Subclinical disease among people with culture-confirmed pulmonary tuberculosis in Singapore - a retrospective study.

Objectives: Subclinical tuberculosis (TB) is challenging to diagnose due to the lack of a clear definition and symptoms. This study aimed to describe the subclinical disease spectrum among people with culture-confirmed pulmonary TB routinely diagnosed in Singapore, a country with moderate incidence, using different definitions. It also aimed to identify risk factors for subclinical TB and the current diagnostic approaches in detecting subclinical TB.

Risk factors for tuberculosis among close IGRA-negative contacts of persons with infectious tuberculosis in Singapore.

Objectives: Contacts of patients with infectious tuberculosis (TB) testing positive on interferon-gamma release assay (IGRA) are followed up to exclude active disease. However, identifying factors that predispose IGRA-negative contacts to TB could improve screening and follow-up strategies in a medium TB burden country such as Singapore.

Methods: We conducted a retrospective study of IGRA-negative contacts aged ≥2 years identified during contact investigation between January 2014 and December 2022.

The yield of tuberculosis contact investigation on relapsed TB patients and analysis of associated risk factors: Singapore's experience.

The yield of contact investigation on relapsed tuberculosis (TB) cases can guide strategies and resource allocation in the TB control programme. We conducted a retrospective cohort study to review the yield of contact investigation in relapsed TB cases and identify factors associated with TB infection (TBI) among close contacts of relapsed TB cases notified between 2018 and 2022 in Singapore. TB infection positivity was higher among contacts of relapsed cases which were culture-positive complex compared to those who were only polymerase chain reaction (PCR)-positive (14.

Implementation of national whole-genome sequencing of , National Public Health Laboratory, Singapore, 2019-2022.

The National Tuberculosis Programme (NTBP) monitors the occurrence and spread of tuberculosis (TB) and multidrug-resistant TB (MDR-TB) in Singapore. Since 2020, whole-genome sequencing (WGS) of isolates has been performed at the National Public Health Laboratory (NPHL) for genomic surveillance, replacing spoligotyping and mycobacterial interspersed repetitive unit-variable number tandem repeats analysis (MIRU-VNTR). Four thousand three hundred and seven samples were sequenced from 2014 to January 2023, initially as research projects and later developed into a comprehensive public health surveillance programme.

Fever Patterns, Cytokine Profiles, and Outcomes in COVID-19.

Background: Prolonged fever is associated with adverse outcomes in dengue viral infection. Similar fever patterns are observed in COVID-19 with unclear significance.

Methods: We conducted a hospital-based case-control study of patients admitted for COVID-19 with prolonged fever (fever >7 days) and saddleback fever (recurrence of fever, lasting <24 hours, after defervescence beyond day 7 of illness).

Correlation of clinical illness with viremia in Zika virus disease during an outbreak in Singapore.

Background: The first autochthonous Zika virus (ZIKV) outbreak in Singapore was detected in August 2016. We report an analysis of the correlation of clinical illness with viremia and laboratory parameters in this Asian cohort.

Methods: We conducted a prospective longitudinal cohort study of patients with a positive blood ZIKV polymerase chain reaction (PCR) result who were admitted to Tan Tock Seng Hospital, Singapore, for isolation and management.

Environmental colonization and onward clonal transmission of carbapenem-resistant (CRAB) in a medical intensive care unit: the case for environmental hygiene.

Background: In May 2015, we noticed an increase in carbapenem-resistant (CRAB) infections in the Medical Intensive Care Unit (MICU). To investigate this, we studied the extent of environmental contamination and subsequent onward clonal transmission of CRAB.

Methods: We conducted a one-day point prevalence screening (PPS) of the patients and environment in the MICU.

Sinonasal natural killer/T-cell lymphoma presenting as pyrexia of unknown origin with nasal symptoms.

A 68-year-old Chinese man presented with an eight-month history of pyrexia of unknown origin and chronic sinusitis despite multiple courses of antibiotics. He underwent extensive investigations, including workups for infections, chronic granulomatous diseases and malignancy. Nasal biopsies were performed twice under local anaesthesia, but did not show any evidence of malignancy.