Deer cannot be blamed for increase in Lyme disease

Transmission of Lyme disease from deer to humans generates public fear and is being used by cull advocates to justify a slaughter

The argument of deer being the culprit for transmission of Lyme disease to humans generates public fear and is being used by cull advocates to justify a slaughter.

Lyme disease is not a significant problem in B.C. and deer are not directly responsible for transmitting the infection to humans.

Recent studies show that there is no correlation between deer population and incidence of Lyme disease. In one of these studies,  removal of up to 80-90 per cent of deer did not significantly reduce the tick numbers.

In fact, sometimes the opposite effect is observed.

This is because deer are not efficient hosts in terms of transmitting the disease – mice and other small mammals are much more efficient in this regard.  There are at least 27 species of mammals serving as effective hosts for adult ticks and, in the absence of deer, ticks simply feed on other species.  Therefore the very term “deer tick” is misleading.

Leading Lyme disease expert Richard Ostfeld confirms in his book Lyme disease – The ecology of a Complex System that “Human risk of exposure to Lyme disease is correlated with the abundance of immature (rodent) hosts and their food resources, not deer numbers.” And “Deer culls merely produce temporary declines in tick populations, as ticks feed on other – more efficient – hosts (tick populations will increase even if the deer population decreases).”

Lyme disease is a very real and serious condition which causes a lot of suffering to those who have it, but blaming the innocent deer for that against scientific evidence is simplistic and unfair.

N.R. Spogliarich, Associate Professor of General and Inorganic Chemistry (Retired)

Saanich