ABSTRACT
Prolonged viral excretion in immunocompromised hosts leads to long oseltamivir treatment and to the subsequent development of oseltamivir-resistant pandemic influenza virus selection. We report the selection and nasopharyngeal shedding kinetics of an oseltamivir-resistant strain in a hospitalized immunocompromised patient with prolonged influenza illness. Viral load quantification and genotyping methods were performed from 7 serial nasopharyngeal samples. Before initial oseltamivir treatment, the viral load was 5.78 log(10) copies/mL of sample and only wild-type virus population was detected. The nasopharyngeal viral load remained above the detection limit although there was a second course of oseltamivir treatment. Twelve days after the onset of symptoms, an oseltamivir-resistant strain was selected. After 12 days of inhaled zanamivir treatment, the patient was discharged asymptomatic. The study emphasizes the importance of viral load quantification and surveillance of emergence of resistant strains prospectively because the information provided has important implications in the clinical management of the patient.
Subject(s)
Antiviral Agents/therapeutic use , Drug Resistance, Viral , Influenza A Virus, H1N1 Subtype/drug effects , Influenza A Virus, H1N1 Subtype/isolation & purification , Influenza, Human/virology , Oseltamivir/therapeutic use , Viral Load , Aged , Antiviral Agents/pharmacology , Genotype , Humans , Immunocompromised Host , Influenza, Human/drug therapy , Male , Nasopharynx/virology , Oseltamivir/pharmacology , RNA, Viral/genetics , Selection, Genetic , Virus SheddingABSTRACT
We report the first strain of 2009 pandemic influenza A (H1N1) virus with V27A mutation in addition to S31N substitution in M2 gen. It was isolated from adamantane non-treated child.
Subject(s)
Adamantane/therapeutic use , Amino Acid Substitution/genetics , Antiviral Agents/therapeutic use , Influenza A Virus, H1N1 Subtype/genetics , Influenza, Human/virology , Mutation, Missense , Adolescent , Female , Humans , Influenza A Virus, H1N1 Subtype/isolation & purification , Spain , Viral Matrix Proteins/geneticsABSTRACT
A polymerase chain reaction (PCR)-based test for Pneumocystis jiroveci (formerly Pneumocystis carinii f. sp. hominis) might be an alternative to histologic diagnoses of P. jiroveci pneumonia (PCP). However, previously developed nested PCR methods tend to have low specificities (high false-positive rates). In this study, nested and quantitative real-time PCR methods for the amplification of the P. jiroveci DHPS (dihydropteroate synthase) gene were evaluated in a variety of stored clinical samples from Spain, South Africa, and Brazil. The sensitivities of both assays were high, ranging from 62.5% to 100% depending on the type of specimen. In a subset of 71 microscopically confirmed PCP cases and 70 negative cases, the sensitivities and specificities were 94% and 81% for nested PCR and 94% and 96% for real-time PCR, respectively. Real-time PCR has a statistically significantly better specificity than nested PCR (P = .015) and is likely to generate fewer false positives.
