Detection of oseltamivir-resistant pandemic influenza A(H1N1)pdm2009 in Brazil: can community transmission be ruled out?
Although surveillance efforts that monitor the emergence of drug-resistant strains of influenza are critical, systematic analysis is overlooked in most developing countries. We report on the occurrence of strains of pandemic influenza A(H1N1)pdm09 with resistance and decreased susceptibility to oseltamivir (OST) in Brazil in 2009, 2011 and 2012. We found 7 mutant viruses, 2 with the mutation S247N and other 5 with the mutation H275Y. Most of these viruses were from samples concentrated in the southern region of Brazil. Some of these resistant viruses were detected prior to the initiation of OST treatment, suggesting that community transmission of mutant viruses may exist. Moreover, we show that one of these OST-resistant (H275Y) strains of A(H1N1)pdm09 was discovered in the tri-border region between Brazil, Argentina and Paraguay, highlighting that this strain could also be found in other Latin American countries. Our findings reinforce the importance of enhanced antiviral resistance surveillance in Brazil and in other Latin American countries to confirm or rule out the community transmission of OST-resistant strains of A(H1N1)pdm09.
Laboratório de Vírus Respiratórios e do Sarampo, Instituto Oswaldo Cruz/Fiocruz, Rio de Janeiro, Rio de Janeiro, Brazil.
Thiago Moreno L
TM
Souza
Paola C
PC
Resende
Natalia
N
Fintelman-Rodrigues
Tatiana Schaffer
TS
Gregianini
Nilo
N
Ikuta
Sandra Bianchini
SB
Fernandes
Ana Luisa Furtado
AL
Cury
Maria do Carmo Debur
Mdo C
Rosa
Marilda M
MM
Siqueira
D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D000998:Antiviral Agents / Q000627:therapeutic use; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D004285:Dogs; D024882:Drug Resistance, Viral / Q000187:drug effects / Q000235:genetics*; D062665:Epidemiological Monitoring; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics* / Q000302:isolation & purification; D007251:Influenza, Human / Q000188:drug therapy / Q000453:epidemiology / Q000635:transmission* / Q000821:virology; D061985:Madin Darby Canine Kidney Cells; D008875:Middle Aged; D009154:Mutation; D009439:Neuraminidase / Q000037:antagonists & inhibitors / Q000235:genetics*; D053139:Oseltamivir / Q000627:therapeutic use; D014764:Viral Proteins / Q000037:antagonists & inhibitors / Q000235:genetics*
D000998:Antiviral Agents; D014764:Viral Proteins; D053139:Oseltamivir; D009439:Neuraminidase