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Clinical response to pandemic H1N1 influenza virus from a fatal and mild case in ferrets.

Martínez-Orellana P, Martorell J, Vidaña B, Majó N, Martínez J, Falcón A, Rodríguez-Frandsen A, Casas I, Pozo F, García-Migura L, García-Barreno B, Melero JA, Fraile L, Nieto A, Montoya M - Virol. J. (2015)

Bottom Line: Animals on S showed a significant decrease in body weight compared to animals on NS at 4 to 7 days post-infection (dpi).The severity in the progress of infection was independent from the virus used for infection suggesting that the host immune response was determinant in the outcome of the infection.The diversity observed in ferrets mimicked the variability found in the human population.

View Article: PubMed Central - PubMed

Affiliation: Centre de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain. pamela.martinez@cresa.uab.cat.

ABSTRACT

Background: The majority of pandemic 2009 H1N1 (A(H1N1)pdm09) influenza virus (IV) caused mild symptoms in most infected patients, however, a greater rate of severe disease was observed in healthy young adults and children without co-morbid conditions. The purpose of this work was to study in ferrets the dynamics of infection of two contemporary strains of human A(H1N1)pdm09 IV, one isolated from a patient showing mild disease and the other one from a fatal case.

Methods: Viral strains isolated from a patient showing mild disease-M (A/CastillaLaMancha/RR5661/2009) or from a fatal case-F (A/CastillaLaMancha/RR5911/2009), both without known comorbid conditions, were inoculated in two groups of ferrets and clinical and pathological conditions were analysed.

Results: Mild to severe clinical symptoms were observed in animals from both groups. A clinical score distribution was applied in which ferrets with mild clinical signs were distributed on a non-severe group (NS) and ferrets with severe clinical signs on a severe group (S), regardless of the virus used in the infection. Animals on S showed a significant decrease in body weight compared to animals on NS at 4 to 7 days post-infection (dpi). Clinical progress correlated with histopathological findings. Concentrations of haptoglobin (Hp) and serum amyloid A (SAA) increased on both groups after 2 dpi. Clinically severe infected ferrets showed a stronger antibody response and higher viral titres after infection (p = 0.001).

Conclusions: The severity in the progress of infection was independent from the virus used for infection suggesting that the host immune response was determinant in the outcome of the infection. The diversity observed in ferrets mimicked the variability found in the human population.

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Related in: MedlinePlus

Viral replication in trachea, lungs and broncheo alveolar lavage (BAL) of infected ferrets. At 4 and 7 dpi, samples of trachea, lung and BAL were collected to measure viral titers. (A) Virus titers in trachea; (B) Lung titers, (C) Viral titers in BAL.
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Fig4: Viral replication in trachea, lungs and broncheo alveolar lavage (BAL) of infected ferrets. At 4 and 7 dpi, samples of trachea, lung and BAL were collected to measure viral titers. (A) Virus titers in trachea; (B) Lung titers, (C) Viral titers in BAL.

Mentions: To test the presence of infectious virus particles, samples of trachea, lung and broncheo alveolar lavage (BAL) were collected at 4 and 7 dpi. Control animals were negative. Data of viral titres of trachea, lung and BAL was analyzed as a set including the three different tissues (Figure 4). Viral titres were similar at 4 dpi in trachea when values from animals in S group and NS group were compared. On the contrary, ferrets with severe clinical signs at 4 dpi exhibited higher viral titres than their counterparts in the NS group in the lungs and BAL. This difference was statistically significant (p = 0.01). No virus was detected in trachea, lung or BAL at 7dpi.Figure 4


Clinical response to pandemic H1N1 influenza virus from a fatal and mild case in ferrets.

Martínez-Orellana P, Martorell J, Vidaña B, Majó N, Martínez J, Falcón A, Rodríguez-Frandsen A, Casas I, Pozo F, García-Migura L, García-Barreno B, Melero JA, Fraile L, Nieto A, Montoya M - Virol. J. (2015)

Viral replication in trachea, lungs and broncheo alveolar lavage (BAL) of infected ferrets. At 4 and 7 dpi, samples of trachea, lung and BAL were collected to measure viral titers. (A) Virus titers in trachea; (B) Lung titers, (C) Viral titers in BAL.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4380011&req=5

Fig4: Viral replication in trachea, lungs and broncheo alveolar lavage (BAL) of infected ferrets. At 4 and 7 dpi, samples of trachea, lung and BAL were collected to measure viral titers. (A) Virus titers in trachea; (B) Lung titers, (C) Viral titers in BAL.
Mentions: To test the presence of infectious virus particles, samples of trachea, lung and broncheo alveolar lavage (BAL) were collected at 4 and 7 dpi. Control animals were negative. Data of viral titres of trachea, lung and BAL was analyzed as a set including the three different tissues (Figure 4). Viral titres were similar at 4 dpi in trachea when values from animals in S group and NS group were compared. On the contrary, ferrets with severe clinical signs at 4 dpi exhibited higher viral titres than their counterparts in the NS group in the lungs and BAL. This difference was statistically significant (p = 0.01). No virus was detected in trachea, lung or BAL at 7dpi.Figure 4

Bottom Line: Animals on S showed a significant decrease in body weight compared to animals on NS at 4 to 7 days post-infection (dpi).The severity in the progress of infection was independent from the virus used for infection suggesting that the host immune response was determinant in the outcome of the infection.The diversity observed in ferrets mimicked the variability found in the human population.

View Article: PubMed Central - PubMed

Affiliation: Centre de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain. pamela.martinez@cresa.uab.cat.

ABSTRACT

Background: The majority of pandemic 2009 H1N1 (A(H1N1)pdm09) influenza virus (IV) caused mild symptoms in most infected patients, however, a greater rate of severe disease was observed in healthy young adults and children without co-morbid conditions. The purpose of this work was to study in ferrets the dynamics of infection of two contemporary strains of human A(H1N1)pdm09 IV, one isolated from a patient showing mild disease and the other one from a fatal case.

Methods: Viral strains isolated from a patient showing mild disease-M (A/CastillaLaMancha/RR5661/2009) or from a fatal case-F (A/CastillaLaMancha/RR5911/2009), both without known comorbid conditions, were inoculated in two groups of ferrets and clinical and pathological conditions were analysed.

Results: Mild to severe clinical symptoms were observed in animals from both groups. A clinical score distribution was applied in which ferrets with mild clinical signs were distributed on a non-severe group (NS) and ferrets with severe clinical signs on a severe group (S), regardless of the virus used in the infection. Animals on S showed a significant decrease in body weight compared to animals on NS at 4 to 7 days post-infection (dpi). Clinical progress correlated with histopathological findings. Concentrations of haptoglobin (Hp) and serum amyloid A (SAA) increased on both groups after 2 dpi. Clinically severe infected ferrets showed a stronger antibody response and higher viral titres after infection (p = 0.001).

Conclusions: The severity in the progress of infection was independent from the virus used for infection suggesting that the host immune response was determinant in the outcome of the infection. The diversity observed in ferrets mimicked the variability found in the human population.

Show MeSH
Related in: MedlinePlus