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Tick Control Crucial to Preventing Fatal Disease

The brown dog tick, a common pest in Arizona, is the cause of Rocky Mountain Spotted Fever, an often-fatal disease that affects Arizona's reservations

Preventing Rocky Mountain Spotted Fever, an often-fatal tick-borne disease, on Arizona’s American Indian reservations would be less costly than treating the disease and dealing with the long-term consequences, according to an article from the Centers for Disease Control, Indian Health Service and two Arizona tribes published in The American Journal of Tropical Medicine and Hygiene.

RMSF affects mostly healthy children and young adults, requires emergency room visits in more than 80 percent of the cases and has a 7-percent fatality rate in Arizona in cases where patients receive treatment, compared with a less-than-1-percent rate nationwide.

Survivors frequently need rehabilitative care and may be permanently disabled. The illness has been endemic in the U.S. for more than a hundred years and reached epidemic proportions on some Arizona reservations in 2003.

The illness can be hard to identify because it presents with non-specific symptoms. On the other hand, early treatment (before the fifth day of symptoms) with the antibiotic doxycycline is essential to avoiding severe long-term consequences, such as neurological deficits, damage to internal organs or death. The death rate for untreated cases of RMSF is 20 percent.

Typical symptoms include “fever, headache, abdominal pain, vomiting, and muscle pain. A rash may also develop, but is often absent in the first few days, and in some patients, never develops,” according to the CDC.

The CDC reports that there has been some reluctance among parents and doctors to use doxycycline in children under 8 years because it was associated with staining of the teeth. New research from CDC and IHS, however, shows that “short courses of the antibiotic doxycycline can be used in children without causing tooth staining or weakening of tooth enamel.” According to the CDC, doxycycline is the most effective treatment or RMSF, which is more likely to be fatal in children than in adults.

There is no vaccine for RMSF, which is caused by the bacterium Rickettsia rickettsii and spread through the bite of the brown dog tick, so prevention efforts must focus on getting rid of the ticks that transmit the disease to humans.

Naomi Drexler, an epidemiologist at the Rickettsial Zoonoses Branch, Division of Vector-borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases at the CDC, said in a statement, "State, federal and tribal health authorities have been working together since the start of the epidemic to build effective community-based tick control programs, and these efforts have produced remarkable reductions in human cases.”

Tribally-run tick control programs include placing tick collars on dogs and treating homes and lawns. These programs have been effective but are expensive.

Drexler added, “These programs are costly, but medical expenses and lives lost cost four times more than Rocky Mountain spotted fever prevention efforts. Increasing access to these prevention efforts is critical to save lives and protect communities.”

The study is based on a review of cases of RMSF on the two hardest-hit Arizona American Indian reservations between 2002 and 2011. Indian Health Service and referral hospital records identified 205 cases; 29 people were admitted to the ICU; 15 died. “The recent emergence of RMSF in Arizona has left devastation in its wake. This severe, but relatively isolated outbreak has cost millions of dollars in medical fees and economic productivity lost,” according to the article.

Researchers looked at direct medical costs associated with acute medical care and indirect costs associated with productivity lost due to illness and premature death were calculated and found that the cost of RMSF in these two communities was $13.2 million. This amount does not include the costs of special medical procedures or long-term losses from disability. The two tribes that participated in the study preferred not to be identified.