A well 6-month-old infant with coronavirus disease 2019 (COVID-19) had persistently positive nasopharyngeal swabs up to day 16 of admission. This case highlights the difficulties in establishing the true incidence of COVID-19, as asymptomatic individuals can excrete the virus. These patients may play important roles in human-to-human transmission in the community.

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections (causing coronavirus disease 2019 [Covid-19]) spread globally, uncertainty surrounds estimates of the true number of infected persons, which is crucial to determining the severity of infection and the incidence of mild or asymptomatic cases and their possible transmission.¹ Modeling estimates suggest that in Wuhan, China, the city with the most Covid-19 cases, there are substantially more cases than were officially reported, because milder cases may not have been captured in hospital-based surveillance.^2,3 Data on travelers returning from areas with cases of Covid-19 could be useful in estimating its incidence.⁴

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was detected from at least 1 buccal specimen in 9 of 11 coronavirus disease 2019 (COVID-19)–infected children (81.8%). Viral loads in buccal specimens were substantially lower than those in nasopharyngeal specimens. Buccal swabs are not good as COVID-19 screening specimens in children.

Disseminated Bacillus Calmette-Guérin (BCG) disease (BCGosis) is a classical feature of children with primary immunodeficiency disorders (PIDs). A 15-year retrospective review was conducted in KK Women's and Children's Hospital in Singapore, from January 2003 to October 2017. Ten patients were identified, mostly male (60.0%). The median age at presentation of systemic signs and symptoms, was 4.0 (0.5 - 27.9) months. All the patients had underlying PIDs - five with Severe Combined Immunodeficiency (SCID), three with Mendelian Susceptibility to Mycobacterial Diseases (MSMD), one with Anhidrotic Ectodermal Dysplasia with Primary Immunodeficiency (EDA-ID), and one with STAT-1 gain-of function mutation. Definitive BCGosis was confirmed in all patients by identification of Mycobacterium bovis subsbp BCG from microbiological cultures. The susceptibility profiles of Mycobacterium bovis subsbp BCG are as follows: Rifampicin (88.8%), Isoniazid (44.47%), Ethambutol (100.0%), Streptomycin (100.0%), Kanamycin (100.0%), Ethionamide (25.0%), and Ofloxacin (100.0%). Four patients (40.0%) received a three-drug regimen. Five patients (50.0%) underwent haematopoietic stem cell transplant (HSCT), of which 3 (60%) have recovered. Overall mortality was 50.0%. Disseminated BCG disease (BCGosis) should prompt immunology evaluation to determine the diagnosis of the immune defect. A three-drug regimen is adequate for treatment if the patient undergoes early HSCT.

Chia Yin Chong, Kai-Qian Kam, Jiahui Li, Matthias Maiwald, Liat Hui Loo, Karen Donceras Nadua, Natalie Woon Hui Tan, Chee Fu Yung, Koh Cheng Thoon; Saliva is n