Twenty years and counting: epidemiology of an outbreak of isoniazid-resistant tuberculosis in England and Wales, 1995 to 2014

Abstract

An outbreak of isoniazid-resistant tuberculosis first identified in London has now been ongoing for 20 years, making it the largest drug-resistant outbreak of tuberculosis documented to date worldwide. We identified culture-confirmed cases with indistinguishable molecular strain types and extracted demographic, clinical, microbiological and social risk factor data from surveillance systems. We summarised changes over time and used kernel-density estimation and k-function analysis to assess geographic clustering. From 1995 to 2014, 508 cases were reported, with a declining trend in recent years. Overall, 70% were male (n = 360), 60% born in the United Kingdom (n = 306), 39% white (n = 199), and 26% black Caribbean (n = 134). Median age increased from 25 years in the first 5 years to 42 in the last 5. Approximately two thirds of cases reported social risk factors: 45% drug use (n = 227), 37% prison link (n = 189), 25% homelessness (n = 125) and 13% alcohol dependence (n = 64). Treatment was completed at 12 months by 52% of cases (n = 206), and was significantly lower for those with social risk factors (p < 0.05), but increased over time for all patients (p < 0.05). The outbreak remained focused in north London throughout. Control of this outbreak requires continued efforts to prevent and treat further active cases through targeted screening and enhanced case management.

Trends in tuberculosis notification and mortality and factors associated with treatment outcomes in Serbia, 2005 to 2015

“…TB disproportionately affects different segments of the population. Higher male-to-female ratio was reported in some studies and surveillance data as well as higher TB notification rate and lower mortality rate among males [1,5,6]. Changes in the occurrence of the disease by age, sex, education, anatomical site of the disease, history of previous treatment, HIV status and drug resistance are also important indicators of TB control programmes [7][8][9][10][11].…”

Resistance at No Cost: The Transmissibility and Potential for Disease Progression of Drug-ResistantM. Tuberculosis

“…5 Multiple molecular epidemiologic studies show that DR-TB strains can be transmitted and that clusters of resistant strains can persist over long periods. [25][26][27][28] However, previous molecular epidemiologic studies have reached different conclusions; some have found that DR strains are more likely to be clustered than DS strains while others have shown the reverse. [29][30][31] Some studies have suggested that the association with clustering depends on the specific drug resistance phenotype and/or mutation.…”

Impact of nursing interventions on adherence to treatment with antituberculosis drugs in children and young people: A nonrandomized controlled trial

“…Adherence to anti‐TB drugs is a complex phenomenon that depends on a wide range of factors, including structural sociodemographic factors (poverty, gender and discrimination), patient‐related factors (motivation, knowledge, beliefs and attitudes) and social context and health service factors (Munro et al., ; Smith et al., ; Woith & Larson, ). For instance, in children, adherence depends on the motivation of the parents, while adherence to any chronic medication becomes more challenging during adolescence (Chang, Eitzman, Nahid, & Finelli, ).…”