HAEMOPHILUS INFECTIONS
STEPHANIE SPECK
Bundeswehr Institute of Microbiology, Department of Virology and Rickettsiology, Munich, Germany
Species in the genus Haemophilus, family Pasteurellaceae are Gram-negative, small pleomorphic rods or coccoba- cilli.
Many Haemophilus are commensals or pathogens of the mucous membranes of animals and humans, most commonly of the upper respiratory and lower genital tracts. Host specificity is a characteristic of Haemophilus species. Haemophilus paragallinarum causes infectious coryza, with inflammation of the paranasal sinus and nasal cavity, in chickens worldwide. It has also been reported in quail, guinea fowl and pheasants, but not in free-living wild birds.Haemophilus parasuis inhabits the nasopharynx of healthy pigs. It is the primary agent of Glasser’s disease (fibrinous inflammation of serous surfaces), a worldwide disease in young pigs, characterized by polyserositis and occasionally meningitis. In older pigs infectious arthritis and pneumonia are seen. Stress (transport, weather, weaning) predisposes animals to Glasser’s disease.
There are two reports regarding H. parasuis in European wild boar (Sus scrofa). In northeastern Spain, H. parasuis was isolated from 2/42 nasal swabs of shot wild boar(75). Two different strains of H. parasuis serotype 2 were obtained. 16S rRNA and multilocus sequence typing (MLST) analyses revealed that these isolates were grouped with non-virulent pig reference strains and were not related to strains isolated from systemic lesions. Owing to the lack of reports regarding Glasser’s disease in wild boar, the authors suggested that the boar strains might be less virulent and constitute part of the respiratory microbiota in this species. The other report refers to H. parasuis antibody detection in wild boar shot in Slovenia(74). Eighteen per cent (33/178) of the animals were seropositive. Another serological study conducted in south-central Spain did not find any positive cases(76). In conclusion, little information is available on H. parasuis in wild boar, and further investigations are needed regarding virulence of Haemophilus strains as well as susceptibility of the wild boar host.