Determinants of latent tuberculosis infection and treatment interruption in long-term care facilities: A retrospective cohort study in Taiwan.

BACKGROUND/PURPOSE: Latent tuberculosis infection (LTBI) treatment is challenging in long-term care facilities (LTCFs) residents due to the occurrence of medical complexities. However, factors associated with treatment interruption have not been extensively studied. This retrospective cohort study aimed to determine LTBI-associated factors and treatment interruption in LTCF residents and employees in Taiwan. METHODS: From May 2017 through September 2020, the residents and employees of 20 LTCFs in Taipei, Taiwan, were screened for LTBI by using QuantiFERON-TB Gold In-Tube test. The LTBI individuals underwent directly observed preventive therapy (DOPT), including regimens of 9-month daily isoniazid (9H) and 3-month weekly isoniazid plus rifapentine (3HP). All the LTBI cases were followed up till treatment completion, death, or treatment interruption. RESULTS: Among 2207 LTCF subjects, 16.8% had LTBI. After controlling for other covariates, residents of public facilities had a significantly higher LTBI prevalence than those of private facilities (adjusted odds ratio [AOR] = 1.43; 95% confidence interval [CI]: 1.08-1.88). Among 264 LTBI cases receiving preventive therapy, 52 (19.7%) had treatment interruption. LTBI cases receiving 3HP were less likely to have treatment interruption than those receiving 9H (AOR = 0.22; 95% CI: 0.07-0.71). CONCLUSIONS: LTCF residents, particular those living in public facilities, had a high LTBI prevalence. 3HP with DOPT is considered the priority regimen for preventive therapy among LTBI cases in LTCFs.

Molecular detection and genetic diversity of Rickettsia spp. in pet dogs and their infesting ticks in Harbin, northeastern China.

BACKGROUND: Pet dogs are important companion animals that share the environment within households, and play an important role in local community life. In addition, pet dogs also are reservoirs of zoonotic agents, including Rickettsia spp., thus increasing the risk of rickettsial infections in humans. It's meaningful to investigate the epidemiology of rickettsial agents in pet dogs, and make contribute to the surveillance of rickettsioses in human in China. RESULTS: In this study, a total of 496 pet dogs' blood samples and 343 ticks infested in pet dogs were collected, and the presence and prevalence of Rickettsia were determined by amplifying the partial gltA and 17-kDa genes, with an overall positive rate of 8.1 % in blood samples and 14.0 % in tick samples. In addition, the rrs, gltA, groEL, and ompA genes of rickettsial were also recovered to determine the species of Rickettsia detected furtherly. Sequencing blast and phylogenetic analyses revealed the presence of three human pathogenic Rickettsia species (Rickettsia raoultii, Candidatus Rickettsia tarasevichiae and Rickettsia felis) in samples associated with pet dogs. Moreover, all the sequences of Rickettsia that we obtained presented close relationship with others available in GenBank, and Rickettsia raoultii was the most predominant Rickettsia species infected in pet dogs' blood samples or in tick samples. CONCLUSIONS: This study provides the molecular epidemiology data about the Rickettsia spp. infection associated with pet dogs in urban areas of Harbin city. Three rickettisae species pathogenic to humans were identified from pet dogs' blood and the infested ticks in urban areas of Harbin city. Considering the intimate relationship between human and pets, these results indicate the potential transmission risk of human rickettisal infections from pet dogs through ectoparasites, and also highlighting that more attention should be paid to rickettsial infection in pet dogs and the infested ticks from the "One health" perspective.

Distribution and molecular characterization of rickettsiae in ticks in Harbin area of Northeastern China.

Tick-borne rickettsioses are world-spreading infectious zoonoses. Ticks serve as reservoirs and vectors for Rickettsia and play a key role in transmission of rickettsioses. Most of the Chinese rickettsiosis patients are reported from Northeastern China but the distribution of tick and tick-borne Rickettsia species in Northeastern China remain poorly studied. In this study, a total of 1,286 ticks were captured from the seven counties of Harbin, an area in Northeastern China, and the tick-borne Rickettsia species were identified by PCR and sequencing of rrs, gltA, groEL, ompA and 17-kDa antigen-encoding genes. Of the 5 identified tick species, Haemaphysalis longicornis and Ixodes persulcatus were the predominant tick species in the livestock and vegetation, respectively. Rickettsia raoultii and "Candidatus Rickettsia tarasevichiae" were the two detectable Rickettsia species in the ticks with a 28.8% positive rate but no rickettsiae were found in ticks of Haemaphysalis concinna. R. raoultii detected in 37.6% of the Dermacentor nuttalli, Dermacentor silvarum and H. longicornis ticks while "Ca. R. tarasevichiae" was only present in 22.8% of the I. persulcatus ticks. In particular, the positive rate of both R. raoultii and "Ca. R. tarasevichiae" in ticks from the livestock (40.7%) was significantly higher than that from the vegetation (19.5%). The results indicate that the tick and tick-borne Rickettsia species are diverse in different regions of Harbin due to geographic difference and the ticks from livestock may play a more important role in transmission of rickettsioses to human.

Prevalence and molecular characterization of Babesia in pet dogs in Shenzhen, China.

Canine babesiosis is an important global tick-borne infectious disease of domestic dogs and wild canids. B. gibsoni and B. vogeli are the most widespread species mainly endemic in dog population in southern and eastern regions of China. In this study, 272 blood samples were collected from pet dogs in five districts of Shenzhen, China. Babesia DNA was detected in 30 samples with an overall prevalence of 11.0 % in pet dogs in Shenzhen. The difference in the positive rate between female and male pet dogs, among different breed, and among the five sampling sites was not significant, while the age and health status of pet dogs significantly influence the positive rate of Babesia spp. infection. Sequencing results showed the presence of only B. vogeli in all of the samples tested. Sequence comparison and phylogenetic analysis revealed that all 30 strains of Babesia identified in this study shared the highest identity with B. vogeli. In sum, all results of this study showed a considerable high infection rate of Babesia spp. in pet dogs, and B. vogeli was the only Babesia species infecting pet dogs in Shenzhen city. Such information is necessary to help to elucidate the epidemiology of canine babesiosis in Shenzhen, and it is necessary to actively monitor this disease in pet dogs.

Molecular evidence of Babesia in pet cats in mainland China.

BACKGROUND: Babesia spp. are important emerging tick-borne protozoan hemoparasites, and pose a great impact on companion animals. Canine babesiosis has been well described worldwide, while felis babesiosis has primarily been reported from South Africa. To the best of our knowledge, Babesia spp. infections in dogs have been well elucidated in pet dog population in China, no report about Babesia spp. infection in cat population in mainland China. RESULTS: In this study, a total of 203 blood samples were collected from pet cats in Shenzhen city, and detected the presence of Babesia spp. with nested-PCR. Sequence comparison based on the 18S rRNA gene and ITS region revealed that three cats (1.48%) were infected with Babesia. vogeli. Notably, the sequences of ITS region obtained in this study shared the highest nucleotide identity with the sequence of B. vogeli strain isolated in cat from Taiwan. CONCLUSIONS: This study is the first report about babesiosis in domestic cats, and also provides molecular evidence of Babesia spp. infection in cat in mainland China. The data present in this study suggest B. vogeli may be circulating in cat population in mainland China. Further study to investigate the epidemiology of Babesia infection in cat nationwide is warranted.

Zebrafish transgenic line huORFZ is an effective living bioindicator for detecting environmental toxicants.

Reliable animal models are invaluable for monitoring the extent of pollution in the aquatic environment. In this study, we demonstrated the potential of huORFZ, a novel transgenic zebrafish line that harbors a human upstream open reading frame of the chop gene fused with GFP reporter, as an animal model for monitoring environmental pollutants and stress-related cellular processes. When huORFZ embryos were kept under normal condition, no leaked GFP signal could be detected. When treated with hazardous chemicals, including heavy metals and endocrine-disrupting chemicals near their sublethal concentrations (LC50), huORFZ embryos exhibited different tissue-specific GFP expression patterns. For further analysis, copper (Cu2+), cadmium (Cd2+) and Chlorpyrifos were applied. Cu2+ triggered GFP responses in skin and muscle, whereas Cd2+ treatment triggered GFP responses in skin, olfactory epithelium and pronephric ducts. Moreover, fluorescence intensity, as exhibited by huORFZ embryos, was dose-dependent. After surviving treated embryos were returned to normal condition, survival rates, as well as TUNEL signals, returned to pretreatment levels with no significant morphological defects observed. Such results indicated the reversibility of treatment conditions used in this study, as long as embryos survived such conditions. Notably, GFP signals decreased along with recovery, suggesting that GFP signaling of huORFZ embryos likely reflected the overall physiological condition of the individual. To examine the performance of the huORFZ line under real-world conditions, we placed huORFZ embryos in different river water samples. We found that the huORFZ embryos correctly detected the presence of various kinds of pollutants. Based on these findings, we concluded that such uORFchop-based system can be integrated into a first-line water alarm system monitoring the discharge of hazardous pollutants.