Lyme Disease Public Health Failure: Why Tick Control Lags Behind Malaria

While there are many differences between disease vectors and the infections they transmit,
the authors seek to answer a critical public health question:
Why did malaria and other mosquito-borne diseases elicit effective interventions,
while Lyme disease and other tick-borne illnesses have not?

Lyme disease is “one of the most challenging contemporary public health problems,”

writes Rochlin.
Although mosquito-borne diseases such as malaria are no longer major public health threats
in the United States, reported Lyme disease cases continue to rise.

“Malaria and Lyme disease were the largest vector-borne epidemics in recent U.S. history,”
the authors write. “The anti-malaria campaign involved large-scale public works eradicating
the disease within two decades.”

By contrast, no comparable national initiative has been undertaken for Lyme disease or
other tick-borne illnesses. “No large-scale vector control programs have been attempted
against ticks transmitting Lyme disease,” Rochlin points out.

In fact, the CDC—a federal agency originally created to combat malaria—“does not even have
a dedicated tick-borne disease branch,” Rochlin writes, despite the expanding geographic
reach of the Lyme epidemic.

“While malaria disappeared completely within two decades of vigorous efforts,
Lyme disease has been on the rise over the last 40 years.”

Why Public Health Approaches Differ

The CDC currently recommends personal protective measures, pesticide application to private
property, and landscaping modifications to reduce tick exposure. However, none of these
strategies have demonstrated a meaningful reduction in Lyme disease incidence.

“The Healthy People 2010 modest goal of a 50% reduction in Lyme disease incidence—from
17.4 to 9.7 per 100,000—was not met,” Rochlin writes. “Instead, incidence increased
threefold.”

“Because Lyme disease is almost never fatal, while malaria carried substantial mortality,
the public health approaches to these two diseases have been markedly different.”

Why Prevention Efforts Have Fallen Short

Although federal funding levels for malaria and Lyme disease have been similar, Rochlin
notes a key difference: “The vast majority of malaria funds were directed toward actual
control and prevention,” while Lyme disease funding has largely supported academic and
clinical research.

Preventive interventions for Lyme disease have yielded disappointing results, including:

• Backyard pesticide use reduced tick counts but had no impact on human disease or
  human–tick encounters.
• Educational interventions increased repellent use to approximately 40%, yet did not
  reduce tick exposure.
• Landscape modifications failed to provide protection against Lyme disease.
• Educational programs improved knowledge but did not decrease tick bites in highly
  endemic areas.
• There remains no definitive evidence linking deer population reduction to lower human
  disease rates.
• Pesticide-treated nesting materials reduced ticks on mice but did not affect the
  density or infection rate of questing ticks.

Even 4-poster devices designed to treat deer with topical acaricides showed inconsistent
results. While some studies demonstrated a threefold reduction in tick exposure, incidence
remained high, with erythema migrans rates of 137.8 per 100,000.

The authors conclude that the CDC “has failed to produce a single useful product for tick
control, host management, or a marketable vaccine.”

What Needs to Change

Rochlin and colleagues urge federal and state governments to lead large-scale, sustained
vector control initiatives to reduce tick populations. However, they acknowledge that
strategies such as deer population reduction or widespread vaccination would be difficult
to implement politically and logistically.

This analysis underscores a broader Lyme disease public health failure:
without coordinated national action, tick-borne diseases continue to expand while relying
on interventions that have not reduced human illness.