Screening contacts of patients with extrapulmonary TB for latent TB infection

Bioinformation Analysis Reveals IFIT1 as Potential Biomarkers in Central Nervous System Tuberculosis

Objective

Central nervous system tuberculosis is the most serious form of extrapulmonary tuberculosis. We aim to discover potential biomarkers involved in the development of the disease.

Methods

Through gene difference analysis, construction of a protein interaction network and tissue specific analysis and other bioinformatics analysis methods, we found out the relatively high expression of important substances in the central nervous system, interferon induced protein with tetratricopeptide repeats 1. Subsequently, the lesion tissue and the resection margin tissue away from the lesion were collected from the 6 cases of central nervous system tuberculosis patients diagnosed from 2019 to 2020, and the pathological manifestations were observed by Hematoxylin and Eosin (H&E) staining, and the expression of IFIT1 was verified by immunohistochemistry.

Results

A total of 101 differential genes were analyzed between extrapulmonary tuberculosis patients and normal people, and they were mainly enriched in the interferon pathway. The protein interaction network unearthed 34 key genes. Through tissue specific analysis, it was found that IFIT1 is relatively high in the central nervous system. H&E staining showed the expression of multinucleated macrophages, and immunohistochemistry showed that IFIT1 was significantly positively expressed in the lesion tissue.

Conclusion

IFIT1 is an important substance involved in central nervous system tuberculosis.

Household contact investigation for the detection of active tuberculosis and latent tuberculosis: a comprehensive evaluation in two high-burden provinces in Iran

Background

Systematic evaluation of household contacts of persons with pulmonary tuberculosis (TB) in low- and middle-income countries is recommended by the World Health Organization (WHO). This study recruited adult household contacts of diagnosed TB patients in two high burden provinces of Iran to estimate the prevalence and incidence of active disease and latent TB infection (LTBI) among individuals exposed to TB cases.

Methods

We conducted a cohort study among adults in household contact with a pulmonary TB index case. All subjects were assessed for active disease through evaluation of symptoms. Tuberculin skin test (TST) and QuantiFERON®-TB Gold Plus (QFT-Plus) were used to define LTBI. These tests were performed at the time of the index TB case diagnosis and repeated if the previous result was negative, at three-, 12-, and 18-months post recruitment. In addition, interferon-γ-induced protein-10 (IP-10) concentrations were measured in QFT-Plus supernatants for all participants three months after diagnosing the index case.

Results

A total of 451 individuals who had close contact with 95 active TB patients were enrolled in this study. Five (1.1%) contacts were diagnosed with active TB and 285 (63.2%) were identified with LTBI during our study. The incidence rate of LTBI among adult household contacts of TB index cases was 0.44 per person per year.

Conclusion

The overall rate of LTBI was high. Systematic screening of all household contacts of pulmonary TB should be expanded in Iran to make the timely achievement of the global end TB strategy feasible.

Safety and feasibility of 1 month of daily rifapentine plus isoniazid to prevent tuberculosis in children and adolescents: a prospective cohort study

BACKGROUND

Shorter regimens for tuberculosis prevention can improve completion rates and protection against developing active tuberculosis disease after tuberculosis exposure. We aimed to assess the safety and feasibility of 1 month of daily isoniazid and rifapentine (1HP) in children and adolescents in a low-resource setting in south Asia with low prevalence of HIV.

METHODS

This prospective cohort study was done in eight tuberculosis facilities in Karachi, Pakistan. Eligible participants were aged 2-19 years and were household contacts of patients with drug-susceptible tuberculosis infection. After clinical, radiological, and laboratory evaluation to rule out tuberculosis disease, participants were prescribed 1HP as a preventive regimen. Isoniazid was administered as 100 mg or 300 mg oral tablets and rifapentine was administered as 150 mg oral tablets. Dosing was according to participant bodyweight. The primary endpoints were the cumulative probability of a household contact completing all stages of the preventive care cascade, assessed in all eligible participants, and the proportion of household contacts completing 1HP, assessed among all those who initiated the regimen. Safety was assessed in all household contacts who initiated the 1HP regimen.

FINDINGS

Between Dec 21, 2019, and March 20, 2020, 1395 household contacts of 253 patients with tuberculosis were identified, including 678 household contacts who were eligible to participate. 628 (93%) completed evaluation, of whom ten (2%) had active tuberculosis disease. Of the 618 individuals eligible for tuberculosis prevention, 408 (66%) initiated 1HP, 385 (94%) of whom completed the regimen. The median duration of 1HP was 31 days (IQR 30-32) in those who completed the regimen. The cumulative probability of completing all steps of the tuberculosis prevention cascade was 58%. A girl aged 11 years developed tuberculosis disease within 6 months of completing 1HP. A boy aged 14 years developed a burning sensation during 1HP therapy and discontinued the regimen. No other adverse events were observed.

INTERPRETATION

1HP can be safely and feasibly implemented as tuberculosis prevention in children and adolescents in programmatic settings.

FUNDING

The Global Fund to Fight AIDS, Tuberculosis and Malaria.

Extrapulmonary Tuberculosis in Denmark From 2009 to 2014; Characteristics and Predictors for Treatment Outcome

Background

Extrapulmonary tuberculosis (EPTB) represents an increasing percentage of tuberculosis (TB) cases in Europe. However, strategies on TB prevention and successful treatment outcomes primarily target pulmonary TB. In this nationwide study, we present characteristics of EPTB, treatment outcomes, and predictors for unfavorable treatment outcomes.

Methods

All patients diagnosed with EPTB from 2009 to 2014 were included. Logistic regression analyses were used to identify risk factors for unfavorable outcome. The following definitions were used: unfavorable outcome: the sum of treatment failed, lost to follow-up, and not evaluated; patient delay: time from TB-related symptom onset until first hospital contact related to TB; doctor delay: time from first TB-related contact in the health care system to start of TB treatment.

Results

A total of 450 EPTB cases were notified, which represented 21.1% of all TB cases in Denmark. Immigrants accounted for 82.9%. Lymph nodes were the most common site of EPTB (55.4%) followed by pleural TB (13.4%). Patient delay was significantly longer among immigrants than Danes (60 vs 30 days; P < .01), whereas doctor delay was significantly longer among Danes (38.5 vs 28 days; P < .01). Treatment completion rates were high and reached 90.9% in 2014. Male gender (odds ratio [OR], 5.18; 95% confidence interval [CI], 1.79–15.04) and age 0–24 years (OR, 16.39; 95% CI, 2.02–132.64) were significantly associated with unfavorable outcome.

Conclusions

EPTB represented a significant number of all TB cases and was predominantly seen among younger immigrants in Denmark. To maintain high treatment completion rates, increased focus on male gender and young age is needed.