Equine influenza is a highly contagious respiratory disease caused by influenza A viruses, specifically affecting horses. The disease is characterized by symptoms such as fever, coughing, nasal discharge, and lethargy. Transmission occurs primarily through aerosolized droplets and direct contact, leading to rapid spread among susceptible populations. Vaccination is a common preventive measure, though the virus's ability to mutate necessitates ongoing surveillance and vaccine updates. This page gathers peer-reviewed research studies and scholarly articles that explore the virology, epidemiology, clinical presentation, and management strategies of equine influenza, with a focus on its impact on equine health and welfare.
Marois P, Pavilanis V, Boudreault A, Di Franco E.The clinical diagnosis of equine influenza was first based on the spectacular contagiousness of the disease, the general clinical resemblances to human influenza and the almost complete absence of complications usually observed in infectious viral arteritis, viral rhinopneumonitis or in other respiratory infections of the horses. The specific viral etiology of the epizootic was ascertained through the isolation of a type A influenza virus and further substantiated by evaluation of the immunological response of the sick horses, as demonstrated by complement fixation and hemagglutination-inhibit...
GAIDAMAKA MG, VAGANOV GP, DROMASHKO AS, SHVETSKAVA BD, FYADINA DD.The research examines an incident of upper respiratory tract disease in horses, marked by severe symptoms, which followed a human influenza epidemic in Kharkov in 1957, challenging previous notions that […]
KAPLAN MM, PAYNE AM.In 1957 the World Health Organization arranged a survey of horse and swine sera in a number of countries in order to gain information on the role and importance of animals in the epidemiology of influenza. The veterinary services of the countries concerned were requested to obtain blood specimens from these animals, if possible both before and after the human pandemic of Asian influenza. This paper reports on the results of haemagglutination-inhibition and complement-fixation tests performed on these sera in WHO Influenza Centres and other collaborating laboratories.It is apparent from these r...
DOLL ER, WALLACE E, RICHARDS MG.Manninger and Csontos reported that mares inoculated with equine abortion virus developed a transient fever 2 to 4 days after pharyngeal or intravenous inoculation and that an uninoculated horse in contact with the experimentally inoculated mares contracted a febrile disease resembling equine influenza. Also, mares that had aborted virus-infected fetuses were resistant to inoculation with equine influenza virus. From these observations, they proposed that virus abortions were a manifestation of infection of pregnant mares by the equine influenza virus. In reports on equine virus abortions, Kre...
Art T, Lekeux P.This study was conducted in order to assess whether exercise- and training-induced cardio-respiratory adjustments are modified during the 10-day period which follows a booster vaccination with an oily adjuvanted inactivated vaccine against influenza and equine herpesvirus-1 (Equiffa). Nine healthy vaccinated thoroughbred horses were used. Six were revaccinated and three were kept as control. All the horses completed a standardised exercise test (SET) that was repeated 4 times, i.e. 10 (SET1) and 2 (SET2) days before revaccination, and 2 (SET3) and 10 (SET4) days after revaccination. During the...
Routledge NB, Harris RC, Harris PA, Naylor JR, Roberts CA.The variation over 24 h of plasma glutamine concentration in nonexercising horses was studied in 3 Thoroughbreds (TB) fed at 1600 h and 0700 h. This indicated a small but regular change associated with feeding. Starting at a mean of 482 mumol/l at 1600 h the concentration increased to 522 mumol/l at 2000 h, falling to 476 mumol/l at 1600 h and increasing again to 525 mumol/l at 2000 h. 'Normal' values were established in 19 part-bred TB horses, lacking clinical signs or remarkable pathology and in light training, by sampling weekly at 1000 h over a 10 week period. The mean concentration was 49...
Boudreault A, Boulay G, Marois P, Pavilanis V.Live human and equine influenza virus strains modified by serial passage on allantois-on-shell system (AOS) in the presence of normal horse serum were administered orally or intranasally to volunteers or horses. Mostly mild clinical short-lasting reactions, replication in nasal mucosae, transmission to placebo recipients and significant local or circulating antibody rises were observed following administration to volunteers of strains modified by five or less serial passages on AOS in the presence of normal horse serum (NHS). Milder clinical reactions, no replication, no viral transmission and...
Zaleska M, Anusz K, Winnicka A, Kita J.Twelve horses, all of them 10 years old, were vaccinated intramuscularly on 0 and 28 days of the experiment with inactivated vaccine containing only antigens of A-equi-2/Miami/63. Another three unvaccinated horses, each at the age of 10 years, were the negative control group. One, ten-year-old horse was vaccinated with commercial inactivated vaccine containing both antigens of A-equi-2/Miami/63 as well as A-equi-1/Praha/56 as positive control. Three horses were challenged intranasally with homotypic strain of Miami/63, while six other were challenged with heterotypic strains--three with Suffol...
Sergeant ES, Cowled BD, Bingham P.This observational study was undertaken in order to evaluate the diagnostic specificity of the blocking enzyme-linked immunosorbent assay (bELISA) for serum antibodies to influenza A virus nucleoprotein during the equine influenza (EI) outbreak response in New South Wales, Australia, in 2007. Using data collected during the outbreak response, bELISA testing data were collated for assumed uninfected horses from areas where EI infection was never recorded. Diagnostic specificity of the bELISA used during the EI response was high, but varied significantly between some regions, although the reason...
Karam B, Wilson WD, Chambers TM, Reedy S, Pusterla N.The use of a hemagglutination inhibition (HI) assay to assess humoral immune response to equine influenza virus (EIV) vaccines from various manufacturers administered to previously immunized adult horses was investigated. Subjects were allocated into one of 3 groups and vaccinated with various commercially available vaccines. Groups were subdivided into subjects that received 1 dose of a particular vaccine and those that received a second dose, 30 d later. Serum was collected at various times to assess antibody responses to contemporary EIV Florida sub-lineage strains. Statistical significance...
Lány P, Pospísil Z, Zendulková D, Cíhal P, Jahn P.A mild outbreak of acute respiratory infection was reported in racing horses in the fall of 1995. Four studs were investigated for the sources and routes of infection. In five horses from two herds, virus isolates were obtained which, in preliminary typing experiments, were identified as the influenza A/equi 2 virus. The presence of this illness in all the examined herds was confirmed by a rise in specific antibody titres. The affected animals included both older vaccinated horses and young horses not yet vaccinated. Epidemiological studies suggested that the spread of infection occurred in si...
Herbst W, Görlich P, Danner K.Of 1081 acute and chronically respiratory diseased as well as clinically normal horses 824 sera and 257 paired serum samples collected 1986 and 1987 were tested for antibodies against several different respiratory viruses such as influenza virus A/equi 1 and 2 (Influenza 1 a. 2), equine herpesvirus type 1/4 (EHV 1/4), mammalian reovirus type 1-3 (Reovirus 1-3), equine rhinovirus type 1 (ERV 1), equine adenovirus type 1 (EAdV 1), and equine arteritis virus (EAV). The investigations resulted in an antibody prevalence of 57.2% (Influenza 1), 59.5% (Influenza 2), 81.5% (EHV 1/4), 50.3% (Reovirus 1...
Goto H, Yamamoto Y, Ohta C, Shirahata T, Higuchi T, Ohishi H.A total of 305 horse sera collected in the Hidaka district of Hokkaido in the years 1988-90 were tested for the presence of hemagglutination-inhibition (HI) antibodies to A/equine/Newmarket/1/77 (H7N7), A/equine/Tokyo/2/71 (H3N8) and A/equine/Kentucky/1/81 (H3N8, Kentucky) strains of equine influenza (EI) virus. Antibodies to the 3 strains were detected in hardly of the 45 sera from 2-years-old horses which were collected before vaccination. Many of the 51 horses, after vaccination with inactivated EI virus, had HI antibodies to the 3 strains in 37 to 88 per cent. However, the number of positi...
Mancini DA, Pereira AS, Mendonça RM, Kawamoto AH, Alves RC, Pinto JR, Mori E, Richtzenhain LJ, Mancini-Filho J.Equines are susceptible to respiratory viruses such as influenza and parainfluenza. Respiratory diseases have adversely impacted economies all over the world. This study was intended to determine the presence of influenza and parainfluenza viruses in unvaccinated horses from some regions of the state of São Paulo, Brazil. Blood serum collected from 72 equines of different towns in this state was tested by hemagglutination inhibition test to detect antibodies for both viruses using the corresponding antigens. About 98.6% (71) and 97.2% (70) of the equines responded with antibody protective tit...
Oakey J, Hawkesford T, Smith C, Hewitson G, Tolosa X, Wright L, Moody N, Rodwell B, Corney B, Waltisbuhl D.Describe the in-house validation of a previously reported influenza virus type A 5'Taq nuclease assay for detecting equine influenza virus A RNA in nasal swab material. Methods: The validation compares the 5'Taq nuclease assay with a gel-based reverse transcription nested polymerase chain reaction (PCR) previously reported by the Irish Equine Centre for detection of H3N8 and H7N7 equine influenza viruses. This test was chosen because it targets a different region of the viral genome to the real-time test, so it is not merely a repeat of the same test in a different format. Moreover, nested PCR...
Mayr A.Prophylactic immunization of animals against obligat and nonobligat pathogenic zoonoses benefit human health in many ways both directly and indirectly. Typical examples of a direct protective effect are the vaccinations of dogs, cats and foxes against rabies as well as the vaccinations against respiratory diseases in cows, horses, dogs and cats to which the most varied species of pathogens of noncompulsory zoonoses contribute. A considerable contribution to the protection of human health is made by the vaccination against salmonellosis and leptospirosis, against vesicular stomatitis, American ...
Dilai M, Piro M, Fougerolle S, El Harrak M, Mahir W, El Mourid R, Legrand L, Paillot R, Fassi Fihri O.In order to evaluate the vaccination status against equine influenza (EI) in Moroccan racehorses, a serological investigation was carried out on 509 racehorses using three serological tests: an Enzyme-Linked Immunosorbent Assay (ELISA), the Hemagglutination Inhibition (HI) test and the Single Radial Haemolysis (SRH) assay. The serological analysis showed 56% of seropositivity by ELISA, 67% by HI and 89.4% by SRH (with 69.9% above the clinical protection threshold). Using the Kappa test, the SRH and HI assays showed a strong agreement, the SRH and ELISA assays had a moderate agreement and the H...
Brown L, Townsend W, Waltisbuhl D.The unique challenges that laboratories in Queensland and New South Wales faced during the response to the 2007 equine influenza outbreak and how these were managed are described.
Khan A, Mushtaq MH, Muhammad J, Ahmed B, Khan EA, Khan A, Zakki SA, Altaf E, Haq I, Saleem A, Warraich MA, Ahmed N, Rabaan AA.There are different opinions around the World regarding the zoonotic capability of H3N8 equine influenza viruses. In this report, we have tried to summarize the findings of different research and review articles from Chinese, English, and Mongolian Scientific Literature reporting the evidence for equine influenza virus infections in human beings. Different search engines i.e. CNKI, PubMed, ProQuest, Chongqing Database, Mongol Med, and Web of Knowledge yielded 926 articles, of which 32 articles met the inclusion criteria for this review. Analyzing the epidemiological and Phylogenetic data from ...
Croft MG, Fraser GC, Gaul WN.A Laboratory Information Management System (LIMS) was used to manage the laboratory data and support planning and field activities as part of the response to the equine influenza outbreak in Australia in 2007. The database structure of the LIMS and the system configurations that were made to best handle the laboratory implications of the disease response are discussed. The operational aspects of the LIMS and the related procedures used at the laboratory to process the increased sample throughput are reviewed, as is the interaction of the LIMS with other corporate systems used in the management...
Glathe H, Strittmatter HU, Kunze M, Sinnecker H.The influence of acidic pH on the infectivity and neuraminidase activity of human, equine and avian type A influenza virus strains has been studied. Following exposure to pH 3 human and equine strains lost their infectivity completely, whereas all investigated strains of the subtypes Hav6N2 and Hav7Neq2 retained a certain amount of infectivity. In contrast to human and equine strains the avian strains retained also 38% of their original neuraminidase activity after acidic treatment. Partial retention of infectivity and the relative stability of the neuraminidase following exposure to acidic pH...
Fontaine M, Fontaine M.In the first part of this paper the conditions for a specific titration of antibodies against the neuraminidase (N) of each of the two horse virus subtypes are defined. The antigens used are: the H72Neq 1 recombining agent to measure the anti Neq1 antibodies and the A/Duck/Ukraine/63 strain for the anti Neq2 antibodies. The immunity response to neuraminidase appears after the natural disease; this response is studied in two foci, one due to a virus belonging to the A equi I subtype (Loire 73 strain), the other to a virus of the A equi 2 subtype (SHN 73 strain). The kinetics of apparition of an...
Horká M, Kubíček O, Kubesová A, Rosenbergová K, Kubíčková Z, Šlais K.Influenza A is viral disease, which is a cause of yearly epidemics and, potentially, pandemics. The conventional techniques used today are equipment-demanding, time-consuming and laborious. Recently, we have confirmed that the capillary isoelectric focusing is a suitable fast alternative for the verifying of virus purity. In the wide pH gradient of pH range 2.0-7.5 the isoelectric points for subtypes of equine (H3N8) and swine (H1N2) influenza A viruses were determined approximately as 6.6 and 6.5, respectively. In this contribution we have verified these findings using different isolates of d...
BMC research notesJuly 12, 2014
Volume 7 448 doi: 10.1186/1756-0500-7-448
Boukharta M, Zakham F, Touil N, Elharrak M, Ennaji MM.The equine influenza (EI) is an infectious and contagious disease of the upper respiratory tract of horses. Two outbreaks were notified in Morocco during 1997 and 2004 respectively in Nador and Essaouira. The aims of the present study concern the amino acids sequences comparison with reference strain A/equine/Miami/1963(H3N8) of the HA2 subunit including the cleavage site of three equine influenza viruses (H3N8) isolated in Morocco: A/equine/Nador/1/1997(H3N8), A/equine/Essaouira/2/2004 (H3N8) and A/equine/Essaouira/3/2004 (H3N8). Results: The obtained results demonstrated that the substitutio...
Eichhorn W.Infections and clinical diseases caused by equine 2 influenza A viruses are observed worldwide. The frequency of these outbreaks supports the hypothesis that antigenic variation of the surface proteins may play an important role. For the demonstration of these variations, monoclonal antibodies (Mabs) were prepared. They are directed against the hemagglutinin or the neuraminidase of the prototype strain a/eq/Miami/1/63. In hemagglutination-inhibition assays with Mabs two reaction patterns were observed: four Mabs inhibited 14 out of 17 strains tested. Another Mab recognized the hemagglutinin of...
Adeyefa CA, McCauley JW, Tomori O.The complete amino acid sequences of the hemagglutinin (HA) glycoprotein of three equine-2 influenza viruses from tropical Africa are presented in comparison with that of a well characterized European equine-2 virus (Suffolk/89) and a consensus sequence from the database. The sequences of the tropical African viruses were deduced from the complete nucleotide sequences of their HA genes reported earlier. Mutational changes in the nucleotide sequences resulted in amino acid changes in the HA which led to the introduction of a new asparagine-linked (N-linked) glycosylation site in two viruses. Th...
Martín-Faivre L, Gaudaire D, Laugier C, Bouraïma-Lelong H, Zientara S, Hans A.Equine arteritis virus (EAV) is an Alphaarterivirus (family Arteriviridae, order Nidovirales) that frequently causes an influenza-like illness in adult horses, but can also cause the abortions in mares and death of newborn foals. Once primary infection has been established, EAV can persist in the reproductive tract of some stallions. However, the mechanisms enabling this persistence, which depends on testosterone, remain largely unknown. We aimed to establish an in vitro model of non-cytopathic EAV infection to study viral persistence. In this work, we infected several cell lines originating f...
Boussetta M, Chabchoub A, Ghram A, Jomaa I, Ghorbel A, Aouina T, Ben Amor H.Using the haemagglutination inhibition and immunodiffusion tests, a national serological survey was carried out to detect antibodies to equine influenza (EI) (A/equi/1/Prague 56 and A/equi/2/Miami 63) and equine infectious anaemia (EIA) in horse sera collected in northeastern Tunisia. 533 samples were analysed for EIA antibodies. All were negative. 13.6% of 433 equine sera tested for EI antibodies were positive. These results are discussed and compared with others obtained in Tunisia and bordering countries.
Tåmová B, Stumpa A, Zakopal J, Vĕzníková D, Mensík J.Equine influenza occurred in Czechoslovakia 14 years after the last epizootic in horses that had returned from abroad. Six strains A (Heq1Neq1) antigenically related to, but not identical with, strain A/eq/Praha/56 were isolated from 10 washings. Seroconversion was demonstrated with paired sera, but the antibody increase was more marked against the newly isolated strain.
Kawanishi N, Kinoshita Y, Kambayashi Y, Bannai H, Tsujimura K, Yamanaka T, Cullinane A, Nemoto M.Equine influenza virus (EIV) infection is one of the most important respiratory diseases in the equine industry around the world. Rapid diagnosis, facilitated by point-of-care testing, is essential to implement movement restrictions and control disease outbreaks. This study evaluated a microfluidic immunofluorescence assay kit, which detects influenza virus and SARS-CoV-2 antigens in human specimens with a 12 min turnaround time, for its potential use in detecting EIV. The microfluidic immunofluorescence assay kit succeeded in detecting 11 EIV strains. Using the real-time reverse transcription...
