An outbreak of cryptosporidiosis in a collection of Stone curlews (Burhinus oedicnemus) in Dubai

Kasamyra Zylan,Tom Bailey,Huw V Smith,Christudas Silvanose,Joerg Kinne,Rolf K Schuster,Kevin Hyland

doi:10.1080/03079450802357019

Abstract

We describe an outbreak of cryptosporidiosis in Stone curlews kept in a mixed-species rearing unit in Dubai. Cryptosporidium was the predominant intestinal pathogen detected, although microbiological investigations revealed a concurrent Salmonella infantis infection in two of the 29 Stone curlew chicks that died. Nineteen of 29 birds had catarrhal enteritis associated with histopathological findings of numerous Cryptosporidium developmental stages at the mucosal surface. Catarrhal enteritis was present without associated Cryptosporidium oocysts in five cases. Histology of the intestine, faecal examination by direct microscopy and antigenic detection by immunochromatography revealed the presence of Cryptosporidium spp. associated with catarrhal enteritis in intestinal sections and faeces. Clinical and histopathological outcomes of infection were severe, including disruption of intestinal epithelial integrity, the presence of numerous endogenous Cryptosporidium stages in intestinal epithelia and the excretion of large numbers of sporulated oocysts. The application of polymerase chain reaction and restriction fragment length polymorphism techniques at two 18S rRNA and one Cryptosporidium oocyst wall protein gene locus confirmed the presence of Cryptosporidium parvum DNA in faecal samples.

Highlights

Captive breeding programmes have been established in Dubai and other locations in the United Arab Emirates for Stone curlews (Burhinus oedicnemus)
We describe an outbreak of cryptosporidiosis in Stone curlews kept in a mixed-species rearing unit in Dubai
Faecal examination by direct microscopy and antigenic detection by immunochromatography revealed the presence of Cryptosporidium spp. associated with catarrhal enteritis in intestinal sections and faeces

Summary

Introduction

Captive breeding programmes have been established in Dubai and other locations in the United Arab Emirates for Stone curlews (Burhinus oedicnemus) They are a popular quarry for Arab falconers and attempts are made to manage local Stone curlew populations by the release of captive bred birds. There are two major clinical presentations of avian cryptosporidiosis*enteric and respiratory*dependent on the species with which birds are infected. Enteric disease can be caused by C. baileyi and C. meleagridis, and presents as lethargy, reduced growth rate, diarrhoea, morbidity and mortality. C. galli infects the proventriculus, causing diarrhoea and high mortality (Morgan et al, 2001; Ryan et al, 2003b; Xiao et al, 2004). Respiratory cryptosporidiosis is due to C. baileyi infection and clinical signs include depression, lethargy, anorexia, unthriftiness, coughing, sneezing, gurgling, dyspnoea and conjunctivitis (Sreter & Varga, 2000)

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