Over 600,000 vector-borne disease cases were reported in the United States (U.S.) in the past 13 years, of which more than three-quarters were tick-borne diseases. Although Lyme disease accounts for the majority of tick-borne disease cases in the U.S., tularemia cases have been increasing over the past decade, with >220 cases reported yearly. However, when comparing Borrelia burgdorferi (causative agent of Lyme disease) and Francisella tularensis (causative agent of tularemia), the low infectious dose (<10 bacteria), high morbidity and mortality rates, and potential transmission of tularemia by multiple tick vectors have raised national concerns about future tularemia outbreaks. Despite these concerns, little is known about how F. tularensis is acquired by, persists in, or is transmitted by ticks. Moreover, the role of one or more tick vectors in transmitting F. tularensis to humans remains a major question. Finally, virtually no studies have examined how F. tularensis adapts to life in the tick (vs. the mammalian host), how tick endosymbionts affect F. tularensis infections, or whether other factors (e.g., tick immunity) impact the ability of F. tularensis to infect ticks. This review will assess our current understanding of each of these issues and will offer a framework for future studies, which could help us better understand tularemia and other tick-borne diseases.
About half of US tularemia cases are associated with tick bite, and annual cases are slowly increasing.
http://www.siumed.edu/medicine/id/tularemia.htm Tularemia, in aerosol form, is considered a possible bioterrorist agent that if inhaled would cause severe respiratory illness. It was studied in Japan through 1945, the USA through the 60’s, and Russia is believed to have strains resistant to antibiotics and vaccines. An aerosol release in a high population would result in febrile illness in 3-5 days followed by pleuropneumonitis and systemic infection with illness persisting for weeks with relapses. The WHO estimates that an aerosol dispersal of 50 kg of F. tularensis over an area with 5 million people would result in 25,000 incapacitating casualties including 19,000 deaths.
Two Exotic Disease-Carrying Ticks Have Just Been Identified in Rhode Island
Hannah C. Sep 29, 2020
Local authorities in Rhode Island announced that two new tick species were identified on Block Island. The tick species were traced back to Eurasia and Asia origins.
Dr. Danielle Tufts from Columbia University identified the two species Haemaphysalis longicornis(Asian long-horned tick) and Haemaphysalis punctata (red sheep tick), reported the state’s Department of Environmental Management (DEM). (See link for article)
(Photo: Asian long-horned tick, adult female dorsal view climbing on a blade of grass – Photo by James Gathany; CDC)
Both ticks are considered live-stock pests but they can and do bite humans, transmitting diseases. Farmers, hunters, and hikes are at greater risk.
A tick species associated with bats has been reported for the first time in New Jersey and could pose health risks to people, pets and livestock, according to a Rutgers-led study in the Journal of Medical Entomology.
This species (Carios kelleyi) is a “soft” tick. Deer ticks, which carry Lyme disease, are an example of “hard” ticks.
“All ticks feed on blood and may transmit pathogens (disease-causing microbes) during feeding,” said lead author James L. Occi, a doctoral student in the Rutgers Center for Vector Biology at Rutgers University-New Brunswick. “We need to be aware that if you remove bats from your belfry, attic or elsewhere indoors, ticks that fed on those bats may stay behind and come looking for a new source of blood.There are records of C. kelleyi biting humans.” (See link for article)
A few important points:
A related species, Carios jersey, was found in amber 2001
C. kelleyi has been found in 29 states so far
Public health risk remains unknown, but it has been found to be infected with harmful pathogens in other states
There are reports of this tick feeding on humans
The bat it feeds on regularly roosts in attics and barns
As if Newtown Health District Director Donna Culbert was not busy enough handling coronavirus issues, she is now grappling with the news that the aggressive lone star tick is proliferating in the region.
Culbert, who has made tickborne disease education a hallmark of her administration, told The Newtown Bee this week that the latest news from colleague Goudarz Molaei, PhD, at the Connecticut Agricultural Experiment Station (CAES) is disturbing considering how many local residents are already suffering from related illnesses.
“The Newtown Health District is always concerned about tick bites and tick-borne disease, and news of the lone star tick becoming established in the region adds to the concern,” Culbert said. “Although our office has not yet received a lone star tick submitted to our office for identification yet this year, I am not naive enough to think that they aren’t out there.”
Review Connecticut’s latest information about the lone star tick by CLICKING HERE (See link for article)
Previously limited to the southeastern US, lone star ticks have been detected in areas with no previous record of activity….
We present a young pregnant woman who developed ulceroglandular tularaemia following a bite wound from a kitten. She grew Francisella tularensis from the ulcer. While awaiting bacterial culture results and serology for Bartonella, she was treated with azithromycin, with resolution of fever and axillary tenderness. Treatment recommendations for tularemia are either gentamicin or doxycycline, both of which can be perilous to the fetus.A Centers for Disease Control and Prevention report on the macrolide susceptibility of North American isolates of this organism has been underappreciated. The unanticipated result from this patient may give another potential option for treatment of tularemia in pregnancy.
Now, Dr. Brown said an increasing number of cases of tularemia that were transmitted by a tick bite are being seen. Tularemia is transmitted by dog ticks, which also can transmit Rocky Mountain spotted fever. Lyme disease, babesiosis and erlichiosis, which are transmitted by tiny deer ticks, also occur on the Vineyard.
And with the relatively recent spread on the Island of lone star ticks, a new species, Dr. Brown said there is added concern about the potential for more disease transmission.
The number of reported cases of human tularemia has increased significantly in Sweden during the end of July and the beginning of August, according to the Public Health Agency of Sweden, or Folkhälsomyndigheten (computer translated).
A total of 212 confirmed cases have been reported, significantly more than reported during an average year, officials note.
Most cases of illness have been reported from Dalarna, Gävleborg and Örebro counties, but the last week also saw an increase in the counties of Västerbotten and Norrbotten. Since the number of illness cases is usually highest in September, the outbreak is expected to grow further in the coming weeks.
The animals most likely to carry the disease are wild hares, hence the name rabbit fever, aka tularemia and rodents, but it can also be transferred to humans via mosquito bites and occasionally tick bites.
Tularemia can be transmitted to people, such as hunters, who have handled infected animals. Infection can also arise from the bite of infected insects (most commonly ticks and deer flies); by exposure to contaminated food, water, or soil; by eating, drinking, putting hands to eyes, nose, or mouth before washing after outdoor activities; by direct contact with breaks in the skin; or by inhaling particles carrying the bacteria (through mowing or blowing vegetation and excavating soil).
Typical signs of infection in humans may include fever, chills, headache, swollen and painful lymph glands, and fatigue. If tularemia is caused by the bite of an infected insect or from bacteria entering a cut or scratch, it usually causes a skin ulcer or pustule and swollen glands. Eating or drinking food or water containing the bacteria may produce a throat infection, mouth ulcers, stomach pain, diarrhea and vomiting. Inhaling the bacteria may cause an infection of the lungs with chest pain and coughing.
Tularemia can be effectively treated with antibiotics. Untreated tularemia can lead to hospitalization and may be fatal if not diagnosed and treated appropriately.