Transmission of multidrug-resistant tuberculosis in Shimen community in Shanghai, China: a molecular epidemiology study

Background Multidrug-resistant tuberculosis (MDR-TB) has become a major public health problem in China, with mounting evidence suggesting that recent transmission accounts for the majority of MDR-TB. Here we aimed to reveal the transmission pattern of an MDR-TB outbreak in the Jing'an District of Shanghai between 2010 and 2015. Methods We used whole-genome sequencing (WGS) to conduct genomic clustering analysis along with field epidemiological investigation to determine the transmission pattern and drug resistance profile of a cluster with ten MDR-TB patients in combining field epidemiological investigation. Results The ten MDR-TB patients with genotypically clustered Beijing lineage strains lived in a densely populated, old alley with direct or indirect contact history. The analysis of genomic data showed that the genetic distances of the ten strains (excluding drug-resistant mutations) were 0–20 single nucleotide polymorphisms (SNPs), with an average distance of 9 SNPs, suggesting that the ten MDR-TB patients were infected and developed the onset of illness by the recent transmission of M. tuberculosis. The genetic analysis confirmed definite epidemiological links between the clustered cases. Conclusions The integration of the genotyping tool in routine tuberculosis surveillance can play a substantial role in the detection of MDR-TB transmission events. The leverage of genomic analysis in combination with the epidemiological investigation could further elucidate transmission patterns. Whole-genome sequencing could be integrated into intensive case-finding strategies to identify missed cases of MDR-TB and strengthen efforts to interrupt transmission.

Re-emergence of Avian leukosis virus subgroup J in the rooster of Hy-line brown layers and its transmission pattern in flocks

Avian leukosis virus subgroup J (ALV-J) is the most prevalent subgroup in chickens and exhibits increasing pathogenicity and stronger horizontal and vertical transmission ability among different kinds of chickens. Although vertical transmission of ALV-J from hens infected through artificial insemination was reported before by the detection of swabs and serum, but there was no further research on the transmission pattern of ALVs in the roosters. In the present study, the introduction of Hy-line brown roosters significantly increased the p27 positive rate of ALV in an indigenous flock detected by ELISA and virus isolation. Sequence analysis and IFA showed that it is classified into ALV-J subgroup, locating in a new branch compared with the domestic and foreign referential sequences. Meanwhile, the gp85 gene of the ALV-J isolated in the hens and its albumens had a homology of 94.1–99.7% with that in the roosters, which means that the strain is quite likely transmitted to the hens and their offspring through insemination of the roosters. In addition, there are four ALV-J infection status in plasma and semen of rooster (V + S+, V-S+, V + S-, V-S-), so the eradication of ALV in rooster requires simultaneous virus isolation of semen and plasma. Additionally, compared with ALV detection in samples by DF-1 cells, directly detecting ALV in semen by ELISA exists some false positives. Collectively, our results suggested that the incomplete eradication process of roosters leads to the sporadic findings of ALV-J in laying hens

The transmission pattern and clinical course identified from 417 patients with COVID-19 pneumonia in Shenzhen, China: a retrospective and observational study

Background To help government formulating epidemic control strategies and spreading Shenzhen's experience. Methods 417 patients admitted to hospital with confirmed COVID-19 infection between 19 January and 21 February 2020 in Shenzhen, China.Observational study of COVID-19 outcomes using quality-assured public data from website of Shenzhen Municipal Health Commission and a COVID-19 diagnosis and treatment fixed-point hospital to transmission patterns and associated factors of sporadic and clustered COVID-19 cases and its critical time courses.Results We Compared the characteristics of clustered and non-clustered cases, found the clustered cases differed significantly from non-clustered cases in age and exposure history. Moreover, we analyzed the time intervals between symptom onset and recovery for three clinical conditions and different stages of transmission patterns, found the time intervals between illness onset and hospital discharge for all patients were no more than 30 days. Finally, we analyzed disease severity conditions, severe patients spent 4-5 more days of hospitalization and medical intervention than moderate and mild patients did.Conclusions The study confirms that severe patients spent 4-5 more days of hospitalization and medical intervention than moderate and mild patients did. Our results also provided robust evidence that timely and effective prevention measures were the key to quickly cut the transmission chains and prevent the transition from clustered transmission pattern to community transmission pattern.

METODE CONDITIONAL AUTOREGRESSIVE DALAM ANALISIS PENYEBARAN KASUS PENYAKIT TUBERCULOSIS

This research discusses the use of CAR model in finding out factors that significantly influence TBC transmission and figuring out its transmission patterns in Gorontalo city. The methods apply CAR model aiming to discover factors that significantly influence TBC transmission and Moran's Index aiming to identify its transmission pattern Findings reveal that the number of impoverished population and highlands in Gorontalo city are factors that significantly influence disease transmission The transmission patterns also indicate positive spatial autocorrelation that signifies a similar category among sub-districts