Foreign-born Tuberculosis Cases Research Articles

Transmission of tuberculosis between foreign-born and Finnish-born populations in Finland, 2014–2017

We describe the epidemiology of tuberculosis (TB) and characterized Mycobacterium tuberculosis (M. tuberculosis) isolates to evaluate transmission between foreign-born and Finnish-born populations. Data on TB cases were obtained from the National Infectious Disease Register and denominator data on legal residents and their country of birth from the Population Information System. M. tuberculosis isolates were genotyped by spoligotyping and Mycobacterial Interspersed Repetitive Unit Variable Number Tandem Repeat (MIRU-VNTR). We characterized clusters by age, sex, origin and region of living which included both foreign-born cases and those born in Finland. During 2014-2017, 1015 TB cases were notified; 814 were confirmed by culture. The proportion of foreign-born cases increased from 33.3% to 39.0%. Foreign-born TB cases were younger (median age, 28 vs. 75 years), and had extrapulmonary TB or multidrug-TB more often than Finnish-born cases (P<0.01 for all comparisons). Foreign-born cases were born in 60 different countries; most commonly in Somalia (25.5%). Altogether 795 isolates were genotyped; 31.2% belonged to 80 different clusters (range, 2-13 cases/cluster). Fourteen (17.5%) clusters included isolates from both Finnish-born and foreign-born cases. An epidemiological link between cases was identified by (epidemiological) background information in two clusters. Although the proportion of foreign-born TB cases was considerable, our data suggests that transmission of TB between foreign and Finnish born population is uncommon.

Tuberculosis drug resistance in Canada: 2018.

Drug-resistant tuberculosis (TB) is a public health issue of global importance that poses a threat to TB control efforts. Canada conducts nationwide surveillance to monitor emerging drug resistance trends and document progress towards reaching the goal of TB elimination. To describe TB drug resistance trends across Canada from 2008-2018, with a focus on 2018, by drug resistance, geographic and demographic patterns. TB drug resistance data are captured through two independent surveillance systems managed by the Public Health Agency of Canada: Canadian Tuberculosis Laboratory Surveillance System (CTBLSS) and the Canadian Tuberculosis Reporting System (CTBRS). Data from these systems were analyzed and descriptive statistics were reported by resistance profile, place of residence (province), age groups, sex and country of birth. In 2018, 1,459 TB isolates underwent drug susceptibility testing, a 4.3% decrease from 2017. Resistance to any first-line drug was reported in 148 isolates (10.1%), compared to 123 (8.1%) in 2017. Of these, 121 were monoresistant, five were polyresistant, 21 were multidrug-resistant tuberculosis (MDR-TB) and one was extensively drug-resistant TB (XDR-TB). Drug resistance was reported in all provinces and territories except Prince Edward Island, Northwest Territories and Yukon. Among individuals younger than 15 years, very little TB drug resistance was detected. Among individuals aged 15 years and older, the distribution of TB drug resistance varied with no discernable trends. The proportion of drug resistance was slightly higher in females than in males. By origin, 10.7% of foreign-born TB cases reported between 2006 and 2016 were drug-resistant. Among the Canadian-born non-Indigenous cases, 9.3% were drug resistant; among Canadian-born Indigenous, 2.4% were drug resistant. In 2018, the proportion of isolates with TB drug resistance in Canada remained low and below global averages, with stable drug resistance, both geographically and demographically.

Tuberculosis drug resistance in Canada: 2017.

Drug-resistant tuberculosis (TB) is a global public health issue. To monitor this in Canada, surveillance systems have been in place for the last 20 years. To describe drug resistance patterns among TB isolates in Canada in 2017 by type of resistance as well as geographic location, demographic data and origin and to compare current data to those of the previous 10 years. Data were derived and analyzed from two sources. The Canadian Tuberculosis Laboratory Surveillance System (CTBLSS) is an isolate-based laboratory surveillance system and was used to obtain information on the results of drug susceptibility testing (DST) as well as province or territory, sex and age of the individual from which the sample originated. The Canadian Tuberculosis Reporting System (CTBRS) is a case-based surveillance system with information on active and retreatment TB cases in Canada and was used to derive origin data, which is defined as either foreign-born, Canadian-born Indigenous or Canadian-born non-Indigenous. Analysis was descriptive and compared with data from these two sources for 2007-2016. In 2017, 1,515 TB isolates were tested for resistance to anti-TB drugs, with 123 (8.1%) demonstrating resistance to any first-line anti-TB drug. Of these, 103 were monoresistant, six were polyresistant and 14 were multidrug-resistant tuberculosis (MDR-TB). No extensively drug-resistant tuberculosis (XDR-TB) isolates were reported. Drug resistance was reported in seven provinces/territories (British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, Quebec and New Brunswick). There were 63 isolates from females with drug resistance (9.5%) and 60 isolates from males with drug resistance (7.0%). Drug resistance was found in a greater percentage of isolates among those aged 25-34 (n=29, 23.6%). By origin, 1,072 (11%) foreign-born TB cases reported between 2005 and 2015 were drug-resistant. Among the Canadian-born non-Indigenous and Canadian-born Indigenous TB cases, 143 (9%) and 54 (2%) were drug-resistant, respectively. Compared with previous years, the number of isolates tested increased slightly (from 1,267 to 1,515); however, there was a decrease in the percentage of isolates with reported drug resistance (from 10.5% in 2007 to 8.1% in 2017). In 2017, TB drug resistance rates remained low in Canada.

Using surveillance data to simulate the impact of a hypothetical pre-entry tuberculosis screening programme in Japan.

Despite a growing burden of foreign-born tuberculosis (TB) patients, Japan does not currently practise pre-entry tuberculosis (TB) screening among foreign-born entrants. To evaluate the impact of a hypothetical pre-entry TB screening programme among new foreign-born entrants into Japan. Using publicly available sources, we estimated 1) the number of prevalent TB cases, defined as bacteriologically or clinically confirmed cases among new foreign-born entrants into Japan in 2015, and 2) the yield from a hypothetical pre-entry TB screening programme under three scenarios: Scenario A, in which screening would be required of all applicants intending to stay for 3 months; Scenario B, screening among applicants for visas for settlement purposes; and Scenario C, screening among student and technical intern visa applicants. The numbers of prevalent TB cases under Scenarios A, B and C were respectively 492, 54 and 248 out of a total of 328 791, 21 554 and 182 879 applicants, respectively 276, 29 and 137 of whom would be detected via the pre-entry screening programme, giving an yield of respectively 83.9, 134.5 and 74.9 per 100 000 screened under each scenario. The yield was the highest under Scenario B; however, the impact was greatest under Scenario A, in that it detected the greatest number of patients and thus contributed the most in reducing the burden of foreign-born TB cases in Japan.

Latent tuberculosis infection in foreign-born communities: Import vs. transmission in The Netherlands derived through mathematical modelling.

While tuberculosis (TB) represents a significant disease burden worldwide, low-incidence countries strive to reach the WHO target of pre-elimination by 2035. Screening for TB in immigrants is an important component of the strategy to reduce the TB burden in low-incidence settings. An important option is the screening and preventive treatment of latent TB infection (LTBI). Whether this policy is worthwhile depends on the extent of transmission within the country, and introduction of new cases through import. Mathematical transmission models of TB have been used to identify key parameters in the epidemiology of TB and estimate transmission rates. An important application has also been to investigate the consequences of policy scenarios. Here, we formulate a mathematical model for TB transmission within the Netherlands to estimate the size of the pool of latent infections, and to determine the share of importation–either through immigration or travel- versus transmission within the Netherlands. We take into account importation of infections due to immigration, and travel to the country of origin, focusing on the three ethnicities most represented among foreign-born TB cases (after exclusion of those overrepresented among asylum seekers): Moroccans, Turkish and Indonesians. We fit a system of ordinary differential equations to the data from the Netherlands Tuberculosis Registry on (extra-)pulmonary TB cases from 1995–2013. We estimate that about 27% of Moroccans, 25% of Indonesians, and 16% of Turkish, are latently infected. Furthermore, we find that for all three foreign-born communities, immigration is the most important source of LTBI, but the extent of within-country transmission is much lower (about half) for the Turkish and Indonesian communities than for the Moroccan. This would imply that contact investigation would have a greater yield in the latter community than in the former. Travel remains a minor factor contributing LTBI, suggesting that targeting returning travelers might be less effective at preventing LTBI than immigrants upon entry in the country.

Tuberculosis in native- and foreign-born populations in Portugal.

Tuberculosis (TB) is a major global health problem, and during the last 20 years, industrialised countries have shown similar patterns in TB notifications: decreasing TB incidence in native populations and increasing incidence in foreign-born populations. To characterise risk factors associated with TB among native- and foreign-born TB patients in Portugal and identify barriers to the management of foreign cases. Analysis of the data from the national tuberculosis surveillance system and data from an online survey of physicians managing TB cases in the country. Risk factors in the two populations differed. Foreign-born patients were younger, less likely to use drugs or alcohol and had fewer comorbidities. They were also more likely to be human immunodeficiency virus positive, to be employed and to be homeless/living in shelters. The outcome of the disease and the time to diagnosis were not significantly different between the two populations. The most important barriers to the management of foreign-born TB cases were language and fear of deportation. As there are significant differences between the two populations, different TB control strategies should be implemented in the two populations.

Preventing tuberculosis in the foreign-born population of Canada: a mathematical modelling study

Foreign-born persons in Canada contribute 67% of all tuberculosis (TB) cases annually, but represent only 21% of the total population. Molecular epidemiological studies suggest that most foreign-born TB cases result from the reactivation of latent tuberculous infection (LTBI) acquired before immigration. To estimate the effect on incidence of a prevention strategy that would screen selected immigrants at arrival for LTBI and offer preventive treatment to those who test positive. A deterministic model was developed to quantify the incidence of active TB in immigrants to Canada and validated with national immigration and TB case data. Model simulations suggested that it would be optimal to screen and treat LTBI in new immigrants from countries of birth with an estimated TB incidence rate in excess of 50 per 100 000 person-years. If this strategy had been implemented in 1986, the national TB incidence rate would have fallen by 18.5%, from 5.4 to 4.4 cases per 100 000 population by 2002. This study suggests that screening and treating LTBI in foreign-born persons from high TB incidence countries is the most effective strategy in terms of total persons screened and treated and percentage reduction in national incidence.

The effectiveness of primary care based risk stratification for targeted latent tuberculosis infection screening in recent immigrants to the UK: a retrospective cohort study

BackgroundMost UK tuberculosis (TB) cases occur in immigrants from high TB incidence areas, implicating reactivation of imported latent TB infection (LTBI). Strategies to identify and treat immigrant LTBI in primary...

Predicting U.S. Tuberculosis Case Counts through 2020

In 2010, foreign-born persons accounted for 60% of all tuberculosis (TB) cases in the United States. Understanding which national groups make up the highest proportion of TB cases will assist TB control programs in concentrating limited resources where they can provide the greatest impact on preventing transmission of TB disease. The objective of our study was to predict through 2020 the numbers of U.S. TB cases among U.S.-born, foreign-born and foreign-born persons from selected countries of birth. TB case counts reported through the National Tuberculosis Surveillance System from 2000–2010 were log-transformed, and linear regression was performed to calculate predicted annual case counts and 95% prediction intervals for 2011–2020. Data were analyzed in 2011 before 2011 case counts were known. Decreases were predicted between 2010 observed and 2020 predicted counts for total TB cases (11,182 to 8,117 [95% prediction interval 7,262–9,073]) as well as TB cases among foreign-born persons from Mexico (1,541 to 1,420 [1,066–1,892]), the Philippines (740 to 724 [569–922]), India (578 to 553 [455–672]), Vietnam (532 to 429 [367–502]) and China (364 to 328 [249–433]). TB cases among persons who are U.S.-born and foreign-born were predicted to decline 47% (4,393 to 2,338 [2,113–2,586]) and 6% (6,720 to 6,343 [5,382–7,476]), respectively. Assuming rates of declines observed from 2000–2010 continue until 2020, a widening gap between the numbers of U.S.-born and foreign-born TB cases was predicted. TB case count predictions will help TB control programs identify needs for cultural competency, such as languages and interpreters needed for translating materials or engaging in appropriate community outreach.

Examining the Impact of Patient Characteristics and Symptomatology on Knowledge, Attitudes, and Beliefs Among Foreign-born Tuberculosis Cases in the US and Canada

Foreign-born individuals represent the majority of TB cases in the US/Canada. Little is known about their TB knowledge, attitudes, and beliefs (KAB). Cross-sectional survey was conducted in 22 sites in the US/Canada among foreign-born adults with active TB. Multiple regression was used to examine KAB factors against covariates. Of 1,475 participants interviewed, most answered the six knowledge items correctly. Significant predictors of correct knowledge included region of origin, education, income, age, visa status, place of diagnosis, BCG vaccination, and TB symptoms. Significant predictors of higher perceived risk/stigma scores included region of origin, age, place of diagnosis, English fluency, time in the US/Canada, TB symptoms, and household rooms. This study examines associations between TB KAB and patient and disease characteristics in foreign-born individuals in the US/Canada. The findings call for improved health education, along with efforts to reduce stigma and enhance realistic risk assessments.

Prevalence of Anti-Tuberculosis Drug Resistance in Foreign-Born Tuberculosis Cases in the U.S. and in Their Countries of Origin

BackgroundForeign-born individuals comprise >50% of tuberculosis (TB) cases in the U.S. Since anti-TB drug resistance is more common in most other countries, when evaluating a foreign-born individual for TB, one must consider the risk of drug resistance. Naturally, clinicians query The Global Project on Anti-tuberculosis Drug Resistance Surveillance (Global DRS) which provides population-based data on the prevalence of anti-TB drug resistance in 127 countries starting in 1994. However, foreign-born persons in the U.S. are a biased sample of the population of their countries of origin, and Global DRS data may not accurately predict their risk of drug resistance. Since implementing drug resistance surveillance in 1993, the U.S. National TB Surveillance System (NTSS) has accumulated systematic data on over 130,000 foreign-born TB cases from more than 200 countries and territories. Our objective was to determine whether the prevalence of drug resistance among foreign-born TB cases correlates better with data from the Global DRS or with data on foreign-born TB cases in the NTSS.Methods and FindingsWe compared the prevalence of resistance to isoniazid and rifampin among foreign-born TB cases in the U.S., 2007–2009, with US NTSS data from 1993 to 2006 and with Global DRS data from 1994–2007 visually with scatterplots and statistically with correlation and linear regression analyses. Among foreign-born TB cases in the U.S., 2007–2009, the prevalence of isoniazid resistance and multidrug resistance (MDR, i.e. resistance to isoniazid and rifampin), correlated much better with 1993–2006 US surveillance data (isoniazid: r = 0.95, P<.001, MDR: r = 0.75, P<.001) than with Global DRS data, 1994–2007 (isoniazid: r = 0.55, P = .001; MDR: r = 0.50, P<.001).ConclusionSince 1993, the US NTSS has accumulated sufficient data on foreign-born TB cases to estimate the risk of drug resistance among such individuals better than data from the Global DRS.

Immigrants and the Spread of Tuberculosis in the United States: A Hidden Cost of Immigration

This panel-data study concerns the incidence of newly diagnosed tuberculosis (TB) in specific U.S. metropolitan areas among immigrants and, in turn, the possible transmission of the disease to the native-born population of these same metropolitan areas. The study includes 50 U.S. Metropolitan Statistical Areas as annual observations, 1993–2007. We find that a 10% increase in the number of high-incidence immigrants results in a 2.87% increase in TB among the foreign-born population, and that a 10% increase in the number of foreign-born TB cases increases the number of new TB cases among the native-born by 1.11%. The study concludes with a benefit/cost analysis of the societal cost of TB and suggests that testing all immigrants for TB would be a cost-effective method to limit the amount of TB that enters U.S. from abroad, thus limiting the transmission to both the foreign- and native-born populations.

Impact of immigration on tuberculosis in a low-incidence area of Italy: a molecular epidemiological approach

The effects that immigration might have on the epidemiology of tuberculosis (TB) in a low-incidence area of Italy was investigated by determining, in autochthonous and immigrant TB patients, the molecular characteristics of the Mycobacterium tuberculosis complex (MTBC) isolates, which may provide information on their phylogeographical origin. A total of 1080 MTBC strains, collected during a 4-year period in Tuscany from 614 Italian-born and 466 foreign-born patients, were genotyped by spoligotyping and assigned to the different phylogeographical lineages that constitute the MTBC. The autochthonous Euro-American phylogeographical lineage, which includes the spoligotype families T, Haarlem, Latin American–Mediterranean (LAM), S and X, was highly prevalent among Italian-born patients, with a total of 477 cases (77.7%), and foreign-born TB patients, with a total of 270 cases (57.9%); 24 Italian-born (3.9%) and 141 foreign-born (30.3%) TB cases were due to MTBC genotypic families associated with distant geographical areas, i.e. East African–Indian (EAI), Beijing, Central Asian (CAS), and Mycobacterium africanum. Strains of Mycobacterium bovis and strains of undefined genotype, which are all considered together, as it is not possible to assign a specific geographical origin, accounted for 113 (18.4%) Italian cases and 55 (11.8%) foreign-born cases. A total of 79 Italian TB cases (12.9%) have been attributed to transmission from immigrants to the local population. No significant contribution to drug resistance appeared to be associated with imported MTBC strains. It is concluded that, at present, the overall impact of imported TB on public health in the low-incidence study area is relatively modest and of the same order as in other western countries.

Impact of immigration on tuberculosis in a low-incidence area of Italy: a molecular epidemiology approach

The effects that immigration might have on the epidemiology of tuberculosis (TB) in a low-incidence area of Italy was investigated by determining, in autochthonous and immigrant TB patients, the molecular characteristics of the Mycobacterium tuberculosis complex (MTBC) isolates, which may provide information on their phylogeographical origin. A total of 1080 MTBC strains, collected during a 4- year period in Tuscany from 614 Italian-born and 466 foreign-born patients, were genotyped by spoligotyping and assigned to the different phylogeographical lineages that constitute the MTBC. The autochthonous Euro-American phylogeographical lineage, which includes the spoligotype families T, Haarlem, Latin American–Mediterranean (LAM), S and X, was highly prevalent among Italian-born patients, with a total of 477 cases (77.7%), and foreign-born TB patients, with a total of 270 cases (57.9%); 24 Italian-born (3.9%) and 141 foreign- born (30.3%) TB cases were due to MTBC genotypic families associated with distant geographical areas, i.e. East African–Indian (EAI), Beijing, Central Asian (CAS), and Mycobacterium africanum. Strains of Mycobacterium bovis and strains of undefined genotype, which are all considered together, as it is not possible to assign a specific geographical origin, accounted for 113 (18.4%) Italian cases and 55 (11.8%) foreign-born cases. A total of 79 Italian TB cases (12.9%) have been attributed to transmission from immigrants to the local population. No significant contribution to drug resistance appeared to be associated with imported MTBC strains. It is concluded that, at present, the overall impact of imported TB on public health in the low-incidence study area is relatively modest and of the same order as in other western countries.

Tuberculosis in Texas 2008

The face of tuberculosis (TB) in Texas is global, bi-national, multiracial, multi-cultural and multi-drug resistant. This disease does not discriminate by age or gender. TB is a condition that impacts all Texans, regardless of social standing, political persuasion, education level, religious denomination or income status. The face of TB in Texas is the face of all Texans. In 2008, there were 1,501 TB cases reported to the Texas Department of State Health Services. This is the lowest number of tuberculosis cases reported in Texas in over forty years. Like the rest of the US, Texas has seen a decline in total tuberculosis cases in recent years. In 2008, Texas ranked second out of fifty states and the District of Columbia in the number of TB cases reported. Two of its major metropolitan cities, Houston and Dallas, ranking second and sixth in number of cases US-wide, respectively. Most of the TB cases reported in Texas in 2008 were male and the majority were Hispanic and African American. Tuberculosis in Texas is disproportionately represented by racial and ethnic minorities. The racial breakdown of the citizens of Texas is about 48% nonHispanic Whites, 11% African Americans and 37% Hispanics. In contrast, 14.9% of tuberculosis cases were non-Hispanics Whites, 22.1% were African Americans, 11.6% were Asian and 50.5% were Hispanics. In 1995, only 28% of the TB cases reported in Texas were born outside the United States. Looking at 2008, 48.6% of the 1,501 Texas TB cases were born outside the United States. The overall decline in tuberculosis cases has occurred primarily in the US born population. Immigrants from other countries frequently bring the endemic rates of tuberculosis from their homeland. There were 56 countries represented among the foreign born persons with TB reported in Texas. Of the 773 foreign born TB cases, 49.0% reported Mexico as their country of origin, 7.8% reported Vietnam, 6.1% reported Honduras, 4.0% reported India. 3.4% reported Philippines, 3.2% reported El Salvador, 2.7% reported Guatemala, and 1.9% reported Ethiopia. In Texas, TB cases are found primarily in the state’s major metropolitan areas and its fourteen border counties. In 2008, the large urban areas of the state and several counties along its border with Mexico continued to report the greatest percentage of the state’s TB cases. The majority of TB cases reported in Texas came from its five major population centers. These counties and their corresponding largest cities were Harris County (Houston), Dallas

Tuberculosis Among Foreign-born Persons in Taiwan, 2002–2005

The foreign-born population has been growing in Taiwan. Most foreign-born persons come from countries with a high burden of tuberculosis (TB). Monitoring the trend and characteristics of TB in this population is essential for TB control in Taiwan. Information about foreign-born persons residing in Taiwan and data of all foreign-born TB cases notified during 2002-2005 were obtained from the national authorities and analyzed. A total of 2,444 foreign-born TB cases were notified during 2002-2005, which accounted for 3.6% of all notified TB cases during that period in Taiwan. The proportion of foreign-born TB cases was constant, without any significant yearly variation. The average annual TB notification rate in the foreign-born population was higher than that in the Taiwan-born population (94.0/100,000 vs. 72.0/100,000). There were significant differences in age, sex and regional distribution between foreign-born and Taiwan-born TB cases (p < 0.001). Foreign-born cases were predominantly female (65.4%) and aged 25-44 years (70.9%), whereas the majority of cases among the Taiwan-born population were male (69.4%) and aged > or = 65 years (49.6%). Most foreign-born TB patients (62.7%) lived in northern Taiwan but only about one-third (36.1%) of Taiwan-born TB cases were notified from that region. Among foreign-born TB cases whose original countries were recorded, the majority came from Mainland China and Vietnam, which accounted for 73.0% of all cases, followed by the Philippines (7.4%), Thailand (7.3%) and Indonesia (6.0%). Foreign-born TB patients have different profiles and a higher case rate compared to Taiwan-born patients. Monitoring the epidemiologic trend of TB among foreign-born persons, especially those who come from high TB-burden countries, is essential in the fight against TB in Taiwan.

Extrapulmonary tuberculosis, human immunodeficiency virus, and foreign birth in North Carolina, 1993 – 2006

BackgroundThe proportion of extrapulmonary tuberculosis (EPTB) reported in the United States has been gradually increasing. HIV infection and foreign birth are increasingly associated with tuberculosis and understanding their effect on the clinical presentation of tuberculosis is important.MethodsCase-control study of 6,124 persons with tuberculosis reported to the North Carolina Division of Public health from January 1, 1993 to December 31, 2006. Multivariate logistic regression was used to obtain adjusted odds ratios measuring the associations of foreign birth region and US born race/ethnicity, by HIV status, with EPTB.ResultsAmong all patients with tuberculosis, 1,366 (22.3%) had EPTB, 563 (9.2%) were HIV co-infected, and 1,299 (21.2%) were foreign born. Among HIV negative patients, EPTB was associated with being foreign born (adjusted ORs 1.36 to 5.09, depending on region of birth) and with being US born, Black/African American (OR 1.84; 95% CI 1.42, 2.39). Among HIV infected patients, EPTB was associated with being US born, Black/African American (OR 2.60; 95% CI 1.83, 3.71) and with foreign birth in the Americas (OR 5.12; 95% CI 2.84, 9.23).ConclusionForeign born tuberculosis cases were more likely to have EPTB than US born tuberculosis cases, even in the absence of HIV infection. Increasing proportions of foreign born and HIV-attributable tuberculosis cases in the United States will likely result in a sustained burden of EPTB. Further research is needed to explore why the occurrence and type of EPTB differs by region of birth and whether host genetic and/or bacterial variation can explain these differences in EPTB.