A Lesser Known Tick-borne Illness: The Powassan Virus

28th Aug 2015 Diseases

Tick-borne illness in Florida and the U.S. has been on the rise. Lyme disease, Rocky Mountain spotted fever, and Babesiosis are some of the most widely reported diseases that occur from tick bites. Many have never heard of the Powassan virus, but it has the potential to cause more morbidity and mortality than these other tick borne illnesses.

The Powassan virus is spread by being bitten by an infected tick. The disease is named for the town in Ontario, Canada where the virus killed a young boy in the 1950’s. While the disease is found in the same type of tick that hosts Lyme disease, the Powassan virus is significantly faster acting and in many cases is untreatable.

At present there are six known species of tick that host the Powassan virus and are typically found in Canada, Minnesota and the northeastern U.S.. Since the virus was first identified in 1958, 70 cases have been reported. In reality, this number may actually be greater as there are no specific tests available for the Powassan virus and many may mistake it for Lyme disease.

There are no medications to treat the Powassan virus. Unlike Lyme disease which can take a couple of days before infection sets in, ticks infected with the Powassan virus can inject the virus within a few hours. Symptoms can be similar to a form of encephalitis and generally begin to show within one to three weeks after being bitten by an infected tick. Fever, vomiting, confusion, weakness, and headache are common symptoms reported. In severe cases, swelling of the brain, pareis, seizures, aphasia and altered mental status may be seen. It has been reported that the mortality rate is approximately 10%, however many of those that survive have permanent neurological complaints.

Fortunately, the number of reported cases and deaths associated with the Powassan virus is much less that what is to be expected considering the number of ticks that are infected.

While this disease has been occurring primarily in Canada and the northeast U.S., it is possible to see cases develop in other areas where conditions support tick populations. These tend to be in wooded areas. The use of tick repellents, long sleeves and long pants is advised. The CDC also advises that immediate bathing and skin checks should be conducted immediately after being outside.


Center for Disease Control and Prevention. http://www.cdc.gov/powassan/index.html

Minnesota Department of Health. http://www.health.state.mn.us/divs/idepc/diseases/powassan/basics.html

TitleGlobal study of disease and disability

21st Aug 2015 Medical News

A very interesting and eye opening study was published this month in THE LANCET in regards to the burden of disease across the world. Collaborators involved in the study analyzed over 35,000 sources of information on injury and disease from 188 countries with populations greater than 50,000 people between 1990 and 2013. Three hundred and one acute diseases, chronic diseases and injuries were included. Additionally 2337 sequelae that results from one or more of the studied disorders was also reviewed. There were many interesting findings. First and foremost, only 1 in 20 people had no health problems in 2013. Over 2.3 billion people (approximately 1/3 of the population) were experiencing more than 5 health ailments!

When researchers looked at the leading causes of years spent in less than optimum health, low back pain, depression, iron-deficient anemia, neck pain, and age related hearing loss have remained on top for nearly 23 years. The study collaborator’s attributed aging as the primary source leading to increasing disease and injury rates.

The study methodology including a review of published systematic reviews, re-analysis of household survey, data taken from hospital discharges, and from other administrative databases. Case reports to the World Health Organization (WHO) were also utilized. Disease estimates were calculated using a Bayesian meta-regression method. Bayesian refers to a method in statistics that utilizes probabilities of events. This allowed for computation of incidence and prevalence statistics for each country and time period. Specific data analyzed showed that under the category of acute disease, upper respiratory illness, interstitial nephritis, urinary tract infection, Dengue, pancreatitis, intestinal obstruction, and unintentional suffocation had the highest rates of increasing incidence during the study period. Similarly, for chronic disease (present for greater than 3 months), oral disorders, neurologic disease, skin disorders, musculoskeletal disorders, neglected tropical diseases, gynecologic disorders, and vision loss had the highest age-standardized rates.

Of the key findings noted from the study, rates of disability are declining at a much slower rate than mortality rates.

The data from this enormous research study have shown that there are many large causes of disability, or less than optimal health, that are largely preventable but require a greater focus or rates will continue to climb.

The study was funded by the Bill and Melinda Gates Foundation. The study funder reportedly had no role in the study design, data collection, data analysis, or data reporting.


Are low levels of Vitamin D associated with the development of dementia?

14th Aug 2015 Diseases, Medical News

A research study from the University of Exeter, published in the Journal of Neurology found a strong relationship between the development of Alzheimer’s disease and other forms of dementia and low levels of Vitamin D. The study included over 1600 adults over 65 years old who participated in the U.S. Cardiovascular Health Study. Participants of the study had their blood samples collected at the start of the study and mental status was assessed nearly 6 years later. Adults who had moderate Vitamin D deficiency had a 53% increased risk of developing dementia of any kind and 69% risk of develop Alzheimer’s disease. For those who were found to be severely Vitamin D deficient, there was a 125% risk of developing dementia and 122% increased risk of developing Alzheimer’s disease.

For the purposes of this study, a Vitamin D level of less than 50 nmol/L appeared to be threshold at which the risk of Alzheimer’s disease and other forms of dementia increased. This study is the largest yet to identify this association.

What remains unknown is the true cause and effect of this. It is unknown if increasing levels of Vitamin D would actually lower the risk of Alzheimer’s or dementia. More than 5 million people in the U.S. are affected by Alzheimer’s disease as the most common form of dementia. Worldwide, it estimated than over 44 million suffer from some form of dementia and this number is expected to grow with an aging population.

The authors of the study concluded that further studies are needed to establish whether the consumption of certain foods or taking a Vitamin D supplement can delay or prevent the onset of Alzheimer’s and dementia. The main source of Vitamin D for many is exposure to sunlight. However, the aging process results in skin that is less efficient at converting sunlight in a usable form of Vitamin D. Therefore, further supplementation through diet may be necessary to achieve adequate levels.

A group from the University of Guelph in Ontario, Canada has recently developed a mobile tracking application (‘App’) to help calculate intake of Vitamin D from food sources and exposure to sunlight. Using this newer technology as a tool may help users identify if they are below levels of adequate Vitamin D intake and lead to healthier behaviors.

References: Littlejohns TJ, Henley WE, Lang IA, Annweiler C, Beauchet O, Chaves PH, Fried L, Kestenbaum BR, Kuller LH, Langa KM, Lopez OL, Kos K, Soni M, Llewellyn DJ. Vitamin D and the risk of dementia and Alzheimer disease. Neurology. 2014 Sep 2; 83(10):920-8.

Goodman S, Morrongiello B, Simpson JR, Meckling K. Vitamin D intake among young Canadian adults: validation of a mobile Vitamin D Calculator App. Journal of Nutrition Education and Behavior. 2015; 47(3): 242.

Potentially fatal bacteria along the coast of Florida

07th Aug 2015 Diseases, Medical News

A potentially deadly bacteria has made it way to Florida beaches. The Vibrio vulnificus bacterium has infected at least seven people and killed two this year in Florida. The two fatal cases have occurred in Brevard and Marion counties.

The bacterium, which appears to be activated by exceptionally warm weather, normally does not pose a risk to a healthy person. However direct contact between seawater and any open cuts or wounds can cause infections and skin ulcers. Sickness can also develop from ingestion of seawater or from eating raw seafood. Abdominal pain, diarrhea, and vomiting are the primary symptoms from ingestion. Redness, swelling, fevers, and chills progressing to life threatening septic shock can occur from a wound infection.

Vibrio vulnificus is a salt requiring gram negative bacteria that is commonly found in marine environments. According to the CDC, bloodstream infections are fatal 50% of the time. Between 1988 and 2006, over 900 cases of Vibrio vulnificus infections were reported along the states that border the Gulf of Mexico. Thirty-two cases of Vibrio vulnificus infection were identified in Florida last year. It is estimated that over 85% of cases occur between May and October when the coastal waters are the warmest.

The diagnosis is made by history assessment and testing. Blood, wound, and stool cultures should be ordered for those who have a history of possible exposure and exhibit clinical symptoms. Medical management includes the use of antibiotics and monitoring of any open wounds. In rare cases, surgical debridement and/or amputation may be necessary for severely infected wounds with extensive soft tissue spread.

Prevention of infection focuses on avoiding entry into the water if any open wounds or cuts are present. Avoid eating raw shellfish. Boiling or frying shellfish for an extended period of time is recommended.