Epidemiology Of Multidrug-resistant Tuberculosis Research Articles

Epidemiology of multi-drug resistant Tuberculosis in the western region of Kenya.

Multidrug-resistant tuberculosis (TB) (MDR-TB), or TB that is simultaneously resistant to both isoniazid (INH) and rifampicin (RIF), is a barrier to successful TB control and treatment. Stratified data on MDR-TB, particularly in the high-burden western Kenya region, remain unknown. This data is important to monitor the efficacy of TB control and treatment efforts. Herein, we determined the molecular epidemiology of drug-resistant TB and associated risk factors in western Kenya. This was a non-experimental, population-based, cross-sectional study conducted between January and August 2018. Morning sputum samples of individuals suspected of pulmonary TB were collected, processed, and screened for Mycobacterium tuberculosis (Mtb) and drug resistance using line probe assay (LPA) and Mycobacterium growth indicator tubes (MGIT) culture. MGIT-positive samples were cultured on brain heart infusion (BHII) agar media, and the presence of Mtb was validated using Immunochromatographic assay (ICA). Drug sensitivity was performed on MGIT and ICA-positive but BHI-negative samples. Statistical significance was set at P < 0.05. Of the 622 Mtb isolates, 536 (86.2%) were susceptible to RIF and INH. The rest, 86 (13.83%), were resistant to either drugs or both. A two-sample proportional equality test revealed that the MDR-TB prevalence in western Kenya (5%) did not vary significantly from the global MDR-TB estimate (3.9%) (P = 0.196). Men comprised the majority of susceptible and resistant TB (75.9% and 77.4%%, respectively). Also, compared with healthy individuals, the prevalence of HIV was significantly higher in MDR-TB patients (35.9% vs 5.6%). Finally, TB prevalence was highest in individuals aged 25-44 years, who accounted for 58.4% of the total TB cases. Evidently, the prevalence of MDRTB in western Kenya is high. Particular attention should be paid to men, young adults, and those with HIV, who bear the greatest burden of resistant TB. Overall, there is a need to refine TB control and treatment programs in the region to yield better outcomes.

Genotypic Distribution and the Epidemiology of Multidrug Resistant Tuberculosis in Upper Northern Thailand.

The epidemiology and genotypes of multidrug-resistant tuberculosis (MDR-TB), a global public health threat, remain limited. The genotypic distribution and factors associated with MDR-TB in upper northern Thailand between 2015 and 2019 were investigated. The DNA sequencing of rpoB, katG, and inhA promoter of 51 multidrug-resistant Mycobacterium tuberculosis isolates revealed nine patterns of the rpoB gene mutation distributed in seven provinces. The S531L mutation was the most common mutation in all provinces. The rpoB mutation in Chiang Rai, Chiang Mai, and Lampang was highly diverse compared to other areas. Here, the mutation profiles that have yet to be reported in northern Thailand (H526P, Q513P, and H526C) were detected in Chiang Rai province. The S315T katG mutation was the most common genotype associated with INH resistance, especially in Chiang Mai and Lampang. Further analysis of data from 110 TB patients (42 MDR-TB and 68 drug-susceptible TB) revealed that &lt;60 years of age was a significant factor associated with MDR-TB (OR = 0.316, 95% CI 0.128-0.784, p = 0.011) and ≥60 years of age was a significant factor associated with the S315T katG-mutation (OR = 8.867, 95% CI 0.981-80.177, p = 0.047). This study highlighted the necessity for continuous surveillance and risk factor monitoring for effective control of MDR-TB.

Multidrug-Resistant Tuberculosis in U.S.-Bound Immigrants and Refugees.

RationaleApproximately two-thirds of new cases of tuberculosis (TB) in the United States are among non–U.S.-born persons. Culture-based overseas TB screening in U.S.-bound immigrants and refugees has substantially reduced the importation of TB into the United States, but it is unclear to what extent this program prevents the importation of multidrug-resistant TB (MDR-TB).ObjectivesTo study the epidemiology of MDR-TB in U.S.-bound immigrants and refugees and to evaluate the effect of culture-based overseas TB screening in U.S.-bound immigrants and refugees on reducing the importation of MDR-TB into the United States.MethodsWe analyzed data of immigrants and refugees who completed overseas treatment for culture-positive TB during 2015–2019. We also compared mean annual number of MDR-TB cases in non–U.S.-born persons within 1 year of arrival in the United States between 1996–2006 (when overseas screening followed a smear-based algorithm) and 2014–2019 (after full implementation of a culture-based algorithm).ResultsOf 3,300 culture-positive TB cases identified by culture-based overseas TB screening in immigrants and refugees during 2015–2019, 122 (3.7%; 95% confidence interval [CI], 3.1–4.1) had MDR-TB, 20 (0.6%; 95% CI, 0.3–0.9) had rifampicin-resistant TB, 382 (11.6%; 95% CI, 10.5–12.7) had isoniazid-resistant TB, and 2,776 (84.1%; 95% CI, 82.9–85.4) had rifampicin- and isoniazid-susceptible TB. None were diagnosed with extensively drug-resistant TB. All 3,300 persons with culture-positive TB completed treatment overseas; of 70 and 11 persons who were treated overseas for MDR-TB and rifampicin-resistant TB, respectively, none were diagnosed with TB disease at postarrival evaluation in the United States. Culture-based overseas TB screening in U.S.-bound immigrants and refugees prevented 24.4 MDR-TB cases per year from arriving in the United States, 18.2 cases more than smear-based overseas TB screening. The mean annual number of MDR-TB cases among non–U.S.-born persons within 1 year of arrival in the United States decreased from 34.6 cases in 1996–2006 to 19.5 cases in 2014–2019 (difference of 15.1; P < 0.001).ConclusionsCulture-based overseas TB screening in U.S.-bound immigrants and refugees substantially reduced the importation of MDR-TB into the United States.

Molecular epidemiology of multidrug resistant tuberculosis in Mongolia and Eastern Siberia: two independent dissemination processes for dominant strains

Mongolia and Russia are among the countries with the high tuberculosis (TB) burden. The prevalence of tuberculosis, including multidrug-resistant tuberculosis (MDR), in Eastern Siberia bordering Mongolia is significantly higher than in the European part of Russia. In addition, unlike Mongolia, Eastern Siberia is characterized by a high prevalence of HIV infection. The cross-border spread of socially significant infections in these countries seems to occur due to their wide-range cooperation and cultural exchange. Whereas the HIV infection has no epidemiological significance for Mongolia at the moment, tuberculosis, however, has a similar prevalence on both sides of the border. The aim was to evaluate the cross-border MDR M. tuberculosis distribution in Mongolia and Eastern Siberia by using molecular genetic data. Materials and methods. A total of 1045 M. tuberculosis strains isolated in Mongolia (291) and the three regions of Eastern Siberia (754) were studied by using the MIRU-VNTR-24 loci genotyping. The CC2/W148 and CC1 subtypes were identified by the specific deletion in the kdpD gene and SNP in the pks17 gene at position 1887060, respectively. Phylogenetic analysis of MIRU-VNTR patterns was carried out by generating UPGMA tree and maximum likelihood tree. Results. The Beijing genotype was found in 75.3% (219/291) and 69.0% (520/754) from Mongolian and East Siberian collection, respectively. Common minor genotypes were LAM (11.0% and 15.1%), T (10.3% and 4.5%), and Haarlem (1.4% and 2.4%) found in Mongolia and Eastern Siberia, respectively. The genotypes S (1.3%) and Ural (5.0%) were found solely in the Russia-derived samples. The main epidemic Beijing subtypes in each country belonged to different clonal complexes (CC): the majority of Mongolian Beijing strains displayed profiles 342-32, 3819-32, 1773-32 MLVA types and belonged to the CC4 subtype; Russian Beijing strains mainly belonged to the CC1 (43.7% — 227/520) and CC2/W148 (34.8% — 181/520) subtypes. The MDR level and distribution patterns differed significantly between Mongolia and Eastern Siberia. Modeling of Beijing strain expansion evidences about extremely subtle contribution of the M. tuberculosis cross-border transmission between Mongolia and Russia. The phylogenetic reconstruction of Beijing CC4 subtype evolution in Mongolia suggests that its distribution is primarily associated with China and other countries of the Western Pacific Region. Three main phylogenetic branches of CC4 subtype were traced, which probably spread throughout Mongolia in the 11—12th centuries. It may be assumed that spreading of the epidemic Beijing CC4 subtype might occur in two stages: early period — emergence of ancestral CC4 variants in Mongolia or their introduction from China (they are homologous to the strains preserved in the Chinese population), later period — dissemination due to the active exchange of M. tuberculosis with countries of Southeast Asia, but not Russia. Conclusion. Using MIRU-VNTR-24 genotyping as well as classification according to specific single nucleotide polymorphisms specific to certain Beijing subtypes, it allowed to describe separate patterns of the epidemic variants spread in Mongolia and Russia. It has been demonstrated that emergence and spread of MDR-TB in Mongolia are entirely iatrogenic in nature, while the epidemic subtypes of the Beijing genotype (subtypes CC1 and CC2/W148) contribute markedly into the MDR-TB spreading in Eastern Siberia.

Multidrug resistant tuberculosis (MDR-TB) in emerging economies in Sub-Saharan Africa: clinicians’ public health concerns

Despite improvement in the control of Tuberculosis globally, the disease remains a major public health problem responsible for high morbidity and mortality. In 2013 alone an estimated 9 million people acquired Tuberculosis, while mortality was at 1.5 million people that year. The emergence of multidrug resistant tuberculosis (MDR-TB) is tending to reverse earlier gains in the Tuberculosis control efforts, especially in resources limited settings in Sub Saharan Africa (SSA). The largest negative impact is expected in high-risk populations in whom the prevalence of pulmonary TB is already high. The challenges in these settings are numerous and are important for the epidemiology of MDR-TB. Alliances of negative forces and social determinants of health such as poverty, low levels of literacy, gender inequality and poorly resourced health systems may play a big role in the spread of MDR-TB. Furthermore, high cost of treatment and lack of health workers are hindrances to proper control of TB. HIV infection and male gender have been cited to be risk factors. Efforts to control this epidemic require control of HIV and more male involvement in the most affected regions. In our perspective we discuss epidemiology of MRD-TB in SSA.

Methicillin-resistant Staphylococcus aureus and multidrug resistant tuberculosis: Part 2.

Drug resistant tuberculosis has been recognized since chemotherapy first became available. However, drug resistance has increased in many countries, and recently strains resistant to both rifampicin and isoniazid (multidrug resistant tuberculosis) have emerged. This review discusses the epidemiology of multidrug resistant tuberculosis (MDRTB), and the control of MDRTB in healthcare facilities. Relevant papers for this review were identified by a systematic literature search on Medline. MDRTB is already established world-wide, and although the overall problem of resistance remains low in the UK, it is of significant clinical importance due to its high case-fatality, higher transmission risk, and complex treatment. The key elements of MDRTB control are prompt recognition, confirmation and treatment of cases, and the institution of strict infection control procedures to reduce the airborne spread of infection from infectious patients to others. This review emphasizes the importance of a multidisciplinary approach to management, with liaison between tuberculosis physicians, the microbiology department, infection control team, consultant in communicable disease, and occupational health.