Archive for category Medicine
After 18 weeks of running on my modified program (two weeks medium, two weeks hard, two weeks off for three cycles. See “Run Till You’re Sick”) I was retested and revisited the cardiologist. The news was less than sparkling. I appear to have sick sinus syndrome. The sinoatrial node, which is the structure in my heart charged with keeping the beat, is not doing its job. When I sleep the node does too. At times I went up to 11 seconds without a heart beat. Very exciting.
This is so exciting that the node has been sacked. Its job is being outsourced and it will be replaced with an artificial pacemaker, one that takes its job a little more seriously. I must confess to feeling let down, disappointed and more than a little annoyed that such a tiny part of my otherwise presumably healthy body can have such a profound and long lasting effect on my life. Woody Allen said, “My brain: it’s my second favorite organ”. My heart would have to come a close third, but I would be more than happy to promote it if I thought that would cheer it up enough that it would live up to its job description.
While the cardiologist thinks the running and the appearance of sick sinus syndrome are all just coincidence I find it a little too convenient that this should flare up shortly after completing my first marathon and settle down when I stop running. From what I have read of marathon runners an alarmingly large number of them have some level of scarring in their heart muscle. I suspect that something I may have been predisposed to was a little unhappy with the extreme level of effort I expended while running the marathon and decided to pack up shop and go home in a huff.
Apparently the good news, apart from not going through airport security scanners any more, is that once the pacemaker is installed I will be as good as new and able to run, jump and leap tall buildings in a single bound again, as long as I only use the mobile phone on my right side, avoid shop security scanners and give up contact sports. So much for Krav Maga. Maybe I could just give up running instead?
Dr. F. Bunny
The Ebola virus was “discovered” in 1976 causing trouble for people living near the Ebola River in the Democratic Republic of Congo (DRC). Since then it has popped up several times in the DRC, Sudan and Uganda. The current outbreak is the first to involve Guinea, Liberia and Sierra Leone.
The virus itself is a filovirus, a group of long filamentous RNA viruses that are surrounded by a lipid envelope. It causes a severe disease in people characterised by vomiting, abdominal pain, fever, headache and bleeding. Symptoms usually appear eight to 10 days after infection but this can range from two to 21 days. Mortality rates can be as high as 90%. Unlike influenza, people tend not to be infectious until they are symptomatic.
The virus is spread via direct contact with blood and body fluids, although there was a publication indicating airborne spread between pigs and monkeys (Weingartl et al 2012). Although not in direct contact the two groups of animals were caged only eight inches apart. According to a second report it appears that the Ebola virus causes a different disease in pigs compared with primates (http://www.vox.com/2014/8/10/5980553/ebola-outbreak-virus-aerosol-airborne-pigs-monkeys/in/5712456). The virus hits the lungs of pigs, whereas the liver is the main target organ in primates. Therefore, while pigs can cough and sneeze out viral particles, primates tend to shed large numbers of virus in the blood and faeces, making airborne transmission unlikely. This is borne out by the current situation. If the Ebola virus was as contagious as the influenza virus we would all be drowning in our own blood by now. Instead the outbreak has remained relatively localised.
The main reservoir of Ebola virus is unknown although, as with most emerging diseases nowadays, bats have been fingered as the main culprit. Ebola has been found in gorillas, chimpanzees and duikers but, as they also develop clinical disease and die, they are unlikely to be a reservoir. However, as they are part of the bush meat cycle they represent a great way for the virus to spread to people.
The virus itself is not particularly hardy. It can survive for several days at room temperature but is destroyed by boiling for five minutes, and common disinfectants such as bleach, phenolics, glutaraldehyde, formaldehyde and 3% acetic acid (vinegar is 4-8% acetic acid). Alcohol hand wipes and washing with soap and water are also effective at killing the virus.
Unfortunately there is no vaccine and no treatment. ZMapp, a drug made of monoclonal antibodies, has been used experimentally but, oddly, there appears to be some debate over the ethics of using this unlicensed drug on people. I know that if I was infected with Ebola and someone waved a drug at me that might or might not work, I would certainly risk it.
The biggest problem in controlling the current epidemic is a lack of infrastructure and knowledge. I can imagine that it is not easy to convince people with very little or no education that a thing that is far too small to see is killing off your family, friends and community. And no, it is not us, the aid workers, who are bringing it in. And yes, you really should stop eating bush meat, even though it is a centuries old tradition. And no, if someone dies don’t wash the body by hand. And yes, we really need you tell us if you, or someone you know, is feeling sick so we can stop them spreading the virus to other people. Please don’t hide them at home. With early medical care they do stand a chance of recovery. Previous Ebola outbreaks had mortality rates of 90%. This one is running at 60%. So it is possible to survive an Ebola infection.
As an interesting aside to the Ebola issue, in 1989 shipments of monkeys were imported into a holding facility in Reston in the US from the Philippines. Those monkeys died with symptoms similar to those caused by an Ebola virus infection. It turned out they were full of a related filovirus subsequently named Reston virus. Interestingly, 14% of the people who had contact with the monkeys had filovirus antibodies, indicating they had also been exposed to the virus. It was just lucky that this, closely related virus, does not appear to cause disease in people. It is amazing that such a small change in viral structure can turn a harmless virus into a lethal one.
Dr. F. Bunny
Weingartl H.M., C. Embury-Hyatt, C. Nfon, A. Leung, G. Smith, and G. Kobinger. 2012. Transmission of Ebola virus from pigs to non-human primates. Scientific Reports 2, 811; DOI:10.1038/srep00811.
1928 was a happy year for humanity as this was the year that a nondescript mould called Penicillium notatum was found to have antibacterial properties. This mould would prove to be the first in a long line of what we now know as antibiotics. Antibiotics are a group of drugs that kill bacteria for us either by interfering with their cell wall, mucking up their DNA or messing with their metabolic processes so they cease to function. Unfortunately they do not affect viruses.
Before the discovery of antibiotics people died from all sorts of minor complaints such as small infected skin wounds (before penicillin1 in 9 skin infections killed people), mild burn infections, tooth abscesses and infected insect stings. Unfortunately, according to a recently published World Health Organisation report (http://www.who.int/drugresistance/documents/surveillancereport/en/), that time could be returning as more and more bacteria are laughing in the face of the antibiotics we use.
The natural world uses a marvellous tool to adapt to changing circumstances. It is called natural selection and it is based on genetic diversity. This means that when a disease comes along it rarely kills everyone. Some people will be naturally resistant to it. They will survive and breed and, before you know it, most people will be resistant and the disease will no longer kill people. Unfortunately the same is true for bacteria and antibiotics. In any given bacterial population some bacteria will be resistant to a given antibiotic. Using that antibiotic will kill off the sensitive bacteria, leaving the resistant ones behind to proliferate. This activity can be accelerated by increasing the use of antibiotics, especially when they are prescribed for conditions that cannot be resolved by antibiotic use, such as the common cold or flu, both of which are viruses and completely unaffected by antibiotics.
If you are prescribed antibiotics, to delay the onset of resistance appearing, it is vital to take your full dose and complete the prescription, even if you feel better ahead of time. Otherwise you have not killed the bacteria but only wounded them, allowing them the opportunity to strike back bigger and better than before.
It is also important to practice effective preventative medicine to minimise the number of times that antibiotics are needed. An example of this is gonorrhoea. More than one million people are infected with gonorrhoea around the world every day. Resistance of this bacterium to all antibiotics is becoming more and more common. Prevention is simple and obvious. All it requires is a condom. Preventative measures for other diseases can include vaccination, washing your hands with soap and water, wearing your protective gear at work, not allowing your pets to stick their tongues down your throat, washing your hands with soap and water, observing good hygiene when preparing food, washing your hands with soap and water, and sticking with bottled water if you are uncertain of the quality of the water supply. Oh, and did I mention washing your hands with soap and water?
Dr. F. Bunny
MERS (Middle East Respiratory Syndrome) is the latest disease in nature’s little bag of tricks, which could turn into the next pandemic and solve our population issues for us. It is closely related to SARS (Severe Acute Respiratory Syndrome), both belonging to the same virus family. But, while SARS appeared in Asia, MERS first popped up in Saudi Arabia in 2012. Since then all cases have been seen either in the Middle East or in people who have travelled to the Middle East. As of June 2014 we have had 697 cases of which 210 people have died. As usual symptoms have been flu-like.
This is quite a high case fatality rate but, like bird flu, the virus has not raced around the world killing a third of the world’s population because it is not easily transferred from person to person, yet.
Any time one of these new diseases pops up it requires quite a bit of detective work to try and determine where it came from and how it works. It will probably come as no surprise that bats are once again implicated, the virus having been found in Egyptian tomb bats, a name guaranteed to generate sympathy with a nervous public.
Intriguingly the virus has also been found in camels, a situation which has some similarities with Hendra virus in Australia. Hendra virus lives happily in bats, infects horses (and kills them) and then spreads from horses to humans. However, as yet, there are no recorded cases of MERS causing disease in camels (although a number of camels have died in the UAE recently of undetermined cause, so this situation may change) and we have only recently seen the first confirmed case of a human catching the disease from a camel. Most of the other cases have been in people who have had very close contact with other sufferers. Where they caught it originally is still open to speculation.
It makes me think that the practice of veterinary medicine may be more dangerous than first thought. While we are all aware of the wonderful things we can catch from our primate neighbours no one really believed there was anything worth catching from our more distant cousins, like horses. Twenty years ago you would not have thought twice about examining a snuffly horse. Two years ago you would not have thought twice about examining a camel.
Australia has the largest feral camel population in the world, but no human cases of MERS. Preliminary testing of 25 camels has failed to find any evidence of MERS, implying that the Middle East camels may have been infected from the tomb bats or that the virus appeared in Middle East camels after the Australian population was established.
The upshot of all this is that we have absolutely no idea where the next fun plague might be coming from. As I get older and more paranoid I am becoming increasingly more nervous about travelling on crowded trains, planes and buses, full of sneezing and coughing people. And I am starting to think that sport is much more enjoyable when viewed from the comfort of my living room than from one of those packed sporting stadiums. I can see the day coming when I refuse to venture outside without my biohazard suit on.
Paranoia aside, most viruses are transferred between us via the things we touch, such as door handles, coffee cups, pens, etc. The best way to prevent this is by washing your hands frequently, with soap and water. To do it properly, sing the Happy Birthday song through twice while you are soaping up your hands. Oh, and don’t kiss bats, camels or any other non-human life forms. And maybe not even the human life forms.
Dr. F. Bunny