Distribution of Mycobacterium tuberculosis lineages in South America Distribución de los linajes de Mycobacterium tuberculosis en Sudamérica

Molecular genotyping of Mycobacterium tuberculosis allows for the identification of circulating lineages and sublineages in the population and their relationship with migratory movements. The purpose of this review is to describe the phylogeography of Mycobacterium tuberculosis reported in South American countries that was analyzed using genotyping tools, analyze the Tuberculosis hotspots for the region and determine the impact of the COVID-19 pandemic on the Tuberculosis control program. The Latin American Mediterranean (LAM) sublineage Resumen. La genotipificación molecular de Mycobacterium tuberculosis permite identificar los linajes y sublinajes circulantes en la población y su relación con los movimientos migratorios. Este artículo de revisión tiene por objetivo describir la filogeografía de Mycobacterium tuberculosis reportada por los países de Sudamérica mediante el uso de técnicas de genotipificación, analizar los puntos críticos de Tuberculosis para la región y determinar el impacto de la pandemia de COVID-19 en el programa de control de la 1 Grupo de Investigación en Sanidad Animal y Humana, Carrera de Ingeniería en Biotecnología, Departamento de Ciencias de la Vida y de la Agricultura, Universidad de las Fuerzas Armadas ESPE, Sangolquí, Ecuador, lpcabezas1@espe.edu.ec. https://orcid.org/0000-0003-1742-2878 2 Grupo de Investigación en Sanidad Animal y Humana, Carrera de Ingeniería en Biotecnología, Departamento de Ciencias de la Vida y de la Agricultura, Universidad de las Fuerzas Armadas ESPE, Sangolquí, Ecuador, apjimenez@espe.edu.ec https://orcid.org/0000-0002-0666-177X ISSN: 2697-3391 Vol. 4, N° 3, p. 34-58, julio-septiembre, 2021 Salud Pública Página 35 www.anatomiadigital.org belonging to the Euro-American lineage (Lineage 4) presents the highest prevalence in South America and is followed by the Beijing sublineage belonging to the East Asian lineage (Lineage 2). The Beijing sublineage is considered of worldwide interest because of its association with multidrugresistant tuberculosis (MDR-TB), which is almost entirely distributed in South America, with Peru being the country with the highest prevalence for this sublineage. On the other hand, the IndoOceanic (Lineage 1), India-East Asia (Lineage 3) and WestAfrican 2 (Lineage 6) sublineages have been reported with lower prevalence in South America. The molecular techniques used in the genotyping studies for Mycobacterium tuberculosis in South America were as follows: typing by complementary oligonucleotide spacer sequences (Spoligotyping), restrictionhybridization patterns (IS6110-RFLP, PGRS-RFLP), mycobacterial interspaced repeat units-variable number tandem repeats (MIRU-VNTR) and whole genome sequencing (WGS). At present, Brazil and Peru are the hotspots for tuberculosis and MDR-TB in South America, where the control of tuberculosis wholly affected by the COVID-19 pandemic. Thus, there have been significant impacts on containment programs and possible post-pandemic scenarios such that scientific contributions will need to be evaluated and implemented with new strategies for prevention, diagnosis, treatment and control of Tuberculosis.

Molecular genotyping of Mycobacterium tuberculosis allows for the identification of circulating lineages and sublineages in the population and their relationship with migratory movements. The purpose of this review is to describe the phylogeography of Mycobacterium tuberculosis reported in South American countries that was analyzed using genotyping tools, analyze the Tuberculosis hotspots for the region and determine the impact of the COVID-19 pandemic on the Tuberculosis control program.
The Latin American Mediterranean (LAM) sublineage

Resumen.
La genotipificación molecular de Mycobacterium tuberculosis permite identificar los linajes y sublinajes circulantes en la población y su relación con los movimientos migratorios. Este artículo de revisión tiene por objetivo describir la filogeografía de Mycobacterium tuberculosis reportada por los países de Sudamérica mediante el uso de técnicas de genotipificación, analizar los puntos críticos de Tuberculosis para la región y determinar el impacto de la pandemia de COVID-19 en el programa de control de la belonging to the Euro-American lineage (Lineage 4) presents the highest prevalence in South America and is followed by the Beijing sublineage belonging to the East Asian lineage (Lineage 2). The Beijing sublineage is considered of worldwide interest because of its association with multidrugresistant tuberculosis (MDR-TB), which is almost entirely distributed in South America, with Peru being the country with the highest prevalence for this sublineage. On the other hand, the Indo-Oceanic (Lineage 1), India-East Asia (Lineage 3) and West-African 2 (Lineage 6) sublineages have been reported with lower prevalence in South America. The molecular techniques used in the genotyping studies for Mycobacterium tuberculosis in South America were as follows: typing by complementary oligonucleotide spacer sequences (Spoligotyping), restrictionhybridization patterns (IS6110-RFLP, PGRS-RFLP), mycobacterial interspaced repeat units-variable number tandem repeats (MIRU-VNTR) and whole genome sequencing (WGS). At present, Brazil and Peru are the hotspots for tuberculosis and MDR-TB in South America, where the control of tuberculosis wholly affected by the COVID-19 pandemic. Thus, there have been significant impacts on containment programs and possible post-pandemic scenarios such that scientific contributions will need to be evaluated and implemented with new strategies for prevention, diagnosis, treatment and control of Tuberculosis.
This review describes the phylogeography of MTB sublineages reported in South American countries that was analyzed using genotyping tools, analyzes the TB hotspots in South America, and determines the impact of COVID-19 on TB control strategies.

The molecular epidemiology techniques
The molecular epidemiology of MTB aims, by a comparative analysis of nucleic acid sequences of strains to determine the relationship when the stains descend from a common ancestor and where the level of closeness and similarity between isolates varies. Molecular markers allow for the determination of the level of genetic relationship between strains according to variations in the DNA sequence due to single nucleotide polymorphisms (SNPs), long sequence polymorphisms (LSPs), or repeated sequence polymorphisms; this method allows for the characterization of the lineages of strains as phylogenetic contributions to control the disease and disrupt the transmission chain (Coll & García de Viedma, 2018).
The techniques used for genotyping are typing by complementary oligonucleotide spacer sequences (spoligotyping), restriction-hybridization patterns (IS6110-RFLP, PGRS-RFLP), mycobacterial interleaved repeat units-variable number tandem repeats (MIRU-VNTR), and whole genome sequencing (WGS). The most advanced technique in the analysis of MTB from clinical samples is WGS, which allows the study of genome microevolution and the preparation of genomic libraries to identify epidemiological events of interest, with greater discrimination when detecting outbreaks, virulence, pathogenesis, transmission chains and mutations associated with resistance to first-and second-line antituberculosis drugs Meehan et al., 2019). MIRU-VNTR is also a highly stable, fast, reproducible and highly discriminatory technique, which is why it is considered for epidemiological studies, population genetics and phylogenetic studies of pathogens belonging to the Mycobacterium tuberculosis complex (MTBC) (Babai Kochkaksaraei et al., 2019;Jiménez et al., 2017). These two molecular techniques are the most widely used for studying the genotyping of MTB, and MIRU-VNTR is used more often in developing countries of South America than WGS.

Description of the circulating lineages in South America
The molecular epidemiological analysis is stratified by country through the molecular characterization of MTB and allows us to know the dynamics of disease transmission and to identify high-risk groups in order to provide an early response to outbreaks. In this way, several studies in South America report the circulating sublineages in each country and their percentage of prevalence is of interest for the control of TB in South America (Hill et al., 2020).

Brazil
It is the country with the highest number of TB cases and the second highest concentration of rifampicin-and multidrug-resistant tuberculosis (RR/MDR-TB) in the American region. In 2019, 76,000 new cases of TB were reported, and nearly 4,500 deaths occurred. Most of the cases reported in this country were concentrated in the southeast, where the state of São Paulo (SP) represented 20% of the disease incidence in the country. As one of the countries with the largest geographical extension in South America and having several borders, Brazil has a great variety of circulating lineages of MTB. There are foreign MTB lineages due to the movement of the population for tourism and commercial events. Currently, TB transmission routes are present in both rural and urban populations, so special attention has been given to study the disease through molecular epidemiology techniques, early diagnosis, and monitored treatment. The HIV-infected population and people deprived of their liberty are vulnerable groups, so plans for diagnosis and observed treatment have been implemented to disrupt the chain of transmission (Esteves et al., 2018;PAHO, 2020) The circulating sublineages in Brazil with the highest percentages of prevalence are LAM (48.87%), RD Rio (22.58%), Haarlem (13.7%), T (16.5%), X (3.6%), and S (2.05%), belonging to lineage 4, which prevails in the American region, due to the stability of its genotype and transmissibility. The lineages with the lowest prevalence are: Beijing (0.65%), Uganda (0.65%), MANU (0.58%), EAI (0.48%), CAS (0.45%), West African (0.26%), H37Rv (0.24%), Ural (0.13%), Cameroon (0.065%), BOV (0.02%) and Ghana (0.02%) ( Table 1). The lineages 3, 4 and 6 have been incorporated into a variety of MTB lineages found in Brazil by the migration of people (Esteves et al., 2018;Salvato et al., 2019). Brazil has a low incidence of unidentified strains (10.5%), which is due to the implementation of molecular techniques such as spoligotyping, MIRU-VNTR (24 and 12 loci) and WGS to determine the transmission routes of TB (Cardoso Oelemann et al., 2011;Dalla Costa et al., 2013;Gomes et al., 2012;Luiz et al., 2013;Machado et al., 2014;Martins et al., 2013;Medeiros et al., 2018;Nogueira et al., 2016;Noguti et al., 2010;Soares et al., 2013;Vasconcellos et al., 2014).
In 2007, MTB isolates from Rio de Janeiro were analyzed for genomic deletions. The RD Rio sublineage was characterized as having a new deletion of a single long-sequence polymorphism (> 26.3 kb) that included 10 genes. This sublineage was derived from a common ancestor that belongs only to the LAM sublineage, and is thus a predominant clade that causes TB in Rio de Janeiro and the most important source of recent transmission. 37 The clinical picture of people infected with MTB RD Rio presents a predisposition to resistance to multiple drugs, hemoptysis (coughing up blood), weight loss, and association with higher bacillary loads (Esteves et al., 2018;Lazzarini et al., 2007).

Peru
After Brazil, Peru is the country with the second highest concentration of TB cases and the first in terms of RR/MDR-TB cases in the American region. In 2018, 31,668 TB cases were reported of which 1,457 corresponded to RR/MDR-TB and 121 to extremely resistant TB (XDR-TB). Metropolitan Lima and Callao account for 64% of TB cases in this country. Some indicators show progress in disease control, such as decreases of 2% and 3% per year for the reported incidence and total morbidity rates; however, the numbers of XDR-TB cases have increased (Centro de Epidemiología, Prevención y Control de & enfermedades, 2019; PAHO, 2020; Soto Cabezas et al., 2020). Peru, because of its political and geographical history, has had visitation of different nationalities that have increased the variety of MTB lineages in this region. Among the visitors are persons from Asia, a continent with a high incidence of TB worldwide and with the presence of lineages with high virulence and pathogenicity, such as Beijing .
The most prevalent sublineages in Peru are LAM (35%), Haarlem (31%), and Beijing (10.27%); these findings are consistent with the data for the incidence of MDR/XDR-TB cases, since the Beijing sublineage is associated with cases of resistance to both first-and second-line anti-tuberculosis drugs. In several studies, the Haarlem sublineage had the highest incidence rates due to the stability of this genotype in the population and the high rate of recent transmission. The sublineages with the lowest prevalence in Peru are X (3.1%), T (7.4%), S (0.32%), U (0.32%), MANU (0.01%), Ghana (0.01%), and EAI (0.01%); the presence of these sublineages correlates with the movement of people from the Asian region (Table 1). The percentage of unidentified strains (12.2%) is relatively low due to the implementation of molecular techniques such as spoligotyping, MIRU-VNTR (24 and 12 loci), and WGS to determine the transmission routes of TB (Barletta et al., 2013(Barletta et al., , 2015Cáceres et al., 2014;Cohen et al., 2011;Farhat et al., 2019;Grandjean et al., 2015Grandjean et al., , 2017Huang et al., 2020;Sheen et al., 2013;Taype et al., 2012).

Colombia
In the American region, Colombia has the fifth-highest concentration of TB cases after Mexico and Haiti and the sixth-highest concentration of RR/MDR-TB cases (PAHO, 2020). In 2019, there were 14,684 cases of TB. The territorial entities with the highest rate are Amazonas, Guainía, Risaralda, Barranquilla, Meta, Arauca, and Casanare. TB is concentrated in the most vulnerable segments of the Colombian population, such as HIV patients (11%), indigenous people (5%), street dwellers (4%), and prisoners (6%) (Instituto Nacional de Salud de Colombia, 2020).

Venezuela
It is the country with the sixth highest number of TB cases and with the eighth highest concentration of RR/MDR-TB in the American region (PAHO, 2020). In 2019, a TB infection rate of 47.8 per 100,000 people was reported (World Health Organization, 2020). In 2017, 10,952 cases of TB were reported (PAHO, 2018).

Argentina
It is the country with the seventh highest number of TB cases and with the seventh with the highest concentration of RR/MDR-TB in the American region (PAHO, 2020). In 2018, 11,670 cases of TB were reported, and 720 deaths occurred. Buenos Aires and Greater Buenos Aires had 45% of the cases at the country level, the incidence rate was 26.2 per 100,000 inhabitants, of which 6 out of 10 were men (Ministerio de Salud Argentina, 2020).
The sublineages with the highest prevalence are those belonging to lineage 4: T (31.55%), LAM (30.9%), and Haarlem (18.4%), with the T sublineage being the one with the highest concentration both in Buenos Aires and in Greater Buenos Aires due to its adaptability in the urban population. The sublineages with the lowest prevalence are S (2.19%), X (1.02%), and Beijing (0.23%), belonging to lineages 2 and 4. The RD Rio sublineage (11.3%), part of the LAM sublineage, has been reported as a foreign sublineage implemented by population movement between Argentina and Brazil (

Bolivia
It is the country with the eighth highest number of TB cases and with the ninth highest concentration of RR/MDR-TB in the American region (PAHO, 2020). In 2018, 7,762 cases of TB were reported, where the Department of Santa Cruz had the highest incidence of TB in the country (42%), with 3,240 cases and 103 deaths (PAHO/WHO, 2019a).

Guyana
Guyana has the twelfth highest concentrations of TB in the American region, after the Dominican Republic, El Salvador and Panama (PAHO, 2020). In 2017, an incidence of 109 cases per 100,000 people and 35.1% of patients with TB and HIV were reported. TB control still has some challenges in this nation, and one of the most critical being the HIV epidemic in the population. This epidemic has been identified as a major concern and ISSN: 2697-3391 Vol. 4, N° 3, p. 34-58, julio-septiembre, 2021

Salud Pública
Página 41 www.anatomiadigital.org underlying cause of the increase in both TB morbidity and mortality (PAHO/WHO, 2019b). In 2018, Guyana was reported to be the country with the highest number of TB deaths in the American region (PAHO, 2020).
The sublineages with the highest prevalence are T (72.62%), EAI (10.8%), and Beijing (1.09%), with the T sublineage being the one found at higher concentrations due to its adaptability in the urban population (Table 1). Unidentified strains (16.2%) were reported in the studies, and the molecular techniques of spolygotipyng and 15-loci-MIRU-VNTR were used Streit et al., 2014).

Ecuador
In 2018 The most prevalent circulating sublineages are LAM (42.9%), Haarlem (26%), S (11.53%), Ghana (7.12%) and X (3.35%). The Beijing sublineage is of phylogenetic interest due to its high virulence and pathogenicity has been found in this country with a prevalence of 1.69%, which shows that the movement of people from frontier countries such as Peru has been able to migrate foreign lineages, increasing the transmission of TB. The sublineages with the lowest prevalence are Cameroon (0.83%) and Delhi (0.4%), which are sublineages belonging to lineages 3 and 4 ( Asunción. This study used spoligotyping, and to confirm the results obtained, the molecular techniques of RFLP and MIRU-VNTR were applied (Candia et al., 2007).

Chile
Very low rates of TB in Chile have been achieved after decades of sustained economic development-related decline and a robust and monitored National TB Program. In 2017, 2,740 cases of TB were reported. In 2018, the incidence rate was 14.7 cases per 100,000 people (Ministerio de Salud, 2018).

Suriname
In 2018, an incidence of TB of 38 cases per 100 000 people and 4.7% of patients with TB and HIV was reported; in 2017, an incidence of 29 cases per 100 000 people was reported, suggesting an increase in TB transmission in the country (Commiesie et al., 2019).

Uruguay
In 2018, an incidence of 33 cases per 100 000 people was reported (PAHO, 2020). This result is currently all the information that is available since no MTB molecular genotyping studies have been performed in this country.

French Guyana
French Guyana has the highest burden of TB among all French territories with a sharp increase in the incidence of TB in recent years to 9.5 cases per 100,000 people. TB is the fourth most frequent opportunistic infection among HIV patients in this country (Nacher et al., 2020).
The sublineages with the highest prevalence are T (32.6%), LAM (23.3%) and Haarlem (22.6%), with the T sublineage having the highest concentration due to its adaptability in the urban population and the LAM sublineage being the main circulating sublineage in South America (Table 1). The prevalence of more sublineages is unknown due to a single ISSN: 2697-3391 Vol. 4, N° 3, p. 34-58, julio-septiembre, 2021 Salud Pública Página 43 www.anatomiadigital.org genotyping study carried out in the French region, and the molecular technique used was spoligotyping (Guernier et al., 2008).   Molecular epidemiology studies in South America used to determine the lineages and sublineages circulating in each country, which the most prevalent are represented graphically according to their distribution and incidence rate of TB (Figure 1). Table 1 with de percentage of prevalence per country. Each country has been shaded according to the estimated TB incidence rate in concordance with the "Tuberculosis in the Americas 2019 regional report", by Pan American Health Organization (2020) [2]. Country codes (http://www.worldatlas.com/aatlas/ctycodes.htm). Source: Own elaboration.

The dynamics of lineage distribution in South America
Susceptibility to MTB varies in every individual and this heterogeneity influences the routes and frequencies of transmission in a population. By understanding the magnitude and distribution of these differences, it is possible to predict the dynamics of the disease to control and reduce TB transmission (Rodrigues et al., 2017). The imminent interactions between host, environment and bacterial factors makes the epidemiological study of MTB difficult due to the independence of strains in phenotypic versus genotypic manifestation, explicitly in terms of virulence, where morbidity and mortality are the measures of proportion, since the virulence of MTB is directly related to transmission (Zhang et al., 2019).

Salud Pública
Página 45 www.anatomiadigital.org them to be distributed worldwide (Zhang et al., 2019). In South America, these lineages are widely dispersed in both rural and urban areas, where factors such as air pollution, smoking, malnutrition, population density, crowded living conditions, HIV incidence and mobility among migrants increase TB transmission and distribution (Esteves et al., 2018). This dispersion is how the LAM sublineage appears in cities with high population concentrations, promoting a more severe disease due to its high mutation rate. In turn, a new mutation from this sublineage has been reported, giving rise to a new RD Rio strain that appears in the population of Rio de Janeiro with a clinical picture that has with high bacillary loads (Moraes et al., 2017); lineage 4 sublineages such as Haarlem and T are directly related to their stability and transmissibility in urban areas and the S sublineage in rural areas, especially in indigenous communities (Díaz Acosta et al., 2019;Garzon-Chavez et al., 2020). The Beijing sublineage is unique due to its high level of virulence, reduced inflammatory response and predisposition to antibiotic resistance. At present, its distribution in South America is not total, not because of its level of transmission and prevalence but because of the scarce genotyping studies in the countries where it is not reported (Cerezo-Cortés et al., 2019). For the circulating sublineages belonging to lineages 1, 3 and 6, since they have a low prevalence, it is not possible to determine their specific level of influence in a population area, except for their increased variability as complex outbreaks and new routes of infection (Garzon-Chavez et al., 2020).

Brazil and Peru are hotspots for tuberculosis in South America
Brazil is the country with the highest incidence of TB in South America, is an economic and tourism power, and has the greatest phylogenetic variety of MTB (lineages 1, 2, 3, 4 and 6). This diversity of lineages arises from the Portuguese impact on the country when it was a colony and the European and Asian impacts in the economic development of the country; thus, the most prevalent lineage is 4, from which comes the RD Rio sublineage that is currently found not only in the population of Rio de Janeiro but also in Paraguay, Argentina and Venezuela (Díaz Acosta et al., 2019;Esteves et al., 2018;Moraes et al., 2017;PAHO, 2020). The geographic extension of Brazil provides border proximity to almost all countries in South America, and thus, political and economic relations increase the movement of people and consequently the distribution of MTB. This phylogenetic diversity that Brazil brings to South America has led to complex outbreaks and new routes of infection to countries that do not have the molecular tools or control strategies to counteract the transmission of TB (Esteves et al., 2018;Medeiros et al., 2018;Rodrigues et al., 2017). It is worth mentioning that despite its population density and large geographic area, the presence of RR/MDR/XDR-TB is not reported as being critical as it is in Peru (Esteves et al., 2018).
Peru is the country with the second highest incidence of TB but the first in terms of RR/MDR-TB, which is related to the level of prevalence of the Beijing sublineage.
Prevalence of the Beijing sublineage in Peru is the highest in South America (10.3%) due to population migration from China associated with labor, commercial and economic factors. China is one of the hotspots with the highest level of TB prevalence in the world (Grandjean et al., 2017;Huang et al., 2020;PAHO, 2020). XDR-TB reports also have a ISSN: 2697-3391 Vol. 4, N° 3, p. 34-58, julio-septiembre, 2021 Salud Pública Página 46 www.anatomiadigital.org higher incidence in this nation than in South America as a whole. The highest density of cases are concentrated in the districts of Lima and Callao and in more than half of the country's departments with high poverty rates (Grandjean et al., 2017;Soto Cabezas et al., 2020

Impact of COVID-19 on TB disease
It is likely that the high prevalence of TB and increasing COVID-19 allow a temporal association that has a synergistic effect both economically and socially, where comorbidity would increase the rate of deaths in both vulnerable individuals and the general population (Homolka et al., 2020). In 2020, there has been a significant decrease in presumptive, confirmed cases and notifications of TB deaths compared to 2019, which is associated with restricted access to the diagnostic testing and treatment centers during confinement and associated with the use of resources such as laboratories, people and supplies that are focused on emergency planning and containment of the COVID-19 pandemic (Buonsenso et al., 2021;Homolka et al., 2020).
One of the possible post-pandemic effects is the increase in morbidity and mortality from TB and RR/MDR/XDR-TB due to overcrowded conditions, treatment abandonment and lack of an active search for cases during confinement and outbreaks of COVID-19, allowing the appearance of new outbreaks and chains of transmission, especially in vulnerable populations; thus, measures should be taken and TB control programs should be evaluated and implemented (Buonsenso et al., 2021;Comella-del-Barrio et al., 2020). TB control requires surveillance interventions, clinical assessment, diagnostic testing, contact tracing, and confirmation of diagnosis with supervised treatment regimens; as all these important actions have been limited, all the recent advances in the End TB Strategy have been affected (Homolka et al., 2020;McQuaid et al., 2020;Motta et al., 2020). It is necessary to respond to the COVID-19 pandemic without neglecting an epidemic such as TB, which is the fifth leading cause of death worldwide. This statement is even more true in South America where countries that are low development regions cannot cope with a coinfection of two infectious diseases or coinfection of up to three diseases if HIV is included.

Conclusions.
• The genotyping of MTB in the American region, mainly in South America, has provided results of epidemiological interest by identifying the circulating lineages that each country has and how migratory movements have contributed to the dissemination of TB and the increase in MTB genotypes in each country. • In this case, Brazil and Peru are the countries with the major incidences of TB and increased phylogenetic diversity of MTB in South America. According to the scientific reports analyzed in this review, a high prevalence of sublineages belonging to lineage 4 can be observed as LAM, Haarlem, Cameroon X, T, S, and Ghana. Additionally, the new sublineage RD Rio has a more severe clinical profile and is currently found not only in Brazil, the country of origin, but also in Argentina, Venezuela and Paraguay. Another important prevalent sublineage is the Beijing, which belongs to lineage 2, and is dispersed throughout the countries of South America except Bolivia, Uruguay and French Guyana, where there are no reports of incidence thus far. • The sublineages of lineages 1, 3 and 6 have a low mutation rate, which correlates with their low transmissibility and adaptability in the population. MIRU-VNTR is highly discriminatory; however, there is still a low percentage of unidentified strains. • Finally, the TB control directions are from the WHO, and each country implements these directions according to the country's resources (laboratories, supplies and people), which has been considered an impediment to harmonize strategies aimed at the control and elimination of the disease. Therefore, the response to the COVID-19 pandemic has a possible post-pandemic effect of a significant resurgence of TB cases; thus, as a scientific community, we must propose projects or seek diagnostic resources to actively search for cases, supervise and complete treatment, and epidemiologically control the disease and thereby disrupt the chain of transmission, especially in vulnerable populations.