Warning as Lepto cases rise

VACCINATION OPTION: Veterinarians point to vaccination as a way to deal with leptospirosis. "It really does stack up financially," said Dr Andrew Cribb from East Coast Farm Vets. "In deer, vaccination has been shown to increase growth rates by 6.1kg and a 5-10 percent weaning increase." Picture supplied

VETERINARIANS in the district have noted a rise in Leptospirosis cases this year and they urge farmers to ensure it has a place in their on-farm health and safety processes.

East Coast Farm Vets veterinarian Dr Andrew Cribb said there have been more cases of it noted in Tairawhiti this year than usual.

The warning also applies to the Wairoa district where the Wairoa Star reports a dramatic increase in the number of clinical cases of Leptospirosis in humans this year.

“Double the number of confirmed cases has been reported this year compared to last year and we have also seen an increase in dogs presenting with the disease,” a Star article said.

Dr Cribb said Leptospirosis was a complicated disease that occurs throughout New Zealand and the world.

“It can infect most mammals including sheep, cattle, deer, goats and dogs.

“It is one of New Zealand’s most important diseases that can be transmitted from animals to humans and as such, it should have a place in all on-farm health and safety policies.”

He said Leptospirosis was complicated in that there were “maintenance” and “accidental” hosts and there were many types of Leptospira.

“For example, Leptosprira pomona, the maintenance host is the pig.

“If a pig contracts Leptospira pomona, there are mild or no clinical signs shown. However, if a cattle beast contracts Leptospira pomona, severe disease occurs.”

Clinical signs can include loss of appetite, abortion (at any stage after the 4th month of gestation, but most commonly in the 6th and 7th months), stillborn or weak and stillborn calves, mastitis, and possible issues with infertility.

“Animals that recover from Leptospirosis continue to excrete leptospires in their urine for a long period of time. For up to 11 months,” Dr Cribb said.

“Leptospires survive well when there are cool, moist environmental conditions and when pH is in the range of 6-8.

“Areas where there are stagnant water and contaminated effluent are the major sources of infection in the environment,” he said.

Dr Cribb said infection in humans was relatively common in agricultural workers, rural veterinarians, abattoir workers (highest incidence are workers from sheep abattoirs) and forestry workers.

“There are two types of infection in humans. In 90 percent of cases, severe flu-like symptoms are encountered, but the immune system will mount an effective response.

“In 10 percent of cases the clinical signs are similar but the body will not mount an effective immune response, and without medical intervention liver and kidney failure can occur.”

Human infection was most likely to occur by contamination with infected urine (for example, urine splashes into the eye, nose, mouth), he said.

“Infection from contact with urine, abortion or placental material may also enter through the skin.

“Consumption of raw milk, from a cow from in the acute phase of infection can also pose a risk of infection.”

Dr Cribb said control was based on vaccination as well as minimising the spread of infection via the environment.

“Calves need to be vaccinated as soon as practically possible to prevent infection.

“The timing of vaccination is contentious and needs to be discussed with your veterinarian.”

Other control measures include the control of rodents, keeping pigs and cattle separate, fencing off or draining contaminated water supplies.

VETERINARIANS in the district have noted a rise in Leptospirosis cases this year and they urge farmers to ensure it has a place in their on-farm health and safety processes.

East Coast Farm Vets veterinarian Dr Andrew Cribb said there have been more cases of it noted in Tairawhiti this year than usual.

The warning also applies to the Wairoa district where the Wairoa Star reports a dramatic increase in the number of clinical cases of Leptospirosis in humans this year.

“Double the number of confirmed cases has been reported this year compared to last year and we have also seen an increase in dogs presenting with the disease,” a Star article said.

Dr Cribb said Leptospirosis was a complicated disease that occurs throughout New Zealand and the world.

“It can infect most mammals including sheep, cattle, deer, goats and dogs.

“It is one of New Zealand’s most important diseases that can be transmitted from animals to humans and as such, it should have a place in all on-farm health and safety policies.”

He said Leptospirosis was complicated in that there were “maintenance” and “accidental” hosts and there were many types of Leptospira.

“For example, Leptosprira pomona, the maintenance host is the pig.

“If a pig contracts Leptospira pomona, there are mild or no clinical signs shown. However, if a cattle beast contracts Leptospira pomona, severe disease occurs.”

Clinical signs can include loss of appetite, abortion (at any stage after the 4th month of gestation, but most commonly in the 6th and 7th months), stillborn or weak and stillborn calves, mastitis, and possible issues with infertility.

“Animals that recover from Leptospirosis continue to excrete leptospires in their urine for a long period of time. For up to 11 months,” Dr Cribb said.

“Leptospires survive well when there are cool, moist environmental conditions and when pH is in the range of 6-8.

“Areas where there are stagnant water and contaminated effluent are the major sources of infection in the environment,” he said.

Dr Cribb said infection in humans was relatively common in agricultural workers, rural veterinarians, abattoir workers (highest incidence are workers from sheep abattoirs) and forestry workers.

“There are two types of infection in humans. In 90 percent of cases, severe flu-like symptoms are encountered, but the immune system will mount an effective response.

“In 10 percent of cases the clinical signs are similar but the body will not mount an effective immune response, and without medical intervention liver and kidney failure can occur.”

Human infection was most likely to occur by contamination with infected urine (for example, urine splashes into the eye, nose, mouth), he said.

“Infection from contact with urine, abortion or placental material may also enter through the skin.

“Consumption of raw milk, from a cow from in the acute phase of infection can also pose a risk of infection.”

Dr Cribb said control was based on vaccination as well as minimising the spread of infection via the environment.

“Calves need to be vaccinated as soon as practically possible to prevent infection.

“The timing of vaccination is contentious and needs to be discussed with your veterinarian.”

Other control measures include the control of rodents, keeping pigs and cattle separate, fencing off or draining contaminated water supplies.

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