The impact of immigration on tuberculosis and HIV burden between Colombia and Venezuela and across frontier regions

Molecular epidemiology of Mycobacterium tuberculosis in Ecuador: Recent advances and future challenges

Tuberculosis (TB) is one of the three leading causes of death from a single infectious agent, Mycobacterium tuberculosis (MTB), together with COVID-19 and HIV/AIDS. This disease places a heavy burden on countries with low socio-economic development and aggravates existing inequalities. For the year 2021, estimations for Ecuador were 8500 TB cases, of which 370 were associated to multiple drug resistance (TB-MDR), and 1160 deaths. In the same year, Ecuador notified 5973 total cases, 401 of them were TB-MDR, pointing out an under diagnosis problem. The few molecular epidemiology studies available conclude that L4 is the most prevalent MTB lineage in Ecuador (with LAM as the main L4 sublineage), but L2-Beijing family is also present at low prevalence. Nevertheless, with less than 1 % MTB isolates genetically characterized by either MIRU-VNTR, spolygotyping or WGS to date, molecular epidemiology research must me improved to assist the TB surveillance and control program in Ecuador.

Adherence to Short-Duration Treatment (3HP) for Latent Tuberculosis among International Migrants in Manaus, Amazonas: Evaluation of the Efficacy of Different Treatment Modalities

Migration, a multifaceted phenomenon, has a significant impact on health. Migrants perform similar movement patterns within their country of origin, in transit, and in the country of destination, thus making it difficult to monitor TB treatment throughout the journey. The objective was to compare the effectiveness of different treatment modalities in adherence to the short-term regimen for LTBI (3HP) among international migrants and refugees. This is a quasi-experimental study conducted in Manaus-AM. The study population was made up of international migrants. The certification and monitoring of medication intake employed three strategies: self-administration (SA), directly observed conventional therapy (DOT), and Video Telemonitoring System for Tuberculosis Treatment (VDOT). The VDOT group and SA group exhibited the lowest rate of treatment dropout or interruption at 16.1%, followed by the DOT group at 23.1%. The results suggest that the most effective strategy for ensuring adherence among migrants and refugees was VDOT (OR_adj 0.26; CI 0.7-0.94), suggesting that migrants may be more likely to adhere to and complete their treatment. The results show that relying on different treatment strategies, adapted to the individuals' needs and risk factors, is a viable and effective way of providing person-centered TB care.

Cancer mortality among Colombian and foreign populations over a 15-year period

Purpose

We aimed to compare cancer mortality among foreign- and Colombian populations in Colombia during the period of 2006-2020.

Methods

This retrospective study utilized vital statistics from the Colombian National Department of Statistics (DANE). The dataset included variables such as age group, sex, country of permanent residency, insurance, education level, marital status, ethnicity, and cause of death. The population data to calculate rates was obtained from the Colombian census and the United Nations. Crude and adjusted rates as well as proportional mortality rates were calculated.

Results

A total of 561,932 cancer deaths occurred in Colombia from 2006 to 2020. The foreign population (country of permanent residency different to Colombia) had a lower crude cancer mortality rate (31.1 per 100,000 inhabitants) than the Colombian population (81.9 per 100,000 inhabitants). However, the age-adjusted cancer mortality rate among the foreign population was 253.6 per 100,000, compared to 86.1 per 100,000 among the Colombian population. The proportional cancer mortality was 10.4 % among foreign population compared to 17.4 % among Colombian population.

Conclusions

The proportional cancer mortality shows that the proportion of cancer-related deaths is greater among the Colombian population compared to the immigrant population. However, immigrants in Colombia have a higher age-adjusted cancer mortality rate than Colombians, indicating that immigrants have worse cancer outcomes than the Colombians even though the immigrant population is younger. This is likely due to the frequent barriers that immigrants encounter in accessing health care in Colombia. Future research needs to focus on access to care for the immigrant population by investigating cancer-related risk factors among immigrants and addressing their barriers to cancer prevention and treatment.

Prevalence, drug resistance, and genotypic diversity of the RDRio subfamily of Mycobacterium tuberculosis in Ecuador: a retrospective analysis for years 2012-2016

Introduction

A major sublineage within the Mycobacterium tuberculosis (MTB) LAM family characterized by a new in-frame fusion gene Rv3346c/55c was discovered in Rio de Janeiro (Brazil) in 2007, called RDRio, associated to drug resistance. The few studies about prevalence of MTB RDRio strains in Latin America reported values ranging from 3% in Chile to 69.8% in Venezuela, although no information is available for countries like Ecuador.

Methods

A total of 814 MTB isolates from years 2012 to 2016 were screened by multiplex PCR for RDRio identification, followed by 24-loci MIRU-VNTR and spoligotyping.

Results

A total number of 17 MTB RDRio strains were identified, representing an overall prevalence of 2.09% among MTB strains in Ecuador. While 10.9% of the MTB isolates included in the study were multidrug resistance (MDR), 29.4% (5/17) of the RDRio strains were MDR.

Discussion

This is the first report of the prevalence of MTB RDRio in Ecuador, where a strong association with MDR was found, but also a very low prevalence compared to other countries in Latin America. It is important to improve molecular epidemiology tools as a part of MTB surveillance programs in Latin America to track the transmission of potentially dangerous MTB stains associated to MDR TB like MTB RDRio.

Population structure of Mycobacterium tuberculosis in El Oro: A first insight into Ecuador-Peru tuberculosis transmission

BACKGROUND

Tuberculosis (TB) is a major public health concern in Ecuador and Peru, both settings of high burden of drug resistance TB. Molecular epidemiology tools are important to understand the transmission dynamics of Mycobacterium tuberculosis Complex (MTBC) and to track active transmission clusters of regional importance. This study is the first to address the transmission of TB between Peru and Ecuador through the population structure of MTBC lineages circulating in the Ecuadorian border province of "El Oro".

METHODS

A total number of 56 MTBC strains from this province for years 2012-2015 were included in the study and analyzed by 24-loci MIRU-VNTR and spoligotyping.

RESULTS

Genotyping revealed a high degree of diversity for MTBC in "El Oro", without active transmission clusters. MTBC L4 was predominant, with less than 2% of strains belonging to MTBC L2-Beijing.

CONCLUSIONS

These results may suggest that TB dynamics in this rural and semi-urban area would not be linked to highly transmitted strains like MTBC L2-Beijing from Peru, but related to TB relapse; although further studies with larger MTBC cultures collection from recent years are needed. Nevertheless, we recommend to reinforce TB surveillance programs in remote rural settings and border regions in Ecuador.

A first insight into tuberculosis transmission at the border of Ecuador and Colombia: a retrospective study of the population structure of Mycobacterium tuberculosis in Esmeraldas province

Objective

Tuberculosis (TB) is a major public health concern in Ecuador and Colombia, considering that both countries are high-burden TB settings. Molecular epidemiology is crucial to understand the transmission dynamics of Mycobacterium tuberculosis complex (MTBC) and to identify active transmission clusters of regional importance.

Methods

We studied the potential transmission of TB between Colombia and Ecuador through the analysis of the population structure of MTBC lineages circulating in the Ecuadorian province of Esmeraldas at the border with Colombia. A total of 105 MTBC strains were characterized by 24-loci MIRU-VNTR and spoligotyping.

Results

MTBC lineage 4 is only present in Esmeraldas; no MTBC strains belonging to Lineage 2-sublineage Beijing were found despite its presence in other provinces of Ecuador and, in Colombia. Genotyping results revealed a high degree of diversity for MTBC in Esmeraldas: Neither active transmission clusters within this province nor including MTBC strains from Colombia or other provinces of Ecuador were found.

Conclusion

Our data suggest that tuberculosis dynamics in this rural and isolated area may be not related to highly transmitted strains but could be influenced by other health determinants that favor TB relapse such as poverty and poor health system access. Further studies including a larger number of MTBC strains from Esmeraldas are necessary to test this hypothesis.

The Vulnerability of International Floating Populations to Sexually Transmitted Infections: A Qualitative Study

With the rapid development of the global economy, along with globalisation, the health of international floating populations (especially their sexual health) has become a problem that cannot be ignored. This study explored the potential vulnerability of international floating populations to sexually transmitted infections (STIs) from the points of view of society, religion, culture, migration, community environment, and personal behaviours. In-depth exploratory interviews with 51 members of the international floating population living in China were conducted in June and July 2022. A qualitative thematic analysis methodology was used to analyse the content of these interviews. We found that a conservative culture orientated around religion leads to a lack of sex education, resulting in insufficient personal knowledge as well as a lack of the motivation and awareness required to encourage condom use during sexual contact. Additionally, both geographical isolation and reduced social supervision have expanded personal space, which has led to social isolation and marginalisation, in addition to challenges for coping with STI risk. These factors have increased the possibility of individuals engaging in risky behaviours.

Evidence on tuberculosis in migrants at Brazil's international borders: A scoping review

Objective

to map scientific evidence on the extent of tuberculosis in migrants from the international borders between Brazil and the countries of South America.

Design

Scoping review of quantitative, qualitative and mixed studies. The research was conducted between February and April 2021. The terms "migrants", "tuberculosis", "Brazil", "Uruguay", "Paraguay", "Bolivia", "Peru", "British Guiana" "English Guiana", "French Guiana", "Suriname", "Venezuela", "Argentina", "Colombia" combined with Boolean operators "AND" and "OR" to identified relevant documents. Studies addressing tuberculosis on migrants from international borders of Brazil were included. Pubmed Central (PMC), LILACS (Scientific and technical literature of Latin America and the Caribbean/BVS), Scopus (Elsevier), Scielo (Scientific Electronic Library Online) and gray literature CAPES thesis database were searched. The study was carried out in three stages where the data was selected and extracted by two independent reviewers for full reading.

Results

A total of 705 articles were extracted from the databases chosen for the search, 04 master's dissertations and 01 doctoral thesis. Of these 456 were excluded because they did not meet at least one of the eligibility criteria for this SR and 4 were further excluded because they were duplicates who had not been previously identified. A total of 58 documents were, thus, selected for assessment of the full text. Of these, 40 were further excluded for not meeting at least one of the eligibility criteria. A total of 18 studies were included for data collection: 15 articles, 2 master's dissertations and 1 doctoral thesis, produced between 2002 and 2021.

Conclusion

This scoping review mapped the existing evidence on tuberculosis at the international borders of Brazil and on access of immigrants with tuberculosis to health services in Brazil.

Descriptors

tuberculosis; immigrants; public health surveillance; epidemiological surveillance; sanitary control of borders; health services accessibility.

Spatio-temporal clusters and patterns of spread of dengue, chikungunya, and Zika in Colombia

Background

Colombia has one of the highest burdens of arboviruses in South America. The country was in a state of hyperendemicity between 2014 and 2016, with co-circulation of several Aedes-borne viruses, including a syndemic of dengue, chikungunya, and Zika in 2015.

Methodology/Principal findings

We analyzed the cases of dengue, chikungunya, and Zika notified in Colombia from January 2014 to December 2018 by municipality and week. The trajectory and velocity of spread was studied using trend surface analysis, and spatio-temporal high-risk clusters for each disease in separate and for the three diseases simultaneously (multivariate) were identified using Kulldorff’s scan statistics. During the study period, there were 366,628, 77,345 and 74,793 cases of dengue, chikungunya, and Zika, respectively, in Colombia. The spread patterns for chikungunya and Zika were similar, although Zika’s spread was accelerated. Both chikungunya and Zika mainly spread from the regions on the Atlantic coast and the south-west to the rest of the country. We identified 21, 16, and 13 spatio-temporal clusters of dengue, chikungunya and Zika, respectively, and, from the multivariate analysis, 20 spatio-temporal clusters, among which 7 were simultaneous for the three diseases. For all disease-specific analyses and the multivariate analysis, the most-likely cluster was identified in the south-western region of Colombia, including the Valle del Cauca department.

Conclusions/Significance

The results further our understanding of emerging Aedes-borne diseases in Colombia by providing useful evidence on their potential site of entry and spread trajectory within the country, and identifying spatio-temporal disease-specific and multivariate high-risk clusters of dengue, chikungunya, and Zika, information that can be used to target interventions.

Dengue, chikungunya, and Zika are diseases transmitted to humans by the bite of infected Aedes mosquitoes. Between 2014 and 2016 chikungunya and Zika viruses started causing outbreaks in Colombia, one of the countries historically most affected by dengue. We used case counts of the diseases by municipality and week to study the spread trajectory of chikungunya and Zika within Colombia’s territory, and to identify space-time high-risk clusters, i.e., the areas and time periods that dengue, chikungunya, and Zika were more present. Chikungunya and Zika spread similarly in Colombia, but Zika spread faster. The Atlantic coast, a famous touristic destination in the country, was likely the place of entry of chikungunya and Zika in Colombia. The south-western region was identified as a high-risk cluster for all three diseases in separate and simultaneously. This region has a favorable climate for the Aedes mosquitoes and other characteristics that facilitate the diseases’ transmission, such as social deprivation and high population mobility. Our results provide useful information on the locations that should be prioritized for interventions to prevent the entry of new diseases transmitted by Aedes and to reduce the burden of dengue, chikungunya and Zika where they are established.