Microbicide Development Strategy Unveiled At International AIDS Conference

Today, leading microbicide experts
unveiled the Microbicide Development Strategy, a plan to accelerate the
development of a safe and affordable microbicide that could help women
reduce their risk of acquiring HIV and other sexually transmitted
infections. Microbicides are recognized as a promising new prevention
approach that could potentially turn the tide of the global HIV/AIDS
epidemic, and have been highlighted in speeches by Bill and Melinda Gates,
Bill Clinton, and other prominent speakers at the XVI International AIDS
Conference in Toronto.

The Microbicide Development Strategy (MDS) is the result of
consultation with more than 100 experts in the microbicide, HIV/AIDS, and
reproductive health fields over the past 18 months, and was initiated by
the Microbicide Donors’ Committee, supported by the Bill & Melinda Gates
Foundation, and coordinated by the Alliance for Microbicide Development.

The MDS will help guide donor decisions for investing in microbicide
research and development, and ensure that resources are used as effectively
as possible. The effort marks the first time that major donors have agreed
on a shared strategy for investing in microbicide development.

The MDS captures critical issues that have arisen in the rapidly
growing field of microbicide development, and identifies opportunities to
ensure that promising microbicide research moves forward as quickly as
possible. Key priorities in the MDS include:

— Developing improved scientific models and markers to help researchers
more quickly identify the most promising microbicide candidates

— Increasing capacity in developing countries to conduct clinical trials
of microbicides by increasing funding for recruiting, training, and
retaining trial staff, and facilitating communication among trial sites

— Expanding market research to better understand consumer preferences
regarding potential microbicide products

— Engaging experts to map regulatory pathways, including strategies to
obtain rapid approval of a microbicide that can be provided without a
prescription

— Developing combination microbicides with multiple mechanisms of action
“An effective microbicide would help put the power of HIV prevention in
the hands of women,” said Renee Ridzon, senior program officer at the Bill
& Melinda Gates Foundation. “This report provides a clear way forward on
microbicides, and it will be an invaluable guide for policymakers, funders,
and researchers.”

“With the widening pipeline of microbicide candidates, there is an
urgent need to build and expand clinical trial capacity in countries with
high HIV incidence rates,” said Professor Salim Abdool Karim, Director of
the Centre for the AIDS Programme of Research in South Africa (CAPRISA).
“Current capacity to conduct microbicide trials is inadequate to ensure
rapid studies of this next generation of microbicide candidates.”

Professor Abdool Karim also emphasized the importance of preparing to
ensure access to microbicides. “Those waiting for this product, especially
women in resource-constrained settings who most need microbicides, must
have access,” he said. “Just as much as we need to learn from failure, we
need to prepare for success. A successful trial that finds an effective
microbicide will need to be translated into public health action. This will
require innovation to address the range of logistical, financial, and
ethical issues involved in manufacturing and distributing this new form of
HIV prevention.”

Polly Harrison, Director of the Alliance for Microbicide Development,
said the creation of the MDS reflects that the microbicide field is at a
new stage. “What do we know now that we didn’t ten or even five years ago?
We didn’t talk about gaps then because, frankly, it was one big gap,” she
said. “Now, we have a real ‘fabric’ of research, development, and advocacy
as well as five pivotal trials currently in place from which we are
learning a great deal. We have candidates with unique mechanisms of action,
a set of theories and reasons for how a microbicide can interact with
target cells, and a variety of delivery mechanisms, formulations, and
evaluation approaches that are being developed and tested. And very
importantly, we have meaningful efforts at coordination which is
illustrated by the MDS.”

A copy of the MDS is available on microbicide.
The Alliance for Microbicide Development is a member of the Caucus for
Evidence-Based Prevention. Comprised of dozens of diverse organizations,
the Caucus for Evidence-Based Prevention was created for the specific
purpose of promoting HIV prevention supported by sound science at the XVI
International AIDS Conference. The Alliance defines itself as a catalyst,
communicator, convener, and problem-solver. It is a global coalition of
representatives from biopharmaceutical companies, nonprofit research
institutions, and health advocacy groups. It is the authoritative source of
information on microbicide development, convener of dialogue on key policy
issues, educator about the public health potential of microbicides, and
advocate for the resources needed to develop them.

Alliance for Microbicide Development
microbicide Continue reading

Douglas A. Jabs, M.D., Honored With Jackson Memorial Lecture By The American Academy Of Ophthalmology

Douglas A. Jabs, MD, MBA, Professor and Chair of the Department of Ophthalmology, CEO of the Faculty Practice Associates, and Dean for Clinical Affairs at The Mount Sinai Medical Center, has been selected to deliver the prestigious Jackson Memorial Lecture at the 2010 Annual Meeting of the American Academy of Ophthalmology. The lecture will be published in the November issue of the American Journal of Ophthalmology.

In a presentation titled “Cytomegalovirus Retinitis and AIDS: Bench to Bedside,” Dr. Jabs will discuss clinical and molecular research over the last 20 years on cytomegalovirus (CMV) retinitis, a viral inflammation in the retina, in people with AIDS. He will provide a synthesis of what researchers have learned about the pathogenesis of CMV retinitis and its interaction with HIV, reviewing several major epidemiologic studies.

“The data we have collected over the years has helped us better understand the behavior of cytomegalovirus retinitis at the molecular level, and bring that knowledge to the clinical setting,” said Dr. Jabs. “Understanding the virology of this opportunistic infection and how it interacts with HIV will help us develop optimal paradigms for treating it.”

A leading expert in inflammatory disorders of the eye, Dr. Jabs has co-authored more than 200 publications and 40 book chapters. His primary research interests include the treatment of uveitis, or the inflammation of the uvea in the eye, and ocular complications associated with AIDS and autoimmune diseases. He is chair of the Multicenter Uveitis Steroid Treatment (MUST) Trial Research Group, which is conducting clinical trials of treatments for severe uveitis, and the Studies of Ocular Complications of AIDS (SOCA) Research Group, which has conducted several randomized, multicenter, controlled trials on CMV retinitis and a long-term cohort study of the ocular complications of AIDS in the current era.

“We are proud that the American Academy of Ophthalmology has recognized Dr. Jabs and his work in CMV retinitis and AIDS,” said Dennis Charney, M.D., Anne and Joel Ehrenkranz Dean of Mount Sinai School of Medicine and Executive Vice President for Academic Affairs at The Mount Sinai Medical Center. “His commitment to ground-breaking translational research in ophthalmology makes him a true asset to Mount Sinai and to the field.”

Prior to joining Mount Sinai, Dr. Jabs was the Alan C. Woods Professor of Ophthalmology and Professor of Medicine at The Johns Hopkins University School of Medicine, Professor of Epidemiology at The Johns Hopkins University Bloomberg School of Public Health, and the Director of the Division of Ocular Immunology at The Wilmer Eye Institute. After receiving his medical degree from The Johns Hopkins University School of Medicine he completed an internship in internal medicine at Cornell Medical Center/New York Hospital, a residency in internal medicine at The Johns Hopkins Hospital, a residency in ophthalmology at The Wilmer Eye Institute, and a fellowship in rheumatology at The Johns Hopkins Medical Institutions. In 1984, he joined the faculty at The Johns Hopkins University School of Medicine, where he remained until joining Mount Sinai in 2007.

Dr. Jabs has received several awards for his research and clinical accomplishments, including the Research to Prevent Blindness Olga Keith Wiess Scholar Award, the Research to Prevent Blindness Lew R. Wasserman Merit Award, the Research to Prevent Blindness Senior Scientific Investigator, the American Academy of Ophthalmology Achievement Award and Senior Achievement Award, and the Ethel Baxter Award for Excellence in Research from the Sj?¬∂gren’s Syndrome Foundation.

The Jackson Memorial Lecture is named for Dr. Edward Jackson, who helped establish the modern ophthalmology field. He helped create the American Board of Ophthalmology and developed its first board examination. He also helped pave the way for future medical conference both within Ophthalmology and in other fields by advocating for instructional courses at the annual meeting. Previous Jackson Memorial Lecturers include: Harry A. Quigley, MD, who spoke about Angle Closure Glaucoma; Frederick L. Ferris III, MD, whose lecture focused on the benefit of clinical trials beyond evaluating treatment effect; and Edwin M. Stone, MD, PhD, who discussed the role of genetic testing in finding a cure for Leber Congenital Amaurosis.

“I am honored and humbled to follow in the footsteps of the long line of research pioneers in ophthalmology who have delivered the Jackson Memorial Lecture,” said Dr. Jabs. “I hope my presentation will help stimulate discussion of improving clinical outcomes in patients with AIDS and CMV retinitis.”

Source:
Mount Sinai Press Office
The Mount Sinai Hospital / Mount Sinai School of Medicine Continue reading

Uganda’s Ministry Of Health To Reintroduce Female Condoms

Uganda’s Ministry of Health will reintroduce female condoms as part of its HIV/AIDS prevention program in response to increased demand, IRIN/PlusNews reports. According to IRIN/PlusNews, the government in 2007 halted distribution of the female condom because of insufficient demand and complaints that the condoms were not user-friendly. However, a recent health ministry analysis determined that women in the country sought an HIV prevention method that allowed them control over preventing sexually transmitted infections, including HIV, and unintended pregnancies.

Vashta Kibirige, coordinator of the condom unit at the health ministry, said the ministry will distribute about 100,000 female condoms, primarily in the eastern and central parts of Uganda. According to IRIN/PlusNews, some women in the western area of the country do not support the reintroduction of the female condom because they do not believe it is supportive of their culture. Kibirige said the ministry would conduct an awareness campaign to promote acceptance of the female condom in all regions of the country.

According to IRIN/PlusNews, the female condoms will be available at government health centers for a small fee. However, advocates argue that some Ugandan women will not be able to afford the fee and therefore will not obtain condoms. Sylvia Namabidde, a member of Uganda’s parliament, said the fee might encourage some women to reuse the condoms, which raises health and hygiene issues. According to IRIN/PlusNews, Uganda in 1999 obtained 1.5 million female condoms and distributed some at no cost. However, the remaining condoms are still on the shelves of the National Medical Stores, IRIN/PlusNews reports (IRIN/PlusNews, 2/12).

Reprinted with kind permission from kaisernetwork. You can view the entire Kaiser Daily Health Policy Report, search the archives, or sign up for email delivery at kaisernetwork/dailyreports/healthpolicy. The Kaiser Daily Health Policy Report is published for kaisernetwork, a free service of The Henry J. Kaiser Family Foundation.

© 2009 Advisory Board Company and Kaiser Family Foundation. All rights reserved. Continue reading

Naryx Pharma Announces Completion Of Enrollment Of A Phase 2b Clinical Trial Of SybryxTM For Chronic Sinusitis

Naryx Pharma, Inc., a leader in the development of new therapies for patients with chronic sinusitis, has completed enrollment of a 180 subject, randomized, double-blind, placebo-controlled Phase 2b trial of SybryxTM (tobramycin solution for nasal inhalation) for the treatment of chronic sinusitis in patients who have undergone previous sinus surgical procedures. The results of the trial will be announced after unblinding the data in the first quarter of 2008.

Previously, the U.S. Food and Drug Administration had granted Fast Track status to SybryxTM, acknowledging that chronic sinusitis that persists after sinus surgery has a serious and enduring adverse impact on the day-to-day functioning of patients who suffer from the condition. Moreover, there are no currently approved medical therapies for the treatment of chronic sinusitis, and the results of a previous Phase 2a trial demonstrated that SybryxTM relieved the symptoms of chronic sinusitis in post-surgical patients.

Robin Campbell, Ph.D., President and CEO of Naryx Pharma, stated, “We are pleased that we have completed this milestone in the development of SybryxTM and would like to thank all of the investigators who are participating in the trial. Many patients are suffering from chronic sinusitis, and we look forward to continuing to develop a treatment for this serious and sometimes debilitating disease.”

About Naryx Pharma

Naryx™ is a privately-held company dedicated to developing innovative therapies for chronic sinusitis, based on advances in the targeted delivery of medications. Chronic sinusitis is a disease that afflicts up to 35 million people in the U.S. alone. The Company will focus on obtaining marketing approvals for its promising intellectual property portfolio of intranasal drug formulations.

naryxpharma Continue reading

$16M Awarded To Pitt’s School Of Medicine For HIV Structural Biology Center

The National Institutes of Health (NIH) has announced that it is awarding the University of Pittsburgh School of Medicine a $16 million, five-year grant to establish the Pittsburgh Center for HIV Protein Interactions (PCHPI). Research at the center will give scientists detailed new insights into the life of HIV, the virus that causes AIDS, and have important implications for developing new drug targets.

One of three centers being funded jointly by the National Institute of General Medical Sciences (NIGMS) and the National Institute of Allergy and Infectious Diseases (NIAID), the PCHPI will specialize in developing methods and tools for understanding what happens to the HIV virus, both structurally and at an atomic level, immediately after it enters the cell and prior to becoming integrated into the host genome. By doing this, PCHPI researchers will be able to identify which cellular processes and components are hijacked by HIV for its nefarious purposes.

“We know how HIV attaches to its host and how it gains entry to cells, but what happens between when it first enters into the cells and when it integrates itself into the host genome is still a mystery. By elucidating the important events during this period, we believe we’ll learn a great deal about the how the virus can be stopped,” said PCHPI director, Angela Gronenborn, Ph.D., the University of Pittsburgh Medical Center Rosalind Franklin Professor and chair of the department of structural biology, University of Pittsburgh School of Medicine. Dr. Gronenborn, who recently was elected to the National Academy of Sciences, is one of the country’s leading structural biologists and an internationally renowned specialist in the application of nuclear magnetic resonance (NMR) spectroscopy for investigating the biochemical mechanisms and cellular structures involved in HIV pathogenesis. The other two NIH-funded HIV structural biology centers are led by Alan Frankel, Ph.D., a biochemist at the University of California, San Francisco, and Wesley Sundquist, Ph.D., a biochemist at the University of Utah.

Although researchers have determined the structures of many HIV proteins in isolation, they know the structures of only a few HIV proteins in their functional state, that is, when they interact with cellular components of host cells. Because HIV works through such interactions, knowing their structures will provide targets for new generations of anti-AIDS drugs. Center researchers will use NMR and X-ray crystallography to identify and characterize atomic structures of key virus interactions and other pivotal events in the immediate post-entry stage of the viral life cycle. They also will use advanced imaging technologies such as cryo-electron tomography to better study the structure of HIV and the host cellular components with which it interacts.

As part of its mission to collaborate with researchers nationally and globally, the center will make the methods and tools it develops available to the HIV research community at large. These resources are expected to have major impact in the global fight against AIDS, which is estimated to afflict more than 40 million people worldwide.

“HIV is so challenging to treat because the virus is extremely adept at evolving resistance against therapies that target individual HIV proteins. Efforts by Dr. Gronenborn and her colleagues to identify and image pivotal virus-host cell interactions could forge new avenues for drug discovery,” explained Ravi Basavappa, Ph.D., the NIGMS program director for the new centers.

In addition to studying the structure and interactions of HIV using advanced technologies, another focus of the center will be to engage virologists, cell biologists and structural biologists in a collaborative effort toward deciding which of these interactions make the best drug targets.

“For many years, structural biologists and virologists have not worked closely in the area of HIV-targeted drugs. This center will allow the two to work collaboratively and help them to determine fairly quickly whether their hypotheses about what happens at the molecular and atomic levels of HIV infection are accurate,” said Dr. Gronenborn.

###

The University of Pittsburgh School of Medicine is considered among the nation’s leading medical schools, renowned for its curriculum that emphasizes both the science and humanity of medicine and its remarkable growth in National Institutes of Health (NIH) grant support, which has more than doubled since 1998. For fiscal year 2005, the University ranked seventh, out of more than 3,000 entities receiving NIH support, with respect to the research grants awarded to its faculty. The majority of these grants were awarded to the faculty of the medical school. As one of the university’s six Schools of the Health Sciences, the School of Medicine is the academic partner to the University of Pittsburgh Medical Center. Their combined mission is to train tomorrow’s health care specialists and biomedical scientists, engage in groundbreaking research that will advance understanding of the causes and treatments of disease and participate in the delivery of outstanding patient care.

Source: Jim Swyers

University of Pittsburgh Schools of the Health Sciences Continue reading

Ekaterina Helwein To Be Honoured At American Society For Microbiology Conference

The 2008 American Society for Microbiology (ASM) ICAAC Young Investigator Award will be presented to Ekaterina Heldwein, Assistant Professor, Department of Molecular Biology and Microbiology, Tufts University, Boston, Massachusetts. Sponsored by the ASM, this award recognizes early career scientists for excellence in research in microbiology and infectious diseases.

Dr. Heldwein’s research is centered on herpes simplex virus and cytomegalovirus. These two viruses have relevance to the susceptibility to and treatment of HIV/AIDS and other diseases of immunocompromised people. She gained prominence in her field by studying viral pathogenesis, in particular the cell entry mechanisms of herpesviruses, using structural techniques. In 2007, Dr. Heldwein was named a Pew Scholar and awarded the prestigious NIH Director’s New Innovator Award and the Zucker Center Award.

Dr. Heldwein received her M.S. in Chemistry from Lomonosov Moscow State University, Russia, and her Ph.D. in Biochemistry from Oregon Health and Sciences University.

The ICAAC Young Investigator Award will be presented during ASM’s 48th Interscience Conference on Antimicrobial Agents and Chemotherapy/46th IDSA Annual Meeting, October 25 – October 28, 2008 in Washington, DC. ASM is the world’s oldest and largest life science organization and has more than 43,000 members worldwide. ASM’s mission is to advance the microbiological sciences and promote the use of scientific knowledge for improved health and economic and environmental well-being.

###

Source: Jim Sliwa

American Society for Microbiology Continue reading

FDA Approves New HIV Treatment

The U.S. Food and Drug Administration today approved Edurant (rilpivirine) in combination with other antiretroviral drugs for the treatment of HIV-1 infection in adults who have never taken HIV therapy (treatment-naive).

Edurant belongs to a class of HIV drugs called non-nucleoside reverse transcriptase inhibitor (NNRTI). The drug works by blocking HIV viral replication. Edurant is to be used as part of a highly active antiretroviral therapy (HAART) regimen that is designed to suppress the amount of HIV (viral load) in the blood. Edurant is a pill taken once a day with food.

“Patients may respond differently to various HIV drugs or experience varied side effects. FDA’s approval of Edurant provides an additional treatment option for patients who are starting HIV therapy,” said Edward Cox, M.D., M.P.H, director, Office of Antimicrobial Products in the FDA’s Center for Drug Evaluation and Research.

The safety and effectiveness of Edurant is based on 48-week data from two Phase 3 clinical trials with 1,368 adult subjects with HIV infection, and from a 96-week (with extension to 192 weeks) trial. Patients had not received prior HIV therapy and were selected to receive treatment with Edurant or efavirenz (another FDA-approved NNRTI for the treatment of HIV infection). Both drugs were given in combination with other antiretroviral drugs.

Edurant was as effective as efavirenz in lowering viral load. In the Edurant and efavirenz groups, 83 percent and 80 percent of subjects, respectively, had undetectable amounts of HIV in their blood after 48 weeks of treatment. Patients receiving Edurant who had a higher viral load at the start of therapy were more likely not to respond to the drug than were patients with a lower viral load at the start of therapy. In addition, persons who failed therapy with Edurant developed more drug resistance than patients who failed efavirenz.

The most commonly reported side effects in patients taking Edurant included depression, difficulty sleeping (insomnia), headache and rash. Fewer patients stopped taking the drug due to side effects as compared to patients taking efavirenz.

Edurant does not cure HIV infection. Patients must stay on continuous HIV therapy to control HIV infection and decrease HIV-related illnesses.

Edurant is manufactured by Raritan, N.J.-based Tibotec Therapeutics, a division of Centocor Ortho Biotech Inc.

Source:

U.S. Food and Drug Administration

View drug information on Edurant. Continue reading

Thai Health Ministry Breaks Patent, Issues Compulsory License For Abbott’s Antiretroviral Kaletra

Thailand’s Ministry of Public Health on Monday said that it has broken a patent on Abbott Laboratories’ antiretroviral drug Kaletra by issuing a compulsory license to produce a lower-cost version of the drug, Reuters UK reports. According to Health Minister Mongkol na Songkhla, the compulsory license was signed into law and took effect on Friday (Pongpiphat, Reuters UK, 1/29). World Trade Organization regulations allow governments to declare a “national emergency” and issue compulsory licenses without consulting the foreign patent owner. Thailand, which has 580,000 people living with HIV/AIDS, has won international recognition for its quick launch of a national drug program that treats more than 82,000 HIV-positive people. However, the government’s commitment to providing universal access to care is facing increasingly high drug costs (Kaiser Daily HIV/AIDS Report, 1/26). Kaletra currently costs about $347 per patient monthly, and the lower-priced version could cost about $120 per patient monthly, according to Medecins Sans Frontieres (AFP/Yahoo! News, 1/29). According to Reuters UK, the compulsory license could save the country as much as $24 million annually. “We have to do this because we don’t have enough money to buy safe and necessary drugs for the people under the government’s universal health scheme,” Mongkol said. Some HIV/AIDS advocates welcomed the announcement concerning Kaletra, according to Reuters UK (Reuters UK, 1/29). According to MSF, lowering the cost of Kaletra will make the drug more widely available. Some pharmaceutical companies criticized the decision, saying that they might have to reconsider their investments in Thailand (AFP/Yahoo! News, 1/29). According to Teera Chakajnorodom, chair of the Pharmaceutical Research and Manufacturers’ Association, the group might petition the country’s Administrative Court, which rules on the legality of government actions, to block the compulsory license (Reuters UK, 1/29). “After the company does 10 years of research, and then suddenly the Thai government would like to impose the compulsory license, taking away their property, their assets — this is not a good practice,” Teera said, adding that the government says the drug is “far too expensive for the Thai public to have access. But they never approached the companies before. Everything is negotiable” (Zamiska, Wall Street Journal, 1/30).

“Reprinted with permission from kaisernetwork. You can view the entire Kaiser Daily Health Policy Report, search the archives, or sign up for email delivery at kaisernetwork/dailyreports/healthpolicy. The Kaiser Daily Health Policy Report is published for kaisernetwork, a free service of The Henry J. Kaiser Family Foundation . © 2005 Advisory Board Company and Kaiser Family Foundation. All rights reserved.

View drug information on Kaletra Capsules and Oral Solution. Continue reading

Policymakers Should Discuss How To Promote Circumcision if Proven an Effective HIV Prevention Method, Editorial Says

HIV/AIDS policymakers “should be discussing how to promote circumcision so they can be ready to act immediately” if studies confirm the findings of recent research showing that the practice can reduce the risk of HIV transmission, according to a New York Times editorial (New York Times, 10/15). The study, released in July, found that circumcision can reduce by about 65% the risk of men contracting HIV through sexual intercourse with women. The randomized, controlled clinical trial enrolled more than 3,000 HIV-negative, uncircumcised men ages 18 to 24 living in a South African township. Half of them were randomly assigned to be circumcised, and the other half served as a control group, remaining uncircumcised. After 21 months, 51 of the uncircumcised men had contracted HIV, compared with 18 of the circumcised men, and the procedure prevented six to seven out of 10 potential HIV infections (Kaiser Daily HIV/AIDS Report, 8/9). Researchers are conducting two similar studies in Kenya and Uganda, and the results are expected in about two years, the editorial says. “Circumcision is no easy sell,” but it might “offer a way to curb the AIDS explosion in some of the most affected nations,” the editorial says, adding, “If an AIDS vaccine were suddenly discovered that could prevent seven out of 10 new infections, the world would be rejoicing” (New York Times, 10/15).

“Reprinted with permission from kaisernetwork. You can view the entire Kaiser Daily Health Policy Report, search the archives, or sign up for email delivery at kaisernetwork/dailyreports/healthpolicy. The Kaiser Daily Health Policy Report is published for kaisernetwork, a free service of The Henry J. Kaiser Family Foundation . ¬© 2005 Advisory Board Company and Kaiser Family Foundation. All rights reserved. Continue reading

Adaptation By Lyme Disease Tick

A new study offers a detailed look at the status of Lyme disease in Central Illinois and suggests that deer ticks and the Lyme disease bacteria they host are more adaptable to new habitats than previously appreciated.

Led by researchers at the University of Illinois, the study gives an up-close view of one region affected by the steady march of deer ticks across the upper Midwest. Their advance began in Wisconsin and Minnesota and is moving at a pace of up to two counties a year in Illinois and Indiana.

Today the deer tick is established in 26 Illinois counties, up from just eight in 1998, said Illinois Department of Public Health entomologist Linn Haramis. Reports of human Lyme disease cases in the state have more than tripled in the same period, he said.

“We’ve had several years in a row where we’ve had over 100 cases, up from about 30 per year more than 10 years ago,” Haramis said. “It’s not a huge increase, but it’s been steady and there’s an upward trend.”

Deer ticks are known to do best in forested areas, where they can readily move from small mammals (which provide their first meal) to moist leaf litter on the forest floor, and then to deer, on which they mate. Deer ticks do not pick up the Lyme infection from deer, said Jennifer Rydzewski, who completed her master’s degree with the study in the department of natural resources and environmental sciences at the University of Illinois.

“The deer tick will feed on a variety of mammals, birds and even reptiles,” she said. “But Borrelia burgdorferi, the bacterium that causes Lyme disease, replicates really well within white-footed mice, so white-footed mice are the main reservoir that passes that bacterium on to the immature ticks that are feeding on it.”

White-footed mice also are forest dwellers. Prior to the new study, little was known about whether, or how, Lyme disease persists in other habitat types.

To determine if Lyme disease had gained a foothold in the patchwork of forests, farms and prairies of Central Illinois, researchers trapped small mammals in Allerton Park, a 1,500-acre (600-hectare) natural area in Piatt County. They focused on four habitat types: young forest, mature forest, a flood plain and a 30-acre (12-hectare) patch of prairie surrounded by woods and agricultural fields.

The researchers removed deer ticks from the mammals they trapped and tested the ticks for Lyme disease.

They found that the immature forest and the prairie hosted the highest percentage of deer-tick-infested mammals, the highest number of ticks per mammal trapped and the highest rates of ticks infected with Lyme disease of the four habitat types evaluated.

“The highest prevalence of B. burgdorferi infection was found (in deer tick larvae) from the prairie (27 percent) followed by the young forest (15 percent), the mature forest (6 percent) and the flood plain (6 percent),” the researchers wrote.

“Interestingly, all of the positive ticks from the prairie were from prairie voles, not the typical white-footed mouse,” Rydzewski said. There also were many more ticks per animal on the prairie voles than on the white-footed mice of the forest, she said.

This is the first study to report evidence that the prairie vole may potentially serve as a competent reservoir host for the Lyme disease bacterium, B. burgdorferi, said Nohra Mateus-Pinilla, a wildlife veterinary epidemiologist at the Illinois Natural History Survey who led the study with Rydzewski and natural resources and environmental sciences emeritus professor Richard Warner. (The Survey is a unit of the Prairie Research Institute at Illinois.)

“The fact that we found tick larvae feeding so prominently on prairie voles and those ticks were infected and hadn’t had a chance to feed on anything else is a very strong indicator that we are dealing with a different reservoir of Lyme disease that deserves more attention,” Mateus-Pinilla said.

The researchers hypothesize that when newly hatched ticks find themselves on the prairie, they latch on to the first small mammal that comes along, which in most cases is a prairie vole (white-footed mice prefer the forest). The abundance of prairie voles in the prairie is much lower than that of the white-footed mice in the forest, so more tick larvae and nymphs end up on the same few prairie voles. Since the number of ticks per animal is higher on the prairie, the likelihood of infection is higher there as well.

“The landscape of Illinois, especially the northern and central area, is very fragmented with agricultural and other development, so there aren’t really big continuous areas that are forested,” Rydzewski said. “And so maybe these ticks are finding new habitats to establish themselves in because of the lack of previous habitats.”

“What’s exciting about the new findings is that we are dealing with potentially new mechanisms of disease transmission that we just have not explored and perhaps we do not understand,” Mateus-Pinilla said. “We need to think outside of what we already know about Lyme disease transmission.”

The new study appears in the journal Vector-Borne and Zoonotic Diseases.

Researchers from the U. of I. department of pathobiology and Michigan State University also contributed to this study.

Source:
Diana Yates

University of Illinois at Urbana-Champaign Continue reading