Estimations of the number people with mental diseases associated with toxoplasmosis and identification of risk factors by continent.

Strong evidence exists based on metanalysis of the relationship between toxoplasmosis and many psychiatric diseases: schizophrenia, bipolar disorder, and suicidal behavior. Herein, we estimate the number of cases based on the attributable fraction due to toxoplasmosis on these diseases. The population attributable fraction of mental disease associated with toxoplasmosis was 20,4% for schizophrenia; 27,3% for bipolar disorder; and 0,29% for suicidal behavior (self-harm). The lower and upper estimated number of people with mental disease associated with toxoplasmosis was 4'816.491 and 5'564.407 for schizophrenia; 6'348.946 and 7'510.118,82 for bipolar disorder; and 24.310 and 28.151 for self-harm; for a global total lower estimated number of 11'189.748 and global total upper estimated number of 13'102.678 people with mental disease associated with toxoplasmosis for the year 2019. According to the prediction through the Bayesian model of risk factors for toxoplasmosis associated with mental disease, these varied in importance geographically; thus, in Africa, the most important risk factor was water contamination and in the European region, the cooking conditions of meats. Toxoplasmosis and mental health should be a research priority given the enormous potential impact of reducing this parasite in the general population.

Identification of Toxoplasma gondii adhesins through a machine learning approach.

Toxoplasma gondii, as other apicomplexa, employs adhesins transmembrane proteins for binding and invasion to host cells. Search and characterization of adhesins is pivotal in understanding Apicomplexa invasion mechanisms and targeting new druggable candidates. This work developed a machine learning software called ApiPredictor UniQE V2.0, based on two approaches: support vector machines and multilayer perceptron, to predict adhesins proteins from amino acid sequences. By using ApiPredictor UniQE V2.0, five SAG-Related Sequences (SRSs) were identified within the Toxoplasma gondii proteome. One of those candidates, TgSRS12B, was cloned in plasmid pEXP5-CT/TOPO and expressed in E. coli BL21 DE3. The resulting recombinant protein was purified via affinity chromatography. Co-precipitation assays in CaCo and Muller cells showed interactions between TgSRS12B-His-tagged and the membrane fractions from both human cell lines. In conclusion, we demonstrated that ApiPredictor UniQE V2.0, a bioinformatic free software, was able to identify TgSRS12B as a new adhesin protein.

Immune response against toxoplasmosis-some recent updates RH: Toxoplasma gondii immune response.

AIMS: Cytokines, soluble mediators of immunity, are key factors of the innate and adaptive immune system. They are secreted from and interact with various types of immune cells to manipulate host body's immune cell physiology for a counter-attack on the foreign body. A study was designed to explore the mechanism of Toxoplasma gondii (T. gondii) resistance from host immune response. METHODS AND RESULTS: The published data on aspect of host (murine and human) immune response against T. gondii was taken from Google scholar and PubMed. Most relevant literature was included in this study. The basic mechanism of immune response starts from the interactions of antigens with host immune cells to trigger the production of cytokines (pro-inflammatory and anti-inflammatory) which then act by forming a cytokinome (network of cytokine). Their secretory equilibrium is essential for endowing resistance to the host against infectious diseases, particularly toxoplasmosis. A narrow balance lying between Th1, Th2, and Th17 cytokines (as demonstrated until now) is essential for the development of resistance against T. gondii as well as for the survival of host. Excessive production of pro-inflammatory cytokines leads to tissue damage resulting in the production of anti-inflammatory cytokines which enhances the proliferation of Toxoplasma. Stress and other infectious diseases (human immunodeficiency virus (HIV)) that weaken the host immunity particularly the cellular component, make the host susceptible to toxoplasmosis especially in pregnant women. CONCLUSION: The current review findings state that in vitro harvesting of IL12 from DCs, Np and MΦ upon exposure with T. gondii might be a source for therapeutic use in toxoplasmosis. Current review also suggests that therapeutic interventions leading to up-regulation/supplementation of SOCS-3, IL12, and IFNγ to the infected host could be a solution to sterile immunity against T. gondii infection. This would be of interest particularly in patients passing through immunosuppression owing to any reason like the ones receiving anti-cancer therapy, the ones undergoing immunosuppressive therapy for graft/transplantation, the ones suffering from immunodeficiency virus (HIV) or having AIDS. Another imortant suggestion is to launch the efforts for a vaccine based on GRA6Nt or other similar antigens of T. gondii as a probable tool to destroy tissue cysts.

In vitro biological activity of extracts from marine bacteria cultures against Toxoplasma gondii and Mycobacterium tuberculosis.

AIMS: To evaluate the biological activity of extracts from cultures of marine bacteria against Toxoplasma gondii and Mycobacterium tuberculosis. METHODS AND RESULTS: Ethyl acetate extracts obtained from seven marine bacteria were tested against T. gondii GFP-RH and M. tuberculosis H37Rv. The cytotoxicity on HFF-1 cells was measured by a microplate resazurin fluorescent approach, and the haemolytic activity was determined photometrically. The extracts from Bacillus sp. (INV FIR35 and INV FIR48) affected the tachyzoite viability. The extracts from Bacillus, Pseudoalteromonas, Streptomyces and Micromonospora exhibited effects on infection and proliferation processes of parasite. Bacillus sp. INV FIR48 extract showed an minimum inhibitory concentration value of 50 µg ml-1 against M. tuberculosis H37Rv. All the extracts exhibited relatively low toxicity to HFF-1 cells and the primary culture of erythrocytes, except Bacillus sp. INV FIR35, which decreased cell viability under 20%. Liquid chromatography coupled to mass spectrometry analysis of the most active bacterial extract Bacillus sp. INV FIR48 showed the presence of peptide metabolites related to surfactin. CONCLUSIONS: The extract from culture of deep-sea Bacillus sp. INV FIR48 showed anti-T. gondii and anti-tuberculosis (TB) biological activity with low cytotoxicity. In addition, peptide metabolites were detected in the extract. SIGNIFICANCE AND IMPACT OF THE STUDY: Toxoplasmosis and TB are among the most prevalent diseases worldwide, and the current treatment drugs exhibit side effects. This study confirm that marine bacteria are on hand sources of anti-infective natural products.

Ciencia, salud pública y toma de decisiones: [Editorial] / Science, public health and decision making: [Editorial]

La pandemia por COVID-19 ha obligado a los gobiernos de todo el mundo a la toma de decisiones con información preliminar, insuficiente o discutible en argumentos científicos, algo que como académicos debemos entender y acompañar y se convierte en un reto mayor: ¿cómo dar recomendaciones con información limitada y reducir las incertidumbres? Para ello, primero que todo, se debe reconocer que estos procesos están sometidos a cambios según la evolución del conocimiento y la comunicación de la información se vuelve crucial para evitar minar la confianza pública ante los cambios. Es así como muchas recomendaciones para el manejo de COVID 19 han venido evolucionando a medida que se conoce mejor la patogénesis, sus mecanismos de transmisión y las particularidades en la respuesta inmune y, por ejemplo, pasamos de una recomendación inicial de medidas de prevención que incluía limpieza de superficies a una en la cual el énfasis es la limitación en número de personas en reunión. La Asociación Colombiana de infectología junto con otras 27 sociedades científicas lleva tres diferentes actualizaciones de recomendaciones basadas en evidencia en los primeros 12 meses de pandemia, es decir cada tres meses se han venido revisando las más de 250 recomendaciones, lo cual ha significado un trabajo enorme de revisión, discusión y presentación final las cuales, afortunadamente, han sido acogidas y tomadas como base de las decisiones gubernamentales.

The COVID-19 pandemic has forced governments around the world to take decisions on preliminary, insufficient The COVID-19 pandemic has forced governments around the world to make decisions with preliminary, insufficient or debatable information on scientific grounds, something that as academics we must understand and accompany and which becomes a major challenge: how to give recommendations with limited information and reduce uncertainties? To do this, first of all, it must be recognised that these processes are subject to change as knowledge evolves and the communication of information becomes crucial to avoid undermining public confidence in the face of change. Thus, many recommendations for the management of COVID 19 have evolved as the pathogenesis, transmission mechanisms and particularities of the immune response have become better understood and, for example, we have gone from an initial recommendation of measures to be taken in response to COVID 19 to a recommendation of measures to be taken in response to COVID 19, we have moved from an initial recommendation for prevention measures that included surface cleaning to one in which the emphasis is on limiting the number of people at a meeting. The Colombian Association of Infectious Diseases, together with 27 other scientific societies, has scientific societies has three different updates of evidence-based evidence-based recommendations in the first 12 months of a pandemic, i.e. every months of the pandemic, i.e. every three months, the more than 250 recommendations have been This has meant an enormous work of review, discussion and final presentation which, fortunately, have been accepted and taken as a basis for governmental decisions. and taken as a basis for governmental decisions.

Vacunas para COVID19: las lecciones de un triunfo de la ciencia biomédica: [Editorial] / Vaccines for COVID19: lessons from the triumph of the biomedical science: [Editorial]

Frente al escepticismo de encontrar una vacuna para COVID19, los resultados de los ensayos clínicos de Fase III dieron la sentencia: se lograron vacunas con alto grado de eficacia que llega al 70% a 95%. Al momento de escribir esta editorial, dos de ellas ya tienen autorización para uso de emergencia por el FDA. La OMS realiza un seguimiento cotidiano a los avances de candidatos vacunales, el reporte para el 22 de Diciembre encontraba 57 en fases de evaluación clínica (entre estas 11 en fase III) y 166 en fase preclínica.

In the face of skepticism about finding a vaccine for COVID19 , the results of the Phase III clinical trials were conclusive: vaccines with a high degree of efficacy of 70% to 95% were achieved. At the time of writing this editorial, two of them have already been authorized for emergency use by the FDA. The WHO monitors the progress of vaccine candidates on a daily basis; the report as of December 22nd found 57 in clinical evaluation phases (including 11 in Phase III) and 166 in preclinical phase.

Evaluación de la prueba de avidez para el seguimiento de niños tratados por toxoplasmosis congénita durante el primer año de vida / Evaluation of the avidity test for the follow up on children treated for congenital toxoplasmosis during the first year of life

RESUMEN Objetivos: determinar la utilidad de la prueba de avidez en el seguimiento de los pacientes diagnosticados con toxoplasmosis congénita a través de la evaluación de su comportamiento en el tiempo. Metodología: estudio retrospectivo a partir de los datos en historias clínicas de niños que tuvieron confirmación diagnóstica y tratamiento para toxoplasmosis congénita, realizado en consulta de toxoplasmosis, tercer nivel de referencia en el centro de salud de la Universidad del Quindío. Se estudiaron 21 niños que fueron seleccionados de una cohorte inicial de 168 pacientes, reclutados en los programas de tamizaje prenatal y los programas de prevención o niños que acudieron para el diagnóstico neonatal. Resultados: no se encontró relación estadísticamente significativa entre el porcentaje de avidez baja en el primer mes y haber recibido tratamiento prenatal (p = 0,47). Tampoco entre la primera y los niveles de IgG o los meses de vida, a pesar de haber recibido tratamiento posnatal. Sin embargo, al estudiar específicamente el grupo de niños de 5 meses de edad, se encontró una correlación significativa con los niveles de IgG anti-Toxoplasma (p = 0,01). Conclusión: en esta cohorte de niños colombianos con toxoplasmosis congénita se encontraron los mismos resultados reportados en series previas con un mayor número de casos en Italia. La avidez no mostró ser útil para el seguimiento de los niños con toxoplasmosis congénita.

SUMMARY Objectives: To determine the use of avidity testing in the follow up of patients diagnosed with congenital toxoplasmosis, through the observation of its behavior in time. Methods: Retrospective study from clinical records of children with confirmed diagnosis and treatment for congenital toxoplasmosis, which took place on atoxoplasmosis consultation in the third reference level University of Quindío clinic. A total of 21 children were selected among an initial cohort of 168 patients, recruited during prenatal screening, neonatal screening or children that attended for neonatal diagnosis. Results: There was no statistical significance found between low avidity during the first month and having received prenatal treatment (p=0,47). There was no statistical relationship either between the percentage of avidity and the levels of IgG or the months of age, despite having received postnatal treatment. Nevertheless, when studying specifically the group of children > 5 months of age a significant correlation was found with levels of IgG (p=0,01). Conclusion: In this cohort of Colombian children with congenital toxoplasmosis, the same results were found comparing with those reported in series with greater number of cases. Avidity testing did not prove to be useful for the follow up of children with congenital toxoplasmosis.

Autonomía farmacéutica y biotecnológica frente a emergencias sanitarias / Autonomous pharmaceutical and biotechnological capabilities during sanitary emergencies

La pandemia de COVID 19, ha puesto de presente la necesidad de contar con políticas de autonomía farmacéutica y biotecnológica para cada país. Esta autonomía es necesaria porque en eventos ocasionados por agentes de riesgo biológico, la afectación masiva de la población mundial hace imposible que se cubran las necesidades para todos los países. Muchos medicamentos de interés en salud pública no son producidos por la industria farmacéutica privada dado que los márgenes de ganancia no son importantes para ellos y se encuentran situaciones de desabastecimiento ante brotes de infecciones inusitados.

The COVID 19 pandemic has highlighted the need for pharmaceutical and biotechnology autonomy policies for each country. This autonomy is necessary because in events caused by biological risk agents, the massive involvement of the world population makes it impossible to cover the needs of all countries. Many drugs of public health interest are not produced by the private pharmaceutical industry because the profit margins are not important for them and there are situations of shortages in the event of outbreaks of unusual infections.

El proceso de validación del conocimiento: el indispensable valor de la revista científica: [Editorial] / The knowledge validation process: the fundamental value of the scientific journal: [Editorial]

Esta pandemia ha dejado grandes lecciones sobre la literatura científica y la evaluación crítica del conocimiento. Aunque grandes revistas, egidas del rigor para validar conocimiento, tuvieron errores estrepitosos, la lección final es que la revisión por pares es el mejor sistema, y hasta ahora el único, que puede garantizar que un trabajo de investigación se ha realizado dentro de las exigencias de la ciencia formal y como se escribe habitualmente, es el menos malo de todos los otros sistemas de evaluación del trabajo científico. En medicina esto es crítico por su implicación en vidas humanas, pero nunca se debe esperar que este proceso esté exento de equivocaciones, la revista JAMA al respecto tuvo una editorial con un título muy diciente: "errar es humano y corregirlo es divino"

This pandemic has left us great lessons regarding scientific literature and the critical evaluation of knowledge. Although important journals that are rigorous when validating knowledge, had resounding errors, the ultimate lesson is that peer review is the best system, and until now the only one, that can ensure that a research work has been carried following scientific requirements, and as it is usually stated, it is the least worse scientific work evaluation systems when compared to others3­5. In medicine, this is critical given the way it affects human lives, but one should never expect this process to be error-free; JAMA journal had an editorial with a very telling title in this regard: "To err is human and to correct it is divine".

Consenso de grupo Ad-hoc sobre recomendaciones para la evaluación y controles de calidad para el diagnóstico molecular y serológico de la infección humana por SARS CoV-2 / Ad-hoc group consensus recommendations on the evaluation and quality control of molecular and serological diagnostics tests for SARS CoV-2 human infection

Se formulan recomendaciones de un grupo de consenso de expertos sobre los criterios para evaluar el desempeño diagnóstico (tamaño y selección de muestras para sensibilidad y especificidad analíticas, criterios para establecer límites de detección, criterios para establecer el estándar de oro para las serologías) que deberían ser tenidos en cuenta al evaluar y validar las pruebas diagnósticas para SARS CoV-2. Con el propósito de asegurar la calidad de las pruebas serológicas a utilizar en el país, se recomienda la participación en un programa de control de calidad externo, que garantice la idoneidad y desempeño en la realización de las pruebas diagnósticas serológicas y moleculares durante esta pandemia, ya que su uso tiene profundas implicaciones para las medidas de intervención clínicas individuales y de seguimiento y control en salud pública.

We formulate recommendations from a consensus working group on the criteria to evaluate the diagnostic performance (size and criteria of selection of samples to determine sensitivity, analytical specificity, criteria for limit of detection, criteria for gold standard to evaluate serological assays) that should be taken into account during the evaluation and validation/verification of diagnostic tests for SARS CoV-2 infection. A national external quality control program should be established to guarantee the suitability and performance of these diagnostic serological and molecular tests during this pandemic, that will have deep implications for decisions on clinical and public health.

Pandemia COVID-19: Reflexiones sobre su impacto para la preparación en el control de enfermedades infecciosas en Colombia: [Editorial] / Pandemic COVID-19: A reflection on the impact for preparedness on the control of infectious diseases in Colombia: [Editorial]

La Organización Mundial de la Salud finalmente declaró al brote por el coronavirus SARS-CoV-2 (Severe acute respiratory syndrome coronavirus 2) como una pandemia el 11 de marzo de 2020 . Al momento de escribir este editorial (Abril 4 de 2020) el mundo sobrepasó el millón de infectados y el número de muertes registraba cerca de 70 mil, con múltiples países sufriendo más de mil muertes diarias . Las características propias de este coronavirus, a pesar de ser similar a otros, como el SARS y el MERS, hace que existan interrogantes sobre su impacto en países de regiones y condiciones socioeconómicas y culturales diferentes.

The World Health Organization finally declared the SARS-CoV-2 (Severe acute respiratory syndrome coronavirus 2) outbreak a pandemic on March 11, 2020 . At the time of writing this editorial (April 4, 2020) the world surpassed one million infected and the number of deaths was close to 70,000, with multiple countries suffering more than one thousand deaths per day. The specific characteristics of this coronavirus, despite being similar to others, such as SARS and MERS, raise questions about its impact in countries of different regions and socioeconomic and cultural conditions.

Protein targets of thiazolidinone derivatives in Toxoplasma gondii and insights into their binding to ROP18.

BACKGROUND: Thiazolidinone derivatives show inhibitory activity (IC50) against the Toxoplasma gondii parasite, as well as high selectivity with high therapeutic index. To disclose the target proteins of the thiazolidinone core in this parasite, we explored in silico the active sites of different T. gondii proteins and estimated the binding-free energy of reported thiazolidinone molecules with inhibitory effect on invasion and replication of the parasite inside host cells. This enabled us to describe some of the most suitable structural characteristics to design a compound derived from the thiazolidinone core. RESULTS: The best binding affinity was observed in the active site of kinase proteins, we selected the active site of the T. gondii ROP18 kinase, because it is an important factor for the virulence and survival of the parasite. We present the possible effect of a derivative of thiazolidinone core in the active site of T. gondii ROP18 and described some characteristics of substituent groups that could improve the affinity and specificity of compounds derived from the thiazolidinone core against T. gondii. CONCLUSIONS: The results of our study suggest that compounds derived from the thiazolidinone core have a preference for protein kinases of T. gondii, being promising compounds for the development of new drugs with potential anti-toxoplasmosis activity. Our findings highlight the importance of use computational studies for the understanding of the action mechanism of compounds with biological activity.

Foodborne parasites in Colombia: [Editorial] / Parásitos transmitidos por alimentos en Colombia: [Editorial]

This number of Infectio includes the first report of Anisakis in edible fish in the Colombian pacific coast. Anisakidiasis has become an increasing threat given the extensive consumption of Sushi and raw fish worldwide as consequence of a global fad food. This report of Anisakis in 42% of the most popular fish specimens consumed in the country, call the attention also about the new health risks present in food, particularly parasites. The Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO) established a ranking of the top foodborne parasites for control priority in 2014. This was the first expert meeting that established which were the most important parasites to be included in risk analysis of food. The consequences are important, not only for the health sector, but also for the agriculture export market of developing countries. As free trade agreements have become a rule for the commercial exchange between countries, the only way to limit the entry of food products in the developed world are the sanitary controls. CODEX Alimentarius Commission (CAC) is the international organism that define the sanitary code and rules for quality and risk analysis in food. The economic importance of the rules defined by this commission is evident and discussions about inclusion of new controls for new risks are intense and a particularly though task inside this commission.

Este número de Infectio incluye el primer reporte de Anisakis en pescado comestible en la costa pacífica colombiana. La anisakidiasis se ha convertido en una amenaza creciente dado el amplio consumo de sushi y pescado crudo en el mundo como consecuencia de una moda alimentaria mundial. Este reporte de Anisakis en el 42% de los ejemplares de pescado más consumidos en el país, llama la atención también sobre los nuevos riesgos para la salud presentes en los alimentos, particularmente los parásitos. La Organización de las Naciones Unidas para la Agricultura y la Alimentación (FAO) y la Organización Mundial de la Salud (OMS) establecieron en 2014 una clasificación de los principales parásitos transmitidos por los alimentos para su control prioritario. Esta fue la primera reunión de expertos que estableció cuáles eran los parásitos más importantes a incluir en el análisis de riesgo de los alimentos. Las consecuencias son importantes, no solo para el sector sanitario, sino también para el mercado de exportación agrícola de los países en desarrollo. Como los acuerdos de libre comercio se han convertido en una norma para el intercambio comercial entre países, la única forma de limitar la entrada de productos alimentarios en el mundo desarrollado son los controles sanitarios. La Comisión del CODEX Alimentarius (CAC) es el organismo internacional que define el código sanitario y las normas de calidad y análisis de riesgo en los alimentos. La importancia económica de las normas definidas por esta comisión es evidente y las discusiones sobre la inclusión de nuevos controles para nuevos riesgos son intensas y una tarea especialmente ardua dentro de esta comisión.

Evidence based guidelines for congenital Chagas: [Editorial] / Guias basadas en evidencia para Chagas congénito: [Editorial]

In this issue of Infectiowe present the version in English language of the Colombian guidelines for congenital Chagas. This guideline was published in Spanish inInfectioin April 20141. This guideline was a consensus report developed by the Colombian task force, that was integrated by experts in the field and financed by the Ministry of Health, Colciencias (Red Chagas Program Cont. Colciencias 080-2011) and the Pan American Health Organization.

En este número de Infectio presentamos la versión en idioma inglés de la guía colombiana para el Chagas congénito. Esta guía fue publicada en español en Infectio en abril de 2014. Esta guía fue un informe de consenso desarrollado por el grupo de trabajo colombiano, que fue integrado por expertos en el tema y financiado por el Ministerio de Salud, Colciencias (Programa Red Chagas Cont. Colciencias 080-2011) y la Organización Panamericana de la Salud.

Evidence based guideline for toxoplasmosis during pregnancy: [Editorial]

Colombia fue el primer país del mundo en desarrollar una guía basada en la evidencia para la toxoplasmosis. El proyecto se presentó en 2010, se inició en 2011 y se publicó en español en Infectio en diciembre de 20121. Esta guía forma parte de las guías basadas en la evidencia para la complicación infecciosa y hemorrágica del embarazo desarrolladas por el Ministerio de Salud y Colciencias: http://gpc.minsalud.gov.co/gpc_sites/Repositorio/Conv_500/GPC_embarazo/gpc_embarazo.aspx.

Colombia was the first country in the world in to develop one evidence based guideline for toxoplasmosis. The project was presented in 2010, begun in 2011 and it was published in Spanish in Infectio in December 20121. This guideline was part of the evidence based guidelines for infectious and hemorrhagic complication of the pregnancy developed by the ministry of Health and Colciencias: http://gpc.minsalud.gov.co/gpc_sites/Repositorio/Conv_500/GPC_embarazo/gpc_embarazo.aspx.

R Script Approach to Infer Toxoplasma Infection Mechanisms From Microarrays and Domain-Domain Protein Interactions.

Pathogen-host protein-protein interaction systems examine the interactions between the protein repertoires of 2 distinct organisms. Some of these pathogen proteins interact with the host protein system and may manipulate it for their own advantages. In this work, we designed an R script by concatenating 2 functions called rowDM and rowCVmed to infer pathogen-host interaction using previously reported microarray data, including host gene enrichment analysis and the crossing of interspecific domain-domain interactions. We applied this script to the Toxoplasma-host system to describe pathogen survival mechanisms from human, mouse, and Toxoplasma Gene Expression Omnibus series. Our outcomes exhibited similar results with previously reported microarray analyses, but we found other important proteins that could contribute to toxoplasma pathogenesis. We observed that Toxoplasma ROP38 is the most differentially expressed protein among toxoplasma strains. Enrichment analysis and KEGG mapping indicated that the human retinal genes most affected by Toxoplasma infections are those related to antiapoptotic mechanisms. We suggest that proteins PIK3R1, PRKCA, PRKCG, PRKCB, HRAS, and c-JUN could be the possible substrates for differentially expressed Toxoplasma kinase ROP38. Likewise, we propose that Toxoplasma causes overexpression of apoptotic suppression human genes.

Detection of protozoa in water samples by formalin/ether concentration method.

Methods to detect protozoa in water samples are expensive and laborious. We evaluated the formalin/ether concentration method to detect Giardia sp., Cryptosporidium sp. and Toxoplasma in water. In order to test the properties of the method, we spiked water samples with different amounts of each protozoa (0, 10 and 50 cysts or oocysts) in a volume of 10 L of water. Immunofluorescence assay was used for detection of Giardia and Cryptosporidium. Toxoplasma oocysts were identified by morphology. The mean percent of recovery in 10 repetitions of the entire method, in 10 samples spiked with ten parasites and read by three different observers, were for Cryptosporidium 71.3 ± 12, for Giardia 63 ± 10 and for Toxoplasma 91.6 ± 9 and the relative standard deviation of the method was of 17.5, 17.2 and 9.8, respectively. Intraobserver variation as measured by intraclass correlation coefficient, was fair for Toxoplasma, moderate for Cryptosporidium and almost perfect for Giardia. The method was then applied in 77 samples of raw and drinkable water in three different plant of water treatment. Cryptosporidium was found in 28 of 77 samples (36%) and Giardia in 31 of 77 samples (40%). Theses results identified significant differences in treatment process to reduce the presence of Giardia and Cryptosporidium. In conclusion, the formalin ether method to concentrate protozoa in water is a new alternative for low resources countries, where is urgently need to monitor and follow the presence of theses protozoa in drinkable water.