Carolyn McBride has religiously vaccinated her Taranaki dairy herd against lepto for the past 30 years, so no one was more surprised than her when she contracted a nasty strain of the disease whose impact still rebounds on her seven years later.
Recurring chills, headaches and muscle aches are a sharp reminder of the leptospirosis infection she picked up seven years ago on the farm, and ultimately traced back to a strain from a Norwegian rat.
“I still have not got a clue as to how it came to be from a rat, I had never seen a black rat of any kind on the farm, they have not been what I would call a problem on the farm, but having said that there was the odd one caught by the cats,” she says.
Carolyn says lepto did not enter her or husband Jim’s mind when she first got ill, thinking it was the flu that was giving her chills and uncontrollable shivering.
“Things started to develop that made me think I had the flu, body aches, shivering, headaches and generally feeling unwell. Panadol would not alleviate the headache, but I did not immediately go to the doctor, thinking it was the flu and bed rest would work.”
But after eight days when she also became light sensitive, dehydrated and was vomiting she went to the doctor, bumping over the road in agony during the trip to town.
A repeat visit to the doctor the next day had her admitted to hospital where she was immediately put on intravenous antibiotics and a saline drip.
“There was some thought it could be meningitis, which can have similar symptoms to leptospirosis.”
Samples came back a day later confirming lepto, and an arduous treatment pathway followed.
“I was put on intravenous antibiotics three times a day, tested regularly to check my liver and spent two nights in hospital.” Her doctor told her when she was discharged she would be ready for work in 10 days.
“But it definitely was not 10 days. The effects, the tiredness especially lasted between 6-12 months. The worst thing for me was the headache which on a scale of 1-10 was a 20.”
Having it confirmed the infection was from a rat had her thinking she may have contracted it cleaning out the garage, and an infection entered through cuts on her hand.
“But I really have little idea how I encountered the urine of a rat.”
While vaccination rates in dairy herds are high, Massey University research shows the level of infections from leptospirosis have increased in the rural sector in recent years, with cases recorded over 2017 to 2019 leaping 90% to 140 a year.
Analysis has revealed equal numbers of dairy and dry stock farmers have been infected, despite the near 100% vaccination rate for dairy herds, indicating other sources of infection including rats are also spreading the disease.
Earlier this year automatic trap company Good Nature partnered up with Zoetis to distribute traps to selected dairy and dry-stock farmers in Wairarapa to help break the leptospirosis infection cycle.
Robbie van Dam, co-founder of Goodnature says the opportunity to set up the trap networks on the farms has a two-fold effect.
"Not only are they helping to break that cycle of leptospirosis transmission, but also help reduce the populations of pests that have a significant environmental impact, particularly on farms where farmers have been working to rebuild native biodiversity."
Carolyn says seven years on she still gets the occasional chill and headache. She since become extra vigilant about taking hygiene measures in the farm dairy, even though the original infection was not from their vaccinated herd.
“The vet did say although the herd is always vaccinated for lepto there is always still a chance of catching it from the cows, so I am wary of urine splashes when milking. I always wear gloves when milking, wash my hands and cover any cuts.
Rats are something she is also more aware of these days and they are now part of the Predator Free Taranaki programme.
“If there are any problems with rats, then we definitely have a trap put out.”