February 11, 2016 Update
Paul Herscu, ND, MPH
If you have not yet read my first posting on this topic, please do so now before reading the following.
My intention with this post is to continue to lay a foundation and build scaffolding so that when you see data or hear the news or learn of novel discoveries, you will have enough history and adequate context to make sense of it and have an informed opinion. These writings should also make it easier for everyone to both predict what the news will be, and to anticipate government and scientific next steps. Here we are focusing on Zika virus, but really the discussion of Zika virus lies within a larger framework. As such I am going to describe a few variables below. They relate to the topic of germs in general and Zika virus specifically. In this update, I describe briefly, the placement of people within biology, the relationship of Zika virus and neurological diseases, vector and coinfection issues, economic issues, and ultimately prevention. At the end of this reading, I expect many of your questions will be answered and much of the future news may find a more logical place.
Into the Water
I am writing this part in the Florida Everglades, within the home range of the Aedes aegypti mosquito. One of my sons and I just finished handling alligators and snakes and now I am about to have lunch. And it occurs to me that these are ‘dirty’ creatures, by which I mean they carry any number of little critters, let alone bacteria and viruses on their skin, which might make me sick. Maybe I should wash my hands extra special! While this may seem like those were exotic creatures, a more common American example would be pet turtles under 4 inches and frogs in the USA that can make the very young, old, or immune compromised people sick or even kill them with Salmonella infections. At its height, the problem was so great, the FDA stepped in to ban the transportation of turtles in the USA.
I begin this update with this tidbit because I want to highlight a point I have been making for decades. We are in a sea change of perception. We are not outside of nature, or strictly guardians of nature—rather, we are right in the middle of nature, with all manner of bugs around us, on us, and in us. In fact we cannot live without the bugs of our own personal internal ecosystem working well together. We have yet to fully comprehend this concept, to embrace its implications, and intentionally incorporate this knowledge into a coherent medical model with prevention and treatment plans and protocols. As a result, we have a fair amount of both confusion from the general population & press as well as hysterical overreaction, or unfortunate under-reactions from science and medical communities at large.
With relation to the Zika virus at this time, we know it is relatively new to the Western Hemisphere and think it has spread more recently through 30 or so countries. As mentioned in my first posting, there are reasons to believe Zika virus is a causative agent in neurological symptoms but its link as a causative agent has yet to be proven, since the work has only now begun. Because of this lack of causational proof at this time, some have argued that this virus is not the true causative agent, and has nothing to do with the neurological symptoms. Here are some reasons why there is debate: Brazil changed its diagnostic criteria for microcephaly last year. The nature of the change has meant that more people have been diagnosed. Genetically modified mosquitoes have been introduced in Brazil. New pesticides have been utilized in Brazil. Specific larvacides were newly used in the areas of Brazil where microcephaly is most seen. Additional new vaccine schedules have been given to pregnant women. And lastly, heightened awareness and surveillance has lead to further scrutiny, which often leads to more diagnoses. Let’s leave this slight mess of a Gordian knot alone for now, and say that there are more people diagnosed with microcephaly for a variety of reasons in Brazil and let’s move on. What I would like to describe are some reasons to support the concept that Brazil is seeing an increase of neurological diseases caused by this virus:
1. The increased incidence of diagnosing microcephaly in Brazil came about six months after the arrival of Zika virus to Brazil. Temporally, this makes sense (but so too does the use of larvacides). Think about the main disease people worry about at this time: microcephaly. The virus appears. It impacts everyone bitten in different ways, but mostly those bitten are asymptomatic. However, for those women pregnant in the first trimester, they are at risk for birthing a baby with microcephaly. That would be found 6-8 months later, at the time of birth. If this winds up being true, we will have a clearer understanding of the cause of microcephaly and or neurological issues in a couple of months at the latest. And if not, then within 6 months. There is a curiosity as to why other countries with Zika virus have not seen this escalation. Perhaps there is something unique to Brazil in this scare, perhaps not, and it is still too newly arrived in those countries, with microcephaly incidence to rise in a few month. Either way, we will know the answer shortly.
2. Because of the above potential threat, epidemiologists decided to conduct a retrospective analysis of the places where Zika virus was newly found. One place studied was French Polynesia. There in 2013-2014, there was a Zika virus epidemic. And looking back, they were able to identify an increased rate of Guillain-Barre syndrome. At that time, there were no new vaccines/GM mosquitoes or new pesticides introduced. Again, this is an association, not causation, but nevertheless the numbers were there. And again, let’s leave out the possibility of co-infections with dengue fever and Chikungunya virus, both of which share similar symptoms, and many people who tested positive for Zika virus also tested positive for one of the other bugs.
3. There was also an old report from a couple of decades ago, asking the question: can pestiviruses cause microcephaly? As you recall from the first post, this virus is very closely related to the Zika virus. And if one species causes this type of symptom, perhaps a very similar species may cause a similar issue. Mind you, this question and paper is from 1987. So while Zika virus and a possible connection with microcephaly seems new, perhaps it is not the first time an association has been questioned.
Because of the above reasons, I believe in the next few weeks or months we will have a very clear causative relationship between Zika virus and some neurological diseases, even if the incidence numbers changes. Specifically, due to some of the other variables mentioned above, there will be a drop in the overall number of Zika virus caused microcephaly by a lot, though still leave us with increased neurological symptoms due to the virus. Causality is sometimes a tricky thing to prove. The example people give is that when interviewing people who developed lung cancer or addiction tendency, it was noted that many had yellow-stained fingers. Now you might think that yellow-stained fingers led to cancer or addiction, but it was the tobacco smoke which led to both. It is the same here. Is Zika virus causing this rise in neurological symptoms or is the vaccination schedule or the larvacide or any other variable. Is Zika virus the confounder here or is the larvacide the confounder here? This is why proving causation is important.
Vector: Spread, Changes, Control
As you are well aware by now, the vector that transmits the Zika virus to people in the Western hemisphere is the Aedes aegypti mosquito. A lot has been made of this. And now there is a question about the Aedes albopictus mosquito, a slightly different but related mosquito to potentially pass Zika virus as well. As I mentioned last time, the reason this is important is while Aedes aegypti is likely to maintain a range in the lower USA, the Aedes albopictus has a range of nearly half the USA, which makes the USA a much larger target. How does this happen? Think of it as a chain: A person has Zika virus. A female Aedes aegypti mosquito who does not have the Zika virus bites this person, ingesting the virus circulating in the person’s blood. Now the virus is in the mosquito, circulates, and ends up in its salivary glands. When that mosquito bites the next person, she will pass along the virus which is also in the mosquito’s saliva, to this new person, and if the person was not infected previously, he is infected with the Zika virus himself, and can now pass it along to the next mosquito that bites him. If instead, the Aedes albopictus mosquito bites an infected person, then the cycle picks up with that new mosquito as a new vector as well.
Has this happened before? An interesting thing can be seen if you look to the fuller history of Zika virus as far as we know it at this time. When you track the viral spread, from Africa through Pacific islands to the Western Hemisphere, several mosquitoes have carried Zika virus at various times, in different countries. For example, it seems as though Aedes africanus mosquito carried the Zika virus in the Zika forest, but Aedes hensilli mosquito carried it in Yap Island, Micronesia in 2007 and the Aedes aegypti mosquito, in part, carried it in French Polynesia. Most importantly, this has occurred previously, and there is nothing to suggest it may not happen again. Most important, Aedes albopictus is able to carry Zika virus in the lab, which means it could do so in the wild. Which mosquito transmits becomes potentially relevant with regard to proper insect controls, something that is in our hands. See below articles on the spread from Africa to Western Hemisphere and changing vectors.
Along these lines, though mosquitoes seem similar to one another, I’d like to highlight the different niches mosquitoes occupy and different lifestyles they maintain. Two very big differences to delineate are time of day, and indoor vs. outdoor preference. The daytime versus nighttime issue is important, as daytime active mosquitoes are a problem for Zika spread, especially during the dawn and dusk hours. Some mosquitoes prefer the outside open spaces, and others prefer indoor areas. It turns out the Aedes aegypti mosquito prefers not just the darkish outside areas, but especially indoor places. What this means is that prevention and precaution occurs inside the house not just outside the house. There is going to be a very big push for ultra-low volume (ULV) applications (spraying) of neighborhoods, from trucks, cars, and planes. This works out fairly well for reducing the overall mosquito count for the outside-loving mosquitoes primarily, but it does not work well for the indoor types, like the one that carries Zika virus, at least not by itself. If you happen to work for your local government or are involved in local politics and public health, shift the focus to include inside the home, not only outside the home efforts. Shift resources to personal habits training, rather than only spraying outside areas.
Economics and Education
We have to touch on economics and education, here. We have known, for a few thousand years, that something small (as in germs) makes us sick, and have started public health projects, thousands of years ago, to protect ourselves from these illnesses. Here I could mention the work of Marcus Terentius Varro from two thousand years ago and the idea of eliminating the swamps surrounding Rome. But better examples include the protection we use to prevent malaria. Those that are both educated and have the means are more or less able to avoid malaria. Those that do not have means or are not educated and are exposed to the carrying mosquito, can easily contract malaria. Being educated is not enough; you have to have the economic resources to do something about prevention. One good example of this, as related to Zika virus, took place in Micronesia in 2007. It is estimated that 73% of Yap Island residents had the Zika virus. A small population sample but still you can see how a lack of resources allows exposure to the elements and to the rapid spread of the bug.
Why do I bring this up? For the longest time, the cultures with economic resources have not dealt as effectively as they could with ‘bad for our species’ germs. Partly, this is the ignorance of the lucky, as we did not have the germs located in our back yards, did not have to lose millions of lives to these germs, did not have to lose whole economic opportunities as population members dealt with being ill. Note for example, that for nearly a decade we have known that this virus, (see all the articles referenced in this update as an example), along with other viruses are on the move, rambling across the globe. It seems that we only begin to care about such viruses in earnest when they threaten the countries with economic means.
But now we have four trends that make this untenable. The economic world is becoming ever more integrated with goods, products, foods, travel by sea and air around the world, and everyone is more vulnerable to exposure to germs than ever. Young people are traveling around the world in record numbers, to developing countries, becoming exposed to species that they were not prepared for, and at times bringing these bugs back home. (I remember contracting dengue fever 15 years ago, during such travel. It was extremely unpleasant, as I felt an armored truck parked on my skull. Very unpleasant indeed!) Third, mass migrations of people is underway, with record number of refugees and immigrants from all around the world. And lastly, the big one, the world is getting warmer. As a result, many species’ ranges of habitat, which may have been predictable for generations, are changing. When I lectured on this topic in 2000, I used to give the example that Europeans would see malaria more than they were used to. For us, we are going to see bugs that we have not seen for a long time. High on my personal list is dengue fever.
But many of us are educated. And many of us have economic resources. And now that these germs are on our horizon, we are going to put an increasing amount of brainpower and financial resources to develop and implement effective solutions.
A sort of short-term solution will be the push towards new vaccines. This is shortsighted in one respect. We can not be vaccinated for thousands of germs. And that is where we are headed. The fact that we do not recognize all the germs now is just a lack of our perception. But as more germs are clearly recognized, we can not just keep adding vaccines. It is not tenable, and no one in science actually thinks it is. We need a better way to protect against a host of germs at the same time. That is what will happen, though not in the short term. A few decades out, perhaps, but the solution cannot be a species-specific vaccine. There are too many species to protect against. Focusing solely on the current vaccine model saps energy from work that could solve for this whole class of germs at the same time, let alone related problems such as chronic viral and post viral syndromes, autoimmune disease and cancer.
Medical science works best when it contextualizes its efforts within the greater knowledge of biology and science. For a moment, I would like to bring in a related topic, that of invasive species. For the past two decades we have heard a great deal about an ever-growing list of invasive species. A very short list exemplifies the variety of invasive species we now have:
Dreissena Polymorpha (Zebra mussel)
Python bivittatus (Burmese python)
Popillia joponica (Japanese beetle)
Pterois volitans (Red lionfish)
Ophiostoma ulmi (Dutch elm disease)
Basically we look at species that either hurt us physically, damage our economic resources, or in some way, shock us. But it is interesting to look at a slightly fuller list to see how we as a species quickly adapt to what is foreign. For example, see the list below:
Passer domesticus (House sparrow)
Sturnus vulgaris (European starling)
Pueraria lobata (Kudzu)
Kali tragus (Tumbleweed)
Each of these species is classified as an invasive species to the USA. But as I write this, in 2016, they have become so common and familiar to the culture of this country, it is impossible, if you are of a certain age, to think of the USA without sparrows and starlings flying around, or any western movie without tumbleweeds.
The fact that species move to take advantage of resources is intuitive and makes sense. A species came from somewhere else and is living here now, and taking over a niche. But for the full biological example, instead of only thinking of large species, think smaller, really small. Just as climate change has led to new big species moving, it may be useful to think of dengue fever, malaria, West Nile virus, and Zika virus as invasive species. They come and they take over for a period of time. Aedes albopictus, the mosquito we are speaking of, is itself an invasive species in the USA, being now found in nearly half the country’s habitat!
What have we learned from invasive species eradication? It mostly does not work. It remains an utmost challenge to fight nature. We need a sort of general solution to mosquito-transmitted diseases. There are too many viruses and bugs that they carry. We need to understand how to deal with the whole lot rather than one at a time. Not just to keep people from catching Zika virus but to keep people from contracting malaria for example. To put it in better terms that relate to the outbreak we are talking about at this time. The same mosquitoes that carry Zika virus carry Chikungunya virus as well as dengue fever. A few years ago until quite recently, there was a great deal of press about both illnesses, and then just as quickly they disappeared from the news, primarily because they were not impacting richer nations. It has little to do with the fact that people are absolutely, definitely, becoming ill from these. But it just did not capture the attention of the media long enough. Zika virus may stay in the news, or it may be forgotten just as West Nile virus has become a sort of ‘house sparrow’ invasive species that we know is around us but don’t do much about. The bottom line is that we need a broader solution for insect vector disease rather than vaccination alone.
An example of popular press can be seen in the following:
One example. Malaria deaths per year are around half a million, let alone the couple of hundred million people that contract malaria annually. Preventing Zika virus in a general way should hopefully and finally lead to an effective and enduring solution for malaria, dengue fever, etc. That is the solution I am looking for.
At this time, for those with means and possibilities (I know how badly that sounds) the best personal prevention is insect repellent. For those in areas where Zika virus has arrived, during the day, and especially at dawn and dusk, and particularly indoors and in dark overcast areas, please use and advise your patients to use repellent. Make sure that the mosquitoes are not in the house, Screens that work are essential. Get rid of standing water in the yard, and the house; this is a must! Aside from that, realize that the very vast majority of people who contract Zika virus will be asymptomatic. It all runs subclinically. This means that the very best thing you can do, as a clinician who uses homeopathy, is make sure that your patient’s constitutional remedy is working well, which will hopefully have them end up in that bin, rather than in the symptomatic bin.
As a public health concern, make sure that you are not bitten. Why? You may be spreading it. For example, someone from Minnesota goes to Brazil, is bitten and contracts Zika virus. Let’s not care if he is symptomatic or not. When he flies back to Minnesota, well, there are no mosquitoes there at this time, just inches of snow. It ends. Similar to what it is like in the rest of the country at this time. Fast forward a similar scenario in the summer. A person from Florida goes to Brazil, gets bitten, contracts Zika virus and flies back to Florida. If he is then bitten in Florida by the next Aedes aegypti mosquito who does not have the virus, the mosquito may then become infected, and then the next person that mosquito bites contracts Zika virus, and boom, the outbreak begins. Keeping yourself from getting bitten is good protection for you but perhaps more importantly, it also stops the spread of the virus. Remember, most people are not even aware they have the virus, so they will not know they are part of the transmission process. Play it safe. No bites.
And here I don’t mean only mosquitoes. Ticks are known to carry certain bugs that have become famous. However, ticks carry many more bugs than we measure. I believe in the future we will find that some of the people that are diagnosed with Chronic Lyme’s disease, actually either carry a virus that they picked up or are suffering from a post viral syndrome. The fact that we are not testing for it does not mean that they do not exist. Play it safe. No bites.
Prevention should also be especially important to the pregnant woman. While we may not know if this specific virus causes the specific developmental issue, we do know that insects carry many microorganisms with them. And while we may not know all of them, and may not know which ones are going to come to our shores, we do know that they carry many germs. Pregnant women in particular should be kept from being bitten. Simple enough concept.
If you are interested in following this topic more closely, consider keeping track of Arbonet, at, for example:
I was in Florida with one of my sons, the one that coaches professional basketball, coaching amongst other people, two Brazilian players, and we got to talking about the Olympics. There are serious discussions now of the USA team not participating in the Olympics in Brazil because of this Zika virus epidemic. That is just plain silly. This is a complete overreaction. Luckily, we know the current vector, we know how the bug passes the virus and we know that for those of a certain social status, as these athletes are, they are able to prevent transmission with some very basic protection. Here, I could give many examples that would make sense but let me just discuss one. There are many, many international competitions in countries that have endemic malaria or yellow fever or HIV for that matter, and we still go. We just take precautions, but the idea of stopping international play because of malaria, or dengue fever, or HIV is out of step. Protect yourself and go! Or think about it this way. Soon it will be in Florida. Are you going to move? Just protect yourself and go!
Which is a good place for me to end this update. The afternoon before we left Florida, we took in a game of golf. This was late afternoon, but we thought we might have enough time for 9 holes. I guess this is a good time for me to mention that I play horribly, and am banned from golf courses for tearing up their turf too badly! Anyway, 9 holes. We were out there for hours. (My record was 15 strokes on one 3-par hole.) We were out there so long, it was dark, and at times it seemed like we were playing more by sound than sight. Luckily we had 20 balls to start with. The reason I am mentioning this golf game here is this: when we were in the midst of the Everglades, we sprayed on bug repellent, enough to keep mosquitoes off of us. However, during the golf game, by the 7th hole, we were out there so long that the repellent was no longer effective and we were getting bitten. I was not so much worried about Zika virus because it was likely a different mosquito, the wrong time of year, and Zika virus not here in force yet. But the point is that it is important to change habits to make sure that the repellent you use is appropriate to the exposure you plan on, and/or to carry more repellent with you when you are out. (Of course, achieving a better golf game and thereby shortening the time on the course might be an option for some, though it continues to elude me.)
And pregnancy? Think of it as part of the precautionary principle. Until we have a global solution, think of insects as carrying all sorts of germs, some we know and most we don’t. Given that, I think it is prudent to keep pregnant women from getting bitten by tics or mosquitoes. You can not stop all bites but limiting them makes sense, not just for Zika virus, or dengue fever, or Lyme’s disease, but as a general principle.
The short takeaway? Zika virus is highly transmitted to humans from mosquitoes. For the vast majority, the virus passes unnoticed, but not for all. It may or may not be the cause of microcephaly, but probably causes neurological symptoms. It may be some other specific cause of increase microcephaly in Brazil. That said, the same vector carries diseases that we are very clear about, that cause misery to many, including in the USA. Given the fact that bites by insects introduce germs into our bloodstream, perhaps it is useful to not get bitten in the first place. And in the long term, we need to understand how to pass beyond the current model of species-specific vaccinations, to new models of solutions that keep us within nature, yet do not let us be ravaged by other species, be it malaria, dengue fever, or influenza.
This is to be the longest update in this sequence, as the next ones will be much, much shorter. Sign up to either our blog (http://paulherscuepidemics.blogspot.com), or Twitter (https://mobile.twitter.com/paulherscu ) for updates.
Until then, DON’T PANIC!
Paul Herscu, ND, MPH