The Use of Quinacrine in Nitroimidazole-resistant Giardia Duodenalis: An Old Drug for an Emerging Problem.

Background: There is little evidence regarding the management of refractory giardiasis after treatment with nitroimidazoles. This study estimates the proportion of persistent giardiasis in 3 hospitals in Barcelona, describes associated risk factors and genotype, and evaluates the efficacy rate of quinacrine in those with persistent giardiasis. Methods: A clinical, prospective, observational study was conducted in patients with giardiasis treated with nitroimidazoles. Those with persistent giardiasis were provided quinacrine. Molecular characterization of Giardia isolates was performed by polymerase chain reaction amplification of a fragment of tpi and bg genes. Results: Seventy-seven patients were recruited and treated with nitroimidazoles, and in 14 of 71 (20%) of patients followed up, Giardia persisted. Refractory giardiasis was associated with malaise (P = .007) and anorexia (P = .02), with previous giardiasis (P = .03), and with previous antibiotic (P = .02) or antiparasitic(P = .04) use. Quinacrine had an effectiveness rate of 100% in refractory giardiasis (n = 13; 95% confidence interval = 75-100). Molecular characterization showed that 17 (25%) Giardia isolates belonged to assemblage A, and 31 (43%) belonged to assemblage B. In refractory giardiasis, assemblage A and B were found responsible in 4 and 6 cases, respectively. Conclusions: Almost 20% of patients presented persistent giardiasis, belonging to both assemblages A and B, after nitroimidazole. Short course of quinacrine was effective in treating refractory cases. Further controlled studies should evaluate its efficacy and safety.

Cryptosporidiosis outbreak in a child day-care center caused by an unusual Cryptosporidium hominis subtype / Brote de cryptosporidiosis en una guardería causado por un subtipo inusual de Cryptosporidium hominis

INTRODUCTION: This work describes the genetic characterization of Cryptosporidium and Giardia involved in an outbreak in a nursery school in Granada, Spain, that affected seven children under the age of 4. METHODS: Nucleic acids were extracted from the seven stool samples positive to Cryptosporidium or Giardia by microscopy and/or immunochromatography. The species and subtypes of Cryptosporidium were identified by PCR-RFLP and PCR of the SSUrRNA and gp60 genes, respectively. The assemblages of Giardia duodenalis isolates were characterized by PCR of the tpi gene. PCR products were sequenced and analyzed. RESULTS: All of the isolates were positive for Cryptosporidium hominis. Five of them belonged to subtype IaA11R2, one to subtype IbA10G2R2, and the other could not be identified. Three of these samples were positive for G. duodenalis by PCR, two belonging to the assemblage A, and the other one to assemblage B. DISCUSSION: This is the first report of Cryptosporidium hominis subtype IaA11R2 as a cause of an outbreak in Europe where subtype IbA10G2R2 is the most frequently identified. In the case of Giardia, an outbreak could not be confirmed because of the low number of positive samples and the low genetic variability of the amplified fragments for assemblage A of tpi gene. CONCLUSIONS: A new subtype, of Cryptosporidium hominis named IaA11R2, has been described as a cause of an outbreak in a nursery school in Granada, Spain. However an outbreak of giardiasis could not be confirmed

INTRODUCCIÓN: Este trabajo describe la caracterización genética de Cryptosporidium y Giardia implicados en un brote en una guardería de Granada, España, que afectó a 7 niños menores de 4 años de edad. MÉTODOS: La extracción de ácidos nucleicos se realizó a partir de las 7 muestras de heces positivas para Cryptosporidium o Giardia mediante técnicas de microscopia y/o inmunocromatografía. Las especies y subtipos de Cryptosporidium fueron identificados por PCR-RFLP y PCR de los genes SSUrRNA ygp60, respectivamente. Los genotipos de los aislamientos Giardia duodenalis fueron caracterizados por PCR del gen tpi. Los productos de PCR obtenidos fueron secuenciados y analizados. RESULTADOS: Todos los aislamientos fueron positivos para Cryptosporidium hominis. Cinco de ellos correspondieron al subtipo IaA11R2, uno al subtipo IbA10G2R2 y otro no pudo ser identificado. Tres de las muestras resultaron positivas para G. duodenalis por PCR, 2 de ellas pertenecientes al genotipo A y la restante al genotipo B. DISCUSIÓN: Esta es la primera identificación del subtipo IaA11R2 de Cryptosporidium hominis como causa de un brote en Europa, donde el subtipo IbA10G2R2 es el más frecuentemente identificado. En el caso de Giardia, el bajo número de muestras positivas y la baja variabilidad genética del fragmento del gen tpiamplificado para el genotipo A no permitieron confirmar un brote. CONCLUSIONES: Un nuevo subtipo de Cryptosporidium hominis, denominado IaA11R2, ha sido descrito como causa de un brote en una guardería de Granada, España. Sin embargo, los resultados obtenidos no permiten confirmar un brote de giardiasis

Cryptosporidiosis outbreak in a child day-care center caused by an unusual Cryptosporidium hominis subtype.

INTRODUCTION: This work describes the genetic characterization of Cryptosporidium and Giardia involved in an outbreak in a nursery school in Granada, Spain, that affected seven children under the age of 4. METHODS: Nucleic acids were extracted from the seven stool samples positive to Cryptosporidium or Giardia by microscopy and/or immunochromatography. The species and subtypes of Cryptosporidium were identified by PCR-RFLP and PCR of the SSUrRNA and gp60 genes, respectively. The assemblages of Giardia duodenalis isolates were characterized by PCR of the tpi gene. PCR products were sequenced and analyzed. RESULTS: All of the isolates were positive for Cryptosporidium hominis. Five of them belonged to subtype IaA11R2, one to subtype IbA10G2R2, and the other could not be identified. Three of these samples were positive for G. duodenalis by PCR, two belonging to the assemblage A, and the other one to assemblage B. DISCUSSION: This is the first report of Cryptosporidium hominis subtype IaA11R2 as a cause of an outbreak in Europe where subtype IbA10G2R2 is the most frequently identified. In the case of Giardia, an outbreak could not be confirmed because of the low number of positive samples and the low genetic variability of the amplified fragments for assemblage A of tpi gene. CONCLUSIONS: A new subtype, of Cryptosporidium hominis named IaA11R2, has been described as a cause of an outbreak in a nursery school in Granada, Spain. However an outbreak of giardiasis could not be confirmed.