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.

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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.

Evidence on the comorbidity between soil-transmitted helminth infections and malaria is scarce and divergent. This study explored the interactions between soil-transmitted helminth infections and uncomplicated falciparum malaria in an endemic area of Colombia. A paired case-control study matched by sex, age and location in Tierralta, Cordoba, was done between January and September 2010. The incident cases were 68 patients with falciparum malaria and 178 asymptomatic controls. A questionnaire was used to gather information on sociodemographic variables. Additionally physical examinations were carried out, stool samples were analysed for intestinal parasites and blood samples for Ig E concentrations. We found associations between infection with hookworm (OR: 4.21; 95% CI: 1.68-11.31) and Ascaris lumbricoides (OR 0.43; 95% CI: 0.18-1.04) and the occurrence of falciparum malaria. The effects of soil-transmitted helminths on the occurrence of malaria were found to be paradoxical. While hookworm is a risk factor, A. lumbricoides has a protective effect. The findings suggest that, in addition to the comorbidity, the presence of common determinants of soil-transmitted helminth infections and malaria could also exist. While the biological mechanisms involved are not clear, public health policies aimed at the control of their common social and environmental determinants are suggested.

Introducción. La disminución de la eficacia de los medicamentos antipalúdicos en el mundo y en Colombia, dificulta el control de la enfermedad. Objetivo. Evaluar la eficacia terapéutica in vivo de la combinación amodiaquina más sulfadoxina-pirimetamina para el tratamiento del paludismo no complicado por Plasmodium falciparum y de la cloroquina para el tratamiento del paludismo por P. vivax en Tierralta, Córdoba. Materiales y métodos. Durante el período de mayo a noviembre de 2006, se realizaron estudios de eficacia in vivo siguiendo los protocolos estandarizados por la Organización Mundial de la Salud y la Organización Panamericana de la Salud, con algunas modificaciones. Se estudiaron pacientes mayores de dos años, con parasitemia entre 500 y 50.000 formas asexuales/µl, seleccionados conforme a los criterios de inclusión y exclusión previamente definidos. Se administró tratamiento supervisado y se realizó seguimiento clínico y parasitológico en los días 0 (inclusión), 1, 2, 3, 7, 14, 21 y 28. El desenlace se definió como respuesta clínica y parasitológica adecuada, fracaso terapéutico precoz o fracaso tardío al tratamiento. Resultados. De los pacientes evaluados, 50/53 (94,3%) (IC95%: 70%-100%) presentaron respuesta clínica y parasitológica adecuada al tratamiento con amodiaquina más sulfadoxinapirimetamina para paludismo no complicado por P. falciparum, un paciente presentó fracaso terapéutico precoz y dos presentaron fracaso terapéutico tardío. Los 50 pacientes evaluados (100%) (IC95%: 74%-100%) presentaron respuesta clínica y parasitológica adecuada al tratamiento con cloroquina para el paludismo por P. vivax. Conclusiones. En Córdoba, la combinación amodiaquina más sulfadoxina-pirimetamina y la cloroquina son eficaces para el tratamiento del paludismo no complicado por P. falciparum y por P. vivax, respectivamente.

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.

Objective To estimate the prevalence of microcephaly and central nervous system (CNS) defects during the Zika virus (ZIKV) epidemic in Colombia and proportion attributable to congenital ZIKV infection. Study design Clinical and laboratory data for cases of microcephaly and/or CNS defects reported to national surveillance between 2015 and 2017 were reviewed and classified by a panel of clinical subject matter experts. Maternal and fetal/infant biologic specimens were tested for congenital infection and chromosomal abnormalities. Infants/fetuses with microcephaly and/or CNS defects (cases) were classified into broad etiologic categories (teratogenic, genetic, multifactorial, and unknown). Cases classified as potentially attributable to congenital ZIKV infection were stratified by strength of evidence for ZIKV etiology (strong, moderate, or limited) using a novel strategy considering birth defects unique or specific to ZIKV or other infections and laboratory evidence. Results Among 858 reported cases with sufficient information supporting a diagnosis of microcephaly or CNS defects, 503 were classified as potentially attributable to congenital ZIKV infection. Of these, the strength of evidence was considered strong in 124 (24.7%) cases; moderate in 232 (46.1%) cases; and limited in 147 (29.2%). Of the remaining, 355 (41.4%) were attributed to etiologies other than ZIKV infection (syphilis, toxoplasmosis, rubella, cytomegalovirus, herpes 1 and herpes 2 viruses only, n = 32 [3.7%]; genetic, n = 16 [1.9%]; multifactorial, n = 42 [4.9%]; unknown, n = 265 [30.9%]). Conclusions Fifty-eight percent of cases of microcephaly and/or CNS defects were potentially attributable to congenital ZIKV infection; however, the strength of evidence varied considerably. This surveillance protocol might serve as a model approach for investigation and etiologic classification of complex congenital conditions. (J Pediatr 2020;222:112-9). See editorial, p 15 I n 2015, the Colombian National Institute of Health (INS) began Zika virus (ZIKV) surveillance, including protocols for testing and management of pregnant women and infants with suspected ZIKV infection. 1,2 In 2016, the World Health Organization declared a Public Health Emergency of International Concern prioritizing global efforts to prevent ZIKV transmission and to perform surveillance for ZIKV transmission and for adverse outcomes related to congenital ZIKV infection, including microcephaly and birth defects of the central nervous system (CNS). 3-6 Building on its existing birth defects surveillance infrastructure, the INS established an enhanced surveillance protocol focused on microcephaly and CNS defects to monitor potential increases in birth prevalence; identify possible causes, including congenital ZIKV infection; determine proportion of reported cases potentially attributable to ZIKV; and direct appropriate public health intervention. The first confirmed case of ZIKV-related congenital microcephaly in Colombia was reported in April 2016. 7 A preliminary report of surveillance

Introducción. El Instituto Nacional de Salud con el fin de mejorar el acceso al diagnóstico de paludismo, evaluó dos pruebas rápidas para el diagnóstico de dicha enfermedad. Objetivo. Evaluar la sensibilidad, especificidad y concordancia de dos pruebas inmunocromatográficas, NOW® ICT Malaria Pf/Pv y OptiMAL®, frente a la gota gruesa. Materiales y métodos. Se llevó a cabo un estudio descriptivo de concordancia en 214 pacientes de Tumaco, captados mediante búsqueda pasiva y brigadas de atención, que presentaran, por lo menos, uno de los síntomas de la tríada clásica. Resultados. NOW® ICT tuvo una sensibilidad general de 98,4% (intervalo de confianza de 95% (IC95%): 90,3-99,9), especificidad general de 98,0% (IC95%: 93,9-99,5). Para Plasmodium falciparum la sensibilidad fue de 98,2% (IC95%: 89,4-99,9) especificidad de 98,1% (IC95%: 94,1-99,5). Esta sensibilidad disminuyó a 80% en el rango de 200-4.000 parásitos/µl. Los valores de sensibilidad y especificidad de NOW® ICT para Plasmodium vivax fueron del 100% y no se afectó la sensibilidad en los rangos de parasitemias establecidos. OptiMAL® tuvo una sensibilidad general de 95,2% (IC95%: 85,8-98,8) y especificidad general de 99,3% (IC95%: 95,8-100,0). Para P. falciparum OptiMAL® tuvo una sensibilidad de 94,7% (IC95%: 84,5-98,6) y especificidad de 99,4% (IC95%: 96,0-100,0). La sensibilidad disminuyó a 60% en el rango de de 200-4.000 parásitos/µl. La sensibilidad de OptiMAL® para P. vivax fue 66,7% (IC95%: 24,1-94,0), pero disminuyó a 50% en el rango de 300-2.500 parásitos/µl. Conclusiones. Se obtuvieron buenos resultados en la sensibilidad y la especificidad para ambas pruebas, pero superiores para NOW® ICT.Palabras clave: malaria/diagnóstico, sensibilidad y especificidad, parasitemia, Plasmodium vivax, Plasmodium falciparum, Colombia. Evaluation of two rapid diagnostic tests, NOW® ICT Malaria Pf/Pv and OptiMAL®, for diagnosis of malariaIntroduction. To increase the accessibility of malaria diagnosis, the Instituto Nacional de Salud de Colombia undertook a field trial to evaluate the sensitivity and specificity of two rapid diagnostic tests. Objective. The sensitivity, specificity and concordance was compared for two rapid diagnostic tests for malaria, NOW® ICT Malaria Pf/Pv and OptiMAL®, Materials and methods. A descriptive and concordance study was performed with 214 patients in the southwestern coastal city of Tumaco, Colombia, each of whom presented at least one of the symptoms of the classical malaria triad. Two strategies were applied for patient recruitmentone by passive search and a second through local health brigades. Results. NOW® ICT showed a general sensitivity of 98.4% (95%CI: 90.3-99.9), and a general specificity of 98.0% (95%CI: 93.9-99.5). For Plasmodium falciparum, the sensitivity was 98.2% (95%CI: 89.4-99.9) and the specificity 98.1% (95%CI: 94.1-99.5). The sensitivity was lower (80.0%) when parasitemia ranged from 200 to 4,000 parasites/ µl. The sensitivity and specificity of the NOW® ICT for P. vivax malaria were 100%. The sensitivity for this tes...