Wednesday, 6 August 2014

Health Care and Ebola Virus

The current deadly disease du jour is the Ebola Virus, primarily because it is currently receiving worldwide attention for an outbreak in West Africa. The World Health Organization (WHO) and other groups have designated the situation there as extremely critical and very dangerous. That status is likely not to change for the better anytime soon as there is now an apparent epidemic in several countries in Africa that are experiencing a rapid expansion of new cases.

Don�t be deceived. Ebola is indeed deadly as there is no known cure for it. The current mortality rate is extremely high of people who have contracted the virus, believed to have originated in bats. The exact source is not known, but it is in form similar to another disease that has been determined by health experts to have the same type of origination.  Here is an infographic site to see the effects of Ebola: http://infographicworld.com/ebola/.

According to WHO, Ebola first appeared in 1976, in 2 simultaneous outbreaks, in Nzara, Sudan, and in Yambuku, Democratic Republic of Congo. The latter was in a village situated near the Ebola River, from which the disease takes its name. Here are a few key facts about the disease:

         Ebola virus disease (EVD), formerly known as Ebola haemorrhagic fever, is a severe, often fatal illness in humans.
         EVD outbreaks have a case fatality rate of up to 90%.
         EVD outbreaks occur primarily in remote villages in Central and West Africa, near tropical rainforests.
         The virus is transmitted to people from wild animals and spreads in the human population through human-to-human transmission.
         Fruit bats of the Pteropodidae family are considered to be the natural host of the Ebola virus.
         Severely ill patients require intensive supportive care. No licensed specific treatment or vaccine is available for use in people or animals.

EVD is a severe acute viral illness often characterized by the sudden onset of fever, intense weakness, muscle pain, headache and sore throat, according to WHO. This is followed by vomiting, diarrhea, rash, impaired kidney and liver function, and in some cases, both internal and external bleeding. Laboratory findings include low white blood cell and platelet counts and elevated liver enzymes.
 
People are infectious as long as their blood and secretions contain the virus.  The incubation period, that is, the time interval from infection with the virus to onset of symptoms, is 2 to 21 days. Much more info on this situation can be found at the WHO website: http://www.who.int/mediacentre/factsheets/fs103/en/.

Accroding to the US Centers for Disease Control (CDC), in Africa confirmed cases of Ebola HF have been reported in these countries:

         Guinea
         Liberia
         Sierra Leone
         Democratic Republic of the Congo (DRC)
         Gabon
         South Sudan
         Ivory Coast
         Uganda
         Republic of the Congo (ROC)
         South Africa (imported)

During outbreaks of Ebola HF, those at highest risk include health care workers and the family and friends of an infected individual. Health care workers in Africa should consult the Infection Control for Viral Hemorrhagic Fevers In the African Health Care Setting to learn how to prevent and control infections.

When cases of the disease do appear, there is increased risk of transmission within health care settings, reported by the CDC. Therefore, health care workers must be able to recognize a case of Ebola HF and be ready to employ practical viral hemorrhagic fever isolation precautions or barrier nursing techniques. They should also have the capability to request diagnostic tests or prepare samples for shipping and testing elsewhere. Barrier nursing techniques include:

         Wearing of protective clothing (such as masks, gloves, gowns, and goggles).
         The use of infection-control measures (such as complete equipment sterilization and routine use of disinfectant).
         Isolation of Ebola HF patients from contact with unprotected persons.

The aim of all of these techniques is to avoid contact with the blood or secretions of an infected patient. If a patient with Ebola HF dies, it is equally important that direct contact with the body of the deceased patient be prevented, according to the CDC. Significant info can also be found at this website: http://www.cdc.gov/vhf/ebola/prevention/index.html.

The current situation with the Ebola outbreak in West Africa is still evolving with continued high death rates close to 1,000 individuals over the past few months. However, except for two health care workers flown to the United States for special treatment, there are no known existing cases of infected Ebola victims in the country. The situation with those medical missionaries was extremely unique and merited special favor for treatment. Fortunately, though still in less than desirable condition, they are showing signs of recovery. Both individuals were administered a serum while still in Africa that has shown incredible results.

According to CNN Health, the experimental drug, known as ZMapp, was developed by the biotech firm Mapp Biopharmaceutical Inc., which is based in San Diego. The patients were told that the treatment had never been tried before in a human being but had shown promise in small experiments with monkeys.

The process by which the medication was made available to the two patients under treatment now is highly unusual. World Health Organization spokesman Gregory Hartl cautioned that health authorities "cannot start using untested drugs in the middle of an outbreak, for various reasons."

And, Doctors Without Borders similarly weighed in on the side of caution. "It is important to keep in mind that a large-scale provision of treatments and vaccines that are in very early stages of development has a series of scientific and ethical implications," the organization said in a statement. "As doctors, trying an untested drug on patients is a very difficult choice since our first priority is to do no harm, and we would not be sure that the experimental treatment would do more harm than good."

According to CNN Health, ZMapp has not been approved for human use and has not even gone through the clinical trial process, which is standard to prove the safety and efficacy of a medication. It may have been given under the U.S. Food and Drug Administration's "compassionate use" regulation, which allows access to investigational drugs outside clinical trials.
 
Getting approval for compassionate use is often long and laborious, but in the case of the medical missionaries now being treated in a special infectious disease unit of Emory University Hospital in Atlanta, Georgia, they received the medication within seven to 10 days of their exposure to the Ebola virus. Although the new serum shows promise, it is not authorized yet for use in every patient. The drug is still considered highly experimental. Much more info can be found at this website: http://www.cnn.com/2014/08/04/health/experimental-ebola-serum/.

Ebola is deadly, and can be contracted under circumstances as outlined in this blog. However, even though there is merit for concern, wide spread fear mongering and disinformation is uncalled for within the media and general public. Knowing about the disease and how you can be infected is significant in your understanding of Ebola. The probability of a similar outbreak in the US is very remote at the present time.  That being said, always be vigilant in your interactions with anyone who appears ill for any reason, or who may have recently traveled to areas of the world with high rates of infected population.

Until next time.

Can Hypothalamic Inflammation and Leptin Resistance be Reversed?

A new study by yours truly begins to address the key question: can hypothalamic inflammation and leptin resistance be reversed?

Leptin is the primary hormonal regulator of body fatness in the human body (1). Secreted by fat tissue, it acts in many places in the body, but its most important effects on body weight occur via the brain, and particularly a brain region called the hypothalamus. The hypothalamus is responsible for keeping certain physiological variables within the optimal range, including blood pressure, body temperature, and body fatness.

In obesity, the brain loses its sensitivity to leptin, and this causes the body to begin 'defending' a higher level of body fatness, analogous to how a person with a fever 'defends' a higher body temperature (1). Once a person has become obese, it's difficult to return to true leanness because this system vigorously opposes major fat loss. Leptin resistance makes fat loss more difficult.

In rodent models, leptin resistance is caused at least in part by inflammatory signaling in the hypothalamus. We can observe this in multiple ways, but one common way is to look at the appearance of specific cells in the brain that change number, size, and shape when inflammation is present (2). These cells are called microglia and astrocytes. In addition to the work in rodents, we've published preliminary evidence that these same inflammatory changes occur in the hypothalamus of obese humans (2).

A key question is whether or not these inflammatory changes can be reversed. Is a person with leptin resistance doomed to have it forever, undermining fat loss efforts for the rest of his or her life? Or can it be corrected, possibly allowing easier and more sustainable fat loss? We just published a study in Endocrinology that begins to answer this question, using a mouse model of dietary obesity (3). I'm co-first author of this study along with my colleague Kathryn Berkseth, MD. My former mentor Mike Schwartz, MD is senior author.

The Study

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