RESUMO
The H7N9 influenza virus causes a severe form of disease in humans. Neuraminidase inhibitors, including oral oseltamivir and injectable peramivir, are the first choices of antiviral treatment for such cases; however, the clinical efficacy of these drugs is questionable. Animal experimental models are essential for understanding the viral replication kinetics under the selective pressure of antiviral agents. This study demonstrates the antiviral activity of peramivir in a mouse model of H7N9 avian influenza virus infection. The data show that repeated administration of peramivir at 30 mg/kg of body weight successfully eradicated the virus from the respiratory tract and extrapulmonary tissues during the acute response, prevented clinical signs of the disease, including neuropathy, and eventually protected mice against lethal H7N9 influenza virus infection. Early treatment with peramivir was found to be associated with better disease outcomes.
Assuntos
Antivirais/farmacologia , Ciclopentanos/farmacologia , Inibidores Enzimáticos/farmacologia , Guanidinas/farmacologia , Subtipo H7N9 do Vírus da Influenza A/efeitos dos fármacos , Infecções por Orthomyxoviridae/tratamento farmacológico , Ácidos Carbocíclicos , Animais , Cães , Esquema de Medicação , Feminino , Humanos , Subtipo H7N9 do Vírus da Influenza A/enzimologia , Subtipo H7N9 do Vírus da Influenza A/crescimento & desenvolvimento , Injeções Intramusculares , Pulmão/efeitos dos fármacos , Pulmão/patologia , Pulmão/virologia , Células Madin Darby de Rim Canino , Camundongos , Camundongos Endogâmicos C57BL , Neuraminidase/antagonistas & inibidores , Neuraminidase/metabolismo , Infecções por Orthomyxoviridae/mortalidade , Infecções por Orthomyxoviridae/patologia , Infecções por Orthomyxoviridae/virologia , Oseltamivir/farmacologia , Análise de Sobrevida , Resultado do Tratamento , Carga Viral/efeitos dos fármacos , Proteínas Virais/antagonistas & inibidores , Proteínas Virais/metabolismo , Replicação Viral/efeitos dos fármacosRESUMO
INTRODUCTION: South China has a proven role in the global epidemiology of previous influenza outbreaks due to its dual seasonal pattern. We present the virologic, genetic and clinical characterization of pandemic H1N1 influenza infection (pH1N1) in Shantou and Nanchang, cities in southern China, during the second wave of the 2009-2010 pandemic. METHODOLOGY: Nasopharyngeal swabs were collected from 165 individuals with influenza-like illness (ILI) who presented to the hospitals in Shantou and Nanchang. Laboratory diagnosis and characterization was performed by real-time PCR, virus isolation in embryonated chicken eggs, and sequencing. RESULTS: pH1N1 activity was sustained in three different temporal patterns throughout the study period. The overall positivity rate of pH1N1 was 50% with major distribution among young adults between the ages of 13 and 30 years. High fever, cough, expectoration, chest pain, myalgia, nasal discharge and efficient viral replication were observed as major clinical markers whereas a substantial number of afebrile cases (17%) was also observed. Rate of hospitalization and disease severity (39%) and recovery (100%) were also high within the region. Furthermore, severe complications were likely to develop in young adults upon pH1N1 infection. Genetic characterization of the HA and NA genes of pH1N1 strains exhibited homogenous spread of pH1N1 strains with 99% identity with prototypic strains; however, minor unique mutations were also observed in the HA gene. CONCLUSION: The study illustrates the detailed characteristics of 2009 influenza pandemic in southern parts of China that might help to strategize preparedness for future pandemics and subsequent influenza seasons.