Directrices para el tratamiento de las leishmaniasis en la región de las américas - 2 ed / Guidelines for the treatment of leishmaniasis in the region of the Americas - 2 ed

Las leishmaniasis son enfermedades infecciosas desatendidas de gran importancia en la Región de las Américas debido a su morbilidad, mortalidad y amplia distribución geográfica. De las tres formas clínicas principales, la cutánea es la más común y la visceral es la forma más grave, ya que puede causar la muerte de hasta 90% de las personas que no reciban tratamiento. En el 2013, la Organización Panamericana de la Salud (OPS) elaboró recomendaciones para el tratamiento de las leishmaniasis en la Región de las Américas utilizando la metodología de clasificación de la valoración, la elaboración y la evaluación de las recomendaciones (GRADE, por su sigla en inglés). No obstante, dada la evidencia acumulada desde entonces, se hizo necesario revisar esas recomendaciones. En esta segunda edición se presentan las recomendaciones actualizadas sobre el tratamiento de las leishmaniasis, y se detallan los esquemas y los criterios de indicación del tratamiento en el contexto regional. Estas directrices presentan modificaciones sustanciales con respecto a la primera edición. En el caso de la leishmaniasis cutánea, se ha eliminado el ketoconazol de las opciones terapéuticas, el número de especies de Leishmania para las que hay evidencia sólida de la eficacia de la miltefosina ha aumentado de dos a cuatro y la recomendación de administrar antimoniales intralesionales ahora es fuerte. Con respecto a la leishmaniasis mucosa, se incluye una recomendación fuerte sobre el uso de antimoniales pentavalentes con o sin pentoxifilina oral. Por lo que respecta a la leishmaniasis visceral, la recomendación fuerte sobre el uso de antimoniales pentavalentes y desoxicolato de anfotericina B ahora es condicional. También hay evidencia contundente en contra del uso de miltefosina en pacientes con leishmaniasis causada por Leishmania infantum. Otros cambios importantes son el desglose de las recomendaciones según si se trata de pacientes adultos o pediátricos, la inclusión de las especies de Leishmania y, en el caso de los pacientes inmunocomprometidos, la introducción de una recomendación fuerte contra el uso de antimoniales pentavalentes. Esta segunda edición es una versión revisada de la publicación Leishmaniasis en las Américas: recomendaciones para el tratamiento: https://iris.paho.org/handle/10665.2/7704

Exuberant case of verrucous cutaneous leishmaniasis

Abstract Cutaneous leishmaniasis represents a public health problem that affects 85 countries. It is an endemic disease in Brazil, having an important socioeconomic impact. An exuberant case of cutaneous leishmaniasis is reported herein. A 28-year-old male patient with Down syndrome had had verrucous plaques on the back for over a year, with progressive growth. PCR of a lesion sample was positive for Leishmania braziliensis. The patient's condition was classified as atypical cutaneous leishmaniasis. He was successfully treated with amphotericin B and miltefosine. The treatment remains a challenge, given the toxicity and low cure rate of the currently recommended drugs.

Successful treatment of diffuse cutaneous leishmaniasis caused by Leishmania amazonensis

Abstract Diffuse cutaneous leishmaniasis is a rare universal disease associated with an inadequate host cell immune response, caused by different species: infantum, aethiopica, major, mexicana, and others, which presents the challenge of a poor therapeutic response. In Brazil, it is caused by L. amazonensis. A case confirmed by histopathology with an abundance of vacuolated macrophages full of amastigotes and lymphocyte scarcity, identified by RFLP-ITS1PCR and in vitro decrease and exhaustion of the host cell immune response to L. amazonensis antigen, was treated early (3 months after the onset) with Glucantime (2 months) and allopurinol (29 months) with clinical cure, after a follow-up for 30 months after treatment.

Acute uveitis: A rare adverse effect of miltefosine in the treatment of post-kala-azar dermal leishmaniasis

Abstract Post-kala-azar dermal leishmaniasis is a skin disorder occurring in 5-10% of visceral leishmaniasis patients after treatment with miltefosine,the first-line drug for this skin disorder. We reported a case of acute anterior uveitis,a rare adverse effect, experienced by a patient treated with miltefosine for post-kala-azar dermal leishmaniasis. This adverse effect developed after 15 days of miltefosine consumption, and the patient himself discontinued the treatment. The ophthalmic complication was completely resolved with antibiotics and steroid eye drops. After recovery from the ophthalmic complication, the patient was successfully treated with liposomal amphotericin B for the skin lesions.

Estimating direct costs of the treatment for mucosal leishmaniasis in Brazil

Abstract INTRODUCTION: The objective of this study was to estimate the direct medical costs of the treatment for mucosal leishmaniasis (ML) using three therapeutic approaches in the Brazilian context. METHODS: We performed this economic assessment from the perspective of the Brazilian public healthcare system. The following therapeutic approaches were evaluated: meglumine antimoniate, liposomal amphotericin B, and miltefosine. Direct medical costs were estimated considering four treatment components: a) drug, b) combined medical products, c) procedures, and d) complementary tests. RESULTS: Treatment with meglumine antimoniate had the lowest average cost per patient (US$ 167.66), followed by miltefosine (US$ 259.92) in the outpatient treatment regimen. The average cost of treatment with liposomal amphotericin B was US$ 715.35 both in inpatient regimen. In all estimates, the drugs accounted for more than 60% of the total cost for each treatment approach. CONCLUSIONS: These results demonstrate the marked differences in costs between the therapeutic alternatives for ML. In addition to efficacy rates and costs related to adverse events, our data have the potential to support a complete cost-effectiveness study in the future. Complete analyses comparing costs and benefits for interventions will assist health managers in choosing drugs for ML treatment in Brazil as well as in establishing effective public health policies.

Unusual manifestation of genital cutaneous leishmaniasis in an immunocompetent patient from São Paulo, Brazil: A case report

Abstract A 31-year-old male patient developed an ulcer on the glans penis that evolved for three months without healing. We diagnosed it as leishmaniasis using polymerase chain reaction. No immunosuppression or associated diseases were observed. The patient was treated with meglumine antimoniate that cured the lesion in a month post-treatment. Here, we report this case of cutaneous leishmaniasis lesion at the unusual location of glans penis in an immunocompetent individual. The lesion likely developed due to the bite of a vector, highlighting the need for considering cutaneous leishmaniasis among differential diagnosis of sexually transmitted diseases in areas endemic for leishmaniasis.

Treatment of tegumentary leishmaniasis in two hemodialysis patients with end-stage renal disease using two series of pentamidine

Abstract In this study, we present two cases of cutaneous leishmaniasis in patients with end-stage renal disease, who were treated solely with intramuscular pentamidine. In such cases, treatment implies a fine line between therapeutic efficacy and toxicity. This is suggestive of a knowledge gap; however, findings indicate that this is still the fastest and safest alternative to the treatment with antimonials. Also, it can help avoid the side effects that occur upon using antimonials.

Molecular variation of Plasmodium vivax dehydrofolate reductase in Mexico and Nicaragua contrasts with that occurring in South America / Variación molecular de la dehidrofolato reductasa de Plasmodium vivax en México y Nicaragua contrasta con la que ocurre en Sudamérica

Abstract: Objective: To research mutations associated to pyrimethamine resistance in dihydrofolate reductase (pvdhfr) of Plasmodium vivax from Mexico and Nicaragua and compare it to that reported in the rest of America. Materials and methods: Genomic DNA was obtained from P. vivax-infected blood samples. A pvdhfr gene fragment was amplified and sequenced. The identified gene variations were compared to those observed in other affected sites of America. Results: No mutations in pvdhfr were detected in P. vivax from Mexico and Nicaragua. One synonymous change and variation in the repeat domain was detected in Nicaraguan parasites. In South America, a high frequency of variant residues 58R and 117N associated to pyrimethamine resistance was reported. Conclusions: The lack of polymorphisms associated with pyrimethamine resistance suggests that drug-resistant P. vivax has not penetrated Mesoamerica, nor have local parasites been under selective pressure. These data contribute to establish the basis for the epidemiological surveillance of drug resistance.

Resumen: Objetivo: Determinar mutaciones en la dihydrofolato reductasa deP. vivax (Pvdhfr) en parásitos de México y Nicaragua, y comparar con lo reportado en América. Material y métodos: Del ADN de sangres infectadas con P. vivax de pacientes, el gen pvdhfr se amplifico y secuenció, y se contrastócon lo observado en América. Resultados: No se detectaron mutaciones asociadas con la resistencia debida a pirimetamina. Los parásitos de Nicaragua tuvieron una mutación sinónima y variación en la región repetida. Se reportaron frecuentes mutaciones asociadas con la resistencia a la pirimetamina en Sudamérica. Conclusiones: La ausencia de polimorfismos en Pvdhfr sugiere que no se han seleccionado ni introducido parásitos resistentes en la zona de estudio, lo que resulta muy útil para la vigilancia epidemiológica.

Urbanorum spp novo parasita no Brasil / Urbanorum spp new parasite in Brazil / Urbanorum spp nuevo parásito en Brasil

Introdução: As enteroparasitoses são foco de investigações científicas no mundo todo. Urbanorumspp. foi reconhecido como parasita em 1994 no Peru, expandindo-se pela América do Sul. Relatado pela primeira vez no Brasil em 2018, Maranhão. Este relato apresenta o segundo caso no estado do Paraná. Relato de caso: Paciente masculino, 56 anos, 75kg, diabético, habitante de São José dos Pinhais, área urbana. Procura atenção primária por dor ao evacuar, tenesmo e cólica abdominal. Nega diarréia, febre, sangue nas fezes e viagem recente. Exame físico abdominal, hemograma e parcial de urina sem alterações. Parasitológico de fezes: Urbanorum spp. Prescrito Nitazoxanida 500mg 12/12h por 3 dias. Paciente retorna com melhora da sintomatologia e parasitológico de controle negativo. Conclusão: Atualmente a escassez de estudos primários prospectivos dificultam o delineamento clínico-epidemiológico e tratamento da parasitose. A disseminação do parasita entre extremos do país em curto intervalo de tempo, aliada à carência de saneamento básico criam um alerta para seu grande potencial epidêmico. Por isso, as políticas de saúde pública devem priorizar ações informativas e preventivas a fim de evitar surtos e complicações. A atenção primária à saúde é fundamental nesse contexto, justamente pela longitudinalidade e abrangência do cuidado.

Background: Enteroparasitosis are the focus of scientific research worldwide. Urbanorum spp. was recognized as a parasite in Peru in 1994, expanding throughout South America. Reported for the first time in Brazil, state of Maranhão, in 2018. This report presents the second case in the state of Paraná. Case report: Male patient, 56 years old, 75kg, diabetic, inhabitant of São José dos Pinhais, urban area, seeks primary care for pain on bowel movement, tenesmus and abdominal cramps. Denies diarrhea, fever, bloody stools, recent trip. Abdominal examination, blood count and partial urine without changes. Stool parasitology: urbanorum spp. Prescribed Nitazoxanide 500mg 12/12h for 3 days. Patient returns with improvement of symptomatology and parasitological negative control. Conclusion:Currently, the scarcity of prospective studies and meta-analyzes make clinical-epidemiological design and treatment of parasitosis difficult. The spread of the parasite between extremes of the country in a short period of time, coupled with the lack of basic sanitation create a warning for its great epidemic potential. Therefore, public health policies should prioritize informative and preventive actions in order to avoid outbreaks and complications. Primary health care is fundamental in this context, precisely because of the longitudinally and comprehensiveness of care.

Introducción: Las enteroparasitosis el punto de enfoque de investigaciones científicas en todo el mundo. Urbanorum spp fue reconocido cómo parásito en 1994 en el Peru, expandiéndose en América do Sul. Relatado por primera vez en Brasil, Maranhão, 2018. Este informe se encuentra en segundo lugar en el estado de Paraná. Relato del caso: Paciente masculino, 56 años, 75 kg, diabético, habitante de São José dos Pinhais, área urbana. Búsqueda atención primaria por dolor al defecar, tenesmo, y dolor abdominal. Nega diarrea, fiebre, sangre en heces o viaje reciente. Examen físico abdominal, hemograma e tests de orina sin modificaciones. Análisis parasitología: urbanorum spp. Prescripto Nitazoxanide 500mg 12/12h durante 3 días. Paciente volvió con alivio sintomático e materia fecal negativo. Conclusión: En la actualidad la escasez de estudios prospectivos y metanálisis dificultan la delineación clínico-epidemiológica y el tratamiento de la parasitosis. La diseminación del parásito entre los extremos del país en un corto período de tiempo, junto con la falta de saneamiento básico, crea una alerta por su gran potencial epidémico. Por lo tanto, las políticas de salud pública deben priorizar las acciones informativas y preventivas para evitar brotes y complicaciones. La atención primaria de salud es fundamental en este contexto, precisamente por la longitudinalidad y la amplitud de la atención.

Infectious keratitis in southern Brazil: a comparison culture negative and culture positive patients / Ceratite infecciosa no sul do Brasil: comparação entre pacientes com cultura negativa e positiva

Abstract Purpose: To compare clinical-epidemiological profile and treatment outcome between culture negative and culture positive keratitis patients. Methods: Patients with suspected infectious keratitis seen at two ophthalmic hospitals in Curitiba, Brazil, between June 2014 and April 2016, were prospectively studied. Ophthalmological exam with corneal scraping and microbiological tests were performed. Data regarding follow up, surgical interventions and treatment outcome were collected after 12 weeks of the first visit trough medical chart review. From the results of the culture, two groups were formed: culture negative keratitis (CNK) and culture positive keratitis (CPK). Results: According to inclusion criteria 21 patients were classified as culture negative keratitis and 20 patients as culture positive keratitis. The number of patients on antibiotic drops at the first visit was greater in CNK group (90.5% versus 60%; p=0.032). Surgical procedures were necessary in 3 patients (15%) in CNK group and in 7 patients (36,8%) in CPK group (p=0.155). Treatment success was achieved by 85% (17/20) of the patients in CNK group and by 61% (11/18) of the patients in CPK group (p=0.144). There was no significant difference between groups regarding age, gender, place of residence, presence of comorbidities, risk factors for infectious keratitis, duration of symptoms and characteristics of corneal ulcer. Conclusions: Previous treatment with antibiotics correlates with negative culture results. There was no significant difference in treatment outcome between culture negative and culture positive keratitis patients.

Resumo Objetivo: Comparar os perfis clinico-epidemiológicos e os desfechos entre pacientes com ceratite com cultura positiva e pacientes com ceratite com cultura negativa. Métodos: Pacientes com ceratite infecciosa, atendidos em dois hospitais oftalmológicos em Curitiba, Brasil, entre junho de 2014 e abril de 2016, foram estudados prospectivamente. Exame oftalmológico, raspado de córnea e exames microbiológicos foram realizados no primeiro atendimento. Os dados quanto a seguimento e desfecho foram coletados após 12 semanas do primeiro atendimento através de revisão de prontuário. A partir dos resultados das culturas, dois grupos foram formados: ceratite com cultura negativa e ceratite com cultura positiva. Resultados: Vinte e um pacientes foram classificados como ceratite com cultura negativa e 20 como ceratite com cultura positiva. O número de pacientes em uso de colírio antibiótico no primeiro atendimento foi maior no grupo de cultura negativa (90,5% versus 60%; p=0,032). Sete pacientes (37%) no grupo cultura positiva precisaram de procedimentos cirúrgicos no manejo da ceratite, versus 3 pacientes (15%) do grupo cultura negativa (p=0,155). Oitenta e cinco por cento (17/20) dos pacientes do grupo cultura negativa alcançaram sucesso no tratamento, contra 61% (11/18) dos pacientes no grupo cultura positiva (p=0,144). Não houve diferença entre os grupos quanto a idade, gênero, local de procedência, presença de comorbidades, fatores de risco, duração dos sintomas e características da úlcera de córnea. Conclusão: Tratamento prévio com colírio de antibiótico correlaciona-se com resultados negativos de cultura. Não houve diferença no desfecho após tratamento entre os pacientes com cultura negativa e cultura positiva.

Efficacy of the 7-chloro-4-(3-hydroxy-benzilidenehydrazo)quinoline derivative against infection caused by Leishmania amazonensis

Abstract INTRODUCTION: The drugs currently available for leishmaniasis treatment have major limitations. METHODS: In vitro and in vivo studies were performed to evaluate the effect of a quinoline derivative, Hydraqui (7-chloro-4-(3-hydroxy-benzilidenehydrazo)quinoline, against Leishmania amazonensis. In silico analyses of absorption, distribution, metabolism, excretion, and toxicity (ADMET) parameters were performed. RESULTS: Hydraqui showed significant in vitro anti-amastigote activity. Also, Hydraqui-treated mice exhibited high efficacy in lesion size (48.3%) and parasitic load (93.8%) reduction, did not cause hepatic and renal toxicity, and showed appropriate ADMET properties. CONCLUSIONS: Hydraqui presents a set of satisfactory criteria for its application as an antileishmanial agent.

Mucocutaneous leishmaniasis in a cocaine user: diagnostic and therapeutic knowledge

Abstract Mucocutaneous leishmaniasis (MCL) is a chronic infection that can affect the skin and mucous membranes. We report a case of oral, nasopharyngeal, and penile lesions in a 35-year-old cocaine user. The patient presented with ulcerated lesions in 2014. Histopathologic analysis revealed amastigotes, and serological test results were positive for leishmaniasis. Systemic therapy with meglumine antimoniate was administered; however, the patient failed to present for follow-up. In 2018, he returned with nasal collapse, and another histopathologic test confirmed MCL. This case illustrates the importance of careful differential diagnosis of skin and mucous ulcers to identify the particular pathology.

The heterologous expression of Escherichia coli MutT enzyme is involved in the protection against oxidative stress in Leishmania braziliensis

BACKGROUND Oxidative stress is responsible for generating DNA lesions and the 8-oxoguanine (8-oxoG) is the most commonly lesion found in DNA damage. When this base is incorporated during DNA replication, it could generate double-strand DNA breaks and cellular death. MutT enzyme hydrolyzes the 8-oxoG from the nucleotide pool, preventing its incorporation during DNA replication. OBJECTIVES To investigate the importance of 8-oxoG in Leishmania infantum and L. braziliensis, in this study we analysed the impact of heterologous expression of Escherichia coli MutT (EcMutT) enzyme in drug-resistance phenotype and defense against oxidative stress. METHODS Comparative analysis of L. braziliensis and L. infantum H2O2 tolerance and cell cycle profile were performed. Lines of L. braziliensis and L. infantum expressing EcMutT were generated and evaluated using susceptibility tests to H2O2 and SbIII, cell cycle analysis, γH2A western blotting, and BrdU native detection assay. FINDINGS Comparative analysis of tolerance to oxidative stress generated by H2O2 showed that L. infantum is more tolerant to exogenous H2O2 than L. braziliensis. In addition, cell cycle analysis showed that L. infantum, after treatment with H2O2, remains in G1 phase, returning to its normal growth rate after 72 h. In contrast, after treatment with H2O2, L. braziliensis parasites continue to move to the next stages of the cell cycle. Expression of the E. coli MutT gene in L. braziliensis and L. infantum does not interfere in parasite growth or in susceptibility to SbIII. Interestingly, we observed that L. braziliensis EcMutT-expressing clones were more tolerant to H2O2 treatment, presented lower activation of γH2A, a biomarker of genotoxic stress, and lower replication stress than its parental non-transfected parasites. In contrast, the EcMutT is not involved in protection against oxidative stress generated by H2O2 in L. infantum. MAIN CONCLUSIONS Our results showed that 8-oxoG clearance in L. braziliensis is important to avoid misincorporation during DNA replication after oxidative stress generated by H2O2.

In vitro-induction of metronidazole-resistant Giardia duodenalis is not associated with nucleotide alterations in the genes involved in pro-drug activation

Giardiasis is an infectious disease caused by Giardia duodenalis. The pro-drug metronidazole (MTZ) is the first-line treatment for giardiasis. Parasite's proteins as pyruvate:ferredoxin oxidoreductase (PFOR), ferredoxin (Fd), nitroreductase-1 (NR-1) and thioredoxin reductase (TrxR) participate in MTZ activation. Here, we showed Giardia trophozoites long-term exposed to MTZ presented higher IC50 than controls, showing the drug influenced the parasite survival. That reduction in MTZ's susceptibility does not seem to be related to mutations in the genes pfor, fd, nr-1 or trxr. It points that different mechanism as alterations in other metabolic pathways can account for Giardia resistance to MTZ therapy.

Characterisation of the in vitro activity of a Nitazoxanide-N-methyl-1H-benzimidazole hybrid molecule against albendazole and nitazoxanide susceptible and resistant strains of Giardia intestinalis and its in vivo giardicidal activity

BACKGROUND It was previously demonstrated that CMC-20, a nitazoxanide and N-methyl-1H-benzimidazole hybrid molecule, had higher in vitro activity against Giardia intestinalis WB strain than metronidazole and albendazole and similar to nitazoxanide. OBJETIVES To evaluate the in vitro activity of CMC-20 against G. intestinalis strains with different susceptibility/resistance to albendazole and nitazoxanide and evaluate its effect on the distribution of parasite cytoskeletal proteins and its in vivo giardicidal activity. METHODS CMC-20 activity was tested against two isolates from patients with chronic and acute giardiasis, an experimentally induced albendazole resistant strain and a nitazoxanide resistant clinical isolate. CMC-20 effect on the distribution of parasite cytoskeletal proteins was analysed by indirect immunofluorescence and its activity was evaluated in a murine model of giardiasis. FINDINGS CMC-20 showed broad activity against susceptible and resistant strains to albendazole and nitaxozanide. It affected the parasite microtubule reservoir and triggered the parasite encystation. In this process, alpha-7.2 giardin co-localised with CWP-1 protein. CMC-20 reduced the infection time and cyst load in feces of G. muris infected mice similar to albendazole. MAIN CONCLUSIONS The in vitro and in vivo giardicidal activity of CMC-20 suggests its potential use in the treatment of giardiasis.

In vivo antileishmanial activity of Annona mucosa extracts

Abstract INTRODUCTION: Leishmaniasis, a disease caused by a parasite endemic to large areas of tropical and subtropical countries, is a growing public health problem. METHODS: Male BALB/c mice were infected with Leishmania amazonensis and treated with extracts isolated from Annona mucosa. RESULTS: Treated groups had significantly reduced footpad swelling. The group treated intraperitoneally with hexane extract showed footpad swelling similar to groups treated with Pentamidine® and Glucantime®. Groups treated with dichloromethane extract and hexane extract presented the recovering phenotype associated with reduced parasite levels. CONCLUSIONS: Extracts of A. mucosa are promising sources of novel antileishmanial compounds.

Leishmania infantum induces high phagocytic capacity and intracellular nitric oxide production by human proinflammatory monocyte

BACKGROUND The mechanism of resistance to SbIII in Leishmania is complex, multifactorial and involves not only biochemical mechanisms, but also other elements, such as the immune system of the host. OBJECTIVES In this study, putative changes in the immunological profile of human monocytes infected with wild-type (WT) and antimony (SbIII)-resistant Leishmania (Viannia) braziliensis and Leishmania (Leishmania) infantum lines were evaluated. METHODS Susceptibility assays WT and SbIII-resistant L. braziliensis and L. infantum were performed using lines THP-1 human monocytic lineage. Phagocytic capacity, cytokine profile, intracellular nitric oxide (NO) production and surface carbohydrate residues profile were performed in peripheral blood monocytes by flow cytometry. FINDINGS The phagocytic capacity and intracellular NO production by classical (CD14++CD16-) and proinflammatory (CD14++CD16+) monocytes were higher in the presence of L. infantum lines compared to L. braziliensis lines. The results also highlight proinflammatory monocytes as the cellular subpopulation of major relevance in a phagocytosis event and NO expression. It is important to note that L. infantum induced a proinflammatory cytokine profile characterised by higher levels of TNF-α in culture supernatant than L. braziliensis. Conversely, both Leishmania lines induce high levels of IL-6 in culture supernatant. Analysis of the expression profile of surface carbohydrates showed that L. braziliensis presents 4.3-fold higher expression of galactose(β1,4)N-acetylglucosamine than L. infantum line. Interestingly, the expression level of α-N-acetylgalactosamine residues was 2-fold lower in the SbIII-resistant L. braziliensis line than its counterpart WT line, indicating differences in surface glycoconjugates between these lines. MAIN CONCLUSIONS Our results showed that L. braziliensis and L. infantum induce different innate immune responses and a highly inflammatory profile, which is characteristic of infection by L. infantum, the species associated with visceral disease.

Characterisation of the in vitro activity of a Nitazoxanide-N-methyl-1H-benzimidazole hybrid molecule against albendazole and nitazoxanide susceptible and resistant strains of Giardia intestinalis and its in vivo giardicidal activity

BACKGROUND It was previously demonstrated that CMC-20, a nitazoxanide and N-methyl-1H-benzimidazole hybrid molecule, had higher in vitro activity against Giardia intestinalis WB strain than metronidazole and albendazole and similar to nitazoxanide. OBJETIVES To evaluate the in vitro activity of CMC-20 against G. intestinalis strains with different susceptibility/resistance to albendazole and nitazoxanide and evaluate its effect on the distribution of parasite cytoskeletal proteins and its in vivo giardicidal activity. METHODS CMC-20 activity was tested against two isolates from patients with chronic and acute giardiasis, an experimentally induced albendazole resistant strain and a nitazoxanide resistant clinical isolate. CMC-20 effect on the distribution of parasite cytoskeletal proteins was analysed by indirect immunofluorescence and its activity was evaluated in a murine model of giardiasis. FINDINGS CMC-20 showed broad activity against susceptible and resistant strains to albendazole and nitaxozanide. It affected the parasite microtubule reservoir and triggered the parasite encystation. In this process, alpha-7.2 giardin co-localised with CWP-1 protein. CMC-20 reduced the infection time and cyst load in feces of G. muris infected mice similar to albendazole. MAIN CONCLUSIONS The in vitro and in vivo giardicidal activity of CMC-20 suggests its potential use in the treatment of giardiasis.