Leptospirosis cases have more than quadrupled in Hawke’s Bay

Mud and silt in Esk Valley after Cyclone Gabrielle. Muddy or silty water can spread leptospirosis. Photo / Paul Taylor

Leptospirosis has spiked in Hawke’s Bay with five times the number of usual cases reported.

Te Whatu Ora Public Health Hawke’s Bay says there have been 15 leptospirosis cases in the year to March 8.

In previous years, there were zero to three cases for the same period.

Dr Simon Baker, medical officer of health, said Hawke’s Bay summers were usually very dry. However, as leptospirosis bacteria survives longer in wet soil, wider leptospirosis outbreaks tend to be more common after heavy rain and flooding.

Seven of the 15 confirmed cases in 2023 were confirmed before Cyclone Gabrielle, which is likely due to the region’s wet summer.

“Leptospirosis, or ‘lepto’, is an infection which can sometimes be picked up from contaminated water or mud after flooding. It can be picked up by drinking contaminated water, or through skin when cuts or grazes are exposed to contaminated water or mud,” he said.

It can make people very unwell with fevers, headaches, sore muscles, tummy pain, vomiting, diarrhoea and red eyes. Sometimes people can become much more unwell after a week or so.

The most important thing is to try to prevent people from getting lepto in the first place, he said.

This means avoiding contact with flood waters or mud where possible, not eating any fruit, vegetables or other food that have had contact with flood waters and ensuring water is safe to drink.

Baker said if contact with flood waters or mud was necessary, it was important to cover cuts or grazes with a dressing, and clean them well with soapy water,particularly before eating or drinking, and wearing protective clothing.

“It usually takes five to 14 days for the symptoms to develop. It is unusual for leptospirosis to be spread from one person to another.”

The Pest Management Association of New Zealand (PMANZ) had earlier reported the cases.

“Over the last three weeks there have been many people involved in the clean-up of silt, moving around standing water, completely unaware of the risk of leptospirosis,” a PMANZ statement read.

“Leptospirosis can live in host animals such as rats. Rats will shed large amounts of this infectious bacteria in their urine into our environment such as damp soil or silt and stagnant flood waters.”

The PMANZ statement said the bacteria can spread through contact with your mouth and nose, as well as into cuts and abrasions.

Leptospirosis can be treated with antibiotics.

The New Zealand Veterinary Association (NZVA) is encouraging pet owners in flood affected areas to keep an eye on their pets’ health, as animals can become seriously ill from leptospirosis.

“It is commonly transmitted in the urine of infected farm animals and rodents that can be spread into the environment via floodwater, so dogs that come into contact with floodwater are at risk,” Sally Cory from NZVA said.

If you feel unwell, you should contact your GP immediately, who will prescribe a course of antibiotics. You can also call Healthline (0800 611 116) for advice. If you are worried your symptoms are getting worse, you should seek urgent care or go to an emergency department.

Common symptoms include:

· Fever and chills

· Headaches and lethargy

· Aching muscles

· Red eyes

· Nausea and vomiting