Agente etiológico: Vírus tipo A(H1N1), classificada como (A/CALIFORNIA/04/2009).
Transmissão: pessoa a pessoa, principalmente por meio da tosse ou espirro e secreções respiratórias de pessoas infectadas. Segundo a OMS, não há registro de transmissão desse novo subtipo por ingestão de carne suína e produtos derivados.
Período de incubação: 1 a 7 dias
Pandemias de Influenza no século 20 1957: “ Gripe Asi á tica ” A(H2N2) 1968: “ Gripe de Hong Kong ” A (H3N2) 25 a 100 milhões de mortes Credit: US National Museum of Health and Medicine 1-4 milhões de mortes 1-4 milhões de mortes 1918: “ Gripe espanhola ” A(H1N1) 2009:Gripe A confirmados 16.455 óbito s
According to WHO, the majority of 2009 H1N1 influenza isolates tested worldwide remain sensitive to oseltamivir, an antiviral medicine used to treat influenza disease. Worldwide, 220 2009 H1N1 isolates tested have been found to be resistant to oseltamivir – 54 of these isolates were detected in the United States. Resistência ao Oseltamivir
Plennevaux E et al. Immune response after a single vaccination against 2009 influenza A H1N1 in USA: A preliminary report of two randomised controlled phase 2 trials. Lancet 2010 Jan 2; 375:41.
Liang X-F et al. Safety and immunogenicity of 2009 pandemic influenza A H1N1 vaccines in China: A multicentre, double-blind, randomised, placebo-controlled trial. Lancet 2010 Jan 2; 375:56.
Vajo Z et al. Safety and immunogenicity of a 2009 pandemic influenza A H1N1 vaccine when administered alone or simultaneously with the seasonal influenza vaccine for the 2009–10 influenza season: A multicentre, randomised controlled trial. Lancet 2010 Jan 2; 375:49.
In a randomized U.S. study, 1300 healthy people received one of three formulations of H1N1 vaccine or placebo.
At baseline, 20% to 30% of adults and relatively few children had protective levels of H1N1 antibody; 21 days after vaccination, seroprotection rates were 92% to 100% in adults and 45% to 69% in children.
In Hungary, researchers randomized 355 adults without detectable H1N1 antibodies to receive single injections of a low-dose H1N1 vaccine, with or without simultaneous trivalent seasonal flu vaccination.
After 21 days, seropositivity rates were about 70% in both groups.
In the two placebo-controlled studies, seroprotection rates essentially were unchanged in placebo recipients, and low-dose immunizations generally were as effective as higher doses in all but the oldest adults.
In all three studies, adverse effects were mild and consisted primarily of injection-site tenderness and low-grade fevers.
Taken together, these studies suggest that various H1N1 vaccines, given according to current recommendations (1 dose for adults and 2 for children), are safe and effective and that a low-dose immunization strategy can optimize vaccine distribution without compromising efficacy.
Perhaps these reports will quell the skepticism and fear with which many patients have greeted the rapid deployment of these novel vaccines.
Journal Watch helps physicians and allied heath professionals save time and stay informed by providing brief, clearly written, clinically focused perspectives on the medical developments that affect practice.
Journal Watch is an independent, trustworthy source, from the publishers of the New England Journal of Medicine .
These slides were derived from Journal Watch General Medicine .
The best way to stay informed with Journal Watch , is through our alerts. To sign up, visit the My Alerts page .
During April 2009, novel pandemic A/H1N1 influenza virus began causing illness in the U.K. In this study, investigators used data from a mandatory reporting system, primary care surveillance networks, and a national phone- and Internet-based pandemic influenza service to estimate H1N1 incidence and influenza-associated mortality in England.
Between June 1 and November 8, 2009, an estimated 540,000 cases of H1N1 influenza occurred, and 138 confirmed deaths from H1N1 influenza were reported, for a case fatality rate of 26 per 100,000.
Incidence and case fatality rates, however, varied by age.
Children (age range, 5 to 14 years) had the highest estimated incidence rate and the lowest case fatality rate (11 per 100,000), whereas elders (age, ≥65) had the lowest estimated incidence rate and highest case fatality rate (980 per 100,000).
For infants and children (age, ≤14 years), adolescents (age range, 15–24), adults (age range, 25–64), and elders (age, ≥65), actual numbers of deaths were 29, 17, 66, and 26, respectively.
Among those who died, 88 (64%) had severe underlying diseases before contracting H1N1 influenza; 108 (78%) had been prescribed antiviral drugs (but only 26 received such drugs within the recommended 48 hours of symptom onset).
These data are entirely consistent with those reported from the U.S., including a higher incidence of H1N1 flu among children and a higher case fatality rate among elders (JW Gen Med Dec 31 2009).
However, this study casts no new light on whether early treatment of H1N1 flu patients with neuraminidase inhibitors (i.e., oseltamivir [Tamiflu] or zanamivir [Relenza]) prevents serious morbidity or flu-related mortality.
Quispe-Laime AM et al. H1N1 influenza A virus-associated acute lung injury: Response to combination oseltamivir and prolonged corticosteroid treatment. Intensive Care Med 2009 Nov 19; [e-pub ahead of print]. (http://dx.doi.org/10.1007/s00134-009-1727-6)
Patients with severe 2009 pandemic influenza A (H1N1) virus infections who present with pneumonia might develop acute respiratory distress syndrome (ARDS).
In a case series of 13 consecutive patients (mean age, 39) with suspected H1N1 influenza, severe hypoxia requiring ventilator support, and clinical sepsis, researchers prospectively evaluated response to treatment with a combination of oseltamivir and corticosteroids in addition to empiric antibiotics administered on admission to an intensive care unit (ICU) in Buenos Aires, Argentina.
Patients with severe ARDS received methylprednisolone (1 mg/kg/day), and other patients received hydrocortisone (300 mg/day) for an average of 21 days.
Most patients (62%) had vasopressor-dependent shock.
Steroids mitigate the inflammatory response that might be responsible for the high mortality from H1N1 influenza in young, otherwise healthy patients with strong immune systems who experience a cytokine storm.
The promising results of this small nonrandomized study suggest that adding low- to moderate-dose steroids to the treatment of critically ill patients with suspected H1N1 influenza might be beneficial.
However, such patients should be carefully monitored for deleterious effects of steroid treatment (i.e., hyperglycemia, GI bleeding, weakness, psychosis, aspergillosis, and avascular necrosis).
Other treatments for critically ill patients with H1N1 influenza include intravenous peramivir and extracorporeal membrane oxygenation (JW Infect Dis Nov 4 2009 and JW Emerg Med Nov 13 2009).
Pandemic 2009 Influenza A(H1N1) Virus Illness Among Pregnant Women in the United States
Alicia M. Siston, PhD; Sonja A. Rasmussen, MD; Margaret A. Honein, PhD; Alicia M. Fry, MD; Katherine Seib, BS; William M. Callaghan, MD; Janice Louie, MD; Timothy J. Doyle, MPH; Molly Crockett, MPH; Ruth Lynfield, MD; Zack Moore, MD; Caleb Wiedeman, MPH; Madhu Anand, MPH; Laura Tabony, MPH; Carrie F. Nielsen, PhD; Kirsten Waller, MD; Shannon Page, BS; Jeannie M. Thompson, MPH; Catherine Avery, CFNP; Chasisity Brown Springs, MSPH; Timothy Jones, MD; Jennifer L. Williams, MSN; Kim Newsome, MPH; Lyn Finelli, DrPH; Denise J. Jamieson, MD; for the Pandemic H1N1 Influenza in Pregnancy Working Group
De agosto a dezembro houve 280 casos novos em gestantes com 165 internamentos em UTI e 56 óbitos
Gestantes são 1% da população americana e representaram 5% dos óbitos por H1N1
Imunização e uso precoce do oseltamivir são essenciais para minimizar os riscos
Obstet Gynecol. 2010 Apr;115(4):711-6. Maternal and neonatal outcomes after antepartum treatment of influenza with antiviral medications. Greer LG, Sheffield JS, Rogers VL, Roberts SW, McIntire DD, Wendel GD Jr. University of Texas Southwestern Medical Center, Department of Obstetrics and Gynecology, Parkland Health and Hospital System, Dallas, Texas 75235-9032, USA. email@example.com Abstract OBJECTIVE: To review the maternal and neonatal outcomes after antepartum exposure to M2 ion channel inhibitors or oseltamivir to provide some guidance on the risk, if any, of antiviral medication during pregnancy. METHODS: This was a retrospective cohort study examining maternal and neonatal outcomes after antepartum exposure to antiviral therapy for influenza. We evaluated maternal characteristics, pregnancy outcomes, and fetal outcomes and compared them with our overall obstetric population.
RESULTS: Exposure to antiviral therapies (M2 ion channel inhibitors [n=104] compared with oseltamivir [n=135] compared with the control group [n=82,097]) during pregnancy was not associated with increased rates of preterm birth (7% compared with 10% compared with 6%, P=.190), premature rupture of membranes (23% compared with 16% compared with 22%, P=.154), gestational diabetes (4% compared with 8% compared with 6%, P=.388), or preeclampsia (6% compared with 1% compared with 4%, P=.209). Exposure was not associated with increased duration of hospital stay for mother or neonate. There were no differences in the incidence of minor malformations (19% compared with 15% compared with 22%, P=.101). Liveborn singletons without major malformations did not have differences in fetal weight (3,238+/-586 g compared with 3,281+/-642 g compared with 3,336+/-571 g, P=.186), need for intubation (2% compared with 0.8% compared with 1%, P=.552), intensive care nursery admission (3% compared with 3% compared with 2%, P=.418), or hyperbilirubinemia (12% compared with 9% compared with 8%, P=.282). Liveborn singletons had no grade 3 or 4 intraventricular hemorrhages, seizures, or neonatal deaths. Two preterm neonates exposed to different classes of medications had necrotizing enterocolitis (1.0% compared with 0.8% compared with 0.02%, P<.001). CONCLUSION: We found no evidence of an association between antepartum antiviral exposure and adverse outcomes. LEVEL OF EVIDENCE: II. PMID: 20308829 [PubMed - in process] Obstet Gynecol. 2010 Apr;115(4):711-6. Maternal and neonatal outcomes after antepartum treatment of influenza with antiviral medications .