Tweet
Source: http://www.stuff.co.nz/stuff/4500420a3600.html
Unvaccinated sheep 'pose serious risk'
NZPA | Tuesday, 29 April 2008
A new study of Hawke's Bay meatworkers butchering sheep has revealed 10 per cent of them have been exposed leptospirosis, confirming sheep pose a serious risk as carriers of the bacterial disease.
Leptospirosis affects the kidneys in humans and can have effects ranging from a mild flu-like condition to renal failure requiring hospitalisation.
Meatworkers are now one of the occupations most at risk of contracting leptospirosis, and made up a third of notifications in 2006. Te Puke meatworker Johnny Taewa, 50, died after he caught the disease in February 2005 at Affco's Rangiuru works.
During 2003-2005 leptospirosis led to 207 hospitalisations, but researchers believe that many cases are not reported as it takes up to 10 days for leptospirosis to be detected by blood tests, and mild cases can be mis-diagnosed as influenza.
Researchers said today the true incidence of leptospirosis is probably many times the reported incidence.
After Mr Taewa's death, industry sources admitted the disease was increasingly showing up in meatworkers. Historically, dairy farmers have been its most common victims, usually infected by splashes of urine carrying the bacteria to broken skin or to their eyes, nose or mouth.
Many farmers have refused to vaccinate sheep against the disease to protect meatworkers.
Vaccination of the national sheep flock would cost more than $10 million a year and a 2003 study said farmers would need to see production benefits before they would be willing to spend the money.
But the most recent study into the disease ? a joint project between Massey University and meat company PPCS Ltd ? has focussed on a high number of cases among Hawke's Bay meatworkers.
Massey researcher Dr Jackie Benschop will present results of the study at the Veterinary Association annual conference starting in Wellington on June 25.
She said today that preliminary findings showed 13 of the 15 patients of those admitted to intensive care at Hawke's Bay hospital suffering from leptospirosis from 1999-2005 were employed as meatworkers or meat inspectors.
In February and March 242 blood samples were taken from volunteers from the PPCS Takapau plant and 23 (9.5 per cent), tested positive to antibodies for the disease.
"These workers had occupational exposure to sheep only and this, in combination with our results, adds weight to the hypothesis that sheep are an important source of leptospiral infections for humans" said Dr Benschop.
A slaughterhouse survey in lambs found 59 per cent of lines had one or more carcasses with antibodies to two of the types of leptospirosis bacteria ? hardjo-bovis or pomona.
Exposure to hardjo-bovis and pomona in beef herds is also high, with prevalence estimates over 50 per cent for the hardjo-bovis type, and a survey of 110 deer farms found hardjo-bovis was present on 61 per cent of them.
The researchers now plan to also investigate exposure to "lepto" among farmers and veterinarians.
"Disease control in New Zealand has focused on dairy cattle and pigs, however an estimated 90 per cent of beef and 10 per cent of dairy herds are still not vaccinated," she said. "Exposure from deer and sheep is also high".
Massey University's EpiCentre leptospirosis team, led by Associate Professor Cord Heuer, is still analysing the data, and checking where any of the workers had "lifestyle exposure" to leptospirosis outside the meatworks.
Further analysis will also show whether the workers most exposed to the disease are those doing the major cuts on the slaughterboard, or are further down the chain, doing work such as boning.
Keith Sandilands, PPCS health and safety manager, said the company had a rigorous policy around the wearing of personal protective equipment.
The Rural Women New Zealand lobby will present a cheque for leptospirosis research to Dr Benschop at its national conference in Blenheim, on May 19.
Unvaccinated sheep 'pose serious risk'
NZPA | Tuesday, 29 April 2008
A new study of Hawke's Bay meatworkers butchering sheep has revealed 10 per cent of them have been exposed leptospirosis, confirming sheep pose a serious risk as carriers of the bacterial disease.
Leptospirosis affects the kidneys in humans and can have effects ranging from a mild flu-like condition to renal failure requiring hospitalisation.
Meatworkers are now one of the occupations most at risk of contracting leptospirosis, and made up a third of notifications in 2006. Te Puke meatworker Johnny Taewa, 50, died after he caught the disease in February 2005 at Affco's Rangiuru works.
During 2003-2005 leptospirosis led to 207 hospitalisations, but researchers believe that many cases are not reported as it takes up to 10 days for leptospirosis to be detected by blood tests, and mild cases can be mis-diagnosed as influenza.
Researchers said today the true incidence of leptospirosis is probably many times the reported incidence.
After Mr Taewa's death, industry sources admitted the disease was increasingly showing up in meatworkers. Historically, dairy farmers have been its most common victims, usually infected by splashes of urine carrying the bacteria to broken skin or to their eyes, nose or mouth.
Many farmers have refused to vaccinate sheep against the disease to protect meatworkers.
Vaccination of the national sheep flock would cost more than $10 million a year and a 2003 study said farmers would need to see production benefits before they would be willing to spend the money.
But the most recent study into the disease ? a joint project between Massey University and meat company PPCS Ltd ? has focussed on a high number of cases among Hawke's Bay meatworkers.
Massey researcher Dr Jackie Benschop will present results of the study at the Veterinary Association annual conference starting in Wellington on June 25.
She said today that preliminary findings showed 13 of the 15 patients of those admitted to intensive care at Hawke's Bay hospital suffering from leptospirosis from 1999-2005 were employed as meatworkers or meat inspectors.
In February and March 242 blood samples were taken from volunteers from the PPCS Takapau plant and 23 (9.5 per cent), tested positive to antibodies for the disease.
"These workers had occupational exposure to sheep only and this, in combination with our results, adds weight to the hypothesis that sheep are an important source of leptospiral infections for humans" said Dr Benschop.
A slaughterhouse survey in lambs found 59 per cent of lines had one or more carcasses with antibodies to two of the types of leptospirosis bacteria ? hardjo-bovis or pomona.
Exposure to hardjo-bovis and pomona in beef herds is also high, with prevalence estimates over 50 per cent for the hardjo-bovis type, and a survey of 110 deer farms found hardjo-bovis was present on 61 per cent of them.
The researchers now plan to also investigate exposure to "lepto" among farmers and veterinarians.
"Disease control in New Zealand has focused on dairy cattle and pigs, however an estimated 90 per cent of beef and 10 per cent of dairy herds are still not vaccinated," she said. "Exposure from deer and sheep is also high".
Massey University's EpiCentre leptospirosis team, led by Associate Professor Cord Heuer, is still analysing the data, and checking where any of the workers had "lifestyle exposure" to leptospirosis outside the meatworks.
Further analysis will also show whether the workers most exposed to the disease are those doing the major cuts on the slaughterboard, or are further down the chain, doing work such as boning.
Keith Sandilands, PPCS health and safety manager, said the company had a rigorous policy around the wearing of personal protective equipment.
The Rural Women New Zealand lobby will present a cheque for leptospirosis research to Dr Benschop at its national conference in Blenheim, on May 19.