Transmission pattern of drug-resistant tuberculosis and its implication for tuberculosis control in eastern rural China

A New Hybrid Model Using an Autoregressive Integrated Moving Average and a Generalized Regression Neural Network for the Incidence of Tuberculosis in Heng County, China

It is a daunting task to eradicate tuberculosis completely in Heng County due to a large transient population, human immunodeficiency virus/tuberculosis coinfection, and latent infection. Thus, a high-precision forecasting model can be used for the prevention and control of tuberculosis. In this study, four models including a basic autoregressive integrated moving average (ARIMA) model, a traditional ARIMA-generalized regression neural network (GRNN) model, a basic GRNN model, and a new ARIMA-GRNN hybrid model were used to fit and predict the incidence of tuberculosis. Parameters including mean absolute error (MAE), mean absolute percentage error (MAPE), and mean square error (MSE) were used to evaluate and compare the performance of these models for fitting historical and prospective data. The new ARIMA-GRNN model had superior fit relative to both the traditional ARIMA-GRNN model and basic ARIMA model when applied to historical data and when used as a predictive model for forecasting incidence during the subsequent 6 months. Our results suggest that the new ARIMA-GRNN model may be more suitable for forecasting the tuberculosis incidence in Heng County than traditional models.

Spoligotype defined lineages of Mycobacterium tuberculosis and drug resistance: Merely a casual correlation?

Drug-resistant tuberculosis (TB) is a major challenge to TB control strategy worldwide. Analysis of genetic polymorphism among drug resistant Mycobacterium tuberculosis (MTB) strains may help provide some insight into the transmission dynamics of these strains. Spoligotyping is a widely used technique to identify genetic polymorphism, based on 43 known spacers interspersed between direct repeat regions. Considerable work has been done in various parts of the world using this technique to identify and analyse the polymorphic nature of MTB. Many studies have been carried out to determine the association of drug resistance with spoligotype defined lineages, and much data has been produced over the years. New information continues to be generated. This review aims to put together the findings of relevant studies in an attempt to understand the correlation of drug resistance with spoligotype defined lineages of MTB. This would help provide a perspective of the available data that can be used as a starting point to understand the molecular epidemiology of drug resistant TB.

Molecular epidemiology of Mycobacterium tuberculosis among South African gold miners

RATIONALE

HIV-associated tuberculosis remains a major health problem among the gold-mining workforce in South Africa. We postulate that high levels of recent transmission, indicated by strain clustering, are fueling the tuberculosis epidemic among gold miners.

OBJECTIVES

To combine molecular and epidemiologic data to describe Mycobacterium tuberculosis genetic diversity, estimate levels of transmission, and examine risk factors for clustering.

METHODS

We conducted a cross-sectional study of culture-positive M. tuberculosis isolates in 15 gold mine shafts across three provinces in South Africa. All isolates were subject IS6110-based restriction fragment length polymorphisms, and we performed spoligotyping analysis and combined it with basic demographic and clinical information.

MEASUREMENTS AND MAIN RESULTS

Of the 1,602 M. tuberculosis patient isolates, 1,240 (78%) had genotyping data available for analysis. A highly diverse bacillary population was identified, comprising a total of 730 discrete genotypes. Four genotypic families (Latin American Mediterranean spoligotype family; W-Beijing; AH or X; and T1-T4) accounted for over 50% of all strains. Overall, 45% (560/1,240) of strains were genotypically clustered. The minimum estimate for recent transmission (n - 1 method) was 32% (range, 27-34%). There were no individual-level risk factors for clustering, apart from borderline evidence for being non-South African and having self-reported HIV infection.

CONCLUSIONS

The high M. tuberculosis genetic diversity and lack of risk factors for clustering are indicative of a universal risk for disease among gold miners and likely mixing with nonmining populations. Our results underscore the urgent need to intensify interventions to interrupt transmission across the entire gold-mining workforce in South Africa.

Prevalence and occurrence rate of Mycobacterium tuberculosis Haarlem family multi-drug resistant in the worldwide population: A systematic review and meta-analysis

BACKGROUND

Transmission of Mycobacterium tuberculosis (M. tuberculosis) can occur in different ways. Furthermore, drug resistant in M. tuberculosis family is a major problem that creates obstacles in treatment and control of tuberculosis (TB) in the world. One of the most prevalent families of M. tuberculosis is Haarlem, and it is associated with drug resistant. Our objectives of this study were to determine the prevalence and occurrence rate of M. tuberculosis Haarlem family multi-drug resistant (MDR) in the worldwide using meta-analysis based on a systematic review that performed on published articles.

MATERIALS AND METHODS

Data sources of this study were 78 original articles (2002-2012) that were published in the literatures in several databases including PubMed, Science Direct, Google Scholar, Biological abstracts, ISI web of knowledge and IranMedex. The articles were systematically reviewed for prevalence and rate of MDR. Data were analyzed using meta-analysis and random effects models with the software package Meta R, Version 2.13 (P < 0.10).

RESULTS

Final analysis included 28601 persons in 78 articles. The highest and lowest occurrence rate of Haarlem family in M. tuberculosis was in Hungary in 2006 (66.20%) with negative MDR-TB and in China in 2010 (0.8%), respectively. From 2002 to 2012, the lowest rate of prevalence was in 2010, and the highest prevalence rate was in 2012. Also 1.076% were positive for MDR and 9.22% were negative (confidence interval: 95%).0020.

CONCLUSION

Many articles and studies are performed in this field globally, and we only chose some of them. Further studies are needed to be done in this field. Our study showed that M. tuberculosis Haarlem family is prevalent in European countries. According to the presence of MDR that was seen in our results, effective control programs are needed to control the spread of drug-resistant strains, especially Haarlem family.

Role of casual contacts in the recent transmission of tuberculosis in settings with high disease burden

Tuberculosis (TB) remains a major cause of morbidity and mortality worldwide. It is expected that combining multiple molecular methods will further help in focusing contact investigations. We performed a population-based molecular epidemiological study in six sites in China between 1 June 2009 and 31 December 2010. A genotyping method combining 7-loci MIRU-VNTR and IS6110-based RFLP was employed to determine predictors of recent transmission. A second interview was performed with the clustered patients to identify potential epidemiological links. The molecular clustering analysis revealed that 187 isolates (15.3%) were clustered by sharing identical VNTR-IS6110 combined patterns, with an estimated recent transmission index being 8.9%. None of these patients reported having contacts with other members within the same cluster. Nineteen of 121 reported having a history of contact with a TB case within 2 years before the current TB diagnosis. Additionally, geographical correlation was established for 19 cases in nine clusters, while only one possible epidemiological link was established in secondary interview. The results underscore the role of casual contact or reactivation of latent TB as a driving factor maintaining the current endemicity in rural China, with high disease burdens of tuberculosis.

Management of patients with multidrug-resistant/extensively drug-resistant tuberculosis in Europe: a TBNET consensus statement

The emergence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis (TB) substantially challenges TB control, especially in the European Region of the World Health Organization, where the highest prevalence of MDR/XDR cases is reported. The current management of patients with MDR/XDR-TB is extremely complex for medical, social and public health systems. The treatment with currently available anti-TB therapies to achieve relapse-free cure is long and undermined by a high frequency of adverse drug events, suboptimal treatment adherence, high costs and low treatment success rates. Availability of optimal management for patients with MDR/XDR-TB is limited even in the European Region. In the absence of a preventive vaccine, more effective diagnostic tools and novel therapeutic interventions the control of MDR/XDR-TB will be extremely difficult. Despite recent scientific advances in MDR/XDR-TB care, decisions for the management of patients with MDR/XDR-TB and their contacts often rely on expert opinions, rather than on clinical evidence.

This document summarises the current knowledge on the prevention, diagnosis and treatment of adults and children with MDR/XDR-TB and their contacts, and provides expert consensus recommendations on questions where scientific evidence is still lacking.

TBNET consensus statement on the management of patients with MDR/XDR-TB has been released in theEur Respir Jhttp://ow.ly/uizRD

Incidence and transmission patterns of tuberculosis among indigenous populations in Brazil

Approximately 10% of the Brazilian indigenous population lives in the state of Mato Grosso do Sul (MS), where a large number of new cases of tuberculosis (TB) are reported. This study was conducted to assess TB occurrence, transmission and the utility of TB diagnosis based on the Ogawa-Kudoh (O-K) culture method in this remote population. The incidence of TB was estimated by a retrospective review of the surveillance data maintained by the Notifiable Diseases Surveillance System for the study region. The TB transmission pattern among indigenous people was assessed by genotyping Mycobacterium tuberculosis isolates using the IS 6110 restriction fragment length polymorphism (RFLP) technique. Of the 3,093 cases identified from 1999-2001, 610 (~20%) were indigenous patients (average incidence: 377/100,000/year). The use of the O-K culture method increased the number of diagnosed cases by 34.1%. Of the genotyped isolates from 52 indigenous patients, 33 (63.5%) belonged to cluster RFLP patterns, indicating recently transmitted TB. These results demonstrate high, on-going TB transmission rates among the indigenous people of MS and indicate that new efforts are needed to disrupt these current transmissions.