An outbreak of tuberculosis in a middle school in Henan, China: Epidemiology and risk factors

Factors associated with tuberculosis care-seeking and diagnostic delays among childhood pulmonary tuberculosis in Zhejiang Province, China: a 10-year retrospective study

We conducted a retrospective study to investigate risk factors for tuberculosis care-seeking delay and diagnostic delays among pediatric pulmonary tuberculosis cases in Zhejiang Province from 2013 to 2022. Among 1274 cases, 49.61% experienced tuberculosis care-seeking delays (> 14 days from symptom onset to first hospital visit) and 14.91% faced diagnostic delays (> 14 days from initial consultation to diagnosis). The proportion of care-seeking delays ranged from 37.42 to 64.89%, while diagnostic delay fluctuated from 6.11 to 21.02%. Urban residence (OR = 0.78, 95% CI 0.62-0.98, P = 0.030), first visiting a municipal-level hospital (OR = 0.57, 95% CI 0.45-0.72, P < 0.001), and diagnostic method (OR = 0.66, 95%CI 0.52-0.84, P < 0.001) were associated with tuberculosis care-seeking delay, whereas first visiting a municipal-level hospital (OR = 2.05, 95% CI 1.49-2.80, P < 0.001) was linked to diagnostic delay. Further analysis using a 28-day cutoff point revealed that children aged 0-4 years, those from migrant populations, laboratory-confirmed patients, and those who first visited a county-level hospital were more likely to experience delays in seeking tuberculosis care. Thus, society should pay more attention to the health of rural, migrant, and 0-4-year-old children, as they are at higher risk of experiencing tuberculosis care-seeking delays.

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.

Factors associated with diagnostic delay of pulmonary tuberculosis among children and adolescents in Quzhou, China: results from the surveillance data 2011-2021

PURPOSE

Tuberculosis is a high-burden disease and a major health concern in China, especially among children and adolescents. The purpose of this study was to assess risk factors for diagnostic delay in students with pulmonary tuberculosis in Quzhou City in eastern China.

PATIENTS AND METHODS

Cases of PTB in students and relevant information in Quzhou from 2011 to 2021 were collected using the TB Management Information System. The outcome of interest was diagnostic delay (i.e. ≥ 28 days between symptom onset and treatment initiation). Risk factors for diagnostic delay were identified using multivariable logistic regression.

RESULTS

A total of 629 students in Quzhou were diagnosed with PTB during the study period, of whom 55.5% were male. The median diagnostic delay was 18 days (Inter Quartile Range, [IQR]: 8-38) and 38.0% of the students had a diagnostic delay. Living in a rural area (adjusted odds ratio, [AOR]: 1.56, 95% confidence interval [CI:] 1.11-2.19), developing PTB symptoms in the first quarter of the year (AOR: 2.18, 95% CI: 1.40-3.40), and no sputum smear result (AOR: 8.73, 95% CI: 1.68-45.30) were significantly associated with a diagnostic delay. Discovery through health examinations (AOR: 0.33, 95% CI: 0.17-0.63) was associated with reduced risk of diagnostic delay.

CONCLUSION

Schools in rural areas should pay special attention to increasing student awareness of the symptoms of tuberculosis and provide health education on tuberculosis prevention and control to students and staff.

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.

Spatial-temporal analysis of pulmonary tuberculosis among students in the Zhejiang Province of China from 2007-2020

Background

Pulmonary tuberculosis (PTB) is a serious chronic communicable disease that causes a significant disease burden in China; however, few studies have described its spatial epidemiological features in students.

Methods

Data of all notified PTB cases from 2007 to 2020 in the student population were collected in the Zhejiang Province, China using the available TB Management Information System. Analyses including time trend, spatial autocorrelation, and spatial-temporal analysis were performed to identify temporal trends, hotspots, and clustering, respectively.

Results

A total of 17,500 PTB cases were identified among students in the Zhejiang Province during the study period, accounting for 3.75% of all notified PTB cases. The health-seeking delay rate was 45.32%. There was a decreasing trend in PTB notifications throughout the period; clustering of cases was seen in the western area of Zhejiang Province. Additionally, one most likely cluster along with three secondary clusters were identified by spatial-temporal analysis.

Conclusion

Although was a downward trend in PTB notifications among students during the time period, an upward trend was seen in bacteriologically confirmed cases since 2017. The risk of PTB was higher among senior high school and above than of junior high school. The western area of Zhejiang Province was the highest PTB risk settings for students, and more comprehensive interventions should be strengthened such as admission screening and routine health monitoring to improve early identification of PTB.

An outbreak of pulmonary tuberculosis and a follow-up investigation of latent tuberculosis in a high school in an eastern city in China, 2016-2019

Background

In October 2016, a senior high school student was diagnosed with sputum-smear positive [SS(+)] pulmonary tuberculosis (TB). We conducted an investigation of an outbreak in the school, including among students and teachers diagnosed with latent TB, who we followed until July 2019.

Methods

We defined latent TB infection (LTBI) as a tuberculin skin test (TST) induration of 15mm or larger; probable TB as a chest radiograph indicative of TB plus productive cough/hemoptysis for at least 2 weeks, or TST induration of 15mm or larger; and confirmed TB as two or more positive sputum smears or one positive sputum smear plus a chest radiograph indicative of TB or culture positive with M. tuberculosis. We conducted mycobacterial interspersed repetitive unit–variable number tandem repeat (MIRU-VNTR) typing based on 24 loci in the isolates.

Results

Between October 2016 and July 2019, we identified 52 cases, including nine probable, six confirmed, and 37 LTBI cases. The index case-student had attended school continuously despite having TB symptoms for almost three months before being diagnosed with TB. We obtained three isolates from classmates of the index case in 2016; all had identical MIRU-VNTR alleles with the index case. The LTBI rate was lower among students (7.41%, 30/405) than among teachers (26.92%, 7/26) (rate ratio [RR] = 0.28, 95% confidential interval [CI]: 0.13–0.57). Among the 17 students who had latent TB and refused prophylaxis in October 2016, 23.53% (4/17) became probable/confirmed cases by July 2019. None of the six teachers who also refused prophylaxis became probable or confirmed cases. Of the 176 students who were TST(-) in October 2016, 1.70% (3/176) became probable/confirmed cases, and among the 20 teachers who were TST(-), 1 became a probable case.

Conclusions

Delayed diagnosis of TB in the index patient may have contributed to the start of this outbreak; lack of post-exposure chemoprophylaxis facilitated spread of the outbreak. Post-exposure prophylaxis is strongly recommended for all TST-positive students; TST-negative students exposed to an SS(+) case should be followed up regularly so that prophylaxis can be started if LTBI is detected.