A tuberculosis school outbreak in China, 2018: reaching an often overlooked adolescent population

Mycobacterium tuberculosis Infection in School Contacts of Tuberculosis Cases: A Systematic Review and Meta-Analysis

Substantial tuberculosis transmission occurs outside of households, and tuberculosis surveillance in schools has recently been proposed. However, the yield of tuberculosis outcomes from school contacts is not well characterized. We assessed the prevalence of Mycobacterium tuberculosis infection among close school contacts by performing a systematic review. We searched PubMed, Elsevier, China National Knowledge Infrastructure, and Wanfang databases. Studies reporting the number of children who were tested overall and who tested positive were included. Subgroup analyses were performed by study location, index case bacteriological status, type of school, and other relevant factors. In total, 28 studies including 54,707 school contacts screened for M. tuberculosis infection were eligible and included in the analysis. Overall, the prevalence of M. tuberculosis infection determined by the QuantiFERON Gold in-tube test was 33.2% (95% CI, 0.0-73.0%). The prevalences of M. tuberculosis infection based on the tuberculin skin test (TST) using 5 mm, 10 mm, and 15 mm as cutoffs were 27.2% (95% CI, 15.1-39.3%), 24.3% (95% CI, 15.3-33.4%), and 12.7% (95% CI, 6.3-19.0%), respectively. The pooled prevalence of M. tuberculosis infection (using a TST ≥5-mm cutoff) was lower in studies from China (22.8%; 95% CI, 16.8-28.8%) than other regions (36.7%; 95% CI, 18.1-55.2%). The pooled prevalence of M. tuberculosis infection was higher when the index was bacteriologically positive (43.6% [95% CI, 16.5-70.8%] versus 23.8% [95% CI, 16.2-31.4%]). These results suggest that contact investigation and general surveillance in schools from high-burden settings merit consideration as means to improve early case detection in children.

The role of Xpert MTB/RIF using bronchoalveolar lavage fluid in active screening: insights from a tuberculosis outbreak in a junior school in eastern China

Background

Tuberculosis (TB) outbreaks in schools present a public health challenge. In order to effectively control the spread of transmission, timely screening, accurate diagnosis and comprehensive epidemiological investigations are essential.

Methods

In July 2021, a TB outbreak occurred in a junior high school in Y City, Zhejiang Province. Students and faculty were screened for TB by symptom screening, chest radiography, and tuberculin skin test during four rounds of contact screenings. For sputum smear-negative and sputum-scarce patients, bronchoscopy was used to collect BAL samples for Xpert Mycobacterium tuberculosis/rifampin (MTB/RIF). Whole-genome sequencing and bioinformatics analysis were performed on isolates to identify the strains of MTB isolates and predict drug resistance.

Results

Between July 2021 and November 2021, a total of 1,257 students and faculty were screened for TB during screenings. A total of 15 students (1.2% of persons screened) aged 15 years were diagnosed with TB. Eighty percent (12/15) of the cases were laboratory-confirmed (10/12 [83%] Xpert MTB/RIF-positive, 2/12 [17%] culture-positive). Most cases (12/15 [80%]) were in students from Class 2. All cases were asymptomatic except for the index case who had symptoms for more than two months. Seven MTB isolates were collected and belonged to lineage 2.

Conclusion

Our findings demonstrated the potential of Xpert MTB/RIF using BAL as a screening tool in school TB outbreaks for sputum smear-negative and sputum-sparse suspects, which may not only rapidly improves diagnostic accuracy, but also facilitates epidemiological investigations and homology analysis.

Epidemiological characteristics of pulmonary tuberculosis among students in Guizhou, China: a retrospective study from 2010 to 2020

OBJECTIVE

We described epidemiological characteristics of pulmonary tuberculosis (PTB) among students and evaluated susceptible populations and areas in Guizhou province and also to provide scientific suggestions for prevention and control.

SETTING

Guizhou, China.

DESIGN

This is a retrospective epidemiological study on PTB in students.

METHODS

Data are from the China Information System for Disease Control and Prevention. We collected all PTB cases among the student population from 2010 to 2020 in Guizhou. Incidence, composition ratio and hotspot analysis were used to describe epidemiological and some clinical characteristics.

RESULTS

A total of 37 147 new student PTB cases were registered among the population aged 5-30 years during 2010-2020. The proportions of men and women were 53.71% and 46.29%, respectively. Cases aged 15-19 years dominated (63.91%), and the proportion of ethnic groups was increasing during the period. Generally, the raw annual incidence of PTB among the population was increasing from 32.585 per 100 000 persons in 2010 to 48.872 per 100 000 persons in 2020 (c 2 trend=1283.230, p<0.001). March and April were the peak months of a year, and cases were clearly grouped in Bijie city. New cases were mainly identified via physical examination, and cases from active screening were still low (0.76%). Additionally, secondary PTB accounted for 93.68%, positive rate of pathogen was only 23.06%, and the recovery rate was 94.60%.

CONCLUSIONS

The population aged 15-19 years is the vulnerable population, and Bijie city is the susceptible area. BCG vaccination and promotion for active screening should be the priority of futural PTB prevention and control. Tuberculosis laboratory capacity should be improved.

Factors associated with refusal of preventive therapy after initial willingness to accept treatment among college students with latent tuberculosis infection in Shandong, China

BACKGROUND

Preventive therapy of latent tuberculosis infection (LTBI) is an important component of tuberculosis (TB) control. Research on acceptance of TB preventive therapy (TPT) is an important topic. Current studies focus on acceptability and compliance. However, it is unclear whether LTBI patients will start TPT after accepting treatment. The study assessed the factors associated with TPT refusal after initial willingness to accept treatment.

METHODS

Data were derived from a baseline survey of prospective study of LTBI treatment among college students in Shandong Province, China. A total of 723 students initially willing to accept TPT were included in the analysis. Stepwise logistic regression was used to explore the individual- and family-level characteristic variables that factors associated with TPT refusal after initial willingness to accept treatment.

RESULTS

Of the 723 LTBI college students who initially had acceptance willingness, 436 (60.3%) finally refused TPT. At the individual level, non-medical students were more likely to refuse TPT [odds ratio (OR) = 4.87, 95% confidence interval (CI): 3.10-7.67)], as were students with moderate physical activity (OR = 1.45, 95% CI: 1.04-2.04). Students with boarding experience (OR = 0.49, 95% CI: 0.31-0.78) and a high level of knowledge about TB (OR = 0.97, 95% CI: 0.95-0.99) were less likely to refuse TPT. At the family level, those with high father's educational level (OR = 1.50, 95% CI: 1.07-2.10) or high household income (OR = 1.80, 95% CI: 1.20-2.71) were more likely to refuse TPT after initially accepting treatment.

CONCLUSIONS

Factors associated with TPT refusal after initial willingness to accept treatment, such as personal (type of students, physical activity, boarding experiences, knowledge of TB) and family characteristics (father's education level, household income) among college student with LTBI, might help identify persons for whom tailored interventions could improve the start of LTBI treatment.

Whole-Genome Sequencing and Epidemiological Investigation of Tuberculosis Outbreaks in High Schools in Hunan, China

Background

Tuberculosis (TB) seriously threatens individual and public health. Recently, TB outbreaks in schools have been reported more frequently in China and have attracted widespread attention. We reported three TB outbreaks in high schools in Hunan Province, China.

Methods

When a tuberculosis patient was reported in a school, we carried out field epidemiological investigations, including tuberculin skin testing (TST), chest X-ray (CXR) and laboratory test for all close contacts, and whole-genome sequencing (WGS) analyses to understand the transmission patterns, the causes and the risk factors for the outbreaks, thereby providing a foundation for the control of TB epidemics in schools.

Results

A total of 49 students with TB patients were identified in the three schools where TB outbreaks occurred, including nine patients in School A, 14 patients in School B, and 26 patients in School C. In Schools A, B and C, the putative attack rates in the classes of the index case were 13.8% (8/58), 7.6% (5/66), and 40.4% (21/52), while the putative attack rates of expanding screening in the school were 0.3% (1/361), 0.2% (9/3955), and 0.2% (5/2080), respectively. Thirteen patients had patient delay, with a median delay interval of 69 days (IQR 30.5–113 days). Twelve patients had a healthcare diagnostic delay with a median delay interval of 32 days (IQR 24–82 days). Phylogenetic analysis of culture-positive patients revealed that most of them shared a small genetic distance (≤12 SNPs), with three separate genetic clusters (including one MDR-TB genomic cluster), indicating the recent transmission of Mycobacterium tuberculosis strains.

Conclusion

This combination of field investigation and WGS analysis revealed the transmission of three TB outbreaks in schools. Reinforced implementation is needed to improve timely case finding and reduce diagnosis delay in routine TB control in the school population.

A university-clustered tuberculosis outbreak during the COVID-19 pandemic in eastern China

During the COVID-19 pandemic in 2020, a tuberculosis outbreak occurred in a university in eastern China, with 4,488 students and 421 staff on the campus. A 19-year-old student was diagnosed in August 2019. Later, the first round of screening was initiated among close contacts, but no active cases were found. Till September 2020, four rounds of screening were performed. Four rounds of screening were conducted on September 9, November 8, November 22-25 in 2019 and September 2020, with 0, 5, 0 and 43 cases identified, respectively. A total of 66 active tuberculosis were found in the same university, including 4 sputum culture-positive and 7 sputum smear-positive. The total attack rate of active tuberculosis was 1.34% (66/4909). The whole-genome sequencing showed that the isolates belonged to the same L2 sub-specie and were sensitive to all tested antituberculosis drugs. Delay detection, diagnosis and report of cases were the major cause of this university tuberculosis epidemic. More attention should be paid to the asymptomatic students in the index class. After the occurrence of tuberculosis cases in schools, multiple rounds of screening should be carried out, and preventive therapy should be applied in a timely manner.

Transmission of multidrug-resistant Mycobacterium tuberculosis in Wuhan, China: A retrospective molecular epidemiological study

How multidrug-resistant tuberculosis (MDR-TB) spreads and expands in Wuhan population is not clear. The study aimed to determine the transmission patterns of MDR-TB in Wuhan city, China, including 149 patients with MDR-TB.Tuberculosis isolates were genotyped by deletion-targeted multiplex polymerase chain reaction, mycobacterial interspersed repetitive unit-variable number tandem repeat typing, and sequencing of drug resistance-associated genes. The risk factors of genomic-clustering were analyzed with logistic regression. The genomic-clustering patients were deeply investigated.The analysis identified 111 unique and 11 clustered genotypes (38 isolates). The clustering rate was 25.50% and the minimum estimate proportion of recent transmission was 18.12%. Two clusters (5 isolates) shared the same mutation, the remain 9 clusters (33 isolates) had different mutation. Logistic regression showed that older than 60 years (adjusted OR 2.360, 95% CI:1.052-5.292) was an independent factor associated with the genomic-clustering of MDR-TB. Among the 38 genomic-clustering cases, 14 cases had epidemiological transmission links. The most common type of transmission link was social contact.The local transmission of MDR-TB in Wuhan was really an issue. The elderly population might be the high-risk groups for transmission of MDR-TB, and the community or public transportation might be the main transmission places.

A Prospective Cohort Study on the Prevalent and Recurrent Tuberculosis Isolates Using the MIRU-VNTR Typing

The study aims to describe the clustering characteristics of Mycobacterium tuberculosis (M.tb) strains circulating in eastern China and determine the ratio of relapse and reinfection in recurrent patients. We recruited sputum smear-positive pulmonary tuberculosis cases from five cities of Jiangsu Province, China, during August 2013 and December 2015. Patients were followed for the treatment outcomes and recurrence based on a cohort design. M.tb strains were isolated and genotyped using the 12-locus MIRU-VNTR. The Beijing family was identified by the extended Region of Difference (RD) analysis. The Hunter-Gaston Discriminatory Index (HGDI) was used to judge the resolution ability of MIRU-VNTR. The odds ratio (OR) together with 95% confidence interval (CI) were used to estimate the strength of association. We performed a cluster analysis on 2098 M.tb isolates and classified them into 545 genotypes and five categories (I, 0.19%; II, 0.43%; III, 3.34%; IV, 77.46%; V, 18.59%). After adjusting for potential confounders, the Beijing family genotype (OR = 118.63, 95% CI: 79.61–176.79, P = 0.001) was significantly related to the dominant strain infections. Patients infected with non-dominant strains had a higher risk of the pulmonary cavity (OR = 1.39, 95% CI: 1.01–1.91, P = 0.046). Among 37 paired recurrent cases, 22 (59.46%) were determined as endogenous reactivation, and 15 (40.54%) were exogenous reinfection. The type of M.tb strains prevalent in Jiangsu Province is relatively single. Beijing family strains infection is dominant in local tuberculosis cases. Endogenous reactivation appears to be a major cause of recurrent tuberculosis in Eastern China. This finding emphasizes the importance of case follow-up and monitoring after the completion of antituberculosis treatment.

Tuberculosis in Adolescents and Young Adults: Emerging Data on TB Transmission and Prevention among Vulnerable Young People

Adolescents and young adults (AYA, ages 10-24 years) comprise a uniquely important but understudied population in global efforts to end tuberculosis (TB), the leading infectious cause of death by a single agent worldwide prior to the COVID-19 pandemic. While TB prevention and care strategies often overlook AYA by grouping them with either children or adults, AYA have particular physiologic, developmental, and social characteristics that require dedicated approaches. This review describes current evidence on the prevention and control of TB among AYA, including approaches to TB screening, dynamics of TB transmission among AYA, and management challenges within the context of unique developmental needs. Challenges are considered for vulnerable groups of AYA such as migrants and refugees; AYA experiencing homelessness, incarceration, or substance use; and AYA living with HIV. We outline areas for needed research and implementation strategies to address TB among AYA globally.