By Scott Saunders, MD
Last month Santa Barbara County sent doctors a report of two cases of Zika virus infection discovered within our borders. The first was found in a pregnant woman, which can cause birth defects so she is being followed. Both cases were in people who had traveled to an area where Zika virus is spread. Since I run a travel clinic and counsel people on preventing illnesses as they travel, I have learned a great deal about this new epidemic.
Zika is a virus. Viral infections are not like bacteria. They get into the cells of our body, hiding from the immune system, mixing their DNA with ours, and taking over control of the cell to make more viruses. Generally, the cell fills up with virus particles and then breaks open, releasing millions of them into our blood, which can then get into other cells and repeat the process. Since they use our own cell mechanisms to replicate, there is very little we can do to stop them. There are no “antibiotics” to kill them (technically, they aren’t even living organisms since they have no independent metabolism or reproduction), nor to prevent infection. There are some antiviral medications which inhibit the enzymes they force your cells to make, but these only slow the reproduction of the virus, not get rid of them. Currently, our most effective way to prevent viral illness is with vaccines to build our immunity against them.
For these reasons, it is hard to stop a virus in its spread around the world. We have a very mobile society, where millions of people travel to foreign countries daily. Going around the world in only a few days is not uncommon so people can bring back all sorts of infections. Moreover, being in cramped quarters on an airplane for many hours may multiply the risks.[i]
The Zika Virus
Zika is a vector-borne virus, which means it is most often injected into the body of a victim by a mosquito. When a female mosquito feeds on the blood of a person infected with the virus, she may get millions of virus particles. If she feeds on another person, those viruses can be injected with her saliva into the victim, causing infection. The Zika virus isn’t only found in the blood, it can be found in other body fluids, and is known to spread by sexual contact. There are also reports of infection by blood products, and Zika has been found in blood donors in areas where the virus is endemic. Because so many have a mild illness, or no symptoms at all, the virus can be spread by people who don’t know they have an infection.[ii]
Symptoms of Zika are highly variable. While the majority, 4 out of 5, have no symptoms at all, a few get severe symptoms. Only one in five get the typical symptoms of fever, joint pain, itchy rash, and bloodshot eyes. Serious infections, or deaths, generally only happen in people who are already debilitated in some way, such as with cancer, HIV, or genetic disorders.
Zika Virus Symptoms
4 of 5 have no symptoms
Of those that get any symptoms:
- Itchy rash
- Joint pain
- Muscle pain
- Bloodshot eyes
- Neurologic problems
One of the problems associated with the Zika virus is found in the nervous systems of children and adults. It causes inflammation of the white matter in the brain, similar to Multiple Sclerosis.
The known cases of Zika causing brain problems include:
- Vision problems
- Thinking difficulty
- Memory deficit
- Motor function
In other words, it can affect many different functions of the brain. Guillán-Barré syndrome (GBS) seems to be the most common nervous system disorder. GBS is a progressive deterioration of the nervous system that gradually destroys the function of both sensory and motor nerves. Because it affects the protective coating around nerve conduction fibers, the longest nerves are the most affected; it usually starts in the feet and progresses up the body. Rarely, people can die from GBS if it affects the muscles of respiration. GBS is thought to be an autoimmune disease that is triggered by the infection. Other infections, surgeries, and vaccinations, such as the flu vaccine, have also been known to cause GBS.[iii]
For the millions of suspected cases of Zika virus around the world, there have been few deaths. In Brazil, where the 2014-2015 epidemic was thought to begin there were about 200,000 suspected cases (most have no symptoms), 78,000 known cases, and 6 deaths.[iv] There has been one death associated with a Zika virus infection in the United States in July 2016. A man in Utah traveled to an outbreak area and likely contracted the disease there. He had other health problems and was discovered to have the virus on post-mortem examination.[v] All cases of Zika in the United States, except for Puerto Rico and Florida, have been travel related.[vi]
While most adults, even pregnant women have no symptoms, it definitely affects a fetus during development. Perhaps the worst effect of the illness happens to a developing fetus if a pregnant woman contracts the virus. Because the virus can infect nervous tissue, it can cause problems with the brains of the developing fetus. In Brazil, where the outbreak started in 2014, a study from the public hospitals showed most of the babies with microcephaly (small head) had the Zika virus, while none of the normal babies did.[vii] Interestingly, 80% of the mothers with the affected babies had Zika, but 64% of the mothers with normal babies also tested positive for the virus. Therefore, it’s clear that not everyone who gets Zika infection during pregnancy will have birth defects.
Sadly, the list of problems in infants infected with Zika during pregnancy is getting longer. Of those pregnant women known to be infected with the virus, 29% were found to have abnormalities on ultrasound. New research is showing many different problems including:
- Short limbs
- Developmental delay
- Joint problems
- Seizure disorders
The type of problem is mostly related to the stage of development. Some of these won’t show up for months or years after birth. Thus, it could be even a majority of fetuses are affected in some way by the virus. This is now one of the few viruses known to cause birth defects, and the research is still in its infancy.[viii]
How does the epidemic happen?
The Zika Virus was first discovered in the Zika forest in Uganda in 1947. It is related to a number of other diseases such as dengue fever, yellow fever, and West Nile Virus. For many years it was primarily located in tropical Africa and Asia, found mostly in monkeys, and occasional humans, but between 2007 and 2013 it came to the Americas, probably Brazil, and started the epidemic of 2014-2015.[ix] Because the populations of that area had not been exposed to it before, there was no immunity against the virus so it was enabled to spread rapidly, infecting many people.
There is no vaccine, and no cure for the illness. There is only treatment of the symptoms once people get the disease, or prevention. Clearly, prevention of infection is the best way.
The virus is found in tropical and sub-tropical areas around the world. (see map) While the majority comes from mosquitos, there is now a significant number known from sexual contact. The virus is found in the body fluids of people with active infections, even when they have no symptoms. For this reason, it can be spread unknowingly by people who travel, even to people who are avoiding travel to Zika infected areas.
Preventing mosquito bites is the best way to avoid a primary infection. There are a few preparations that will help. The mosquito that carries the virus is active during the day, but can bite during the night as well. If you are traveling to a tropical or sub-tropical area it is a good idea to use a mosquito repellant. The only two preparations that are known to actually prevent mosquito bites are equally as effective.
- DEET (found in most over-the-counter preparations)
- Lemon Eucalyptus oil is as effective as DEET in warding off virus.[x]
The advantage of DEET-based repellents is that they last longer. The advantage of Lemon Eucalyptus is that it’s natural. Follow the directions on the label, and don’t be afraid to re-apply them – the active ingredients evaporate over time, so continued protection would include using it as directed on exposed areas.
Another way to keep the mosquitos from biting is to wear clothing. Of course, the virus lives in very warm climates so our natural inclination is to wear less. Mosquitos can bite through tight clothing as well. Mosquito nets at night will keep the buggers out of your bed.
Besides mosquitos, it’s important to consider contact with those who are infected. Since the infection may last anywhere from a week to several months, anyone with recent travel to a Zika infected area is a possible carrier. There isn’t any issue with casual contact, such as shaking hands, however, close contact with body fluids can cause the spread of infection. Condoms are often recommended for sexual contact, but there is no evidence that they will actually prevent disease transmission.
What makes the difference between those who have a mild infection, and those who get serious nervous system complications? The immune system. It’s possible that those who have been exposed to it before may have antibodies that protect them from further infections, but we cannot be sure. A poorly functioning immune system can allow reactions to the presence of the virus that cause many of the serious neurological problems, or worse symptoms.
Good immune health is not difficult because it is the same as having good health in general:
- Eat good food, getting plenty of nutrition.
- Exercise regularly
- Avoid toxins, especially sugar (except what comes in fruit)
- Manage stress
- Get adequate sleep
Some supplements are important to keep the immune system functioning well, especially for prevention of viral infections. These are good to take all the time, but especially if you’ll be traveling.
- Vitamin D3 50,000 IU per week.
- Vitamin A 5,000 IU per day
- Selenium 200mcg per day
A good immune system means you will fight off the virus so it won’t do any permanent damage. Also, you will be protected long-term from getting another infection (we hope). And, you won’t cause inflammatory or autoimmune problems. This is much better than treating the symptoms after you have an infection.
I recommend the following for my patients who are traveling:
- Look before you travel. Know if you are at risk, and what the risks are so you can take precautions if needed. The CDC publishes travel advisories for every area of the world on their website (http://wwwnc.cdc.gov/travel/ ).
- Use mosquito protection in all tropical/subtropical areas
- Be aware of partners who are traveling to Zika areas
- Keep your immune system in excellent condition.
- Avoid travel to Zika infected areas if you are, or plan to be, pregnant.
The purpose if information is not to create fear, and make you stay home and not take that dream vacation, but rather to use the knowledge to protect yourself. If you get sick, ignorance is most definitely not bliss! Be aware, use caution, and your travel will be much more enjoyable.
[iii] “Guillain-Barré Syndrome Fact Sheet”. NIAMS. June 1, 2016. Retrieved 13 August 2016.