OBSERVATIONS ON LEPTOSPIRA HARDJO INFECTION IN NEW SOUTH WALES

Leptospirosis in Animals and Man

“…In severely anaemic calves appropriate supportive therapy such as blood transfusion should be considered. Streptomycin has been found to give a good clinical response in cows suffering from L. hardjo mastitis and it appeared that treatment at this stage reduced the risk of subsequent abortion (Hoare and Claxton 1972). Also in cattle and in pigs with established leptospiruria it has been demonstrated that a single intramuscular dose of streptomycin at a dose rate of 25 mg/kg permanently eliminates urinary excretion of leptospires within 24 hours.…”

“…Leptospires are excreted in the milk, but the leptospirocidal effect of milk would be expected to minimise the public health risk. Following outbreaks of L. hardjo mastitis, abortions have been observed in 510% of affected cows (Hoare and Claxton 1972). The interval between infection and abortion varied from 6 to 12 weeks.…”

Leptospira Interrogans Serovar Hardjo Infection of Cattle

“…The high reactor rates found in the surveys may be attributed to the sub-clinical nature of L. hardjo infection in the cattle population (Hoare and Claxton 1972), and the longevity of the immune response in individual animals. Although the microscopic agglutination (MA) test can at best be regarded as serogroup specific (Turner 1968), serovar hardjo is the sole member of the Hebdomadis serogroup to be isolated from Victorian cattle to date (Gordon 1977).…”

Leptospira Serogroup Hebdomadis Infection as an Australian Zoonosis

“…The first recorded Australian isolation of hardjo was from a cow in 1969 (Sullivan and Stallman 1969) and there have subsequently been a number of reports of farm worker infections attributed to this serovar (Corbould 1971;Davidson 1971;Stallman 1972;Gordon 1977). It has been suggested that the incidence of human infection with hardjo may in fact be even higher than is presently assumed (Davidson 1971;Hoare and Claxton 1972). This present study illustrates an outbreak of leptospirosis in farm workers caused by a member of the Hebdomadis serogroup (probably serovar hardjo) and emphasises the high incidence of infection with this serogroup in a sample of adult Victorian cattle.…”