Influenza A virus infection in Brazilian swine herds following the introduction of pandemic 2009 H1N1.
Influenza A virus (FLUAV) infections are endemic in pork producing countries worldwide but in Brazil it was not considered an important pathogen in pigs. Since the emergence of 2009 pandemic H1N1 (H1N1pdm) FLUAV, many outbreaks of respiratory disease were observed in pig herds. The aim of this study was to evaluate FLUAV infection in swine in 48 pig farms located in seven Brazilian states with previous reports of influenza-like signs by clinical, serological and virological cross-sectional studies. Serological results showed that pigs from all farms had anti-influenza antibodies by NP-ELISA. Antibodies to H3N2, H1N2 and H1N1pdm were detected by HI in pigs from 24 farms. Co-infection with two or more FLUAV subtypes was detected in pigs in seven of those 24 farms. Detection of FLUAV in nasal swabs and oral fluids by RT-qPCR indicated a global concordance >81% for the two biological samples. Moreover, our results show that H1N1pdm, H1N2 and H3N2 viruses are widespread in Brazilian pig herds. The monitoring of FLUAV emergence and evolution in pigs is urgent, as well the study of the pathogenesis of Brazilian isolates, aiming to control influenza in pigs.
Embrapa Swine and Poultry, Animal Health Laboratory, BR 153, Km 110, P.O. Box 21, Distrito de Tamanduá, Concórdia CEP 89.700-000, Santa Catarina, Brazil.
Janice Reis
JR
Ciacci-Zanella
Embrapa Swine and Poultry, Animal Health Laboratory, BR 153, Km 110, P.O. Box 21, Distrito de Tamanduá, Concórdia CEP 89.700-000, Santa Catarina, Brazil. Electronic address: rejane.schaefer@embrapa.br.
Rejane
R
Schaefer
Embrapa Swine and Poultry, Animal Health Laboratory, BR 153, Km 110, P.O. Box 21, Distrito de Tamanduá, Concórdia CEP 89.700-000, Santa Catarina, Brazil.
Danielle
D
Gava
PIBIC, CNPq-University of the Western Santa Catarina (UNOESC), Getúlio Vargas 2125, Joaçaba CEP 89.600-000, Santa Catarina, Brazil.
Vanessa
V
Haach
Embrapa Swine and Poultry, Animal Health Laboratory, BR 153, Km 110, P.O. Box 21, Distrito de Tamanduá, Concórdia CEP 89.700-000, Santa Catarina, Brazil.
Maurício Egídio
ME
Cantão
Embrapa Swine and Poultry, Animal Health Laboratory, BR 153, Km 110, P.O. Box 21, Distrito de Tamanduá, Concórdia CEP 89.700-000, Santa Catarina, Brazil.
Arlei
A
Coldebella
D000818:Animals; D001938:Brazil / Q000453:epidemiology; D003430:Cross-Sectional Studies; D004196:Disease Outbreaks / Q000662:veterinary*; D053118:Influenza A Virus, H1N1 Subtype / Q000302:isolation & purification*; D009976:Orthomyxoviridae Infections / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology; D060888:Real-Time Polymerase Chain Reaction; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology / Q000821:virology*
Brazil; Influenza A virus; Oral fluid; Serology; Swine