Tuberculosis Transmission Research Articles

A caputo fractional-order model of tuberculosis incorporating enlightenment and therapy using the Laplace-Adomian decomposition method

ABSTRACT In this study, we used a deterministic model to investigate tuberculosis transmission dynamics while considering control measures. We analyzed four compartmental models representing susceptible, latent, infected, and recovered populations. To assess the potential spread of the disease, we calculated the basic reproduction number using the next-generation matrix after establishing a disease-free equilibrium. Additionally, we explored the endemic equilibrium, as well as local and global stabilities. To obtain numerical solutions, we employed the Laplace-Adomian decomposition method. For constructing the model, we utilized Maple 18 software and varied the order (0 < ψ < 1) to examine the impact of enlightenment and therapy. Graphical representations were used to analyze the effects of non-integer order Caputo derivative parameters on the susceptible, latent, infected, and recovered populations over time. Our detailed discussion highlights the crucial role of mathematical models based on Caputo fractional derivatives in effectively controlling and eradicating tuberculosis from society. These findings contribute valuable insights to inform strategies for combating the disease and promoting public health initiatives.

SPREADING PATTERN OF INFECTIOUS DISEASES: SUSCEPTIBLE INFECTED RECOVERED MODEL WITH VACCINATION AND DRUG-RESISTANT CASES (APPLICATION ON TB DATA IN INDONESIA)

Mycobacterium tuberculosis is the causative agent of the infectious illness tuberculosis (TB). Indonesia is the world's third-highest TB burden country. TB transmission is prevented by the BCG vaccination. A directly observed treatment, short-course (DOTS) treatment approach can cure TB illness. Recurrent TB may occur due to either relapse or reinfection with drug-resistant bacteria. The goals of this article are formulating the SVITR model with relapse and drug-resistant cases, applying the model to the TB data in Indonesia, determining the model accuracy, determining the spreading pattern and interpreting the result, and simulating the parameters. Literature study and application methods are used in this research. The SVITR model with relapse and drug-resistant cases is a first-order nonlinear differential equation system. The model is applied to TB in Indonesia based on annual data from Indonesian Health Profile, World Bank, and WHO. The model is solved by the fourth-order Runge-Kutta method. The model is accurate enough to explain the spread of TB in Indonesia with a MAPE value of 15,5%. The spreading pattern of tuberculosis infection is upward from 2010 to 2050. In 2050, there are still 8.115.976 TB cases in Indonesia. Hence in 2050, Indonesia's free of TB target has yet to be achieved. Simulation is conducted by increasing BCG vaccination to 95%, reducing contact with TB patients to 5%, increasing treatment to 95%, and lowering relapses and drug-resistant cases to 0.00005%, so the Indonesia free of TB target in 2050 can be achieved from 2042.

A review of bovine tuberculosis transmission risk in European wildlife communities

Abstract Understanding how disease moves through wildlife communities is essential to managing outbreaks of zoonotic diseases across the globe. Bovine tuberculosis is a disease caused by the bacterium Mycobacterium bovis that can threaten domestic and wildlife species. The mechanism by which Mycobacterium bovis is spread between species is still poorly understood. Previous reviews are limited in the breadth of species considered and are primarily concerned with transmission from wildlife to domestic species. We conducted a review and analysis of Mycobacterium bovis prevalence rates in European wildlife species to identify species of concern for the transmission of bovine tuberculosis in a wildlife community. We subsequently conducted a narrative review of these species assessing the risk of Mycobacterium bovis transmission in a wildlife community based on available literature. We calculated weighted mean disease prevalence rates to be highest in fallow deer (Dama dama, 20%), Eurasian badgers (Meles meles, 11%), wild boar (Sus scrofa, 9%) and red foxes (Vulpes vulpes, 4%). We considered these species to be of particular concern for the transmission of Mycobacterium bovis and selected them as the focus of our narrative review and risk assessment. Our risk assessment considered disease pathology, spatiotemporal activity patterns and animal behaviour as factors affecting the likelihood of Mycobacterium bovis transmission between wildlife species. We found that prior research has principally focused on a few individual species, but that Mycobacterium bovis transmission through a wildlife community is likely more complex. We determined that disease transmission between multiple species may compound the severity of an outbreak of bovine tuberculosis. Broad, multi‐species sampling campaigns and standardised Mycobacterium bovis testing protocols should be implemented in future studies. We also determined that an in‐depth analysis of spatiotemporal overlap between species was needed to better assess the risk of transmission between wildlife species.

Tuberculosis in Wild Pigs from Argentina.

Mycobacterium bovis, a member of the Mycobacterium tuberculosis complex (MTC) and non-tuberculous Mycobacteria (NTM), may infect wild and domestic mammals, including humans. Although cattle are the main hosts and spreaders of M. bovis, many wildlife hosts play an important role worldwide. In Argentina, wild boar and domestic pigs are considered important links in mammalian tuberculosis (mTB) transmission. The aim of this work was to investigate the presence of M. bovis in wild pigs from different regions of Argentina, to characterize isolates of M. bovis obtained, and to compare those with other previously found in vertebrate hosts. A total of 311 samples from wild pigs were obtained, and bacteriological culture, molecular identification and genotyping were performed, obtaining 63 isolates (34 MTC and 29 NTM). Twelve M. bovis spoligotypes were detected. Our findings suggest that wild pigs have a prominent role as reservoirs of mTB in Argentina, based on an estimated prevalence of 11.2 ± 1.8% (95% CI 8.0-14.8) for MTC and the frequency distribution of spoligotypes shared by cattle (75%), domestic pigs (58%) and wildlife (50%). Argentina has a typical scenario where cattle and pigs are farm-raised extensively, sharing the environment with wildlife, creating conditions for effective transmission of mTB in the wildlife-livestock-human interface.

Prevalence of Smear-Positive, Rifampicin-Resistant Mycobacterium tuberculosis and Related Factors Among Residents with Cough in Northern Ethiopian Refugee Health Facilities.

To ascertain the prevalence of Mycobacterium tuberculosis (M.tb) among refugees suspected of tuberculosis (TB) and related risk factors, including smear-positive and Rifampicin-resistant M.tb. A cross-sectional study was conducted between January 2020 and May 2020 among 384 refugees in four refugee camps in Northwest Tigray, Ethiopia. Socio-demographic and clinical data were collected from refugees with a history of cough for more than two weeks prospectively. Spot-spot sputum samples were collected and transported in an ice box to the Shire Suhul Hospital Microbiology laboratory; and then examined using a Fluorescent Microscope. All smear-positive samples were further processed by GeneXpert to detect Rifampicin-resistant MTB. Data were analyzed using SPSS version 21 and a p-value <0.05 was considered statistically significant. The overall prevalence of smear-positive PTB infection was 5.5% (21/384), but No TB case was resistant to Rifampicin detected by GeneXpert MTB/RIF assay. About 70% of the smear-positive pulmonary TB identified were females. Five (23.8%) of the smear-positive pulmonary tuberculosis cases were co-infected by HIV. Sharing of drink and food materials (AOR = 4.36, 95% CI = 1.19-15.89), active TB contact (AOR 7.24, 95% CI = 1.62-32.125), BMI (AOR = 5.23, 95% CI = 1.28-21.29), opening window practice (AOR = 4.32, 95% CI = 1.02-18.30) and HIV status (AOR = 9.36, 95% CI = 1.64-53.35) were statistically significant predisposing factors. The prevalence of smear-positive pulmonary TB among northwest Tigray refugee camps was still high. The prevalence of TB/HIV co-infection was also high. Minimizing close contact with active TB cases, reducing malnutrition, rapid TB/HIV screening, and establishing a ventilation system can reduce the transmission of TB among refugees.

STUDY ON DYNAMIC BEHAVIORS OF TUBERCULOSIS MODEL WITH GENDER AND AGE-STRUCTURE

This paper deals with the dynamics of tuberculosis transmission model with different genders and age structures. The basic reproduction numbers [Formula: see text] are defined, where [Formula: see text] and [Formula: see text] are the basic reproduction number of tuberculosis transmission in female and male populations, respectively. The global stability of the disease-free equilibrium was discussed when [Formula: see text]; The existence, uniqueness and global stability of the endemic equilibrium, and the persistence of the system both were proved when [Formula: see text]. The findings indicate that the tuberculosis dynamical model with different genders and age structures will experience the classical threshold dynamic behaviors, that is, if [Formula: see text], the disease will disappear; while if [Formula: see text], the disease will spread within the population, and eventually lead to a endemic disease. Finally, the theoretical analysis of the model is verified by numerical simulation and we proposed that male infected individuals should be focused on in the prevention and control of tuberculosis in the future.

Health Seeking Behaviour among the Internally Displaced Persons in the North East Nigeria: Case Study of Tuberculosis Patients

Over two million people are internally displaced in north-eastern Nigeria due to the complex humanitarian catastrophe. Overcrowded and unclean living conditions increase the risk of tuberculosis (TB) transmission, sickness, and death. The seeking behaviour of internally displaced persons (IDPs) in northeastern Nigeria was explored to improve disease surveillance and response in IDP camps and host communities.

Who Transmits Tuberculosis to Whom: A Cross-Sectional Analysis of a Cohort Study in Lima, Peru.

Rationale: The persistent burden of tuberculosis (TB) disease emphasizes the need to identify individuals with TB for treatment and those at a high risk of incident TB for prevention. Targeting interventions toward those at high risk of developing and transmitting TB is a public health priority. Objectives: We aimed to identify characteristics of individuals involved in TB transmission in a community setting, which may guide the prioritization of targeted interventions. Methods: We collected clinical and sociodemographic data from a cohort of patients with TB in Lima, Peru. We used whole-genome sequencing data to assess the genetic distance between all possible pairs of patients; we considered pairs to be the result of a direct transmission event if they differed by three or fewer SNPs, and we assumed that the first diagnosed patient in a pair was the transmitter and the second was the recipient. We used logistic regression to examine the association between host factors and the likelihood of direct TB transmission. Measurements and Main Results: Analyzing data from 2,518 index patients with TB, we identified 1,447 direct transmission pairs. Regardless of recipient attributes, individuals less than 34 years old, males, and those with a history of incarceration had a higher likelihood of being transmitters in direct transmission pairs. Direct transmission was more likely when both patients were drinkers or smokers. Conclusions: This study identifies men, young adults, former prisoners, alcohol consumers, and smokers as priority groups for targeted interventions. Innovative strategies are needed to extend TB screening to social groups such as young adults and prisoners with limited access to routine preventive care.

BURDEN OF TUBERCULOSIS IN INDIA: INFORMATION FROM NFHS-5

Tuberculosis (TB) is an infectious disease and is caused by germ (bacterium) called Mycobacterium Tuberculosis. Transmission of tuberculosis is mainly through air by inhalation of infected droplet nuclei, which are discharged in the air when a patient with untreated sputum positive tuberculosis (TB) coughs or sneezes. Other modifier of the risk of disease are age, with greater risk during infancy and adolescence, and gender, with young women more likely to develop disease soon after infection. This article reports a self-reported levels and socioeconomic patterns in the distribution of tuberculosis (TB) cases in India, based on information collected under the National Family Health Survey-Round 5 (NFHS-5, 2019–21). The prevalence of TB in various characteristics of households along with Rural-Urban break-up is studied and it is seen that the prevalence of TB is 1% at India level. The prevalence of TB is higher in Rural areas as compare to Urban areas. The percentage distribution of sample households by with TB patients are also influenced by other socio-economic characteristics. KEYWORDS: Tuberculosis, NFHS-5, Households

Trends of type 2 diabetes with pulmonary tuberculosis patients,2013–2022, and changes after the coronavirus disease 2019 (COVID-19) pandemic

BackgroundTo describe the trends of Type 2 Diabetes with Pulmonary Tuberculosis (T2DM-TB) patients from 2013 to 2022 and to investigate the impact of COVID-19 lockdown on glycemic control and associated factors in T2DM-TB. MethodsIn this population-based study of the First Affiliated Yijishan Hospital of Wannan Medical College in China, we described the 10-year trends of patients diagnosed with T2DM-TB. We included patients diagnosed with TB, T2DM-TB and T2DM-TB patients for comparative analysis, aged 15 years or older. Data were missing, and both multidrug-resistant (MDR) TB patients and non-T2DM patients were excluded from our study. ResultsWe pooled Type 2 Diabetes (T2DM) and Tuberculosis (TB) data from The First Affiliated Yijishan Hospital of Wannan Medical College in China, gathered between January 1, 2013, and December 31, 2022. The data included 14,227 T2DM patients, 6130 TB patients, and 982 T2DM-TB patients. During the past 10 years, the number of inpatients with TB decreased, while the number of patients with T2DM and T2DM-TB increased year by year. To rule out any influence factors, we analyzed the ratio of the three groups. The ratio of TB/T2DM decreased year by year (p < 0.05), while the ratio of TB-T2DM/TB increasing year by year (p = 0.008). During the COVID-19 epidemic period, there was no significant change in the ratio of TB-T2DM/T2DM (p = 0.156). There was no significant change in the proportion of male patients with TB and TB-T2DM (p = 0.325; p = 0.190), but the proportion of male patients with T2DM showed an increasing trend (p < 0.001). The average age of TB patients over the past 10 years was 54.5 ± 18.4 years and showed an increasing trend year by year (p < 0.001). However, there was no significant change in the age of T2DM or TB-T2DM patients (p = 0.064; p = 0.241). Patients data for the first (2013–2017) and the last (2018–2022) five years were compared. We found that the number of T2DM and TB-T2DM in the last five years was significantly higher than in the first five years, but the number of TB was significantly lower than in the first five years. There is a significant statistical difference in the proportion of TB/T2DM and TB-T2DM/TB, which is similar to the previous results. The average age (56.0 ± 17.6 years) of TB patients in the last five years is significantly higher than in the first five years (53.1 ± 18.9) (p < 0.001). The number of male patients with T2DM in the last five years is higher than that in the first five years, with significant difference (p < 0.001). ConclusionThe trends of T2DM-TB among hospitalized TB patients have increased significantly over the past 10 years, which may be related to the increase in the number of T2DM cases. The COVID-19 pandemic has been effective in controlling the transmission of TB, but it has been detrimental to the control of T2DM. Male patients with T2DM and elderly TB patients are the key populations for future prevention and control efforts.

Inferring Mycobacterium Tuberculosis Drug Resistance and Transmission using Whole-genome Sequencing in a High TB-burden Setting in China

ObjectiveChina is among the 30 countries with a high burden of tuberculosis (TB) worldwide, and TB remains a public health concern. Kashgar Prefecture in the southern Xinjiang Autonomous Region is considered as one of the highest TB burden regions in China. However, molecular epidemiological studies of Kashgar are lacking. MethodsA population-based retrospective study was conducted using whole-genome sequencing (WGS) to determine the characteristics of drug resistance and the transmission patterns. ResultsA total of 1,668 isolates collected in 2020 were classified into lineages 2 (46.0%), 3 (27.5%), and 4 (26.5%). The drug resistance rates revealed by WGS showed that the top three drugs in terms of the resistance rate were isoniazid (7.4%, 124/1,668), streptomycin (6.0%, 100/1,668), and rifampicin (3.3%, 55/1,668). The rate of rifampicin resistance was 1.8% (23/1,290) in the new cases and 9.4% (32/340) in the previously treated cases. Known resistance mutations were detected more frequently in lineage 2 strains than in lineage 3 or 4 strains, respectively: 18.6% vs. 8.7 or 9%, P < 0.001. The estimated proportion of recent transmissions was 25.9% (432/1,668). Multivariate logistic analyses indicated that sex, age, occupation, lineage, and drug resistance were the risk factors for recent transmission. Despite the low rate of drug resistance, drug-resistant strains had a higher risk of recent transmission than the susceptible strains (adjusted odds ratio, 1.414; 95% CI, 1.023–1.954; P = 0.036). Among all patients with drug-resistant tuberculosis (DR-TB), 78.4% (171/218) were attributed to the transmission of DR-TB strains. ConclusionOur results suggest that drug-resistant strains are more transmissible than susceptible strains and that transmission is the major driving force of the current DR-TB epidemic in Kashgar.

Whole Genome Sequence Dataset of Mycobacterium tuberculosis Strains from Patients of Campania Region

Tuberculosis (TB) is one of the deadliest infectious disorders in the world. To effectively TB manage, an essential step is to gain insight into the lineage of Mycobacterium tuberculosis (MTB) and the distribution of drug resistance. Although the Campania region is declared a cluster area for the infection, to contribute to the effort to understand TB evolution and transmission, still poorly known, we have generated a dataset of 159 genomes of MTB strains, from Campania region collected during 2018–2021, obtained from the analysis of whole genome sequence. The results show that the most frequent MTB lineage is the 4 according for 129 strains (81.11%). Regarding drug resistance, 139 strains (87.4%) were classified as multi susceptible, while the remaining 20 (12.58%) showed drug resistance. Among the drug-resistance strains, 8 were isoniazid-resistant MTB, 4 multidrug-resistant MTB, while only one was classified as pre-extensively drug-resistant MTB. This dataset expands the existing available knowledge on drug resistance and evolution of MTB, contributing to further TB-related genomics studies to improve the management of this disease.

Biosecurity Challenges: How Defense Strategies Against Tuberculosis In Asean Countries

This comprehensive research provides a thorough analysis of tuberculosis (TB) incidence trends and sanitation challenges within the ASEAN region spanning from 2005 to 2021. It underscores the critical need for robust defense strategies against TB, particularly in light of setbacks exacerbated by the COVID-19 pandemic. The research, conducted in Jakarta, Indonesia, from June to July 2023, delved into biosecurity challenges of tuberculosis in ASEAN countries, using a quantitative approach and cross-sectional design. Data from 2005 to 2021, sourced from the ASEAN database, underwent descriptive statistics and trend analysis to explore TB incidence rates, ensuring a comprehensive investigation scope. The study places emphasis on the imperative of implementing comprehensive measures encompassing prevention, screening, swift diagnosis, utilization of advanced treatment regimens, and ensuring robust patient support systems. Moreover, it highlights the pivotal role of addressing sanitation challenges, as substandard conditions significantly heighten the risks of TB transmission. The study's scope encompasses an array of critical subjects, with a central focus on TB incidence rates, as well as the crucial aspects of access to improved sanitation facilities and sanitation services. The conclusion is the ASEAN region, especially the Philippines, faces a notable tuberculosis burden, coupled with uneven access to sanitation. Effective interventions and collaboration are vital for improving public health and sanitation standards in ASEAN countries.

Transmission of drug-resistant Mycobacterium tuberculosis isolates between Finnish- and foreign-born cases, 2014–2021: A molecular epidemiological study

BackgroundData on the molecular epidemiology and transmission of drug-resistant Mycobacterium tuberculosis (MTB) in low-incidence settings with immigration from high-incidence settings is limited. MethodWe included 115 drug-resistant (DR) MTB isolates with whole-genome sequencing data isolated in Finland between 2014 and 2021. Potential transmission clusters were identified using a threshold of 12 single-nucleotide polymorphisms (SNPs). Highly related clusters were identified using a threshold of 5 SNPs. ResultOf the 115 DR MTB isolates, 31 (27.0%) isolates were from Finnish-born cases and 84 (73.0%) were from foreign-born cases. The proportion of multidrug-resistant (MDR) MTB isolates (30/84, 35.7%) from foreign-born cases was higher than that of MDR MTB isolates from Finnish-born cases (8/31, 25.8%). Lineage 2 (40/115, 34.8%) and lineage 4 (40/115, 34.8%) were the most prevalent lineages. A total of 25 (21.7%) isolates were classified into eight potential transmission clusters (≤12 SNPs). Furthermore, five highly related clusters (≤5 SNPs) were identified, including three DR MTB isolates from Finnish-born cases and 14 DR isolates from foreign-born cases. ConclusionThe risk of DR MTB transmission between Finnish- and foreign-born persons is not negligible. Further research on clustering analysis in drug-susceptible MTB is worth to inform tuberculosis management and control in low-incidence settings with increasing immigration.

A first insight into tuberculosis transmission at the border of Ecuador and Colombia: a retrospective study of the population structure of Mycobacterium tuberculosis in Esmeraldas province.

Tuberculosis (TB) is a major public health concern in Ecuador and Colombia, considering that both countries are high-burden TB settings. Molecular epidemiology is crucial to understand the transmission dynamics of Mycobacterium tuberculosis complex (MTBC) and to identify active transmission clusters of regional importance. We studied the potential transmission of TB between Colombia and Ecuador through the analysis of the population structure of MTBC lineages circulating in the Ecuadorian province of Esmeraldas at the border with Colombia. A total of 105 MTBC strains were characterized by 24-loci MIRU-VNTR and spoligotyping. MTBC lineage 4 is only present in Esmeraldas; no MTBC strains belonging to Lineage 2-sublineage Beijing were found despite its presence in other provinces of Ecuador and, in Colombia. Genotyping results revealed a high degree of diversity for MTBC in Esmeraldas: Neither active transmission clusters within this province nor including MTBC strains from Colombia or other provinces of Ecuador were found. Our data suggest that tuberculosis dynamics in this rural and isolated area may be not related to highly transmitted strains but could be influenced by other health determinants that favor TB relapse such as poverty and poor health system access. Further studies including a larger number of MTBC strains from Esmeraldas are necessary to test this hypothesis.

Accuracy of digital chest x-ray analysis with artificial intelligence software as a triage and screening tool in hospitalized patients being evaluated for tuberculosis in Lima, Peru.

Tuberculosis (TB) transmission in healthcare facilities is common in high-incidence countries. Yet, the optimal approach for identifying inpatients who may have TB is unclear. We evaluated the diagnostic accuracy of qXR (Qure.ai, India) computer-aided detection (CAD) software versions 3.0 and 4.0 (v3 and v4) as a triage and screening tool within the FAST (Find cases Actively, Separate safely, and Treat effectively) transmission control strategy. We prospectively enrolled two cohorts of patients admitted to a tertiary hospital in Lima, Peru: one group had cough or TB risk factors (triage) and the other did not report cough or TB risk factors (screening). We evaluated the sensitivity and specificity of qXR for the diagnosis of pulmonary TB using culture and Xpert as primary and secondary reference standards, including stratified analyses based on risk factors. In the triage cohort (n = 387), qXR v4 sensitivity was 0.91 (59/65, 95% CI 0.81-0.97) and specificity was 0.32 (103/322, 95% CI 0.27-0.37) using culture as reference standard. There was no difference in the area under the receiver-operating-characteristic curve (AUC) between qXR v3 and qXR v4 with either a culture or Xpert reference standard. In the screening cohort (n = 191), only one patient had a positive Xpert result, but specificity in this cohort was high (>90%). A high prevalence of radiographic lung abnormalities, most notably opacities (81%), consolidation (62%), or nodules (58%), was detected by qXR on digital CXR images from the triage cohort. qXR had high sensitivity but low specificity as a triage in hospitalized patients with cough or TB risk factors. Screening patients without cough or risk factors in this setting had a low diagnostic yield. These findings further support the need for population and setting-specific thresholds for CAD programs.

Investigating socio-ecological factors influencing implementation of tuberculosis infection prevention and control in rural Papua New Guinea.

Tuberculosis (TB) is a highly transmissible infectious disease killing millions of people yearly, particularly in low-income countries. TB is most likely to be transmitted in healthcare settings with poor infection control practices. Implementing TB infection prevention and control (TB-IPC) is pivotal to preventing TB transmission in healthcare settings. This study investigated diverse stakeholders' perspectives relating to barriers and strategies for TB-IPC in rural hospitals in Papua New Guinea. Multiple qualitative case studies were conducted with 32 key stakeholders with experience in TB services. Data collection drew on three primary sources to triangulate data: semi-structured interviews, document reviews and field notes. The data were analyzed using hybrid deductive-inductive thematic analysis. Our results reveal that key stakeholders perceive multiple interdependent factors that affect TB-IPC practice. The key emerging themes include strategic planning for and prioritizing TB-IPC guidelines; governance, leadership and accountability at the provincial level; community attitudes towards TB control; institutional capacity to deliver TB care, healthcare workers' safety, and long-term partnership and integration of TB-IPC programmes into the broad IPC programme. The evidence suggests that a multi-perspective approach is crucial for TB-IPC guidelines in healthcare institutions. Interventions focusing on addressing health systems strengthening may improve the implementation of TB-IPC guidelines.

The Recent Transmission and Associated Risk Factor of Mycobacterium tuberculosis in Golmud City, China.

Tuberculosis (TB) remains a severe public health problem globally, and it is essential to comprehend the transmission pattern to control tuberculosis. Herein, we evaluated the drug-resistant characteristics, recent transmission, and associated risk factors of TB in Golmud, Qinghai, China. In this study, we performed a population-based study of patients diagnosed with TB in Golmud from 2013 to 2018. Drug-susceptibility testing and whole-genome sequencing were performed on 133 Mycobacterium tuberculosis strains. The genomic clustering rate was calculated to evaluate the level of recent transmission. Risk factors were identified by logistic regression analysis. Our results showed that 46.97% (62/132) of strains were phylogenetically clustered and formed into 23 transmission clusters, suggesting a high recent transmission of TB in the area. 12.78% (17/133) strains were multidrug-resistant/rifampicin tuberculosis (MDR/RR-TB), with a high drug-resistant burden. Based on drug resistance gene analysis, we found 23 strains belonging to genotype MDR/RR-TB, where some strains may have borderline mutations. Among these strains, 65.2% (15/23) were found within putative transmission clusters. Additionally, risk factor analysis showed that recent transmission of TB happened more in patients with Tibetan nationality or older age. Overall our study indicates that the recent transmissions of MTB strains, especially genotypic MDR/RR strains, drive the tuberculosis epidemic in Golmud, which could contribute to developing effective TB prevention and control strategies.

Implementing a continuous quality-improvement framework for tuberculosis infection prevention and control in healthcare facilities in China, 2017-2019.

Tuberculosis (TB) infection prevention and control (IPC) in healthcare facilities is key to reducing transmission risk. A framework for systematically improving TB IPC through training and mentorship was implemented in 9 healthcare facilities in China from 2017 to 2019. Facilities conducted standardized TB IPC assessments at baseline and quarterly thereafter for 18 months. Facility-based performance was assessed using quantifiable indicators for IPC core components and administrative, environmental, and respiratory protection controls, and as a composite of all control types We calculated the percentage changes in scores over time and differences by IPC control type and facility characteristics. Scores for IPC core components increased by 72% during follow-up when averaged across facilities. The percentage changes for administrative, environmental, and respiratory protection controls were 39%, 46%, and 30%, respectively. Composite scores were 45% higher after the intervention. Overall, scores increased most during the first 6 months. There was no association between IPC implementation and provincial economic development or volume of TB services. TB IPC policies and practices showed most improvement early during implementation and did not differ consistently by facility characteristics. The training component of the project helped increase the capacity of healthcare professionals to manage TB transmission risks. Lessons learned here will inform national TB IPC guidance.

Prison as a driver of recent transmissions of multidrug-resistant tuberculosis in Callao, Peru: a cross-sectional study

We sought to identify resistance patterns and key drivers of recent multidrug-resistant tuberculosis (MDR-TB) transmission in a TB-prevalent area in Peru. Cross-sectional study including MDR Mycobacterium tuberculosis complex (Mtbc) strains identified in Callao-Peru between April 2017 and February 2019. Mtbc DNA was extracted for whole genome sequencing which was used for phylogenetic inference, clustering, and resistance mutation analyses. Clusters indicative of recent transmission were defined based on a strain-to-strain distance of ≤5 (D5) single nucleotide polymorphisms (SNPs). Epidemiologic factors linked to MDR-TB clustering were analyzed using Poisson regression. 171 unique MDR-Mtbc strains were included; 22 (13%) had additional fluoroquinolone resistance and were classified as pre-XDR. Six strains (3.5%) harboured bedaquiline (BDQ) resistance mutations and were classified as MDR+BDQ. 158 (92%) Mtbc strains belonged to lineage 4 and 13 (8%) to lineage 2. Using a cluster threshold of ≤5 SNPs, 98 (57%) strains were grouped in one of the 17 D5 clusters indicative of recent transmission, ranging in size from 2 to the largest cluster formed by 53 4.3.3 strains (group_1). Lineage 4.3.3 strains showed the overall highest cluster rate (43%). In multivariate analyses, current or previous imprisonment was independently associated with being part of any MDR-TB transmission clusters (adjusted prevalence ratio [aPR], 1.45; 95% CI, 1.09-1.92). Pre-XDR-TB emerged in more than 10% of the MDR-TB strains investigated. Transmission of 4.3.3 Mtbc strains especially of the dominant group_1 clone is a major driver of the MDR-TB epidemic in Callao. Current or previous imprisonment was linked to recent MDR-TB transmissions, indicating an important role of prisons in driving the MDR-TB epidemic. This work was supported in part by the ERANet-LAC Network of the European Union, Latin America and the Caribbean Countries on Joint Innovation and Research Activities, and FONDECYT. Additional support was received from Leibniz Science Campus Evolutionary Medicine of the Lung, the Deutsche Forschungsgemeinschaft (German Research Foundation, under Germany's Excellence Strategy-EXC 2167 Precision Medicine in Inflammation), and the Research Training Group 2501 TransEvo.