Excerpt:

Ticks harbor numerous bacterial, protozoal, and viral pathogens
that can cause serious infections in humans and domestic animals.
Active surveillance of the tick vector can provide insight into
the frequency and distribution of important pathogens in the
environment. Nucleic-acid based detection of tick-borne
bacterial, protozoan, and viral pathogens requires the extraction
of both DNA and RNA (total nucleic acids) from ticks. Traditional
methods for nucleic acid extraction are limited to extraction of
either DNA or the RNA from a sample.
Here we present a simple bead-beating based protocol for
extraction of DNA and RNA from a single tick and show detection
of Borrelia burgdorferi and Powassan virus from individual,
infected Ixodes scapularis ticks. We determined expected yields
for total nucleic acids by this protocol for a variety of adult
tick species. The method is applicable to a variety of arthropod
vectors, including fleas and mosquitoes, and was partially
automated on a liquid handling robot.

Excerpt:

During the years 1999–2002, a total of 4,898 individuals of 26 species of hematophagous insects (4,149 mosquitoes, 583 black flies, and 166 tabanid flies) was examined for the presence of spirochetes using dark-field microscopy.

There was an overall recovery of spirochetes from the midguts of Culicidae and Simuliidae of 23.5% and 11.4%, respectively. Spirochetes were not detected in Tabanidae.

Seven spirochetal strains have been successfully recovered from mosquitoes and black flies: BR149 (Culex pipiens), BR151 (Cx. pipiens), BR173 (Cx. pipiens), BR177 (Cx. pipiens), BR193 (Aedes cinereus), BR208 (Cx. pipiens), and BR231 (Simulium noelleri). The strains have been adapted to laboratory conditions (BSK-H Complete medium). Their preliminary determination based on 16S rRNA gene sequencing has shown that they differ from the Lyme disease spirochete Borrelia burgdorferi sensu lato as well as other members of the Order Spirochaetales indicating novel bacterial species in the Family Spirochaetaceae.

Excerpt:

As experts from around the world met in New York this week they discussed the need for greater understanding of the threat posed by ticks, fleas and sand flies. Leading scientists called on veterinarians and dog-owners around the world to take action to protect dogs and humans from potentially lethal diseases.

Ticks, mosquitoes, fleas and, in some countries, sand flies are critical in the transmission of diseases to both dogs and humans, including life-threatening conditions such as Lyme Disease, Leishmaniasis and other important diseases such as Ehrlichiosis.

In Italy, dogs and cats are at risk of becoming infected by
different vector-borne pathogens, including protozoa, bacteria,
and helminths. Ticks, fleas, phlebotomine sand flies, and
mosquitoes are recognized vectors of pathogens affecting cats and
dogs, some of which (e.g., Anaplasma phagocytophilum, Borrelia
burgdorferi, Dipylidium caninum, Leishmania infantum, Dirofilaria
immitis, and Dirofilaria repens) are of zoonotic concern. Recent
studies have highlighted the potential of fleas as vectors of
pathogens of zoonotic relevance (e.g., Rickettsia felis) in this
country. While some arthropod vectors (e.g., ticks and fleas) are
present in certain Italian regions throughout the year, others
(e.g., phlebotomine sand flies) are most active during the summer
season.

Excerpt: http://www.liai.org/

Finding has major implications for efforts to develop a first-ever vaccine against the dangerous infectious disorder

SAN DIEGO – (February 11, 2010) A leading immunology research institute has validated the long-held and controversial hypothesis that antibodies – usually the “good guys” in the body’s fight against viruses – instead contribute to severe dengue virus-induced disease, the La Jolla Institute for Allergy & Immunology announced today. The finding has major implications for the development of a first-ever vaccine against dengue virus, a growing public health threat which annually infects 50 to 100 million people worldwide, causing a half million cases of the severest form.

“Our lab has proven the decades old hypothesis that subneutralizing levels of dengue virus antibodies exacerbate the disease,” said La Jolla Institute scientist Sujan Shresta, Ph.D, noting this occurs in people with secondary dengue virus infections who have antibodies to the virus due to a previous infection. “This is a situation where antibodies can be bad for you, which is counter to everything we know about the normal function of antibodies. It also presents a special challenge for researchers working to develop a dengue virus vaccine, since most vaccines work by prompting the body to produce antibodies.”

¶ Minnesota health officials last week reported the state’s first death from Rocky Mountain spotted fever, as well as the state’s second-ever case of brain inflammation from the Powassan virus _ similar to West Nile, but spread by ticks instead of mosquitoes.

¶ Officials are also watching to see if the lone star tick, which can spread a Lyme-like disease, establishes itself permanently. The tick until recently wasn’t often found north of southern Iowa, but about a dozen have been identified in Minnesota this year. So far, no infections have been reported.

¶ Scientists aren’t sure why tick populations are expanding, but many suspect one factor could be that subtle changes in the climate are tipping the ticks’ complicated ecosystems toward expansion. The Minnesota Health Department has applied for a grant to study how climate change is affecting the state’s tick population, and Wisconsin is seeking funding for its own study.

¶ “We think about climate change all the time,” said David Neitzel, a Minnesota department expert in insect-borne diseases. With climate change, he said, “There is going to be a change in all the diseases we work on.”

¶ Deer ticks are a well-known threat to infect humans with their bite. Lyme disease, the best known infection spread by ticks, can result in fever, headache, fatigue and rash, and if left untreated can linger and spread damage to joints, the heart and the nervous system.

¶ Rocky Mountain spotted fever is spread by the American dog tick, also called the wood tick. While the tick is common in Minnesota, the bacteria is considered very rare here. Nationally, most cases are in the southeastern U.S. The symptoms include fever, vomiting, severe headache and a distinctive spotted rash.

¶ While none of the Upper Midwest states do a comprehensive tick census, they track the spread of ticks by following up on confirmed disease cases, doing some of their own sampling and identifying ticks sent in by the public.

¶ In Minnesota, deer ticks have expanded to the northwest from the traditional high-risk areas of eastern and central Minnesota. Neitzel said he’s seen it personally on his property in Becker County.

¶ “I’ve been stomping around up there since the early 1970s, but in just the last few years we’re seeing black-legged ticks up there,” he said. Deer ticks are also known as black-legged ticks.

¶ Canadian health officials report a growing deer tick population just north of Minnesota’s northern border, where there were none in the early 1990s. In Wisconsin, the ticks are marching from the northwest to the southeast. And in Iowa, the deer ticks are moving from the northeast toward the southeast and the center of the state.

¶ “We’re watching it, and certainly we’re concerned,” said Dr. Patty Quinlisk, Iowa state epidemiologist.

¶ The number of Lyme disease cases has been climbing in each state since 1993, according to figures from the Centers for Disease Control and Prevention. The number of cases more than doubled from 2000 to 2007 in all three states, reaching 1,814 cases in Wisconsin, 1,238 cases in Minnesota and 123 cases in Iowa.

¶ In Canada, government health researcher Nicholas Ogden found that in the early 1990s there was only one area infested by the ticks. Now, there are tick populations all along the northern border of Minnesota and the northeastern United States.

¶ “Recent studies have suggested that the risk of exposure to Lyme disease is emerging in Canada because the range (of the black-legged tick) is expanding, a process that is predicted to accele rate with climate change,” he wrote in a June 2009 article of the Canadian Medical Association Journal.

¶ Melissa Kemperman, an expert in tick-borne diseases with the Minnesota Department of Health, said a changing climate can affect many variables for the ticks. “It’s not just the heat and humidity,” she said.

¶ For example, if birds and mammals move into new territory their ticks could hitch a ride. If that new habitat has plenty of food and shelter _ and doesn’t get too cold in the winter _ the ticks could get established year-round, she said.

¶ Also, humans can change tick habitat. To cite just one example, Neitzel said, when timber companies cut down an older section of a forest the new growth is better for ticks. There are more ground-level shrubs to live in and more mice and deer on which to feed.

¶ Public health officials say the changes mean anyone who goes into the woods needs to be extra vigilant. It also means that more doctors need to be on the lookout for tick-borne diseases in their patients.