Numerous nosocomial infections were observed in hospitals and other healthcare facilities during the COVID-19 pandemic, largely attributed to asymptomatic or pre-symptomatic carriers. SARS-CoV-2 screening data at admission of all hospitalised patients and accompanying persons of a tertiary-care hospital in Germany was included from 1 April 2020 to 31 December 2021. The first oropharyngeal swab of each newly admitted individual was tested for SARS-CoV-2 RNA using reverse transcription polymerase chain reaction (RT-qPCR). The overall testing costs and the costs per positively tested individual were analysed. Out of 111,271 screened individuals, 705 (0.6%) tested positive for SARS-CoV-2 by RT-qPCR. Among these, 236 cases (0.2%) had not been previously diagnosed and were identified through RT-qPCR admission screening. Of the newly detected cases,110 (0.1%) were asymptomatic without any known positive contact history. The specificity of RT-qPCR in screening use was 99.997% (95% CI 99.992-99.999%). The mean testing costs of identifying one SARS-CoV-2-positive individual through admission screening was €8,082.87. Long-term universal RT-qPCR admission screening detected a substantial number of otherwise unidentified SARS-CoV-2-positive individuals, proving its value as a infection control tool with an excellent specificity in screening use during the COVID-19 pandemic. This strategy represents an important lesson learned from the pandemic and may serve as a valuable infection control tool for future pandemics or seasonal pathogen surges.

In March 2025, a married couple in Jiaxing City, Zhejiang Province, China, presented with fever and pneumonia. Metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid confirmed Chlamydia psittaci (C. psittaci) infection. Epidemiological investigation revealed exposure to a pet budgerigar purchased one month prior. Environmental sampling detected C. psittaci in the bird's feces and the patients' living spaces. Phylogenetic analysis of the ompA gene identified the strains as genotype A, and multilocus sequence typing (MLST) determined the sequence type (ST) as ST388. Two cohabiting elderly parents without bird exposure remained asymptomatic and PCR-negative. Phylogenetic analysis showed the avian and environmental isolates formed a distinct clonal cluster. This report highlights the risk of zoonotic transmission from asymptomatic avian carriers and the utility of genomic surveillance in outbreak investigation. Clinicians should consider psittacosis in atypical pneumonia cases with bird exposure.