The virus that causes foot-and-mouth disease (FMD) can survive for up to six months in certain types of material, which must be taken into account by farmers when taking biosecurity measures. This was the advice of Dr Aamira Vally, a veterinarian with the Agricultural Research Council Irene Animal Production, at a cattle farmers’ day at Dr Pieter de Kock’s farm near Thabazimbi.
By Charl van Rooyen, senior journalist at African Farming and Landbouweekblad
Dr Vally said it takes 3-28 days for an animal to show clinical signs.
The FMD virus can survive for 3-28 days in soil and for 2 days in the human pharyngeal cavity or pharynx (previously it was said to last for 5 days, but according to the newest research it is 2 days), during which it can transmit the virus to animals. It can survive for 14 days in dry manure, 39 days in urine, 20 weeks in hay and livestock’s bedding, and 6 months in wet manure.
She warned that FMD viruses that stick to organic matter at the bottom of a vehicle’s chassis pose a greater risk of contamination than the outer tires. The chassis must therefore be thoroughly disinfected.
The virus can be rendered harmless in several ways:
- exposure to sunlight
- temperature (higher than 56°C)
- extreme acidity (higher than pH6 and lower than pH9)
- chemical agents such as citric acid
- effective commercial disinfectants
- sodium carbonate (soda ash or washing soda)
- sodium hydroxide (caustic soda used in soaps and drain cleaners, among others)
- calcium hypochlorite (bleach or pool chlorine)
- vinegar
Also read: FMD | What to do while we wait for vaccines
The recommended biosecurity measures are:
- foot baths and hand sanitising
- disinfection of all vehicles at the farm gate
- wearing gloves when working with animals
- daily wearing of clean overalls and other clothing
- taking a full shower every day
- letting different workers work with different animal species
- not touching animals unnecessarily
Also read: FMD | Vaccine still on its way – ‘Keep your farm gates closed!’
Vally said the hooves and mouths of new animals taken to the farm should be examined for sores and blisters. Quarantine is a sensible step and the quarantine time varies depending on whether there are new cases,
If some of the animals have FMD, the farmer must report it to a state veterinarian. Then the entire farm is quarantined for six to twelve months, during which the farmer is not allowed to take away animals or their products.
In addition to her qualification as a veterinarian, Dr Aamira Vally also obtained a BSc honours degree in biochemistry which equips her with extensive knowledge of the epidemiology of viruses. At present she is doing her compulsory community service.
Also read:
FMD | Practical biosecurity advice from North West vets
FMD | A farmer shares what helped his animals recoverFrom crisis to prevention: New Proudly SA disinfectant proven to kill FMD virus
