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Human infection from avian-like influenza A (H1N1) viruses in pigs, China.

Yang H, Qiao C, Tang X, Chen Y, Xin X, Chen H - Emerging Infect. Dis. (2012)

Bottom Line: In investigating influenza in an immunodeficient child in China, in December 2010, we found that the influenza virus showed high sequence identity to that of swine.Serologic evidence indicated that viral persistence in pigs was the source of infection.Continued surveillance of pigs and systemic analysis of swine influenza isolates are needed.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Veterinary Biotechnology–Harbin Veterinary Research Institute, Harbin, People’s Republic of China.

ABSTRACT
In investigating influenza in an immunodeficient child in China, in December 2010, we found that the influenza virus showed high sequence identity to that of swine. Serologic evidence indicated that viral persistence in pigs was the source of infection. Continued surveillance of pigs and systemic analysis of swine influenza isolates are needed.

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Related in: MedlinePlus

Phylogenetic tree of selected swine, human, and avian H1 hemagglutinin 1 sequences. An unrooted phylogenetic tree was generated by the distance-based maximum-likelihood method by using MEGA5 software (www.megasoftware.net). Bootstrap values were calculated on the basis of 1,000 replications; A/swine/Jiangsu/40/2011 is in boldface. Scale bar indicates nucleotide substitutions per site.
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Figure 1: Phylogenetic tree of selected swine, human, and avian H1 hemagglutinin 1 sequences. An unrooted phylogenetic tree was generated by the distance-based maximum-likelihood method by using MEGA5 software (www.megasoftware.net). Bootstrap values were calculated on the basis of 1,000 replications; A/swine/Jiangsu/40/2011 is in boldface. Scale bar indicates nucleotide substitutions per site.

Mentions: After notification of the boy’s infection from the Ministry of Health, we performed active public health surveillance to locate the origin of the infection. A total of 60 nasal swab specimens were collected from pigs at the patient’s family farm and a local slaughterhouse. Each swab was placed in 2 mL of minimal essential medium supplemented with penicillin (2,000 U/mL) and streptomycin (2,000 U/mL). Virus was isolated by using 10-day-old specific pathogen-free embryonated chicken eggs. Hemagglutinin (HA) and neuraminidase (NA) subtypes were determined as described (5). Three A (H1N1) SIVs were obtained, including 2 isolates from pigs in the slaughterhouse and 1 from a pig raised at the family’s farm. Viral RNA was extracted and reverse transcribed under standard conditions by using the Uni12 (5′-AGCAAAAGCAGG-3′) primer. The viral genomes were amplified by PCR and sequenced by using segment-specific primers (sequences available on request). Genomic sequencing ultimately showed that the 3 isolates were virtually identical, and the sequence of the entire genome of the representative strain A/swine/Jiangsu/40/2011 (Sw/JS/40/11) is available in GenBank (accession nos. JQ319645–JQ319652). Unrooted phylogenetic trees were generated by using MEGA5 software (www.megasoftware.net). The A (H1N1) viruses isolated in this study fell into the European avian-like swine A (H1N1) lineage (Figure 1). The homology of the polymerase basic protein (PB) 2, PB1, polymerase acidic protein, HA, nucleocapsid protein, NA, matrix (M), and nonstructural protein genes between the Sw/JS/40/11 virus and the A/Jiangsu/1/2011 (JS/1/11) virus, which was isolated from the child, were 99.3%, 99.3%, 99.3%, 99.7%, 99.7%, 99.4%, 99.6%, and 99.1%, respectively, indicating that they might have been derived from the same ancestor.


Human infection from avian-like influenza A (H1N1) viruses in pigs, China.

Yang H, Qiao C, Tang X, Chen Y, Xin X, Chen H - Emerging Infect. Dis. (2012)

Phylogenetic tree of selected swine, human, and avian H1 hemagglutinin 1 sequences. An unrooted phylogenetic tree was generated by the distance-based maximum-likelihood method by using MEGA5 software (www.megasoftware.net). Bootstrap values were calculated on the basis of 1,000 replications; A/swine/Jiangsu/40/2011 is in boldface. Scale bar indicates nucleotide substitutions per site.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3376805&req=5

Figure 1: Phylogenetic tree of selected swine, human, and avian H1 hemagglutinin 1 sequences. An unrooted phylogenetic tree was generated by the distance-based maximum-likelihood method by using MEGA5 software (www.megasoftware.net). Bootstrap values were calculated on the basis of 1,000 replications; A/swine/Jiangsu/40/2011 is in boldface. Scale bar indicates nucleotide substitutions per site.
Mentions: After notification of the boy’s infection from the Ministry of Health, we performed active public health surveillance to locate the origin of the infection. A total of 60 nasal swab specimens were collected from pigs at the patient’s family farm and a local slaughterhouse. Each swab was placed in 2 mL of minimal essential medium supplemented with penicillin (2,000 U/mL) and streptomycin (2,000 U/mL). Virus was isolated by using 10-day-old specific pathogen-free embryonated chicken eggs. Hemagglutinin (HA) and neuraminidase (NA) subtypes were determined as described (5). Three A (H1N1) SIVs were obtained, including 2 isolates from pigs in the slaughterhouse and 1 from a pig raised at the family’s farm. Viral RNA was extracted and reverse transcribed under standard conditions by using the Uni12 (5′-AGCAAAAGCAGG-3′) primer. The viral genomes were amplified by PCR and sequenced by using segment-specific primers (sequences available on request). Genomic sequencing ultimately showed that the 3 isolates were virtually identical, and the sequence of the entire genome of the representative strain A/swine/Jiangsu/40/2011 (Sw/JS/40/11) is available in GenBank (accession nos. JQ319645–JQ319652). Unrooted phylogenetic trees were generated by using MEGA5 software (www.megasoftware.net). The A (H1N1) viruses isolated in this study fell into the European avian-like swine A (H1N1) lineage (Figure 1). The homology of the polymerase basic protein (PB) 2, PB1, polymerase acidic protein, HA, nucleocapsid protein, NA, matrix (M), and nonstructural protein genes between the Sw/JS/40/11 virus and the A/Jiangsu/1/2011 (JS/1/11) virus, which was isolated from the child, were 99.3%, 99.3%, 99.3%, 99.7%, 99.7%, 99.4%, 99.6%, and 99.1%, respectively, indicating that they might have been derived from the same ancestor.

Bottom Line: In investigating influenza in an immunodeficient child in China, in December 2010, we found that the influenza virus showed high sequence identity to that of swine.Serologic evidence indicated that viral persistence in pigs was the source of infection.Continued surveillance of pigs and systemic analysis of swine influenza isolates are needed.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Veterinary Biotechnology–Harbin Veterinary Research Institute, Harbin, People’s Republic of China.

ABSTRACT
In investigating influenza in an immunodeficient child in China, in December 2010, we found that the influenza virus showed high sequence identity to that of swine. Serologic evidence indicated that viral persistence in pigs was the source of infection. Continued surveillance of pigs and systemic analysis of swine influenza isolates are needed.

Show MeSH
Related in: MedlinePlus