[Evaluation of a change in the serological diagnostic algorithm for Chagas disease in ColombiaAvaliação da mudança do algoritmo de diagnóstico sorológico da doença de Chagas na Colômbia]. / Evaluación del cambio del algoritmo de diagnóstico serológico para la enfermedad de Chagas en Colombia.

Objective: To evaluate the effects of changing the algorithm for serological diagnosis of T. cruzi infection in departmental-level public health laboratories and in the National Reference Laboratory of Colombia, from the perspective of access to diagnosis. Methods: A descriptive, cross-sectional study was carried out, based on secondary sources between 2015 and 2021, consolidating the number of serological tests carried out by the laboratories. A survey was developed to identify benefits and limitations in the implementation of the new algorithm for serological diagnosis. Totals, proportions, and averages of the number of tests were estimated by comparing two different periods. Results: Information from 33 public health laboratories was analyzed, 87.9% of which processed serological assays during the period under study. The use of serological tests increased after the publication of the new guideline in 2017, and the capacity to perform the second test increased from four to 33 public health laboratories. In absolute terms, ELISAs for antigens and recombinant antigens became the most performed tests in Colombia after 2017. Conclusions: The change in the algorithm for serological diagnosis of Chagas disease in Colombia in 2017 had positive effects on access to diagnosis since it facilitated the use of the second test. This change resulted in increased diagnostic coverage. The country's laboratories have access to a simple, timely, quality algorithm that could be implemented in almost any clinical laboratory in the country.

Objetivo: Avaliar os efeitos da mudança do algoritmo de diagnóstico sorológico da infecção por T. cruzi nos Laboratórios Departamentais de Saúde Pública e no Laboratório Nacional de Referência da Colômbia desde a perspectiva do acesso ao diagnóstico. Métodos: Foi realizado um estudo descritivo transversal a partir de fontes secundárias do período entre 2015 e 2021, consolidando-se o número de testes sorológicos realizados pelos laboratórios. Foi desenvolvido um questionário para identificar benefícios e limitações na implementação do novo algoritmo de diagnóstico sorológico. Os totais, as proporções e as médias do número de testes foram estimados pela comparação de dois períodos diferentes. Resultados: Dados de 33 laboratórios de saúde pública foram analisados, e constatou-se que 87,9% processaram testes sorológicos durante o período analisado. O uso de testes sorológicos aumentou após a publicação das novas diretrizes em 2017, e a capacidade de realizar um segundo teste aumentou de 4 para 33 laboratórios de saúde pública. O ELISA com antígeno total e o ELISA com antígeno recombinante se consolidaram como os testes mais realizados na Colômbia após 2017. Conclusões: A mudança no algoritmo de diagnóstico sorológico da doença de Chagas na Colômbia em 2017 teve efeitos positivos no acesso ao diagnóstico, facilitando o uso do segundo teste, o que resultou em maior cobertura diagnóstica. Os laboratórios do país têm à sua disposição um algoritmo simples, oportuno e de alta qualidade que poderia ser implementado em quase todos os laboratórios clínicos do país.

Evaluación del cambio del algoritmo de diagnóstico serológico para la enfermedad de Chagas en Colombia / Evaluation of a change in the serological diagnostic algorithm for Chagas disease in Colombia / Avaliação da mudança do algoritmo de diagnóstico sorológico da doença de Chagas na Colômbia

[RESUMEN]. Objetivo. Evaluar los efectos del cambio del algoritmo de diagnóstico serológico para la infección por T. cruzi en los Laboratorios de Salud Pública Departamentales y en el Laboratorio Nacional de Referencia de Colombia, desde una perspectiva del acceso al diagnóstico. Métodos. Se realizó un estudio descriptivo, transversal, a partir de fuentes secundarias entre el 2015 y 2021, se consolidó el número de ensayos serológicos realizados por los laboratorios. Se elaboró una encuesta para identificar beneficios y limitaciones en la implementación del nuevo algoritmo de diagnóstico serológico. Se estimaron totales, proporciones y promedios del número de pruebas comparando dos periodos diferentes. Resultados. Se analizó la información de 33 Laboratorios de Salud Pública, encontrando que el 87,9% de ellos procesaron ensayos serológicos durante el periodo analizado. El uso de las pruebas serológicas aumentó después de la publicación del nuevo lineamiento en 2017 y la capacidad de realización de la segunda prueba paso de 4 a 33 Laboratorios de Salud Pública. La ELISA de antígenos totales y de antígenos recombinantes se consolidaron como las pruebas más realizadas en Colombia después del 2017. Conclusiones. El cambio del algoritmo de diagnóstico serológico para la enfermedad de Chagas en Colombia en 2017 tuvo efectos positivos en el acceso al diagnóstico ya que facilitó el uso de la segunda prueba, esta modificación se tradujo en aumento de la cobertura diagnóstica. Los laboratorios del país tienen disponible un algoritmo sencillo, oportuno, de calidad y que podría ser implementado en casi cualquier laboratorio clínico del país.

[ABSTRACT]. Objective. To evaluate the effects of changing the algorithm for serological diagnosis of T. cruzi infection in departmental-level public health laboratories and in the National Reference Laboratory of Colombia, from the perspective of access to diagnosis. Methods. A descriptive, cross-sectional study was carried out, based on secondary sources between 2015 and 2021, consolidating the number of serological tests carried out by the laboratories. A survey was developed to identify benefits and limitations in the implementation of the new algorithm for serological diagnosis. Totals, proportions, and averages of the number of tests were estimated by comparing two different periods. Results. Information from 33 public health laboratories was analyzed, 87.9% of which processed serological assays during the period under study. The use of serological tests increased after the publication of the new guideline in 2017, and the capacity to perform the second test increased from four to 33 public health laboratories. In absolute terms, ELISAs for antigens and recombinant antigens became the most performed tests in Colombia after 2017. Conclusions. The change in the algorithm for serological diagnosis of Chagas disease in Colombia in 2017 had positive effects on access to diagnosis since it facilitated the use of the second test. This change resulted in increased diagnostic coverage. The country's laboratories have access to a simple, timely, quality algorithm that could be implemented in almost any clinical laboratory in the country.

[RESUMO]. Objetivo. Avaliar os efeitos da mudança do algoritmo de diagnóstico sorológico da infecção por T. cruzi nos Laboratórios Departamentais de Saúde Pública e no Laboratório Nacional de Referência da Colômbia desde a perspectiva do acesso ao diagnóstico. Métodos. Foi realizado um estudo descritivo transversal a partir de fontes secundárias do período entre 2015 e 2021, consolidando-se o número de testes sorológicos realizados pelos laboratórios. Foi desenvolvido um questionário para identificar benefícios e limitações na implementação do novo algoritmo de diagnóstico sorológico. Os totais, as proporções e as médias do número de testes foram estimados pela comparação de dois períodos diferentes. Resultados. Dados de 33 laboratórios de saúde pública foram analisados, e constatou-se que 87,9% processaram testes sorológicos durante o período analisado. O uso de testes sorológicos aumentou após a publicação das novas diretrizes em 2017, e a capacidade de realizar um segundo teste aumentou de 4 para 33 laboratórios de saúde pública. O ELISA com antígeno total e o ELISA com antígeno recombinante se consolidaram como os testes mais realizados na Colômbia após 2017. Conclusões. A mudança no algoritmo de diagnóstico sorológico da doença de Chagas na Colômbia em 2017 teve efeitos positivos no acesso ao diagnóstico, facilitando o uso do segundo teste, o que resultou em maior cobertura diagnóstica. Os laboratórios do país têm à sua disposição um algoritmo simples, oportuno e de alta qualidade que poderia ser implementado em quase todos os laboratórios clínicos do país.

Laboratory evaluation of eleven rapid diagnostic tests for serological diagnosis of Chagas disease in Colombia.

BACKGROUND: Chagas disease is a public health challenge in Colombia, where only an estimated 1.2% of people at risk have accessed diagnosis, while less than 0.5% of affected people have obtained treatment. The development of simplified diagnostic algorithms would enable progress in access to diagnosis; however, the current diagnostic algorithm relies on at least two laboratory-based tests that require qualified personnel, processing equipment, and infrastructure, which are still generally lacking at the primary care level. Rapid diagnostic tests (RDTs) for Chagas disease could simplify diagnosis, but their performance in the epidemiological context of Colombia is not well known. METHODOLOGY: A retrospective analytical observational study of RDTs was performed to estimate the operational characteristics of 11 commercially available RDTs designed for in vitro detection of anti-T. cruzi IgG antibodies. The study was performed under controlled laboratory conditions using human serum samples. PRINCIPAL FINDINGS: Eleven RDTs were assessed, ten using 585 serum samples and one using 551 serum samples. Employing the current national diagnostic algorithm as a reference standard for serological diagnosis of chronic infection, the sensitivity of the assessed RDTs ranged from 75.5% to 99.0% (95% CI 70.5-100), while specificity ranged from 70.9% to 100% (95% CI 65.3-100). Most tests (7/11, 63.6%) had sensitivity above 90%, and almost all (10/11, 90.9%) had specificity above 90%. Five RDTs had both sensitivity and specificity above 90%. CONCLUSIONS/SIGNIFICANCE: The evaluation of these 11 commercially available RDTs under controlled laboratory conditions is a first step in the assessment of the diagnostic performance of RDTs in Colombia. As a next step, field studies will be conducted on available RDTs with sensitivity and specificity greater than 90% in this study, to evaluate performance in real world conditions, with the final goal to allow simplified diagnostic algorithms.

Evaluación del cambio del algoritmo de diagnóstico serológico para la enfermedad de Chagas en Colombia / Evaluation of a change in the serological diagnostic algorithm for Chagas disease in Colombia / Avaliação da mudança do algoritmo de diagnóstico sorológico da doença de Chagas na Colômbia

RESUMEN Objetivo. Evaluar los efectos del cambio del algoritmo de diagnóstico serológico para la infección por T. cruzi en los Laboratorios de Salud Pública Departamentales y en el Laboratorio Nacional de Referencia de Colombia, desde una perspectiva del acceso al diagnóstico. Métodos. Se realizó un estudio descriptivo, transversal, a partir de fuentes secundarias entre el 2015 y 2021, se consolidó el número de ensayos serológicos realizados por los laboratorios. Se elaboró una encuesta para identificar beneficios y limitaciones en la implementación del nuevo algoritmo de diagnóstico serológico. Se estimaron totales, proporciones y promedios del número de pruebas comparando dos periodos diferentes. Resultados. Se analizó la información de 33 Laboratorios de Salud Pública, encontrando que el 87,9% de ellos procesaron ensayos serológicos durante el periodo analizado. El uso de las pruebas serológicas aumentó después de la publicación del nuevo lineamiento en 2017 y la capacidad de realización de la segunda prueba paso de 4 a 33 Laboratorios de Salud Pública. La ELISA de antígenos totales y de antígenos recombinantes se consolidaron como las pruebas más realizadas en Colombia después del 2017. Conclusiones. El cambio del algoritmo de diagnóstico serológico para la enfermedad de Chagas en Colombia en 2017 tuvo efectos positivos en el acceso al diagnóstico ya que facilitó el uso de la segunda prueba, esta modificación se tradujo en aumento de la cobertura diagnóstica. Los laboratorios del país tienen disponible un algoritmo sencillo, oportuno, de calidad y que podría ser implementado en casi cualquier laboratorio clínico del país.

ABSTRACT Objective. To evaluate the effects of changing the algorithm for serological diagnosis of T. cruzi infection in departmental-level public health laboratories and in the National Reference Laboratory of Colombia, from the perspective of access to diagnosis. Methods. A descriptive, cross-sectional study was carried out, based on secondary sources between 2015 and 2021, consolidating the number of serological tests carried out by the laboratories. A survey was developed to identify benefits and limitations in the implementation of the new algorithm for serological diagnosis. Totals, proportions, and averages of the number of tests were estimated by comparing two different periods. Results. Information from 33 public health laboratories was analyzed, 87.9% of which processed serological assays during the period under study. The use of serological tests increased after the publication of the new guideline in 2017, and the capacity to perform the second test increased from four to 33 public health laboratories. In absolute terms, ELISAs for antigens and recombinant antigens became the most performed tests in Colombia after 2017. Conclusions. The change in the algorithm for serological diagnosis of Chagas disease in Colombia in 2017 had positive effects on access to diagnosis since it facilitated the use of the second test. This change resulted in increased diagnostic coverage. The country's laboratories have access to a simple, timely, quality algorithm that could be implemented in almost any clinical laboratory in the country.

RESUMO Objetivo. Avaliar os efeitos da mudança do algoritmo de diagnóstico sorológico da infecção por T. cruzi nos Laboratórios Departamentais de Saúde Pública e no Laboratório Nacional de Referência da Colômbia desde a perspectiva do acesso ao diagnóstico. Métodos. Foi realizado um estudo descritivo transversal a partir de fontes secundárias do período entre 2015 e 2021, consolidando-se o número de testes sorológicos realizados pelos laboratórios. Foi desenvolvido um questionário para identificar benefícios e limitações na implementação do novo algoritmo de diagnóstico sorológico. Os totais, as proporções e as médias do número de testes foram estimados pela comparação de dois períodos diferentes. Resultados. Dados de 33 laboratórios de saúde pública foram analisados, e constatou-se que 87,9% processaram testes sorológicos durante o período analisado. O uso de testes sorológicos aumentou após a publicação das novas diretrizes em 2017, e a capacidade de realizar um segundo teste aumentou de 4 para 33 laboratórios de saúde pública. O ELISA com antígeno total e o ELISA com antígeno recombinante se consolidaram como os testes mais realizados na Colômbia após 2017. Conclusões. A mudança no algoritmo de diagnóstico sorológico da doença de Chagas na Colômbia em 2017 teve efeitos positivos no acesso ao diagnóstico, facilitando o uso do segundo teste, o que resultou em maior cobertura diagnóstica. Os laboratórios do país têm à sua disposição um algoritmo simples, oportuno e de alta qualidade que poderia ser implementado em quase todos os laboratórios clínicos do país.

An overview of the trypanosomatid (Kinetoplastida: Trypanosomatidae) parasites infecting several mammal species in Colombia.

BACKGROUND: Trypanosomatids are among the most critical parasites for public health due to their impact on human, animal, and plant health. Diseases associated with these pathogens manifest mainly in poor and vulnerable populations, where social, environmental, and biological factors modulate the case incidence and geographical distribution. METHODS: We used Sanger and amplicon-based next-generation sequencing (NGS) in samples from different mammals to identify trypanosomatid infections in several departments in Colombia. A total of 174 DNA samples (18 humans, 83 dogs, and 73 wild mammals) were analyzed by conventional PCR using a fragment of the heat shock protein 70 (Hsp70) gene and Sanger sequenced the positive samples. Twenty-seven samples were sent for amplicon-based NGS using the same gene fragment. Data obtained were used to perform diversity analyses. RESULTS: One hundred and thirteen samples were positive for PCR by Hsp70 fragment; these corresponded to 22.1% Leishmania spp., 18.6% L. amazonensis, 9.7% L. braziliensis, 14.2% L. infantum, 8% L. panamensis, and 27.4% Trypanosoma cruzi. Comparison of the identified species by the two sequencing technologies used resulted in 97% concordance. Alpha and beta diversity indices were significant, mainly for dogs; there was an interesting index of coinfection events in the analyzed samples: different Leishmania species and the simultaneous presence of T. cruzi and even T. rangeli in one of the samples analyzed. Moreover, a low presence of L. braziliensis was observed in samples from wild mammals. Interestingly, to our knowledge, this is the first report of Leishmania detection in Hydrochaeris hydrochaeris (capybara) in Colombia. CONCLUSIONS: The Hsp70 fragment used in this study is an optimal molecular marker for trypanosomatid identification in many hosts and allows the identification of different species in the same sample when amplicon-based sequencing is used. However, the use of this fragment for molecular diagnosis through conventional PCR should be carefully interpreted because of this same capacity to identify several parasites. This point is of pivotal importance in highly endemic countries across South America because of the co-circulation of different genera from the Trypanosomatidae family. The findings show an interesting starting point for One Health approaches in which coevolution and vector-host interactions can be studied.

Amplicon-based next-generation sequencing reveals the co-existence of multiple Leishmania species in patients with visceral leishmaniasis.

Visceral leishmaniasis (VL) is a mammalian protozoal disease propagated in the Americas by female phlebotomine sandflies, mainly caused by Leishmania infantum. However, in recent years, cases of VL caused by different Leishmania species, such as L. amazonensis and L. colombiensis, have been reported in the continent. This study used an amplicon-based next-generation sequencing approach to identify VL aetiologic species using high-depth sequencing targeting a region on the Heat Shock Protein 70 gene. In this first approach, six samples from five patients diagnosed with VL were selected and analysed to identify DNA of Leishmania spp. All samples harboured DNA of L. infantum; five samples were found to be co-infected with other Leishmania spp. or with Trypanosoma cruzi, and just one sample was mono-infected with L. infantum. This study demonstrates the usefulness of this methodology to identify trypanosomatid co-infections in clinical samples, which presents an interesting study panorama considering their biological, clinical and epidemiological implications.