Louisiana report on the two caseshttp://www.google.com/url?sa=t&rct=j&q= ... 77y-clZI0w
Two Reports of Human Infection with Swine Influenza A (H3N2) in Maine and Indiana
• Two reports of human infection with swine-origin triple-reassortant (tr) influenza A (H3N2) virus have been reported to CDC: one by the state of Maine and another by Indiana.
• These reports have been laboratory confirmed at CDC.
• Genetic sequencing indicated that the swine-origin viruses in both of these cases have the Matrix gene, or “M” gene, from the pandemic 2009 H1N1 (pH1N1) virus.
• These cases of swine-origin triple reassortant influenza are not epidemiologically linked and there is no indication of human-to-human transmission around either of these cases.
• Swine influenza A (H3N2) viruses normally infect pigs. These viruses rarely infect humans. However, human infections have occurred, usually following exposure to infected pigs.
• The patients in Maine and Indiana both reported exposure to pigs prior to illness onset.
• One patient has recovered from his illness, while the other patient continues to recover.
• These cases bring the number of human infections with swine-origin influenza viruses reported in the United States to 28 since December 2005, with 15 of these having been infected with swine-origin trH3N2 viruses and 7 of those 15 being the new triple reassortant H3N2 virus with the 2009 H1N1 M gene.
• This particular combination of gene segments was first identified in August 2011 in one patient from Indiana, and subsequently in three patients from Pennsylvania in September, and in one patient in Maine in October.
• The M gene plays a role in influenza virus infection, assembly and replication.
• The prevalence of this reassortant virus in swine is unknown.
• CDC is continuing to investigate the implications of this genetic change.
• In 2007, human infection with a novel influenza A virus became a nationally notifiable condition in the United States. Novel influenza A virus infections include all human infections with influenza A viruses that are different from currently circulating human influenza H1 and H3 viruses. These viruses include those that are subtyped as non-human in origin and those that are unsubtypable with standard methods and reagents.
• International Health Regulation (IHR) reports were submitted for both cases on October 31, 2011 per the World Health Organization (WHO) reporting requirements in the event of a human infection with a novel or animal-origin influenza virus.
• The IHR is an international legal instrument that is binding on 194 countries, including the United States.
• The goal of the IHR is to help the international community prevent and respond to public health risks with potential global impact.
• The IHR, which entered into force in June 2007, requires countries to report certain disease outbreaks and public health events, including any confirmed case of human infection with a novel influenza virus.
• These cases are reported in the November 4, 2011 FluView (http://www.cdc.gov/flu/weekly
) and additional information is provided in a “Have You Heard” update on the CDC website at http://www.cdc.gov/media/haveyouheard/s ... irus2.html
• Seasonal flu vaccine would not be expected to protect against these swine flu viruses because they are very different from seasonal human influenza A (H3N2) viruses.
• While there is no vaccine to protect humans against these swine–origin influenza viruses, there are two FDA–cleared drugs that can be used to treat illness with these viruses.
• CDC has provided a swine origin trH3N2 vaccine virus to manufacturers for them to begin vaccine production if it becomes necessary.
• The antiviral drugs oseltamivir and zanamivir – which are used to treat infection with human seasonal influenza viruses – also have shown activity against swine–origin influenza viruses.
• Genetic sequence information for these viruses has been posted to GISAID (http://www.gisaid.org/
• A male child became ill with influenza-like symptoms (fever, cough, chills and body aches) on October 22, 2011. The child continues to recover from his illness.
• The patient was seen by a local health care provider on October 24, 2011, where a respiratory specimen was collected and forwarded to the Maine Health and Environmental Testing Laboratory.
• The patient did not receive influenza antiviral medications.
• On October 28, 2011, diagnostic testing at the state laboratory was weakly positive for influenza A (H3), but negative for swine-origin influenza targets. The specimen was forwarded to CDC.
• On October 30, 2011, partial genome sequencing confirmed the virus as a swine-origin triple reassortant influenza A (H3N2) virus with the M gene from pH1N1.
• The patient reported multiple instances of close contact with pigs where sick pigs were present.
• No other ill persons have been identified at this time and no human-to-human transmission of this virus is suspected.
• An adult male developed fever, cough, shortness of breath, nausea, vomiting and body aches on October 20, 2011. The patient was hospitalized, but has been discharged and is recovered from his illness.
• The patient did not receive influenza antiviral medications.
• On October 22, 2011, a respiratory specimen was collected during hospital admission and after conflicting results were obtained at the hospital laboratory, the specimen was forwarded to the Indiana state public health laboratory.
• On October 28, 2011, testing at the Indiana public health laboratory indicated a likely swine-origin influenza A (H3) virus.
• The specimen was forwarded to CDC on October 29, 2011. On October 31, partial genome sequencing confirmed the virus as a swine-origin triple reassortant influenza A (H3N2) virus with the M gene from pH1N1.
• The patient reported exposure to pigs in the week prior to illness onset.
• No additional ill persons have been identified, but investigation is ongoing.
• There are no epidemiologic links between this case and the previous case identified in Indiana.
Human Infections with Swine-Origin Influenza Viruses
• Pigs are susceptible to swine, avian and human influenza viruses.
• Swine flu viruses do not normally infect humans. However, sporadic human infections with swine flu have occurred.
• Swine-origin triple reassortant influenza A (H3N2) viruses were first detected in North American swine herds in the late 1990s when swine likely became infected from contact with infected humans.
• Triple reassortant swine influenza A (H3N2) viruses commonly circulate in pigs in North America, but only rare cases of human infections with these viruses have been detected.
• Most commonly, cases of human infection with swine-origin influenza viruses occur in people who have been in close proximity to infected pigs.
• From 2005-2007, CDC received reports of approximately one human infection with a swine influenza virus every one to two years, but since 2007, about three to four cases have been reported per year; this increased reporting may partially be because human infection with novel influenza viruses became a nationally notifiable condition in 2007.
• Although the vast majority of instances of human infection with animal influenza viruses do not result in human-to-human transmission, these cases should be fully investigated to be sure that such viruses are not spreading among humans and to limit further exposure of humans to infected animals if infected animals are identified.
• CDC publicly reports human infections with novel influenza viruses in its FluView U.S. Weekly Influenza Surveillance Report.
Acquisition of the “M” Gene into Swine-Origin trH3N2 Influenza Viruses in Humans
• Genetic sequencing of swine-origin H3N2 influenza viruses from Indiana, Pennsylvania, and Maine indicates that these viruses have acquired the “M” gene from the 2009 H1N1 virus.
• The M gene encodes two proteins, which play a role in the structure, replication and maturation of influenza A viruses.
• The significance of this genetic variation is uncertain.
Swine Influenza, General
• Swine Influenza (swine flu) is a respiratory disease of pigs caused by type A influenza virus that regularly causes outbreaks of influenza in pigs. Swine flu viruses can cause high levels of illness and low death rates in pigs. Swine influenza viruses may circulate among swine throughout the year, but most outbreaks occur during the late fall and winter months similar to outbreaks in humans.
• There are four main influenza type A virus subtypes that have been isolated in pigs: H1N1, H1N2, H3N2, and H3N1. Most flu viruses circulating in pigs are referred to as triple reassortant viruses because these flu viruses contain genes from human, swine and avian influenza viruses.
• Swine influenza viruses are not transmitted to humans by food. Humans cannot get swine influenza by eating or handling pork or pork products.
• For more information about swine influenza, see “Background Information on Influenza in Pigs” at http://www.cdc.gov/flu/swineflu
The above report is from the Nov 4 key points published by the Louisiana Department of Health and Hospitals