Challenging diagnosis of Plasmodium ovale malaria in a Colombian traveler: the importance of including P. ovale wallikeri in molecular screening.

This study reports a challenging diagnosis of Plasmodium ovale malaria in a Colombian citizen returning from Cameroon. Initial microscopy screenings conducted at two private hospitals yielded conflicting results, with the first showing negative smears and the second diagnosing P. vivax. Subsequent microscopy examinations at two government laboratories identified P. ovale, although the routine species-specific PCR strategy was negative. PCR confirmation was finally obtained when P. ovale wallikeri primers were used. Although P. ovale is not frequently found in Colombia, there is a clear need to include both P. ovale curtisi and P. ovale wallikeri in the molecular diagnostic strategy. Such need stems primarily from their extended latency period, which affects travelers, the increasing number of African migrants, and the importance of accurately mapping the distribution of Plasmodium species in Colombia.

[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.

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.

Molecular surveillance for anti-malarial drug resistance and genetic diversity of Plasmodium falciparum after chloroquine and sulfadoxine-pyrimethamine withdrawal in Quibdo, Colombia, 2018.

BACKGROUND: Resistance to anti-malarial drugs is associated with polymorphisms in target genes and surveillance for these molecular markers is important to detect the emergence of mutations associated with drug resistance and signal recovering sensitivity to anti-malarials previously used. METHODS: The presence of polymorphisms in genes associated with Plasmodium falciparum resistance to chloroquine and sulfadoxine-pyrimethamine was evaluated by Sanger sequencing, in 85 P. falciparum day of enrollment samples from a therapeutic efficacy study of artemether-lumefantrine conducted in 2018-2019 in Quibdo, Colombia. Samples were genotyped to assess mutations in pfcrt (codons 72-76), pfdhfr (codons 51, 59, 108, and 164), and pfdhps genes (codons 436, 437, 540, and 581). Further, the genetic diversity of infections using seven neutral microsatellites (NMSs) (C2M34, C3M69, Poly α, TA1, TA109, 2490, and PfPK2) was assessed. RESULTS: All isolates carried mutant alleles for pfcrt (K76T and N75E), and for pfdhfr (N51I and S108N), while for pfdhps, mutations were observed only for codon A437G (32/73, 43.8%). Fifty samples (58.8%) showed a complete neutral microsatellites (NMS) profile. The low mean number of alleles (2 ± 0.57) per locus and mean expected heterozygosity (0.17 ± 0.03) showed a reduced genetic diversity. NMS multilocus genotypes (MMG) were built and nine MMG were identified. CONCLUSIONS: Overall, these findings confirm the fixation of chloroquine and pyrimethamine-resistant alleles already described in the literature, implying that these drugs are not currently appropriate for use in Colombia. In contrast, mutations in the pfdhps gene were only observed at codon 437, an indication that full resistance to sulfadoxine has not been achieved in Choco. MMGs found matched the clonal lineage E variant 1 previously reported in northwestern Colombia.

Concordance analysis of three diagnostic tests for malaria in the symptomatic population of Colombian endemic municipalities / [Análisis de concordancia de tres pruebas para el diagnóstico de malaria en la población sintomática de los municipios endémicos de Colombia].

Introduction: Taking into account the difficulty of performing malaria microscopic diagnosis in rural areas, rapid diagnostic tests (RDT) are a good alternative, but it is important to verify their diagnostic performance. Objective: To evaluate the diagnostic performance of the RDTs used in five Colombian departments by comparing them with the microscopic diagnosis and using PCR as the reference standard. Materials and methods: Thick blood film and RDTs were used to diagnose symptomatic individuals; additionally, the filter paper was impregnated with blood for the molecular test. Results: We included 314 samples whose percentage of positivity for malaria was 49% by PCR, 48% by microscopy and 46% by RDT; parasitemia ranged between 180 and 23,800 p/µL of blood. The concordance of the results from the microscopy units and those of the PCR (National Laboratory of Reference) was as follows: Cohen's kappa coefficient, 0.975 (95% CI: 0.950-0.999); sensitivity, 97% (95% CI 95-100); specificity 100% (95% CI: 100-100), and kappa index of species, 0.958 (IC95%: 0.912-1.00). The concordance between the Pf/Pv RDT (at the microscopy units) and the PCR (National Laboratory of Reference) was as follows: kappa coefficient, 0.878 (95% CI: 0.784-0.973); sensitivity, 94% (95% CI: 87-100); specificity, 95% (95% CI: 90-100), and kappa index of species, 1.0 (95% CI: 1.00-1.00). The concordance between the Pf/Pan RDT versus PCR was: Cohen's kappa coefficient, 0.920 (95 % CI: 0.865- 0.974); sensitivity, 94% (95% CI: 90-98); specificity, 99% (95% CI 95-100), and kappa index of species, 0.750 (IC95% 0,637-0,863). Conclusion: The results of this study support the use of RDTs in Colombia; however, more training of the personnel is required to accurately differentiate Plasmodium species.

Introducción. Dadas las dificultades del diagnóstico microscópico de la malaria o paludismo en las áreas rurales, las pruebas de diagnóstico rápido constituyen una buena alternativa, por lo que es importante conocer su desempeño. Objetivo. Evaluar el desempeño de las pruebas de diagnóstico rápido utilizadas en cinco departamentos para al diagnóstico microscópico de la malaria usando la reacción en cadena de la polimerasa (PCR) como estándar de referencia. Materiales y métodos. Se usaron la prueba de gota gruesa y las pruebas de diagnóstico rápido y, además, se impregnó papel de filtro con sangre para la prueba molecular (PCR), en individuos sintomáticos. Resultados. Se incluyeron 314 muestras cuyo porcentaje de positividad para malaria fue de 49 % con la PCR, de 48 % con microscopía y de 46 % con las pruebas de diagnóstico rápido; la parasitemia fluctuó entre 180 y 23.800 parásitos/µl de sangre. La concordancia de los resultados de los puestos de microscopía comparados con la PCR (Laboratorio Nacional de Referencia) fueron los siguientes: coeficiente kappa de Cohen de 0,975 (IC95% 0,950-0,999), sensibilidad de 97 % (IC95% 95-100) y especificidad de 100 % (IC95% 100-100), e índice kappa de especie de 0,958 (IC95% 0,912-1,00). La concordancia de los resultados de la prueba de diagnóstico rápido Pf/Pv en los puestos de microscopía y los de la PCR (Laboratorio Nacional de Referencia), fue la siguiente: coeficiente kappa de 0,878 (IC95% 0,784-0,973), sensibilidad de 94 % (IC95% 87-100), especificidad de 95 % (IC95% 90-100), e índice kappa de especie de 1,0 (IC95% 1,00-1,00). La concordancia entre la prueba de diagnóstico rápido Pf/Pan y la PCR fue la siguiente: coeficiente kappa de Cohen de 0,920 (IC95% 0,865-0,974), sensibilidad de 94 % (IC95% 90-98), especificidad de 99 % (IC95% 95-100), e índice kappa de especie de 0,750 (IC95% 0,637-0,863). Conclusión. Los resultados de este estudio respaldan el uso de las pruebas de diagnóstico rápido en Colombia, aunque se requiere un mejor entrenamiento del personal para diferenciar eficientemente las especies de Plasmodium.

Análisis de concordancia de tres pruebas para el diagnóstico de malaria en la población sintomática de los municipios endémicos de Colombia / Concordance analysis of three diagnostic tests for malaria in the symptomatic population of Colombian endemic municipalities

Introducción. Dadas las dificultades del diagnóstico microscópico de la malaria o paludismo en las áreas rurales, las pruebas de diagnóstico rápido constituyen una buena alternativa, por lo que es importante conocer su desempeño. Objetivo. Evaluar el desempeño de las pruebas de diagnóstico rápido utilizadas en cinco departamentos para al diagnóstico microscópico de la malaria usando la reacción en cadena de la polimerasa (PCR) como estándar de referencia. Materiales y métodos. Se usaron la prueba de gota gruesa y las pruebas de diagnóstico rápido y, además, se impregnó papel de filtro con sangre para la prueba molecular (PCR), en individuos sintomáticos. Resultados. Se incluyeron 314 muestras cuyo porcentaje de positividad para malaria fue de 49 % con la PCR, de 48 % con microscopía y de 46 % con las pruebas de diagnóstico rápido; la parasitemia fluctuó entre 180 y 23.800 parásitos/pl de sangre. La concordancia de los resultados de los puestos de microscopía comparados con la PCR (Laboratorio Nacional de Referencia) fueron los siguientes: coeficiente kappa de Cohen de 0,975 (IC95% 0,950-0,999), sensibilidad de 97 % (IC95% 95-100) y especificidad de 100 % (IC95% 100-100), e índice kappa de especie de 0,958 (IC95% 0,912-1,00). La concordancia de los resultados de la prueba de diagnóstico rápido Pf/Pv en los puestos de microscopía y los de la PCR (Laboratorio Nacional de Referencia), fue la siguiente: coeficiente kappa de 0,878 (IC95% 0,784-0,973), sensibilidad de 94 % (IC95% 87-100), especificidad de 95 % (IC95% 90-100), e índice kappa de especie de 1,0 (IC95% 1,00-1,00). La concordancia entre la prueba de diagnóstico rápido Pf/Pan y la PCR fue la siguiente: coeficiente kappa de Cohen de 0,920 (IC95% 0,865-0,974), sensibilidad de 94 % (IC95% 90-98), especificidad de 99 % (IC95% 95-100), e índice kappa de especie de 0,750 (IC95% 0,637-0,863). Conclusión. Los resultados de este estudio respaldan el uso de las pruebas de diagnóstico rápido en Colombia, aunque se requiere un mejor entrenamiento del personal para diferenciar eficientemente las especies de Plasmodium.

Introduction: Taking into account the difficulty of performing malaria microscopic diagnosis in rural areas, rapid diagnostic tests (RDT) are a good alternative, but it is important to verify their diagnostic performance. Objective: To evaluate the diagnostic performance of the RDTs used in five Colombian departments by comparing them with the microscopic diagnosis and using PCR as the reference standard. Materials and methods: Thick blood film and RDTs were used to diagnose symptomatic individuals; additionally, the filter paper was impregnated with blood for the molecular test. Results: We included 314 samples whose percentage of positivity for malaria was 49% by PCR, 48% by microscopy and 46% by RDT; parasitemia ranged between 180 and 23,800 p/µl of blood. The concordance of the results from the microscopy units and those of the PCR (National Laboratory of Reference) was as follows: Cohen's kappa coefficient, 0.975 (95% CI: 0.9500.999); sensitivity, 97% (95% CI 95-100); specificity 100% (95% CI: 100-100), and kappa index of species, 0.958 (IC95%: 0.912-1.00). The concordance between the Pf/Pv RDT (at the microscopy units) and the PCR (National Laboratory of Reference) was as follows: kappa coefficient, 0.878 (95% CI: 0.784-0.973); sensitivity, 94% (95% CI: 87-100); specificity, 95% (95% CI: 90-100), and kappa index of species, 1.0 (95% CI: 1.00-1.00). The concordance between the Pf/Pan RDT versus PCR was: Cohen's kappa coefficient, 0.920 (95 % CI: 0.865- 0.974); sensitivity, 94% (95% CI: 90-98); specificity, 99% (95% CI 95-100), and kappa index of species, 0.750 (IC95% 0,637-0,863). Conclusion: The results of this study support the use of RDTs in Colombia; however, more training of the personnel is required to accurately differentiate Plasmodium species.

Artemether-Lumefantrine Efficacy for the Treatment of Uncomplicated Plasmodium falciparum Malaria in Choco, Colombia after 8 Years as First-Line Treatment.

Artemether-lumefantrine (AL) is the first-line treatment for uncomplicated Plasmodium falciparum infection in Colombia. To assess AL efficacy for uncomplicated falciparum malaria in Quibdo, Choco, Colombia, we conducted a 28-day therapeutic efficacy study (TES) following the WHO guidelines. From July 2018 to February 2019, febrile patients aged 5-65 years with microscopy-confirmed P. falciparum mono-infection and asexual parasite density of 250-100,000 parasites/µL were enrolled and treated with a supervised 3-day course of AL. The primary endpoint was adequate clinical and parasitological response (ACPR) on day 28. We attempted to use polymerase chain reaction (PCR) genotyping to differentiate reinfection and recrudescence, and conducted genetic testing for antimalarial resistance-associated genes. Eighty-eight patients consented and were enrolled; four were lost to follow-up or missed treatment doses. Therefore, 84 (95.5%) participants reached a valid endpoint: treatment failure or ACPR. No patient remained microscopy positive for malaria on day 3, evidence of delayed parasite clearance and artemisinin resistance. One patient had recurrent infection (12 parasites/µL) on day 28. Uncorrected ACPR rate was 98.8% (83/84) (95% CI: 93.5-100%). The recurrent infection sample did not amplify during molecular testing, giving a PCR-corrected ACPR of 100% (83/83) (95% CI: 95.7-100%). No P. falciparum kelch 13 polymorphisms associated with artemisinin resistance were identified. Our results support high AL efficacy for falciparum malaria in Choco. Because of the time required to conduct TESs in low-endemic settings, it is important to consider complementary alternatives to monitor antimalarial efficacy and resistance.

Análisis de los programas de evaluación del desempeño de malaria de los laboratorios de salud pública y privados de Colombia 2015-2016 / Performance evaluation analysis of malaria's programs of Colombian public and private health laboratories 2015-2016

Resumen Introducción. Para el fortalecimiento de la calidad del diagnóstico de malaria en Colombia, se desarrollan los Programas de Evaluación del Desempeño (PED) en los que participan laboratorios privados y públicos del país. Objetivo. Analizar los resultados obtenidos en los programas de evaluación del desempeño de malaria de los laboratorios de salud pública y privados de Colombia en el lapso 2015-2016. Materiales y métodos. Se realizó un estudio de tipo retrospectivo mediante la revisión de los resultados obtenidos por los LSP y laboratorios privados participantes en los programas de evaluación directa e indirecta del desempeño (PEDD, PEID) de malaria durante los años 2015 y 2016 en términos de participación, concordancia de positividad y negatividad (Índice Kappa de Cohen), concordancia de especie, de formas parasitarias y de recuento (Z score). Resultados. La participación en el PEID se incrementó de 15% en 2015 a 51% en 2016, así como el total de láminas enviadas que en su mayoría cumplían con los criterios establecidos por el Laboratorio Nacional de referencia (LNR). La participación en el PEDD se incrementó de 88% en 2015 a 94% en 2016, con un Índice Kappa de Cohen de 0,97, una media de concordancia de especie parasitaria de 83,3% y de formas parasitarias de 62,5% y una concordancia del recuento parasitario más frecuente entre -0,9 y 0,9, evidenciándose un mejor desempeño en 2016. Conclusión. Basados en los resultados obtenidos es necesario promover una mayor participación de los LSP en los PED de malaria, especialmente en el PEID y aumentar la participación de los laboratorio privados.

Abstract Introduction. In order to strengthen the quality of malaria diagnosis in Colombia, Performance Evaluation Programs (PED) are developed in which private and public laboratories of the country participate. Objective. To analyze the results obtained in the malaria evaluation programs of the public and private health laboratories of Colombia from 2015 to 2016. Materials and methods. A retrospective study was carried out by reviewing the results obtained by the LSPs and private laboratories participating in the direct and indirect evaluation programs of malaria during the years 2015 and 2016 in terms of participation, concordance of positivity and negativity (Cohen's Kappa Index), species concordance, parasitic and counting agreement (Z score). Results. Participation in PEID increased from 15% in 2015 to 51% in 2016, as well as the total number of sheets sent, which mostly met the criteria established by the National Reference Laboratory (NRL). Participation in the PEDD increased from 88% in 2015 to 94% in 2016, with a Cohen's Kappa Index of 0.97, an average of parasitic species concordance of 83.3% and parasitic forms of 62.5% and a more frequent parasitic count concordance between -0.9 and 0.9, showing a better performance in 2016. Conclusion. Based on the results obtained, it is necessary to promote greater participation of LSPs in malaria PEDs, especially in SIDS, and to increase the participation of private laboratories.

Comparison of methodologies for microscopic malaria diagnosis

Introduction: As part of the pre-elimination plan for malaria in Colombia, it has been proposed to develop activities within the line of work: "Improve access and quality of malaria diagnosis". Objective: To compare the methodology recommended by PAHO/WHO with that used in Colombia for the diagnosis of malaria. Materials and methods: Samples were collected and 88 slides were prepared for malaria diagnosis, under different scenarios according to the parameters to be evaluated. After duplicate mycroscopic reading, the respective variance calculations were performed for all possible staining comparisons with the two methods used (thick smear, combined thick smear), according to the staining (modified Romanowsky or Giemsa), with the result variable being the parasite density (500, 1,000, 5,000 and 10,000 parasites/µl of blood). Results: A Cohen kappa index of inter-rater agreement of 0.923 (95% CI: 0.768-1.078) was obtained. None of the factors (A: stain, B: methodology) or interactions (AB) had a statistically significant effect on the results with a 95% confidence level. Conclusion: Based on the results of the study, the preparation of two thick smears in the same slide stained with the modified Romanowsky stain is a suitable methodology for the diagnosis of malaria in Colombia, due to its technical characteristics, of storage, low cost, use and care.

Perfil clínico y parasitológico de la malaria por Plasmodium falciparum y Plasmodium vivax no complicada en Córdoba, Colombia / Clinical and parasitological profiles of patients with non-complicated Plasmodium falciparum and Plasmodium vivax malaria in northwestern Colombia

Antecedentes. En Colombia existen pocos estudios que buscan encontrar diferencias clínicas y parasitológicas en la malaria causada por Plasmodium falciparum y Plasmodium vivax. Objetivo. Describir el perfil clínico y parasitológico de las malarias por Plasmodium falciparum y Plasmodium vivax no complicadas en Tierralta, Córdoba, Colombia. Materiales y métodos. Se evaluaron pacientes con paludismo no complicado por Plasmodium falciparum y Plasmodium vivax según los protocolos estandarizados por la Organización Panamericana de la Salud y se recolectó información clínica y parasitológica. De igual forma, se utilizó análisis multivariado por correspondencias múltiples para describir diferentes perfiles de pacientes con paludismo no complicado por estas dos especies antes de recibir tratamiento. Resultados. Se evaluaron 112 pacientes con edad entre 6 y 64 años, 59 (52.7%) con Plasmodium falciparum y 53 (47.3%) con Plasmodium vivax. Los síntomas más frecuentes fueron fiebre en 111 pacientes (99.1%; IC 95%: 81.5-100), sudoración en 105 (93.8%; IC 95%: 76.7-100) y dolor osteomuscular en 105 (93.8%; IC 95%: 76.7-100). Se presentaron con mayor frecuencia, y con diferencia significativa, en las infecciones por Plasmodium falciparum: diarrea en 18 pacientes (30.5%; IC 95%: 18.1-48.2); decaimiento en 49 (83%; IC 95%: 61.4-109.8); palidez palmar en 39 (66.1%; IC 95%: 47-90.4) y sequedad de mucosas en 12 (20.3%; IC 95%: 10.5-35.5). El escalofrío se presentó con mayor frecuencia en Plasmodium vivax (98.1%; IC 95%: 73.4-128.1). El análisis multivariado agrupó las variables en cuatro perfiles distintos de presentaciones clínicas así: 1) síntomas clínicos y su relación con el recuento parasitario, 2) características clínicas en relación con la edad y sexo, 3) antecedentes de malaria en relación con características demográficas y clínicas y 4) especie del parásito en relación con antecedentes, clínica y variables demográficas. Conclusión. Se identificaron algunas diferencias clínicas entre los enfermos con Plasmodium vivax y los enfermos con Plasmodium falciparum, y las variables estudiadas se agruparon en cuatro perfiles que permiten una variedad de interpretaciones.

Background. There are few studies in Colombia that have aimed at finding clinical and parasitological differences between Plasmodium falciparum and Plasmodium vivax malaria. Objective. To describe the clinical and parasitological profile of non-complicated malaria caused by Plasmodium falciparum and Plasmodium vivax in Tierralta, Cordoba, Colombia. Materials and Methods. Patients with non-complicated malaria caused by Plasmodium falciparum and Plasmodium vivax were evaluated according to standardized protocols recommended by the Pan American Health Organization. Both clinical and parasitological information was collected. A multiple correspondence multivariate analysis was used to describe the different profiles of patients suffering non-complicated malaria caused by these two species before the administration of the required treatment. Results. One hundred and twelve patients aged 6 to 64 were evaluated, 59 (52.7%) suffering Plasmodium falciparum malaria and 53 (47.3%), Plasmodium vivax malaria. The most frequent symptoms were fever in 111 (99.1%; 95% CI: 81.5- 100), sweating in 105 (93.8%; 95% CI: 76.7-100) and musculoskeletal pain in 105 (93.8%; IC 95%: 76.7-100). Regarding the Plasmodium falciparum infections there was a higher frequency, with significant difference, in the following clinical manifestations: diarrhea: 18 patients (30.5%; 95%: 18.1-48.2); asthenia: 49 patients (83%; 95% CI: 61.4-109.8); palmar pallor: 39 patients (66.1%; 95% CI: 47-90.4); mucosal dryness: 12 patients (20.3%; 95%CI: 10.5-35.5). The chills appeared with higher frequency in Plasmodium vivax malaria (98.1%; 95%CI: 73.4-128.1). The multivariate analysis grouped the variables into four different profiles of clinical presentations: Clinical symptoms and their relation to the parasite count; clinical characteristics in relation to age and sex; history of malaria regarding demographic and clinical characteristics; and parasite species in relation to historic, clinical and demographic variables. Conclusions. Some clinical differences between patients with Plasmodium vivax and patients with Plasmodium falciparum were identified and the studied variables were grouped into four profiles which allow for a variety of interpretations.

[Gene polymorphisms in the dihydrofolate reductase ( dhfr ) and dihydropteroate synthase ( dhps ) genes and structural modelling of the dhps gene in Colombian isolates of Toxoplasma gondii]. / Polimorfismos en los genes de dihidrofolato-reductasa ( dhfr ) y dihidropteroato-sintasa ( dhps ) y modelado estructural del gen dhps en aislamientos colombianos de Toxoplasma gondii.

INTRODUCTION: There are no reports describing polymorphisms in target genes of anti- Toxoplasma drugs in South American isolates. OBJECTIVE: This study sought to perform cloning and sequencing of the dihydrofolate reductase ( dhfr ) and dihydropteroate-synthase ( dhps ) genes of the reference Rh strain and two Colombian isolates of Toxoplasma gondii . MATERIALS AND METHODS: Two isolates were obtained from the cerebrospinal fluid of HIV-infected patients with cerebral toxoplasmosis. A DNA extraction technique and PCR assay for the dhfr and dhps genes were standardized, and the products of amplification were cloned into Escherichia coli and sequenced. RESULTS: One polymorphism (A « G) was found at position 235 of exon 2 in the dhps gene. In addition, two polymorphisms (G « C) at positions 259 and 260 and one polymorphism (T « G) at position 371 within exon 4 of the dhps gene were detected. In this last exon, a bioinformatic analysis revealed a non-synonymous polymorphism in the coding region that could lead to the substitution of Glu (CAA or CAG) for His (encoded by codons AAU or AAC). A structural model of the T. gondii DHPS protein was calculated, and the results revealed modifications in secondary structure due to mutations. CONCLUSIONS: The methods described in this study can be used as a tool to search for polymorphisms in samples from patients with different clinical manifestations of toxoplasmosis and to examine their relationship with the therapeutic response.

Polimorfismos en los genes de dihidrofolato-reductasa ( dhfr ) y dihidropteroato-sintasa ( dhps ) y modelado estructural del gen dhps en aislamientos colombianos de Toxoplasma gondii / Gene polymorphisms in the dihydrofolate reductase ( dhfr ) and dihydropteroate synthase ( dhps ) genes and structural modelling of the dhps gene in Colombian isolates of Toxoplasma gondii

Introducción. No existen reportes sobre las variaciones en la secuencia de los genes blanco de los medicamentos anti- Toxoplasma en aislamientos provenientes de Suramérica. Objetivo. Clonar y secuenciar los genes de la dihidrofolato-reductasa ( dhfr ) y la dihidropteroato-sintetasa ( dhps ) de la cepa de referencia RH y de dos aislamientos colombianos de Toxoplasma gondii. Materiales y métodos. Se obtuvieron dos aislamientos de T. gondii en líquido céfalorraquídeo de pacientes colombianos positivos para HIV con toxoplasmosis cerebral. Se extrajo el ADN de los genes dhfr y dhps y se amplificaron mediante reacción en cadena de la polimerasa (PCR). Los productos fueron clonados en el vector pGEM-T y secuenciados. Resultados. Se encontró un cambio de adenina por guanina (A « G) en la posición 235 del exón 2 del gen dhps , dos cambios de guanina por citocina (G « C) en las posiciones 259 y 260 y un cambio de timina por guanina (T « G) en la posición 371 del exón 4 del gen dhps. Por análisis bioinformático, en este último exón se identificó un polimorfismo no sinónimo en la región codificante, que podría llevar al cambio de una Glu (CAA o CAG) por una His (codificada por los codones AAU o AAC). Se calculó el modelo estructural de la enzima dihidropteroato-sintetasa (DHPS) de T. gondii y se identificaron las modificaciones en la estructura secundaria ocasionadas por las mutaciones. Conclusiones. La metodología estandarizada puede servir como base para la búsqueda de polimorfismos en muestras de pacientes con diferentes manifestaciones clínicas de toxoplasmosis y para establecer su posible relación con los cambios en la sensibilidad a los antifolatos y la reacción al tratamiento.

Introduction: There are no reports describing polymorphisms in target genes of anti- Toxoplasma drugs in South American isolates. Objective: This study sought to perform cloning and sequencing of the dihydrofolate reductase ( dhfr ) and dihydropteroate-synthase ( dhps ) genes of the reference Rh strain and two Colombian isolates of Toxoplasma gondii . Materials and methods: Two isolates were obtained from the cerebrospinal fluid of HIV-infected patients with cerebral toxoplasmosis. A DNA extraction technique and PCR assay for the dhfr and dhps genes were standardized, and the products of amplification were cloned into Escherichia coli and sequenced. Results: One polymorphism (A « G) was found at position 235 of exon 2 in the dhps gene. In addition, two polymorphisms (G « C) at positions 259 and 260 and one polymorphism (T « G) at position 371 within exon 4 of the dhps gene were detected. In this last exon, a bioinformatic analysis revealed a non-synonymous polymorphism in the coding region that could lead to the substitution of Glu (CAA or CAG) for His (encoded by codons AAU or AAC). A structural model of the T. gondii DHPS protein was calculated, and the results revealed modifications in secondary structure due to mutations. Conclusions: The methods described in this study can be used as a tool to search for polymorphisms in samples from patients with different clinical manifestations of toxoplasmosis and to examine their relationship with the therapeutic response.

Comparación del cultivo "in vitro" de Toxoplasma gondii cepa RH en las líneas celulares Hep-2 y Vero / Comparison of "in vitro" culture of Toxoplasma gondii RH strain in Hep-2 and Vero cell lines

Introducción: La toxoplasmosis es una zoonosis causada por Toxoplasma gondii, parásito intracelular obligado capaz de replicarse en todas las células nucleadas, permitiendo su aislamiento y mantenimiento en cultivo celular. Objetivo: Comparar el cultivo de Toxoplasma gondii (RH), en células Hep-2 y Vero empleadas para propagación parasitaria. Métodos: Se optimizaron las condiciones para cultivo de Toxoplasma gondii (RH), en células Vero y Hep-2; se sembraron 500.000 y 1.000.000cel./mm3 y se infectaron 1.000.000 y 2.000.000taq/mm3 respectivamente, se hizo seguimiento hasta las 120 horas para determinar invasión celular, porcentaje de rosetas, de viabilidad y rendimiento de taquizoitos. Resultados: A las 48 horas de incubación se evidenció el 90% de invasión parasitaria en las dos líneas celulares así como el mayor recuento de rosetas; a las 120 horas se obtuvieron los mayores recuentos de taquizoitos extracelulares y un mayor índice de rendimiento de 185,9 en las células Hep-2, en la concentración de 500.000cel./mm3 y 1.000.000taq/mm3. Se obtuvo una viabilidad parasitaria promedio superior al 80% para las dos líneas celulares. Conclusiones: Se obtuvo un mayor rendimiento parasitario viable en las células Hep-2 por lo que esta línea celular puede considerarse como el mejor modelo para la propagación y mantenimiento parasitario de T. gondii (RH).

Introduction: Toxoplasmosis is a zoonosis caused by Toxoplasma gondii, which is an obligate intracellular parasite capable of replicate itself in all nucleated cells, allowing their isolation and maintenance in cell culture. Objective: To compare cultivation Toxoplasma gondii (RH) in Hep-2 cells and Vero employed to spread parasitic. Methods: The conditions were optimized for cultivation of Toxoplasma gondii (RH) in Vero and Hep-2 cells lines, 500.000 and 1.000.000cel./mm³ were seeded and 1.000.000 and 2.000.000taq/mm³ were infected respectively, a track to determine cell invasion, percentage of rosettes and viability and efficiency of tachyzoites was made until the 120 hours. Results: After 48 hours of incubation, 90% of parasite invasion was evident in both cell lines as well as the largest count rosettes. At 120 hours higher counts of extracellular tachyzoites and a higher rate of performance of 185.9 in Hep-2 cells at concentration of 1.000.000taq/mm³ and 500.000cel./mm³ were obtained. Average parasite viability over 80 % was obtained for both cell lines. Conclusions: Higher parasitic performance was obtained viable in Hep-2 cells, so that this cell line can be considered as the preferred model for the propagation and maintenance of T. gondii (RH).

[Characterization of the national malaria diagnostic network, Colombia, 2006-2010]. / Caracterización de la Red Nacional de Diagnóstico de Malaria, Colombia, 2006-2010.

INTRODUCTION: The implementation and development of activities of the quality assurance system of malaria diagnosis, allows the adequate operation of the national diagnostic network, needed to strengthen prevention and control actions of this important public health problem. OBJECTIVE: To characterize the malaria diagnosis network in Colombia between 2006 and 2010. MATERIALS AND METHODS: A retrospective study was made by reviewing the annual reports of malaria diagnosis network activities that were sent by the Public Health Laboratories (PHL) between 2006 and 2010. The study included analysis of diagnostic coverage in population at risk and an evaluation of activities and training to the people responsible for malaria diagnosis. RESULTS: Malaria diagnostic coverage has increased in Colombia, from 53% of municipalities covered in 2006 to 80% in 2010. The number of places that perform diagnosis increased by 31% with a significant increase, for the same period, of the number of microscopists (56%) and laboratories (30%), to 1,195 and 1,780 respectively, registered in 2010. During the period of study, the percentage of PHL that carried out at least 3 of the activities of the quality assurance system for the diagnostic network at local level was 67%. CONCLUSIONS: It is necessary to continue strengthening the malaria diagnosis network to provide timely and adequate diagnosis in order to reduce the morbidity and mortality by malaria.

Caracterización de la Red Nacional de Diagnóstico de Malaria, Colombia, 2006-2010 / Characterization of the National Malaria Diagnostic Network, Colombia, 2006-2010

Introducción. La implementación y desarrollo de actividades del sistema de gestión de la calidad del diagnóstico de malaria, permiten el adecuado funcionamiento de la red nacional de diagnóstico, necesario para fortalecer acciones de prevención y control de este evento, importante en salud pública. Objetivo. Caracterizar la Red de Diagnóstico de Malaria en Colombia, entre 2006 y 2010. Materiales y métodos. Se hizo un estudio retrospectivo mediante la revisión de los informes anuales de actividades de la Red de Diagnóstico de Malaria, enviados por los laboratorios de salud pública entre 2006 y 2010. Se analizó la cobertura de diagnóstico en la población en riesgo, las actividades de evaluación del desempeño y las capacitaciones al personal que hace el diagnóstico. Resultados. La cobertura del diagnóstico de malaria se ha incrementado en el país, pasando de 53 % de los municipios, en 2006, a 80 %, en 2010. El número de sitios que hacen el diagnóstico aumentó en 31 %, con un incremento en el número de microscopistas (56 %) y de laboratorios (30 %), para un total de 1.195 y 1.780, respectivamente, registrados en 2010. En el periodo de estudio, se mantuvo el porcentaje de laboratorios de salud pública (67 %) que llevan a cabo, al menos, tres de las actividades del sistema de gestión de la calidad a la Red de Diagnóstico de Malaria a nivel local. Conclusiones. Es necesario continuar con el fortalecimiento de la Red de Diagnóstico de Malaria, para brindar diagnóstico oportuno y con calidad con el fin de reducir la morbimortalidad por esta causa.

Introduction. The implementation and development of activities of the quality assurance system of malaria diagnosis, allows the adequate operation of the national diagnostic network, needed to strengthen prevention and control actions of this important public health problem. Objective. To characterize the malaria diagnosis network in Colombia between 2006 and 2010. Materials and methods. A retrospective study was made by reviewing the annual reports of malaria diagnosis network activities that were sent by the Public Health Laboratories (PHL) between 2006 and 2010. The study included analysis of diagnostic coverage in population at risk and an evaluation of activities and training to the people responsible for malaria diagnosis. Results. Malaria diagnostic coverage has increased in Colombia, from 53% of municipalities covered in 2006 to 80% in 2010. The number of places that perform diagnosis increased by 31% with a significant increase, for the same period, of the number of microscopists (56%) and laboratories (30%), to 1,195 and 1,780 respectively, registered in 2010. During the period of study, the percentage of PHL that carried out at least 3 of the activities of the quality assurance system for the diagnostic network at local level was 67%. Conclusions. It is necessary to continue strengthening the malaria diagnosis network to provide timely and adequate diagnosis in order to reduce the morbidity and mortality by malaria.

Concordancia entre ELISA e IFI para la determinación de anticuerpos tipo IgG contra Toxoplasma gondii / Concordance between ELISA and IFA, for IgG antibodies detection against Toxoplasma gondii

Objetivo. Medir el grado de concordancia entre las técnicas de inmunofluorescencia indirecta y de ELISA, empleadas para la detección de anticuerpos IgG anti-Toxoplasma gondii en humanos. Materiales y métodos. Se llevó a cabo un estudio descriptivo comparativo de dos técnicas diagnósticas para la detección de anticuerpos IgG anti-T. gondii, en 243 sueros humanos del banco de muestras del Laboratorio de Parasitología-Red Nacional de Laboratorios del Instituto Nacional de Salud, recolectados durante los años 2000 a 2006. Resultados. El porcentaje de reactividad para la detección de anticuerpos IgG anti-T. gondii fue de 54% (131 sueros) por la técnica IFI y de 56,3% (137 sueros) por la técnica ELISA; además, el 46% (112 sueros) de las muestras fueron negativas por la técnica IFI y el 44% (106 sueros) negativas fueron por la técnica ELISA. El valor del índice kappa fue de 0,916 (IC95% 0,866-0,976), el cual refleja una concordancia casi absoluta entre las dos técnicas. Conclusiones. El índice kappa muestra una concordancia casi absoluta entre las técnicas, IFI y ELISA, lo cual hace que los laboratorios departamentales de salud pública del país puedan cumplir con la determinación de anticuerpos IgG anti-T. gondii como prueba diagnóstica en el control prenatal, cuando no se cuente con la infraestructura necesaria para la técnica de IFI, teniendo en cuenta que la de ELISA está fundamentada en el grado de afinidad de anticuerpos por un antígeno determinado y no mide el nivel real de éstos en una muestra de suero, como sí lo hace la técnica de IFI.

Objective. To measure the degree of correlation between the indirect fluorescence antibody test (IFAT) and the ELISA techniques used for the detection of anti-Toxoplasma gondii IgG antibodies in humans. Materials and methods. We conducted a comparative study of two diagnostic techniques for the detection of anti-T. gondii IgG, using 243 human serum samples, collected during the years 2000-2006, from the serum collection of the Laboratorio de Parasitología- Red Nacional de Laboratorios of the Instituto Nacional de Salud. Results. The percentage of reactivity for anti-T.gondii IgG was 54% (131 sera) by the IFAT technique and 56.3% (137 sera) by the ELISA technique, while 46% (112 sera) of the samples were negative by IFAT and 44% (106 sera) by ELISA. The kappa value was 0.916 (95%CI: 0.866 – 0.976), which reflects an almost perfect agreement between the two techniques. Conclusions. The kappa index shows an almost perfect agreement between ELISA and IFAT. This will help the departmental public health laboratories of the country to comply with the determination of IgG anti-T.gondii as a diagnostic tool during prenatal care, if they do not have the infrastructure needed for the IFAT, bearing in mind that ELISA is based on the degree of affinity of antibodies for a specific antigen and does not measure the actual antibody level in a serum sample, as does the IFAT technique.

Seroprevalencia de la toxoplasmosis y factores relacionados con las enfermedades transmitidas por alimentos en trabajadores de plantas de beneficio animal en cinco ciudades capitales de Colombia, 2008 / Seroprevalence of toxoplasmosis and factors related to foodborne diseases in workers in animal processing plants in five capital cities in Colombia, 2008

El Instituto Nacional de Salud de Colombia, con el fin de conocer la prevalencia de toxoplasmosis en trabajadores de mataderos, realizó la determinación de anticuerpos contra Toxoplasma gondii en la población seleccionada. El objetivo fue determinar la seroprevalencia de toxoplasmosis, mediante la técnica ELFA (Enzyme Linked Fluorescent Assay), en trabajadores de plantas de beneficio animal en cinco ciudades del país durante el año 2008. Se llevó a cabo un estudio de corte transversal en 400 trabajadores de las plantas de beneficio animal que trabajan en el área limpia, quienes fueron seleccionados de forma aleatoria. En los 400 trabajadores encuestados, se encontró una seroprevalencia del 71.8% (287) de anticuerpos anti-IgG contra Toxoplasma gondii y del 2.8% (8) de anticuerpos anti-IgM contra Toxoplasma gondii, estos últimos residentes en las ciudades de Bogotá, Bucaramanga, Medellín (2 casos cada una), Montería y Restrepo (un caso cada una). El mayor porcentaje de positivos para anti-IgG contra Toxoplasma gondii se halló en las ciudades de Restrepo y Villavicencio. Los riesgos de exposición para contraer toxoplasmosis se derivan de no usar los elementos de protección completos, no lavar adecuadamente los alimentos, el consumo de carne mal cocida, exposición a animales y la manipulación de tierra.

Asymptomatic Plasmodium spp. infection in Tierralta, Colombia.

With the aim of determining the prevalence of asymptomatic Plasmodium spp. infection by thick smear and PCR and its association with demographic and epidemiological characteristics in the village of Nuevo Tay, Tierralta, Córdoba, Colombia, a cross-sectional population study was carried out, using random probabilistic sampling. Venous blood samples were taken from 212 people on day 0 for thick smear and PCR. Clinical follow-up and thick smears were carried out on days 14 and 28. The prevalence of Plasmodium spp. infection was 17.9% (38/212; 95% CI: 12.5-23.3%) and the prevalence of asymptomatic Plasmodiumspp. infection was 14.6% (31/212; 95% CI: 9.6-19.6%). Plasmodium vivax was found more frequently (20/31; 64.5%) than Plasmodium falciparum (9/31; 29%) and mixed infections (2/31; 6.5%). A significantly higher prevalence of asymptomatic infection was found in men (19.30%) than in women (9.18%) (prevalence ratio: 2.10; 95% CI: 1.01-4.34%; p = 0.02). People who developed symptoms had a significantly higher parasitemia on day 0 than those who remained asymptomatic, of 1,881.5 +/- 3,759 versus 79 +/- 106.9 (p = 0.008). PCR detected 50% more infections than the thick smears. The presence of asymptomatic Plasmodium spp. infection highlights the importance of carrying out active searches amongst asymptomatic populations residing in endemic areas.

Asymptomatic Plasmodium spp. infection in Tierralta, Colombia

With the aim of determining the prevalence of asymptomatic Plasmodium spp. infection by thick smear and PCR and its association with demographic and epidemiological characteristics in the village of Nuevo Tay, Tierralta, Córdoba, Colombia, a cross-sectional population study was carried out, using random probabilistic sampling. Venous blood samples were taken from 212 people on day 0 for thick smear and PCR. Clinical follow-up and thick smears were carried out on days 14 and 28. The prevalence of Plasmodium spp. infection was 17.9 percent (38/212; 95 percent CI: 12.5-23.3 percent) and the prevalence of asymptomatic Plasmodiumspp. infection was 14.6 percent (31/212; 95 percent CI: 9.6-19.6 percent). Plasmodium vivax was found more frequently (20/31; 64.5 percent) than Plasmodium falciparum (9/31; 29 percent) and mixed infections (2/31; 6.5 percent). A significantly higher prevalence of asymptomatic infection was found in men (19.30 percent) than in women (9.18 percent) (prevalence ratio: 2.10; 95 percent CI: 1.01-4.34 percent; p = 0.02). People who developed symptoms had a significantly higher parasitemia on day 0 than those who remained asymptomatic, of 1,881.5 ± 3,759 versus 79 ± 106.9 (p = 0.008). PCR detected 50 percent more infections than the thick smears. The presence of asymptomatic Plasmodium spp. infection highlights the importance of carrying out active searches amongst asymptomatic populations residing in endemic areas.