Since July 2009, there has been a community outbreak of leishmaniasis in the south-west area of the Madrid autonomous community, Spain, affecting residents from four towns that are geographically close together and share extensive park areas. As of December 2012, 446 cases were reported (6 in 2009, 97 in 2010, 196 in 2011 and 147 in 2012), a mean incidence rate of 22.2 per 100,000 inhabitants during July 2009 and December 2012. The mean age was 44 years (range: 2 months to 95 years); 61.0% were male. A total of 68 (15.2%) had immunosuppressive conditions; 160 (35.9%) had visceral leishmaniasis and 286 (64.1%) cutaneous. A total of 421 (94.4%) cases were confirmed. Leishmania infantum was identified as the agent. Monitoring revealed high densities of the vector Phlebotomus perniciosus. The surveillance system for canine leishmaniasis did not detect any increase in prevalence during the period. Environmental control measures have been taken, such as improvements in sanitation and disinsection in the risk areas and control of the overpopulation of Leporidae, as xenodiagnosis studies have shown that hares play a role as active reservoirs. This is the largest reported community outbreak of leishmaniasis in Europe. The discovery of the new reservoir stands out in the multifactorial aetiology of the outbreak. Epidemiological research and environmental intervention measures are continuing.
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.
In this study, use of the capture-recapture technique allowed us to combine epidemiological information obtained by conventional and molecular methods to quantify the number of cases of recently transmitted TB in the community and identify specific populations at high risk of disease. This information is clearly important because such groups are a prime target for improved TB control measures. In the long term, this combination of techniques may contribute significantly to control the spread of TB.
To determine effect of recent tuberculosis transmission rates on incidence rates, we conducted 2 prospective population-based molecular epidemiologic studies in Madrid during 1997-1999 (4% immigrants) and 2002-2004 (14.9% immigrants). Case rates decreased in association with declining clustered case rates among Spanish-born persons. New strains were introduced through immigration. D uring the past decade in Madrid, Spain, tuberculosis (TB) case rates have decreased substantially while the proportion of foreign-born persons with TB has increased (2.6% in 1994 to 33.7% in 2003) (1). We used a combination of genotyping and conventional epidemiologic investigation to determine the extent to which the decline in incidence of TB in Madrid was affected by changes in rate of recent transmission of disease. The StudyWe conducted 2 prospective population-based studies of TB patients in 3 urban districts of Madrid over 2 separate periods: 1997-1999 (population 455,050; 4% immigrants) and 2002-2004 (population 488,518; 14.9% immigrants). We included all TB patients in these 3 districts and used the same methods for both studies. All clinical samples were sent to the Microbiology Department of Hospital 12 de Octubre for TB testing. All patient information was collected by using a standardized protocol based on the Regional Registry of Tuberculosis Cases in Madrid.Clinical specimens were processed according to standard methods. DNA fi ngerprinting was performed by restriction fragment length polymorphism (RFLP) analysis with the insertion sequence IS6110. Computer-assisted analysis was performed by using Bionumerics software (Applied Maths, Kortrijk, Belgium). All strains with <6 copies of IS6110 were spoligotyped. Within each study period, cases were considered to be clustered if common RFLP patterns containing >6 indistinguishable IS6110 bands or patterns containing <5 indistinguishable IS6110 bands and identical spoligotyping patterns were found.For each period we calculated average annual TB case rates and rates of clustered and nonclustered cases. Census populations of each district were used as denominators. Statistical analyses used Epi Info version 3.3 (Centers for Disease Control and Prevention, Atlanta, GA, USA) and Epidat (Pan American Health Organization, Washington, DC, USA).Case numbers were 412 during 1997-1999 (average incidence 30.2 cases/100,000) and 377 during 2002-2004 (average incidence 25.7/100,000); p<0.001 (Table 1). The 150 (19%) foreign-born patients were from 20 different countries. Date of arrival in Spain was available for 81 (54%); 78 (96.3%) had been in Spain <5 years before TB diagnosis, and 39 (48.2%) diagnoses were made within the fi rst 2 years of residence. Median time from arrival to onset of treatment was 30.1 months (25th-75th percentiles 8.0-50.7).In the fi rst period, 328 cases (79.6%) were confi rmed by isolation of Mycobacterium tuberculosis. RFLP analysis was performed on 212 isolates (64.6% of culture-positive cases and 51.4% of TB cases), and 95 of the 212 isolates (44.8%) share...
The demographic characteristics of the population of Madrid, with a steady increase in immigrants, from 4.7% in 1998 to 17.4% in 2007, provide an opportunity to study in depth the transmission of TB. Our aim was to compare two 3-year longitudinal molecular studies of TB to define transmission patterns and predictors of clustering. Two prospective population-based molecular and epidemiological studies (2002-2004 and 2005-2007) of TB patients were conducted in nine urban districts in Madrid using the same methodology. During the period 2002-2007, 2248 cases of TB were reported, and the incidence decreased from 23.5 per 100,000 in 2002 to 20.8 in 2007 (p <0.001). A total of 1269 isolates were molecularly characterized and included in the study. The comparison between the two periods showed that the percentage of foreign-born patients among TB cases increased from 36.2% to 45.7% (p <0.001). Furthermore, the percentage of clustered cases decreased (36.6% vs. 30.6%; p 0.028), and this decline was associated with a decrease of clustered cases among men and people under 35 years. We also observed a decrease in cases belonging to clusters containing ≥ 6 people (14.2% vs. 8.2%; p <0.001), and in cases belonging to mixed clusters containing Spanish-born and foreign-born patients (18.5% vs. 11.1%, p <0.001). Our molecular epidemiology study provides clues to interpret the decrease in the incidence of TB in a context of steady increase of immigration. In our region, the decrease in the incidence of TB can be explained predominantly as a result of a decline in recent transmission.
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