Epidemiological investigations on the role of clinically healthy racing pigeons as a reservoir for avian paramyxovirus-1 and avian influenza virus

Abstract

Clinically healthy racing pigeons may harbour notifiable pathogens and serve as an unnoticed reservoir. Thus, 3480 healthy racing pigeons from 172 different lofts were monitored over a period of 2 years for the presence of avian influenza virus (AIV) and avian paramyxovirus-1 (APMV-1). Pharyngeal and cloacal swabs as well as blood samples were collected from juvenile and adult pigeons. Pools of five pharyngeal swabs per loft and age group were initially screened by real-time reverse transcriptase-polymerase chain reaction (rRT-PCR). Pharyngeal and cloacal samples from lofts that were positive or suspect in the AIV rRT-PCR or the APMV-1 rRT-PCR were inoculated into embryonated chicken eggs for virus isolation. In addition, sera were examined for antibodies against AIV by enzyme-linked immunosorbent assay. The antibody levels after vaccination against APMV-1 were determined by haemagglutination inhibition assay. Of the investigated lofts, 0.0 to 1.4% were positive by rRT-PCR for APMV-1 and 0.0 to 6.7% for AIV during this 2-year period with a total of four samplings. No sample yielded replicating virus in egg culture. No antibodies against AIV were detected. Haemagglutination inhibition test of vaccinated racing pigeons indicated age-dependent APMV-1 titres. The results suggest that the examined racing pigeons may have had contact with AIV, but virus replication may have been too low to induce detectable circulating antibody levels. Only a low percentage of samples were positive for APMV-1, but two outbreaks were observed in monitored flocks, indicating ongoing circulation of APMV-1 in the racing pigeon population. These observations highlight the relevance of APMV-1 vaccination and indicate the importance of flock immunity.

Pigeons are resistant to experimental infection with H7N9 avian influenza virus

“…Although several reports described the isolation of avian influenza virus from pigeons or the detection of different subtypes of influenza virus by RT-PCR (Gronesova et al, 2009;Mansour et al, 2014), the majority of the studies showed that pigeons are generally resistant to avian influenza virus replication and are not likely to be a major reservoir and transmission host for avian influenza virus (Liu et al, 2007;Kohls et al, 2011;Smietanka et al, 2011;Yamamoto et al, 2012;Teske et al, 2013;Kalthoff et al, 2014;PantinJackwood et al, 2014). Here, we investigated the susceptibility of pigeons to avian H7N9 subtype.…”

Investigation into diseases in free-ranging ring-necked pheasants (Phasianus colchicus) in northwestern Germany during population decline with special reference to infectious pathogens

“…Furthermore, marble spleen disease caused by siadenovirus has already been described as a common disease in pheasants raised on farms but not yet in free-ranging individuals (Fitzgerald et al 1992;Fitzgerald and Reed 1989;Pennycott 2000). The disease occurs naturally in pheasants 3-8 months of age (Swayne 2013). Characteristic pathomorphological lesions are splenomegaly associated with yellow and gray-white spots on the spleen's surface resulting in the characteristic marble-like look (Orlic et al 2003), but normal appearance of spleen can also occur (Pennycott 2000;Pennycott 2001).…”

“…Characteristic pathomorphological lesions are splenomegaly associated with yellow and gray-white spots on the spleen's surface resulting in the characteristic marble-like look (Orlic et al 2003), but normal appearance of spleen can also occur (Pennycott 2000;Pennycott 2001). Other typical gross lesions are oedematous congested lungs (Fitzgerald and Reed 1989;Swayne 2013). Data about the occurrence of infectious bursal disease in pheasants are controversial.…”

Microbiological and parasitological survey of zoonotic agents in apparently healthy feral pigeons

“…from pigeons, direct transmission to humans has not yet been reported (Haag-Wackernagel and Moch 2004). On the basis of their studies regarding the adhesion and invasion models, Teske et al (2013) suggested that pigeon-derived C. jejuni isolates were capable of infecting human enterocytes and producing the virulence factor cytolethal-distending toxin.…”

“…A review of health hazards caused by feral pigeons reported one single case of S. enterica serotype Kiambu infection in man (Haag Wackemagel and Moch 2004). In a two-year study carried out on racing pigeons, Teske et al (2013) reported a range from a minimum of 0.9 to 3.7% of the positive lots investigated. In older studies (Vindevogel and Duchatel, 1979) the incidence of Salmonella spp.…”