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PostPosted: Fri Sep 02, 2011 2:21 pm 
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This report describes two cases of febrile respiratory illness caused by swine-origin influenza A (H3N2) viruses identified on August 19 and August 26, 2011, and the current investigations. No epidemiologic link between the two cases has been identified, and although investigations are ongoing, no additional confirmed human infections with this virus have been detected.

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PostPosted: Fri Sep 02, 2011 2:25 pm 
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Swine-Origin Influenza A (H3N2) Virus Infection in Two Children --- Indiana and Pennsylvania, July--August 2011
Early Release
September 2, 2011 / 60(Early Release);1-4


Influenza A viruses are endemic in many animal species, including humans, swine, and wild birds, and sporadic cases of transmission of influenza A viruses between humans and animals do occur, including human infections with avian-origin influenza A viruses (i.e., H5N1 and H7N7) and swine-origin influenza A viruses (i.e., H1N1, H1N2, and H3N2) (1). Genetic analysis can distinguish animal origin influenza viruses from the seasonal human influenza viruses that circulate widely and cause annual epidemics. This report describes two cases of febrile respiratory illness caused by swine-origin influenza A (H3N2) viruses identified on August 19 and August 26, 2011, and the current investigations. No epidemiologic link between the two cases has been identified, and although investigations are ongoing, no additional confirmed human infections with this virus have been detected. These viruses are similar to eight other swine-origin influenza A (H3N2) viruses identified from previous human infections over the past 2 years, but are unique in that one of the eight gene segments (matrix [M] gene) is from the 2009 influenza A (H1N1) virus. The acquisition of the M gene in these two swine-origin influenza A (H3N2) viruses indicates that they are "reassortants" because they contain genes of the swine-origin influenza A (H3N2) virus circulating in North American pigs since 1998 (2) and the 2009 influenza A (H1N1) virus that might have been transmitted to pigs from humans during the 2009 H1N1 pandemic. However, reassortments of the 2009 influenza A (H1N1) virus with other swine influenza A viruses have been reported previously in swine (3). Clinicians who suspect influenza virus infection in humans with recent exposure to swine should obtain a nasopharyngeal swab from the patient for timely diagnosis at a state public health laboratory and consider empiric neuraminidase inhibitor antiviral treatment to quickly limit potential human transmission (4).

Case Reports
Patient A. On August 17, 2011, CDC was notified by the Indiana State Department of Health Laboratories of a suspected case of swine-origin influenza A (H3N2) infection in a boy aged <5 years. The boy, who had received influenza vaccine in September 2010, experienced onset of fever, cough, shortness of breath, diarrhea, and sore throat on July 23, 2011. He was brought to a local emergency department (ED) where a respiratory specimen later tested positive for influenza A (H3). The boy was discharged home, but was not treated with influenza antiviral medications. He has multiple chronic health conditions, returned to the ED on July 24, 2011, and was hospitalized for treatment of those health problems, which had worsened. The boy was discharged home on July 27, 2011, and has since recovered from this illness. As part of routine CDC-supported influenza surveillance, the respiratory specimen collected on July 24, 2011, was forwarded to the Indiana State Department of Health Laboratories, where polymerase chain reaction (PCR) testing identified a suspect swine-origin influenza A (H3N2) virus on August 17, 2011. The specimen was forwarded to CDC where the findings were confirmed through genome sequencing on August 19, 2011.

No direct exposure to swine was identified for this child; however, a caretaker reported direct contact with asymptomatic swine in the weeks before the boy's illness onset and provided care to the child 2 days before illness onset. No respiratory illness was identified in any of the child's family or close contacts, the boy's caretaker, or in the family or contacts of the caretaker.

Patient B. On August 24, 2011, CDC was notified by the Pennsylvania Department of Health of a suspected case of swine-origin influenza A (H3N2) virus infection in a girl aged <5 years. The girl, who had received influenza vaccine in September 2010, experienced acute onset of fever, nonproductive cough, and lethargy on August 20, 2011. She was brought to a local hospital ED where a nasopharyngeal swab tested positive for influenza A by rapid influenza diagnostic test. She was not treated with influenza antiviral medications and was discharged home the same day. The girl has completely recovered from this illness.

A nasopharyngeal swab and nasal wash specimen were obtained at the ED and forwarded to the Pennsylvania State Department of Health Bureau of Laboratories for additional testing as part of routine CDC-supported influenza surveillance. On August 23, 2011, the state public health laboratory identified a suspected swine-origin influenza A (H3N2) virus by PCR testing, and both specimens were forwarded to CDC. On August 26, 2011, genome sequencing confirmed the virus as swine-origin influenza A (H3N2). On August 16, 2011, the girl was reported to have visited an agricultural fair where she had direct exposure to swine and other animals. No additional illness in the girl's family or close contacts has been identified, but illness in other fair attendees continues to be investigated. No additional confirmed swine-origin influenza virus infections have been identified thus far.

Epidemiologic and Laboratory Investigations
As of September 2, 2011, no epidemiologic link between patients A and B had been identified, and no additional cases of confirmed infection with the identified strain of swine-origin influenza A (H3N2) virus had been identified. Surveillance data from both states showed low levels of influenza activity at the time of both patients' illnesses. Case and contact investigations by the county and state human and animal health agencies in Indiana and Pennsylvania are ongoing, and enhanced surveillance for additional human cases is being implemented in both states.

Preliminary genetic characterization of these two influenza viruses has identified them as swine-origin influenza A (H3N2) viruses. Full genome sequences have been posted to publicly available web sites. The viruses are similar, but not identical to each other. Seven of the eight gene segments, including the hemagglutinin (HA) and neuraminidase (NA) genes, are similar to those of swine H3N2 influenza viruses circulating among U.S. pigs since 1998 (2) and previously identified in the eight other sporadic cases of human infection with swine-origin influenza A (H3N2) viruses in the United States since 2009.* The one notable difference from the viruses previously identified in human infections with swine-origin influenza A (H3N2) virus is that these two viruses have a matrix (M) gene acquired from the 2009 influenza A (H1N1) virus, replacing the classical swine M gene present in the prior eight swine-origin influenza A (H3N2) virus infections in humans.

Although reassortment between swine influenza and 2009 influenza A (H1N1) viruses has been reported in pigs in the United States (3), this particular genetic combination of swine influenza virus segments is unique and has not been reported previously in either swine or humans, based on a review of influenza genomic sequences publicly available in GenBank.† Analysis of data submitted to GenBank via the U.S. Department of Agriculture (USDA) Swine Influenza Virus Surveillance Program subsequent to this case identified two additional influenza A (H3N2) isolates from swine containing the M gene from the 2009 influenza A (H1N1) virus. Genome sequencing is underway to completely characterize the genetic composition of these two swine influenza isolates. (USDA Agricultural Research Service and USDA Animal and Plant Health Inspection Service, unpublished data, 2011).

The viruses in these two patients are resistant to amantadine and rimantadine, but are susceptible to the neuraminidase inhibitor drugs oseltamivir and zanamivir. Because these viruses carry a unique combination of genes, no information currently is available regarding the capacity of this virus to transmit efficiently in swine, humans, or between swine and humans.

Reported by
Kumar Nalluswami, MD, Atmaram Nambiar, MD, Perrianne Lurie, MD, Maria Moll, MD, James Lute, PhD, Owen Simwale, MPH, Erica Smith, MPH, Larry Sundberg, MPH, Brian Seiler, Stephen Swanson, Pennsylvania Dept of Health; Nanette Hanshaw, DVM, Craig Shultz, DVM, Erin Moore, DVM, Pennsylvania Dept of Agriculture. Shawn Richards, Mark Glazier, Katie Masterson, Lyndsey Hensler, MS, Indiana State Dept of Health; Cheryl Miller, DVM, Melissa Justice, DVM, Indiana Board of Animal Health. Swine Influenza Virus Team, US Dept of Agriculture. Scott Epperson, MPH, Lynnette Brammer, MPH, Lyn Finelli, DrPH, Susan Trock, DVM, Michael Jhung, MD, Joseph Bresee, MD, Stephen Lindstrom, PhD, Alexander Klimov, PhD, Daniel Jernigan, MD, Nancy Cox, PhD, Influenza Div, National Center for Immunization and Respiratory Diseases; Jeffrey Miller, MD, Div of Applied Sciences, Office of Surveillance, Epidemiology, and Laboratory Services, CDC. Corresponding Contributor: Scott Epperson, sepperson@cdc.gov, 404-639-3747.

Editorial Note
To detect human infections with animal influenza viruses more effectively, CDC and state and local health departments have strengthened laboratory and epidemiologic procedures to promptly detect sporadic cases such as these. Since 2005, state public health laboratories have had the capability to detect non-human origin--influenza A viruses by PCR testing. From 2005 to 2007, CDC received reports of approximately one human infection with a swine-origin influenza virus each year. In 2007, human infection with a novel influenza A virus, including swine-origin influenza virus infections, became a nationally notifiable condition. Since that time, CDC has received approximately three to five reports a year of human infections with swine-origin influenza viruses. The recent increase in reporting might be, in part, a result of increased influenza testing capabilities in public health laboratories that allows for identification of human and swine-origin influenza viruses, but genetic changes in swine influenza viruses and other factors also might be contributing to this increase (5--7). During December 2005--November 2010, before the two cases described in this report, 21 cases of human infection with swine-origin influenza were reported (12 cases with swine-origin influenza A (H1N1) virus infection, eight cases with swine-origin influenza A (H3N2) virus infection, and one case with swine-origin influenza A (H1N2) virus infection). Six of these 21 cases occurred in patients who reported direct exposure to pigs; 12 patients reported being near pigs; human-to-human transmission was suspected in two cases after epidemiologic investigations revealed no reported contact with swine in either case, but contact with ill persons who reported swine exposure was the suspected source of infection; the exposure in one case was unknown (8) (CDC, unpublished data; 2011). Although the vast majority of human infections with animal influenza viruses do not result in human-to-human transmission (9,10), each case should be investigated fully to ascertain whether these viruses are transmitted among humans and to limit further exposure of humans to infected animals, if infected animals are identified. Such investigations require close collaboration between CDC, state and local public health officials, and animal health officials.

The lack of known direct exposure to pigs in one of the two cases described in this report suggests the possibility that limited human-to-human transmission of this influenza virus occurred. Likely transmission of swine-origin influenza A (H3N2) virus from close contact with an infected person has been observed in past investigations of human infections with swine-origin influenza A virus, but has not resulted in sustained human-to-human transmission. Preliminary evidence from the investigation of the Indiana case shows no ongoing transmission. No influenza illness has been identified, but if additional chains of transmission are identified rapid intervention is warranted try to prevent further spread of the virus. Clinicians should consider swine-origin influenza A virus infection as well as seasonal influenza virus infections in the differential diagnosis of patients with febrile respiratory illness who have been near pigs. Clinicians who suspect influenza virus infection in humans with recent exposure to swine, should obtain a nasopharyngeal swab from the patient, place the swab in a viral transport medium, contact their state or local health department to facilitate transport and timely diagnosis at a state public health laboratory, and consider empiric neuraminidase inhibitor antiviral treatment (4). CDC requests that state public health laboratories send all suspected swine-origin influenza A specimens to the CDC, Influenza Division, Virus Surveillance and Diagnostics Branch Laboratory.

References
1.Wright PF, Neumann G, Kawaoka Y. Orthomyxoviruses. In: Knipe DM, Howley PM, eds. Fields virology. Vol. 2. 5th ed. Philadelphia, PA: Lippincott, Williams, and Wilkins; 2007:1692--740.
2.Vincent AL, Ma W, Lager KM, Janke BH, Richt JA. Swine influenza viruses: a North American perspective. Adv Virus Res 2008;72:127--54.
3.Duchatez MF, Hause B, Stigger-Rosser E, et al. Multiple reassortment between pandemic (H1N1) 2009 and endemic influenza viruses in pigs, United States. Emerg Infect Dis 2011;17:1624--9.
4.CDC. Antiviral agents for the treatment and chemoprophylaxis of influenza: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR 2011;60(No. RR-1).
5.Vincent AL, Ma W, Lager KM, Janke BH, Richt JA. Swine influenza viruses: a North American perspective. Adv Virus Res 2008;72:127--54.
6.Vincent AL, Swenson SL, Lager KM, Gauger PC, Loiacono C, Zhang Y. Characterization of an influenza A virus isolated from pigs during an outbreak of respiratory disease in swine and people during a county fair in the United States. Vet Microbiol 2009;137:51--9.
7.Newman AP, Reisdorf E, Beinemann J, et al. Human case of swine influenza A (H1N1) triple reassortant virus infection, Wisconsin. Emerg Infect Dis 2008;14:1470--2.
8.Shinde V, Bridges CB, Uyeki TM, et al. Triple reassortant swine influenza A (H1) in humans in the United States, 2005--2009. N Engl J Med 2009;25:2616--25.
9.Myers KP, Olsen CW, Gray GC. Cases of swine influenza in humans: a review of the literature. Clin Infect Dis 2007;44:1084--8.
10.Wells DL, Hopfensperger DJ, Arden NH, et al. Swine influenza virus infections. Transmission from ill pigs to humans at a Wisconsin agricultural fair and subsequent probable person-to-person transmission. JAMA 1991;265:478--81.


* Additional information is available at http://www.cdc.gov/flu/weekly/pastreports.htm.

† Available at http://www.ncbi.nlm.nih.gov/Genbank.



What is already known on this topic?

During December 2005--November 2010, 21 cases of human infection with swine-origin influenza were reported, including 12 cases with swine-origin influenza A (H1N1) virus infection, eight cases with swine-origin influenza A (H3N2) virus infection, and one case with swine-origin influenza A (H1N2) virus infection.

What is added by this report?

This report describes two cases of febrile respiratory illness caused by swine-origin influenza A (H3N2) viruses identified on August 19 and August 26, 2011. The viruses identified in these cases are unique in that one of the eight gene segments (matrix [M] gene) is from the 2009 influenza A (H1N1) virus.

What are the implications for public health practice?

Non-human influenza virus infections rarely result in human-to-human transmission, but the implications of sustained ongoing transmission between humans is potentially severe; therefore, prompt and thorough identification and investigation of these sporadic human infections with non-human influenza viruses are needed to reduce the risk for sustained transmission.

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PostPosted: Fri Sep 02, 2011 2:26 pm 
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HARRISBURG, Pa., Sept. 2, 2011 /PRNewswire-USNewswire/ -- The Pennsylvania Department of Health is advising the public of an investigation into a human case of novel influenza A virus in Pennsylvania and is urging the public to take everyday precautions to prevent the spread of respiratory viruses.

The case involves a child who has fully recovered from the illness. No additional human infections with this virus have been identified to date.

Influenza viruses are commonly found in humans, swine, birds and other animals. The case in Pennsylvania is similar to previous, rare human infections with swine-origin H3N2 viruses, but is unique in that it contains a genetic component of the H1N1 virus.

"At this time, with only one case of this kind identified in Pennsylvania, we cannot yet say there is a significant risk to public health," said Pennsylvania Department of Health Secretary Dr. Eli Avila. "However, it is something that we are taking very seriously and actively investigating."

The virus was identified quickly through collaboration between a local hospital, Pennsylvania Department of Health's Bureaus of Laboratories and Epidemiology and the Centers for Disease Control and Prevention (CDC). It is genetically similar to a case identified in Indiana earlier this year, although no link has been identified between the two cases. The Centers for Disease Control and Prevention included the two cases in a Morbidity and Mortality Weekly Report, issued online today.

Symptoms experienced in the patient in Pennsylvania were similar to that of seasonal influenza, and included fever, lethargy, lack of appetite and coughing. Other influenza symptoms may also include a runny nose, sore throat, eye irritation, nausea, vomiting and diarrhea.

As the investigation into the case continues, the Pennsylvania Department of Health reminds residents to take everyday preventative actions, including:
•Covering the nose and mouth with a tissue when coughing or sneezing or sneezing into your sleeve or elbow if you do not have a tissue;
•Washing your hands often with soap and water for at least 20 seconds, especially after you cough or sneeze, or using an alcohol-based hand cleaner; and
•Staying home from work, school, and social gatherings if you have flu-like and feverish symptoms to help prevent others from catching your illness.


If you or your children become ill with symptoms of influenza, the Pennsylvania Department of Health recommends you contact your health care provider.

For more information about influenza, visit www.health.state.pa.us or www.flufreepa.com.

Media contacts:
Christine Cronkright or Brandi Hunter-Davenport, Pa. Department of Health; 717-787-1783
Tom Skinner, Centers for Disease Control and Prevention; 404-639-3286


SOURCE Pennsylvania Department of Health


http://www.prnewswire.com/news-releases ... 10723.html

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PostPosted: Fri Sep 02, 2011 2:28 pm 
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http://www.recombinomics.com/News/09021 ... Match.html

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PostPosted: Fri Sep 02, 2011 2:51 pm 
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New flu virus infects two U.S. children, CDC reports
By Rob Stein, Friday, September 2, 2:09 PM
Two U.S. children were infected with a previously unknown flu virus that apparently formed when a pig influenza virus picked up a gene from the strain that caused the swine flu pandemic in 2009, federal health officials reported Friday.

Both of the children recovered, however, and there is no evidence that the virus is spreading easily among people, meaning that it does not appear to pose a threat of becoming a significant public health concern, officials said.

We want people to be aware of these things and we want physicians to be aware,” said Lyn Finelli, chief of surveillance and response at the federal Centers for Disease Control and Prevention’s Influenza Division. “But we don’t think that these cases in themselves are alarming.”

Both children are 2 years old and both apparently were infected by exposure to pigs at county fairs. In one, case, a boy in Indiana was apparently infected by a “caretaker” who had been showing pigs at a county fair a few days before the boy became ill, Finelli said. In the other, a girl in Pennsylvania appears to be have been infected when she went to a county fair and petting zoo, she said. No one else, including family members of the two children, appear to have become infected.

“We see four or five of these cases every year. They are commonly reported during times of state fairs and county fairs when there is more contact between people and pigs,” Finelli said. “These infections are similar to those that have been reported before.”

The Indiana boy developed a fever, cough, shortness of breath and diarrhea on July 23. Because he had other chronic health problems, he was hospitalized the next day, but returned home three days later and completely recovered. The Pennsylvania girl developed fever, a cough and fatigue on Aug. 20. She was treated at a local hospital but sent home and recovered.

Samples from both children were sent to state laboratories, which determined they were unusual and sent them to the CDC for further analysis. CDC scientists found the viruses were a strain known as H3N2, but had picked up a so-called M or “matrix” gene from the 2009 H1N1 virus that caused the 2009-2010 swine flu pandemic.

Flu viruses commonly pick up genes from one another when different strains infect the same person or animal. Such “reassortment” events can be a concern when the mix produces a strain that may be more easily spread, cause more serious illness or to which people have little immunity. Twenty-three such novel flu viruses have been detected since 2004, when state laboratories were beefed up to look for them more aggressively to try to identify the next potential pandemic quickly, Finelli said.

“This does point out how successful the surveillance is. States are recognizing unusual cases,” said Michael Shaw, the associate director of laboratory surveillance in the CDC’s influenza division.

Although neither last year’s or this year’s flu vaccines would protect against the new strain, federal health officials are not concerned because similar viruses have circulated among people as recently as the early 1990s, meaning most people would have some immunity against it.

“All the major pandemics of the past were instances where a totally new ... type of virus had appeared--something the human population had little or no immunity to, which allowed it to spread very quickly,” Shaw said.

In this case, that does not appear to be the case. By the time the first H1N1 pandemic cases were reported, the virus had already spread widely in Mexico, Finelli noted.

“There’s no evidence there’s more influenza than normal in these areas so we think it’s very different,” Finelli said. “When we first heard about the first pandemic case we had heard about a lot cases. We had a reasonable suspicion that there was a lot of influenza illness out there. We don’t see that background of influenza illness here. We don’t think this virus is being transmitted from person to person in a very significant way.”

http://www.washingtonpost.com/national/ ... story.html

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PostPosted: Fri Sep 02, 2011 3:33 pm 
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Commentary

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PostPosted: Fri Sep 02, 2011 6:09 pm 
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2 flu cases transmitted from pigs
You may remember "swine flu" as the 2009 H1N1 virus, which sent people out for hand sanitizer in droves and avoiding anyone who was coughing and sneezing. No one actually caught it from a pig; it's transmitted from person to person. But on Friday, the Centers for Disease Control and Prevention reports on two children who were indeed sickened by a flu virus that originated from pigs.

The CDC report "describes two cases of febrile respiratory illness caused by swine-origin influenza A (H3N2) viruses identified on August 19 and August 26." Researchers also discovered that the virus that sickened the children had a genetic component of the 2009 H1N1 flu virus that was incorrectly tagged as a swine flu. Transmission of the flu from pigs to humans is rare, but it does happen.

Don't panic, though: CDC officials say that this is a rare occurrence and that the virus is not at all likely to spread.

"It’s a biological freak. It is not a harbinger of things to come," said Dr. William Schaffner, professor and chairman of the Department of Preventive Medicine at Vanderbilt University School of Medicine.

In Indiana, a 5-year-old boy who had gotten an influenza vaccine in September started showing unusual symptoms in July: fever, cough, diarrhea, sore throat and shortness of breath. He went to a local emergency department and was discharged but returned the following day, when he was hospitalized for treatment of multiple chronic health conditions that had gotten worse. He tested positive for a swine-origin influenza A virus and has since recovered.

Although the boy hadn't had direct contact with a pig, one of his caretakers reportedly did have direct contact with swine who didn't show flu symptoms in the weeks before the boy had gotten sick. But the child's family, caretaker and other close contacts did not get sick, according to the report.

In Pennsylvania, a girl younger than 5 who had visited an agricultural fair August 16, when she had direct exposure to pigs and other animals, came down with a fever, nonproductive cough and lethargy four days later. She had also received a flu vaccine in September.

It does not appear that either child transmitted the virus to anyone else. Scientists have not found any link between the two patients. The influenza viruses they had are similar but not identical and carry a unique genetic combination never seen before. It includes bits of genetic material from the 2009 H1N1 virus, which is itself a recombination of material from other types of flu. This is not surprising: Reassortment of genetic materials from the 2009 flu virus and other swine flu viruses has been seen before, according to the report.

"We think the impact will be very marginal. There's no evidence that these viruses are spreading," Schaffner said.

There have been about 22 human cases since 2005 of influenza that originated from pigs, CDC officials said.

"These events occur rarely and are now being detected with greater frequency because we have this incredible laboratory capacity to actually diagnose these sorts of infections, which we didn't have years ago," Schaffner said.

Rather than worrying about such rare pig-human transmission events, adults and children over 6 months old should get flu vaccines to protect against more common forms of influenza in humans. A single shot now protects against standard flu and the 2009 H1N1 virus (although children 6 months to 9 years of age need two doses four or more weeks apart during their first season of vaccination.) Here's more from the CDC on flu and children.

http://thechart.blogs.cnn.com/2011/09/0 ... from-pigs/

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PostPosted: Fri Sep 02, 2011 8:45 pm 
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INFLUENZA (51): SWINE-ORIGIN H3N2 REASSORTANT, CHILDREN
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Date: Fri 2 Sep 2011
Source: MMWR Morb Mortal Wkly Rep 2011; 60(early release): 1-4
[abridged, edited]
<http://www.cdc.gov/mmwr/preview/mmwrhtml/mm60e0902a1.htm?s_cid=mm60e0902a1_e&source=govdelivery>


Swine-origin influenza A (H3N2) virus infection in 2 children
-------------------------------------------------------------
Influenza A viruses are endemic in many animal species, including
humans, swine, and wild birds, and sporadic cases of transmission of
influenza A viruses between humans and animals do occur, including
human infections with avian-origin influenza A viruses (that is, H5N1
and H7N7) and swine-origin influenza A viruses (that is, H1N1, H1N2,
and H3N2) (1). Genetic analysis can distinguish animal origin
influenza viruses from the seasonal human influenza viruses that
circulate widely and cause annual epidemics. This report describes 2
cases of febrile respiratory illness caused by swine-origin influenza
A (H3N2) viruses identified on 19 Aug 2011 and 26 Aug 2011, and the
current investigations. No epidemiologic link between the 2 cases has
been identified, and although investigations are ongoing, no
additional confirmed human infections with this virus have been
detected. These viruses are similar to 8 other swine-origin influenza
A (H3N2) viruses identified from previous human infections over the
past 2 years, but are unique in that one of the 8 gene segments
(matrix [M] gene) is from the 2009 influenza A (H1N1) virus. The
acquisition of the M gene in these 2 swine-origin influenza A (H3N2)
viruses indicates that they are "reassortants" because they contain
genes of the swine-origin influenza A (H3N2) virus circulating in
North American pigs since 1998 (2) and the 2009 influenza A (H1N1)
virus that might have been transmitted to pigs from humans during the
2009 H1N1 pandemic. However, reassortments of the 2009 influenza A
(H1N1) virus with other swine influenza A viruses have been reported
previously in swine (3). Clinicians who suspect influenza virus
infection in humans with recent exposure to swine should obtain a
nasopharyngeal swab from the patient for timely diagnosis at a state
public health laboratory and consider empiric neuraminidase inhibitor
antiviral treatment to quickly limit potential human transmission
(4).

Case reports
------------
Patient A -- On 17 Aug 2011, the United States Centers for Disease
Control and Prevention [CDC] was notified by the Indiana State
Department of Health Laboratories of a suspected case of swine-origin
influenza A (H3N2) infection in a boy aged <5 years. The boy, who had
received influenza vaccine in September 2010, experienced onset of
fever, cough, shortness of breath, diarrhea, and sore throat on 23 Jul
2011. He was brought to a local emergency department (ED) where a
respiratory specimen later tested positive for influenza A (H3). The
boy was discharged home, but was not treated with influenza antiviral
medications. He has multiple chronic health conditions, returned to
the ED on 24 Jul 2011, and was hospitalized for treatment of those
health problems, which had worsened. The boy was discharged home on 27
Jul 2011, and has since recovered from this illness. As part of
routine CDC-supported influenza surveillance, the respiratory specimen
collected on 24 Jul 2011, was forwarded to the Indiana State
Department of Health Laboratories, where polymerase chain reaction
(PCR) testing identified a suspect swine-origin influenza A (H3N2)
virus on 17 Aug 2011. The specimen was forwarded to CDC where the
findings were confirmed through genome sequencing on 19 Aug 2011.

No direct exposure to swine was identified for this child; however, a
caretaker reported direct contact with asymptomatic swine in the weeks
before the boy's illness onset and provided care to the child 2 days
before illness onset. No respiratory illness was identified in any of
the child's family or close contacts, the boy's caretaker, or in the
family or contacts of the caretaker.

Patient B -- On 24 Aug 2011, CDC was notified by the Pennsylvania
Department of Health of a suspected case of swine-origin influenza A
(H3N2) virus infection in a girl aged <5 years. The girl, who had
received influenza vaccine in September 2010, experienced acute onset
of fever, nonproductive cough, and lethargy on 20 Aug 2011. She was
brought to a local hospital ED where a nasopharyngeal swab tested
positive for influenza A by rapid influenza diagnostic test. She was
not treated with influenza antiviral medications and was discharged
home the same day. The girl has completely recovered from this
illness.

A nasopharyngeal swab and nasal wash specimen were obtained at the ED
and forwarded to the Pennsylvania State Department of Health Bureau of
Laboratories for additional testing as part of routine CDC-supported
influenza surveillance. On 29 Aug 2011, the state public health
laboratory identified a suspected swine-origin influenza A (H3N2)
virus by PCR testing, and both specimens were forwarded to CDC. On 26
Aug 2011, genome sequencing confirmed the virus as swine-origin
influenza A (H3N2). On 16 Aug 2011, the girl was reported to have
visited an agricultural fair where she had direct exposure to swine
and other animals. No additional illness in the girl's family or close
contacts has been identified, but illness in other fair attendees
continues to be investigated. No additional confirmed swine-origin
influenza virus infections have been identified thus far.

Epidemiologic and laboratory investigations
-------------------------------------------
As of 2 Sep 2011, no epidemiologic link between patients A and B had
been identified, and no additional cases of confirmed infection with
the identified strain of swine-origin influenza A (H3N2) virus had
been identified. Surveillance data from both states showed low levels
of influenza activity at the time of both patients' illnesses. Case
and contact investigations by the county and state human and animal
health agencies in Indiana and Pennsylvania are ongoing, and enhanced
surveillance for additional human cases is being implemented in both
states.

Preliminary genetic characterization of these 2 influenza viruses has
identified them as swine-origin influenza A (H3N2) viruses. Full
genome sequences have been posted to publicly available Web sites. The
viruses are similar, but not identical to each other. 7 of the 8 gene
segments, including the hemagglutinin (HA) and neuraminidase (NA)
genes, are similar to those of swine H3N2 influenza viruses
circulating among U.S. pigs since 1998 (2) and previously identified
in the 8 other sporadic cases of human infection with swine-origin
influenza A (H3N2) viruses in the United States since 2009 [Additional
information is available at
<http://www.cdc.gov/flu/weekly/pastreports.htm>]. The one notable
difference from the viruses previously identified in human infections
with swine-origin influenza A (H3N2) virus is that these 2 viruses
have a matrix (M) gene acquired from the 2009 influenza A (H1N1)
virus, replacing the classical swine M gene present in the prior 8
swine-origin influenza A (H3N2) virus infections in humans.

Although reassortment between swine influenza and 2009 influenza A
(H1N1) viruses has been reported in pigs in the United States (3),
this particular genetic combination of swine influenza virus segments
is unique and has not been reported previously in either swine or
humans, based on a review of influenza genomic sequences publicly
available in GenBank. Analysis of data submitted to GenBank via the US
Department of Agriculture (USDA) Swine Influenza Virus Surveillance
Program subsequent to this case identified 2 additional influenza A
(H3N2) isolates from swine containing the M gene from the 2009
influenza A (H1N1) virus. Genome sequencing is under way to completely
characterize the genetic composition of these 2 swine influenza
isolates. (USDA Agricultural Research Service and USDA Animal and
Plant Health Inspection Service, unpublished data, 2011).

The viruses in these 2 patients are resistant to amantadine and
rimantadine, but are susceptible to the neuraminidase inhibitor drugs
oseltamivir and zanamivir. Because these viruses carry a unique
combination of genes, no information currently is available regarding
the capacity of this virus to transmit efficiently in swine, humans,
or between swine and humans.

MMWR editorial note
-------------------
From 2005 to 2007, CDC received reports of about one human infection
with a swine-origin influenza virus each year. In 2007, human
infection with a novel influenza A virus, including swine-origin
influenza virus infections, became a nationally notifiable condition.
Since that time, CDC has received about 3 to 5 reports a year of human
infections with swine-origin influenza viruses. The recent increase in
reporting might be, in part, a result of increased influenza testing
capabilities in public health laboratories that allows for
identification of human and swine-origin influenza viruses, but
genetic changes in swine influenza viruses and other factors also
might be contributing to this increase (5--7). During December
2005--November 2010, before the 2 cases described in this report, 21
cases of human infection with swine-origin influenza were reported (12
cases with swine-origin influenza A (H1N1) virus infection, 8 cases
with swine-origin influenza A (H3N2) virus infection, and one case
with swine-origin influenza A (H1N2) virus infection). 6 of these 21
cases occurred in patients who reported direct exposure to pigs; 12
patients reported being near pigs; human-to-human transmission was
suspected in 2 cases after epidemiologic investigations revealed no
reported contact with swine in either case, but contact with ill
persons who reported swine exposure was the suspected source of
infection; the exposure in one case was unknown (8) (CDC, unpublished
data; 2011). Although the vast majority of human infections with
animal influenza viruses do not result in human-to-human transmission
(9,10), each case should be investigated fully to ascertain whether
these viruses are transmitted among humans and to limit further
exposure of humans to infected animals, if infected animals are
identified.

The lack of known direct exposure to pigs in one of the 2 cases
described in this report suggests the possibility that limited
human-to-human transmission of this influenza virus occurred. Likely
transmission of swine-origin influenza A (H3N2) virus from close
contact with an infected person has been observed in past
investigations of human infections with swine-origin influenza A
virus, but has not resulted in sustained human-to-human transmission.
Preliminary evidence from the investigation of the Indiana case shows
no ongoing transmission. No influenza illness has been identified, but
if additional chains of transmission are identified rapid intervention
is warranted try to prevent further spread of the virus. Clinicians
should consider swine-origin influenza A virus infection as well as
seasonal influenza virus infections in the differential diagnosis of
patients with febrile respiratory illness who have been near pigs.
Clinicians who suspect influenza virus infection in humans with recent
exposure to swine, should obtain a nasopharyngeal swab from the
patient, place the swab in a viral transport medium, contact their
state or local health department to facilitate transport and timely
diagnosis at a state public health laboratory, and consider empiric
neuraminidase inhibitor antiviral treatment (4).

[Interested readers should access the original document at the source
URL to view the references cited in the above text]

--
communicated by:
ProMED-mail
<promed@promedmail.org>

[This report describes 2 cases of febrile respiratory illness caused
by swine-origin influenza A (H3N2) viruses identified on 19 Aug 2011
and 26 Aug 2011. The viruses identified in these cases are unique in
that one of the 8 gene segments (matrix [M] gene) is derived from the
2009 influenza A (H1N1) virus.

Non-human influenza virus infections rarely result in human-to-human
transmission, but the implications of sustained ongoing transmission
between humans is potentially severe; therefore, prompt and thorough
identification and investigation of these sporadic human infections
with non-human influenza viruses are needed to reduce the risk for
sustained transmission. The 2 children had been vaccinated in the
previous year and had no known contact.

Although reassortment between swine influenza and 2009 influenza A
(H1N1) viruses has been reported in pigs in the United States
[Duchatez MF, Hause B, Stigger-Rosser E, et al. Multiple reassortment
between pandemic (H1N1) 2009 and endemic influenza viruses in pigs,
United States. Emerg Infect Dis. 2011;17:1624-9], this particular
genetic combination of swine influenza virus segments is unique and
has not been reported previously in either swine or humans. There was
no evidence of onward transmission of this particular reassortant in
humans

Therefore clinicians should consider swine-origin influenza A virus
infection as well as seasonal influenza virus infections in the
differential diagnosis of patients with febrile respiratory illness
who have been near pigs. - Mod.CP]

[see also:
Influenza (50): Australia (NS) H275Y mutation cluster 20110825.2594
Influenza (49): China, narcolepsy 20110823.2561
Influenza (48): ACIP recommendations 20110818.2510
Influenza (47): ECDC report, virus characterization 20110816.2477]
.................................................cp/ejp/sh

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PostPosted: Fri Sep 02, 2011 8:48 pm 
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Location: Pittsburgh, PA USA
Novel Influenza A Virus:
Two human infections with novel influenza A virus were reported; one case from the Indiana State Department of Health and one case from the Pennsylvania Department of Health. Both patients were infected with swine-origin influenza A (H3N2) viruses. The Indiana case experienced symptom onset on July 23, 2011 and was hospitalized on July 24, 2011 for worsening of chronic health problems. No contact with pigs has been identified in the Indiana case in the week before symptom onset; however the case had contact with individuals who reported swine exposure in the week preceding the patient’s illness onset. The Pennsylvania case reported contact with pigs in the week preceding symptom onset on August 20, 2011. Both patients have fully recovered from their illness. These viruses are genetically related, but different enough to suggest there was not a common source of infection. No epidemiologic link between these two cases has been identified. For additional information on these cases see link to MMWR.

Early identification and investigation of human infections with novel influenza A viruses is critical to evaluate the extent of the outbreak and possible human-to-human transmission. Surveillance for human infections with novel influenza A viruses continues year round.

http://www.cdc.gov/flu/weekly/

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PostPosted: Fri Sep 02, 2011 8:58 pm 
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Location: Pittsburgh, PA USA
Novel H3N2 swine flu viruses infected 2 children, CDC says
Robert Roos News Editor


Sep 2, 2011 (CIDRAP News) – In separate instances, influenza A/H3N2 viruses circulating in swine picked up a gene from the pandemic 2009 H1N1 virus and recently infected two young children, one in Indiana and one in Pennsylvania, the Centers for Disease Control and Prevention (CDC) reported today.

Both of the children recovered, though one was briefly hospitalized, and there is no sign that the viruses spread from the children to others, but any evidence of ongoing transmission would require a rapid response, the CDC said.

The agency also said one of the children had no direct contact with pigs, which suggests he caught it from another person. Both children are under age 5.

The two viruses are similar to eight other swine-origin H3N2 viruses found in humans in the past 2 years, but they are unique in that they contain the matrix (M) gene from the 2009 H1N1 virus, the CDC reported in an early online posting in Morbidity and Mortality Weekly Report (MMWR). The two viruses are similar but not identical.

"I don't think these [viruses] have pandemic potential; it looks like both of these are sort of dead-end transmissions," Lyn Finelli, DrPH, chief of the surveillance and outbreak response team in the CDC's influenza division, told CIDRAP News.

But she also commented, "One of the reasons we publish this data is that reassortment happens in swine viruses and in humans, so we always want to have surveillance in place so we can detect the next emerging reassortant. Viruses like these do have pandemic potential."

Though no further cases have been found, the report says, "If additional chains of transmission are identified rapid intervention is warranted [to] try to prevent further spread of the virus."

Case details
The first case involved an Indiana boy who got sick with a fever, cough, shortness of breath, diarrhea, and sore throat on Jul 23, the report says. He was seen at a hospital emergency department (ED) and was sent home without receiving antiviral treatment; a respiratory sample taken during the visit later tested positive for influenza A/H3. The boy, who has chronic health conditions, returned to the ED Jul 24 and was hospitalized for treatment of those conditions. He was released Jul 27 and has since recovered.

A specimen from the boy was sent to the Indiana state public health laboratory as part of routine surveillance, and a suspected swine-origin H3N2 virus was identified on Aug 17. The lab sent the specimen to the CDC, which used genome sequencing to confirm the finding Aug 19.

The boy had had no direct exposure to pigs, but a person who took care of him 2 days before he got sick reported direct contact with apparently healthy pigs in the preceding weeks. The CDC said this suggests that the virus might have spread from the caretaker to the boy. Investigators found no respiratory illness in the boy's family or close contacts or the caretaker's contacts.

In the second case, a girl in Pennsylvania experienced a fever, cough, and lethargy on Aug 20 and was taken to a local ED, where a rapid flu test was positive for influenza A. She was sent home the same day without receiving antiviral treatment and has since recovered, the report says.

In routine surveillance, samples from the girl were sent to Pennsylvania's state health department lab, which identified a suspected swine-origin H3N2 virus and forwarded the samples to the CDC. The agency confirmed the finding on Aug 26.

The girl on Aug 16 had visited a fair, where she was exposed to pigs and other animals. No illnesses have been found among the girl's family or close contacts, according to the report. Finelli said the CDC is also checking for illnesses among others who attended the fair, but has found none so far.

Children more susceptible
The fact that both patients were children may be related to the recent history of H3N2 virus circulation, according to Finelli. She said most of the swine flu human infections reported in recent years have been in children, with a median age of 10 or 11.

"The H3N2 that circulated in humans before 1990 was a relative of this [new] virus," so people exposed at that time would have some cross-reactive immunity to the new strain, she explained. "So people under 20 are probably more susceptible than people that are older."

The report says seven of the eight gene segments in the two viruses are similar to those of swine H3N2 viruses that have circulated in US pigs since 1998 and were identified in eight other human cases of swine-origin flu since 2009. But the two viruses contain the M gene from the 2009 H1N1 virus, which has previously been identified in pigs a few times. This particular combination of genes had not been reported previously in pigs or humans, the CDC said.

Finelli noted that flu viruses are common in pigs in the United States and worldwide. Between 50% and 90% of mature pigs (about 2 years and older) have antibodies signifying exposure to flu viruses, and there are flu outbreaks in swine herds every year, she said.

"Different viruses are circulating simultaneously among pigs—this virus being one of those," she said. But she said she has no idea how common this particular reassortant might be.

Reports of human infections with swine-origin flu viruses have increased in recent years, at least partly because of increased testing and reporting, according to the report. The CDC received about one report per year from 2005 to 2007. In 2007 infection with novel influenza A viruses became a nationally notifiable condition, and since then the CDC has received about three to five reports of swine-origin viruses in humans each year.

In 2004 and 2005, state health departments received CDC money to run polymerase chain reaction tests on uncommon flu strains, Finelli said. "Because of the new requirement to report and new technologies to test viruses, we have sort of a confluence of events that makes these more likely to be reported," she commented. "We do hear of about four or five of these cases every year, and they're often around state and county fair time."

The two new viruses are resistant to the older flu drugs, amantadine and rimantadine, but susceptible to oseltamivir (Tamiflu) and zanamivir (Relenza), the CDC report says.

Finelli said she didn't find it surprising that the two children were not treated with antivirals. "The reason it's not [surprising] is that this is not flu season, though these clinicians were very smart to get samples from the kids. People don't expect flu to be circulating now, so they don't treat empirically with antivirals. This is one of the reasons we put out this piece. We want them to sample and we want them to treat empirically."

Andrew T. Pavia, MD, chief of the Division of Pediatric Infectious Diseases at the University of Utah in Salt Lake City, told CIDRPA News via e-mail that the CDC report "should serve as a reminder that new reassortants can emerge at any time and any place. I don't think we can safely say that the 2009 H1N1 pandemic reset the clock and guarantees a long period of calm before the next storm."

"Pigs continue to play a very important role in flu epidemiology, and we need to have a good surveillance system for viruses emerging in swine agriculture," Pavia added. "This can be a challenge both because of threatened funding cuts and because of sensitivity within the industry."

He called the cases noteworthy but not alarming. "We need to wait and see if either strain has spread. We would not predict that addition of the matrix segment from H1N1 would make a swine H3N2 that spreads poorly in people have pandemic potential BUT our ability to predict is not great. A different reassortant might easily arise from mixing human, pig, and bird segments with the capacity to be dangerous, either because of a new H [hemagglutinin] type or because of high level antiviral resistance."

CDC. Swine-origin influenza A (H3N2) virus infection in two children—Indiana and Pennsylvania, July-August 2011. MMWR 2011 Sep 2 (Early release) [Full text]

http://www.cidrap.umn.edu/cidrap/conten ... swine.html

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