Abstract On January 22, 2024, Yueqing People's Hospital in Zhejiang Province reported a confirmed PTB case (index case) from an enterprise. Yueqing Center for Disease Control and Prevention conducted an on-site epidemiological investigation in accordance with the China Tuberculosis Prevention and Control Technical Guidelines and the Zhejiang Province Tuberculosis Cluster Infection Response Technical Plan (2022 Edition). Screening for latent tuberculosis infection (LTBI) and case confirmation were performed according to the Diagnosis for Pulmonary Tuberculosis. Two rounds of screening were carried out in March and April 2024, covering 341 individuals. A total of 122 LTBI cases were detected, with an overall detection rate of 35.78%; 23 PTB cases were identified, with an attack rate of 6.74%. The cases were predominantly male and registered residents of Liangshan Yi Autonomous Prefecture, Sichuan Province, both accounting for 65.22%. Cases were concentrated in workshops on the 2nd and 3rd floors of Zone C at the workplace, with the enterprise dormitory as the main residence. Secondary cases were diagnosed mainly between April and May 2024, and all had a clear history of exposure within the enterprise. Global spatial autocorrelation analysis showed spatial clustering of case distribution, with local hotspots identified as the inspection area on the 2nd floor and Line 1 on the 3rd floor of Zone C. There were 11 confirmed PTB cases and 12 clinically diagnosed cases. Four strains were isolated, and whole-genome sequencing analysis revealed that they belonged to Lineage 2 and Lineage 4, with pairwise single nucleotide polymorphism differences all exceeding 12. Based on the epidemiological investigation and laboratory testing, the PTB outbreak in the enterprise was determined to be a cluster outbreak resulting from multi-source importation and close contact transmission of Mycobacterium tuberculosis within the same workshop, dormitory, and household registration group, possibly associated with a concentration of migrant workers, poor ventilation in the workplace, and the lack of pre-employment PTB screening.

Dirofilaria immitis (heartworm) infections affect domestic dogs, cats, and various wild mammals with increasing incidence in temperate and tropical areas. More sensitive antibody detection methodologies are required to diagnose asymptomatic dirofilariasis with low worm burdens. Applying current transcriptomic technologies would be useful to discover potential diagnostic markers for D. immitis infection. A filarial homologue of the mammalian translationally controlled tumor protein (TCTP) was initially identified by screening the assembled transcriptome of D. immitis (DiTCTP). A BLAST analysis suggested that the DiTCTP gene shared the highest similarity with TCTP from Loa loa at protein level (97%). A histidine-tagged recombinant DiTCTP protein (rDiTCTP) of 40 kDa expressed in Escherichia coli BL21 (DE3) showed immunoreactivity with serum from a dog experimentally infected with heartworms. Localization studies illustrated the ubiquitous presence of rDiTCTP protein in the lateral hypodermal chords, dorsal hypodermal chord, muscle, intestine, and uterus in female adult worms. Further studies on D. immitis-derived TCTP are warranted to assess whether this filarial protein could be used for a diagnostic purpose.
Animal Structures/chemistry ; Animals ; Antibodies, Helminth/blood ; Antigens, Helminth/chemistry/*genetics/immunology/*isolation & purification ; Cloning, Molecular ; Dirofilaria immitis/chemistry/*genetics/immunology ; Disease Models, Animal ; Dogs ; Escherichia coli/genetics ; Gene Expression ; Molecular Sequence Data ; Molecular Weight ; Recombinant Fusion Proteins/chemistry/genetics/immunology/isolation & purification ; Sequence Analysis, DNA ; Tumor Markers, Biological/chemistry/*genetics/immunology/*isolation & purification