Prevención y control de las tuberculosis importadas

Newly Arrived African Migrants to Spain: Epidemiology and Burden of Disease

The aim of this study is to describe the epidemiological profile, clinical characteristics, and microbiological findings in African immigrants newly arrived to Spain attended at a specialized reference unit from October 2004 to February 2017. A common protocol for the screening of imported and cosmopolitan diseases was designed to evaluate patients with ≤ 12 months of stay in Spain. A total of 523 patients were included in the study, 488 (93.3%) of sub-Saharan origin. A high number of helminthic infections were diagnosed in sub-Saharan patients, including geohelminthiasis (hookworms 14.3%; Trichuris trichiura 4.1%; Ascaris lumbricoides 3.1%), schistosomiasis (12.3%), strongyloidiasis (17.2%), and filariasis (8.4%). Thirty-five patients (7.2%) had malaria, most by Plasmodium falciparum. Among communicable diseases, 33.6% of sub-Saharans presented HBsAg positivity compared with 5.7% of North African patients (P = 0.001). Thirteen patients were diagnosed with active tuberculosis. Seventy percent of the sub-Saharans and 40% of the North Africans who were tested had a latent tuberculosis infection (LTI). Treatment of LTI was administered in selected cases (14%), achieving end of treatment in 80% of them. In light of these results, effective screening strategies, particularly within the sub-Saharan immigrant population, including potentially communicable diseases and certain potentially serious parasitic diseases (Strongyloides, Schistosoma), should be implemented. It is necessary to facilitate fully and free of charge access to the public health system to newly arrived immigrants, as well as to implement programs and actions aimed at favoring care and follow-up, especially for communicable diseases. Empirical treatment of some parasitic diseases could be a cost-effective action.

[Tuberculosis and immigration]

The incidence of tuberculosis worldwide is declining. However, in Western countries this decline is slower due to the impact of immigration. Tuberculosis in the immigrant population is related to health status in the country of origin and with overcrowding and poverty conditions in the host country. Immigrants with tuberculosis are younger, have a higher prevalence of extrapulmonary forms, greater proportion of drug resistance and higher treatment default rates than those of natives. New molecular techniques not only reduce diagnostic delay time but also allow the rapid identification of resistances and improve knowledge of transmission patterns. It is necessary to implement measures to improve treatment compliance in this population group like facilitating access to health card, the use of fixed-dose combination drugs, the participation of cultural mediators and community health workers and gratuity of drugs.

[Epidemiology of hospitalizations for tuberculosis in Spain: analysis of minimum data set 1999-2009]

INTRODUCTION

The National Hospital Discharge Registry is a clinical-administrative database on hospital discharges, which is very useful at a regional level as a complementary source for surveillance. There are few national studies on tuberculosis (TB) using the National Hospital Discharge Registry, thus it was considered of interest to study the characteristics and trends of hospital discharges for TB in Spain.

METHODS

A descriptive study was performed using the main variables in the National Hospital Discharge Registry (sex, age, main diagnosis, type of discharge, length of stay), and trend analysis of hospitalization rates per 100,000 population, as well as primary diagnosis, by sex, age group, and type of TB (pulmonary [TBP]/extrapulmonary [TBEP]), for the period 1999-2009 in Spain.

RESULTS

A total of 65,609 hospital discharges were included in the study (66% male, 66% TBP, and 52% between 15-44 years). The overall rate of TB for the entire hospitalization period was 13.93 per 100,000 inhabitants, being 18.83 in males and 9.18 in females. The hospitalization rates for TBP and TBEP decreased in the period 1999-2009 in both sexes (TBP in males, from 18 to 13, and in females, from 8 to 6; TBEP in males from 4 to 3, and from 3 to 2 in female hospitalizations/100,000 habitants). In TBP, children are those with a smallest decline, and in TBEP there is an increase in males in all age groups from 2005.

CONCLUSIONS

The results are consistent with those from surveillance. The slow decline in rates in children and the increase in extrapulmonary forms in males may be related to immigration, so it is necessary to improve TB monitoring in these groups.

Community health workers improve contact tracing among immigrants with tuberculosis in Barcelona

BACKGROUND

The important increase in immigration during recent years has changed the epidemiology and control strategies for tuberculosis (TB) in many places. This study evaluates the effectiveness of intervention with community health workers (CHW) to improve contact tracing among immigrants.

METHODS

The study included all TB cases detected by the Barcelona TB Program from 2000 to 2005 and compared a period without CHW intervention (2000-2002) to a period with CHW intervention (2003-2005). The influence on contact tracing of sex, age, hospital of diagnosis, district of residence, birthplace, HIV, homeless and CHW intervention was analysed by logistic regression. Odds ratio (OR) and 95% confidence intervals (CI) were calculated.

RESULTS

960 foreign born TB cases were detected, 388 in the intervention period. Contact tracing was performed on 65,7% of 201 smear-positive cases during the pre-intervention period compared to 81.6% of 152 smear-positive TB cases during the intervention period (p < 0.001). Risk factors associated with incomplete contact tracing of smear-positive index cases included being diagnosed in two hospitals without contact tracing TB unit (OR = 3.5; CI:1.4-8.9) and (OR = 4.6; CI:1.6-13.5) respectively, birth place in India-Pakistan (OR = 4.4; CI:1.9-10.3) or North Africa (OR = 4.3; CI:1.8-10.5), having an unknown residence (OR = 5.4; CI:1.6-18.0), being HIV-infected (OR = 6.1; CI:2.5-14.8) or homeless (OR = 3.3; CI:1.3-8.2), and the absence of CHW intervention (OR = 2.4; CI:1.3-4.3).

CONCLUSIONS

The effectiveness of contact tracing for TB control in areas with high immigration can be improved by incorporating CHWs who act as translators, cultural mediators and facilitators who accompany cases and contacts through treatment and follow-up.

Imported malaria in a cosmopolitan European city: a mirror image of the world epidemiological situation

Background

International travel and migration have been related with an increase of imported malaria cases. There has been considerable immigration to Barcelona from low-income countries (LIC) in recent years. The objective is to describe the epidemiology and to determine the trends of the disease in Barcelona.

Methods

Analysis of the cases notified among city residents between 1989 and 2005. Patients were classified as: tourists, voluntary workers, resident immigrants (visiting friends and relatives, VFR) and recently arrived immigrants. An analysis was conducted using the chi² test and comparison of means. As a measure of association we calculated the Relative Risk (RR) and Odds Ratio (OR) with a Confidence Interval of 95% (CI) and carried out a trends analysis.

Results

Of the total of 1,579 imported cases notified, 997 (63.1%) lived in Barcelona city, and 55.1% were male. The mean age of patients was 32.7 years. The incidence increased from 2.4 cases/100,000 in 1989 to 3.5 cases/100,000 in 2005 (RR 1.46 CI:1.36–1.55). This increase was not statistically significant (trends analysis, p = 0.36). In terms of reason for travelling, 40.7% were VFR, 33.6% tourists, 12.1% voluntary workers and 13.6% were recently arrived immigrants. The most frequent species found was Plasmodium falciparum (71.3%), mainly in visitors to Africa (OR = 2.3, CI = 1.7–3.2). The vast majority (82.2%) had had some contact with Africa (35.9% with Equatorial Guinea, a Spanish ex-colony) and 96.6% had not completed chemoprophylaxis. Six deaths were observed, all tourists who had travelled to Africa and not taken chemoprophylaxis (3.9% fatality rate).

Conclusion

Over the period studied there is an increase in malaria incidence, however the trend is not statistically significant. Lack of chemoprophylaxis compliance and the association between Africa and P. falciparum are very clear in the imported cases. Most of the patients with malaria did not take chemoprophylaxis.

Analysis of changes in recent tuberculosis transmission patterns after a sharp increase in immigration

We conducted a population-based molecular epidemiological study of tuberculosis (TB) in Madrid, Spain (2002 to 2004), to define transmission patterns and factors associated with clustering. We particularly focused on examining how the increase in TB cases among immigrants in recent years (2.8% in 1997 to 1999 to 36.2% during the current study) was modifying transmission patterns. Mycobacterium tuberculosis isolates obtained from patients living in nine districts of Madrid (1,459,232 inhabitants) were genotyped. The TB case rate among foreign-born people was three to four times that of Spanish-born people, and the median time from arrival to the onset of treatment was 22.4 months. During the study period, 227 (36.3%) patients were grouped in 64 clusters, and 115 (50.7%) of them were in 21 clusters with mixed Spanish-born and foreign-born patients. Three of the 21 mixed clusters accounted for 21.1% of clustered patients. Twenty-two of 38 (57.9%) immigrants in mixed clusters were infected with TB strains that had already been identified in the native population in 1997 to 1999, including the three most prevalent strains. Factors identified as independent predictors of clustering were homelessness (odds ratio [OR], 2.3; 95% confidence interval [95% CI], 1.2 to 4.5; P = 0.011) and to be born in Spain (OR, 1.8; 95% CI, 1.2 to 2.6; P = 0.002). The results indicated that (i) TB transmission was higher in Spanish-born people, associated mainly with homelessness, (ii) that foreign-born people were much less likely to be clustered, suggesting a higher percentage of infection before arriving in Spain, and (iii) that an extensive transmission between Spanish- and foreign-born populations, caused mainly by autochthonous strains, was taking place in Madrid.

Control y eliminación de la tuberculosis en España: las estrategias para el siglo XXI

OBJECTIVE

The objective of tuberculosis (TBC) control is to eradicate the disease by interrupting transmission of Mycobacterium tuberculosis. The WHO's strategy to achieve global control of this disease is known as directly observed treatment, short-course (DOTS). The goals are to detect 70% of cases of bacilliferous TBC and to successfully treat 85% of these cases in order to reduce the number of sources of infection. Analysis of the epidemiology of TBC in Spain has revealed an incidence of > 20 cases per 100,000 inhabitants.

METHODS

The strategies that should be applied are those for disease control: to improve case detection and treatment of cases with surveillance of cure (especially in contagious cases), to identify, investigate and treat individuals exposed to contagious persons, and to control epidemic outbreaks of TBC. Treatment of infected individuals is an elimination strategy and should be reserved for groups at high risk of developing the disease.

Analysis of Mycobacterium tuberculosis genotypes in Madrid and identification of two new families specific to Spain-related settings

In Spain, tuberculosis (TB) patterns are changing because of the recent increase in the number of cases among immigrants. To establish the composition of circulating Mycobacterium tuberculosis strains before the effects of foreign strains appear, this study focused on molecular characterization of 233 patient isolates using spoligotyping. The spoligotyping data were further analyzed using an international database, SpolDB4. The results obtained showed that the general features of the M. tuberculosis population in Spain are coherent with those of other European countries, with the Latin American and Mediterranean group, and with the Haarlem 3 and T1 families as the most prevalent genotypes. The Spanish isolates clustered mostly with genotypes which had previously been isolated in countries linked with Spain. We also describe and fully characterize two novel M. tuberculosis families, Madrid1 and Madrid2, which are specific to Spain-related settings. The data reported here provide a solid reference when monitoring changes in the composition of the M. tuberculosis population in Spain as a consequence of the increasing rate of TB in the foreign population.