[Analysis of infection and drug-resistance in 6 107 cases of extrapulmonary tuberculosis in Chengdu area]

Epidemiology of Nontuberculous Mycobacteria in Tuberculosis suspects, Southwest of China, 2017-2022

Objectives

This study summarizes the epidemiological characteristics, species distribution, and drug sensitivity of clinical nontuberculous mycobacteria (NTM) isolates at the Public Health Clinical Center of Chengdu, China, from January 2017 to December 2022.

Methods

We retrospectively analyzed data from patients with clinically isolated NTM strains. Chi-square analysis assessed the rate of Mycobacterium strain isolation over 6 years.

Results

The number of samples tested for Mycobacterium tuberculosis (MTB) and/or NTM increased each year, while MTB detection decreased and NTM detection rose significantly each year (P=0.03). The average age of NTM patients was 51 ± 17.53 years, with a 14.1% HIV infection rate. The predominant isolates were Mycobacterium avium-intracellulare (MAC) and M. chelonae/M. abscessus, with 96.4% of cases being of Han ethnicity. Amikacin, moxifloxacin, and clarithromycin were effective against M. avium and M. intracellulare; linezolid, amikacin, and cefoxitin were effective against M. chelonae/M. abscessus. Over 90% of NTM cases originated from the respiratory tract.

Conclusion

The NTM isolation rate in Southwest China has risen in recent years, primarily among elderly patients with a high HIV co-infection rate. The main NTM isolates were MAC and M. chelonae/M. abscessus. Amikacin, moxifloxacin, clarithromycin, and linezolid exhibited strong antibacterial activity against SGM, while amikacin and linezolid displayed relatively better antibacterial activity against RGM. The prevalence of NTM infection may be positively associated with regional economic development and health conditions.

Osteoarticular tuberculosis cases in the southwest of China: A 9-year retrospective study

Background

Osteoarticular tuberculosis (TB) is an uncommon form of extrapulmonary TB. In this study, we analyzed the epidemiological characteristics, common sites, and drug resistance profiles of osteoarticular TB infections occurring in southwest China.

Methods

A total of 3,254 cases of patients clinically diagnosed with osteoarticular TB infections between 2013 and 2021 were retrospectively analyzed. Patients' demographic and clinical characteristics were collected. Drug sensitivity testing was performed using the microporous plate ratio method. Chi-squared analysis was used to analyze the rates of and trends in mycobacterial isolates.

Results

Of the 3,254 patients, 1,968 (60.5%) were men and boys, and 1,286 (39.5%) were women and girls; patients' ages ranged from 1 to 91 years, with an average of 42 ± 19.3 years. In terms of disease, 2,261 (69.5%) had spinal TB, mainly thoracic (815, 36%) or lumbar (1,080, 48%); joint TB was found in 874 cases (26.9%), mainly occurring in the knee (263, 30%) or hip (227, 26%); and both spinal and joint TB were observed in 119 cases (3.7%). Drug susceptibility tests were performed on 241 isolated strains of MTB; 70 strains (29.0%) were resistant to at least one drug, and MDR-TB and XDR-TB were observed in 7.1 and 1.2% of strains, respectively.

Conclusions

In southwest China over this period, osteoarticular TB mainly affected middle-aged and young men with poor nutritional status. Patients from ethnic minority areas also accounted for a large proportion of cases. Spinal TB is prone to occur in the lumbar and thoracic vertebrae, and joint TB is prone to occur in the lower limb joints. Additionally, there has been an increasing trend in the number of TB cases over the past 9 years, and drug resistance has also increased.

A comparative study of ultrasound-guided puncture biopsy combined with histopathology and Xpert MTB/RIF in the diagnosis of lymph node tuberculosis

Background

Cervical tuberculous lymphadenitis (CTBL) is a disease often ignored in clinical work, and pathology and Xpert MTB/RIF (Xpert) are the commonly used methods for tuberculosis diagnosis. This study aimed to compare ultrasound-guided puncture biopsy combined with histopathology and Xpert in the diagnosis of lymph node tuberculosis.

Methods

A total of 217 patients highly suspected for CTBL were retrospectively enrolled. All patients underwent ultrasound-guided puncture sampling. All samples were subjected to pathological examination and Xpert test. The sensitivity and specificity of the two methods were compared for all samples. The kappa value was calculated to assess the consistency of the pathological examination and Xpert test using comprehensive diagnosis as the gold standard. Receiver operating characteristic curves of the pathological examination, Xpert test, and their combination were generated, and the areas under the curve (AUCs) were calculated to compare the diagnostic value of the three methods.

Results

The sensitivity and specificity of the pathological diagnosis of CTBL were 70.1 and 100%, respectively. The sensitivity and specificity of Xpert for CTBL diagnosis were 82.5 and 97.5%, respectively. The results of the pathological examination and Xpert test showed poor consistency in the diagnosis of CTBL, with a kappa value of 0.388. The AUC of the pathological diagnosis of CTBL was 0.850 (95% CI: 0.796-0.895), whereas that of Xpert was 0.900 (95% CI: 0.852-0.936), and the difference was statistically significant (P = 0.0483). The AUC of pathological examination combined with Xpert for the diagnosis of CTBL was 0.956 (95% CI: 0.920-0.979), and the difference between pathological examination combined with Xpert for the diagnosis of CTBL was statistically significant compared with pathological examination and Xpert alone, respectively (both P < 0.001).

Conclusion

The diagnostic efficiency of Xpert test is higher than that of pathological examination, but its sensitivity is still not ideal for clinical diagnosis. According to this study, the consistency of Xpert test and pathological diagnosis is poor, and the combination of Xpert test and pathological diagnosis can significantly increase the diagnostic efficiency.

Epidemiological, clinical characteristics and drug resistance situation of culture-confirmed children TBM in southwest of China: a 6-year retrospective study

BACKGROUND

Sichuan is a province located in southwestern China, which have a higher incidence of tuberculosis (TB). This study aimed to analyze the epidemiological and clinical characteristics, as well as drug resistance in culture-confirmed children with Tuberculosis meningitis (TBM) in Southwest of China.

METHODS

We performed a retrospective study on children (< 14 years old) with cerebrospinal fluid (CSF) culture-confirmed TBM between January 2013 and December 2018 at Public Health Clinical Center of Chengdu (PHCCC). Mycobacterium tuberculosis (MTB) drug sensitivity testing (DST) was performed using the MicroDST™ method. The age, gender, family history of tuberculosis, status of Bacillus Calmette-Guérin (BCG) vaccination, residential areas information, clinical, laboratory, and radiological features were recorded. Data were analyzed using SPSS Statistics Client 25.0, and the change in drug resistance rate was examined using the Cruskal-Wallis test.

RESULTS

Among 319 patients clinically diagnosed with TBM, 42 (13.2%) were Mycobacterial culture positive. Their median age was nine years, and the distribution was equal among female and male patients. Among 42 patients who were enrolled in the study, 1/42 (2.38%) passed away. Children with TBM were concentrated in the minority areas of western Sichuan, where 34/42 (81.0%) patients with TBM belonged to ethnic minorities, and only 2/42 (4.76%) received BCG vaccination in the past. Chest X-rays changes were observed in all patients. Fever and headache were the most common presenting symptom. Thirty-five (83.3%) patients suffered from neck stiffness, and 30/42 (71.4%) had high CSF pressure. DST results showed that the resistance rate was high; resistance to any anti-tuberculosis drug (ATD) was observed in 13 (31.0%) patient isolates, while multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB) were found in 2 (4.8%) and 1 (2.4%) patients, respectively.

CONCLUSIONS

TBM among children in Southwest China was mainly concentrated in the minority areas of western Sichuan and more than 95% of patients did not receive BCG vaccination at birth. The most common symptoms were fever, headache, and neck stiffness and all patients had positive chest X-ray findings. In addition, high rates of drug resistance were found.