non-VOC variants, consistent with a substantial rise in the incidence of cases observed in primary schools and children aged 5-12 since the alpha variant became dominant in March 2021. Lack of mandatory masking, insufficient ventilation and lack of physical distancing also probably contributed to the school outbreaks. The rise of the delta variant (B.1.617.2) since July 2021 which is estimated to be 55% more transmissible than the alpha variant, provides additional urgency to adequate infection prevention in school settings.