The plant pathogen genus Phytophthora, a water mold with similarities to a fungus, is a worldwide threat to ornamental and commercially valuable plants due to how it can develop undetected in the early stages of an infestation. While there are some species of Phytophthora that begin an infestation on the above ground portion of a plant, a much larger portion of the approximately 170 known species of the pathogen start out destroying a plant from within its roots. Phytophthora moves upward from the roots through the water channels of the plant, interfering with the plant’s ability to absorb water as it goes. The effect makes the plant appear drought-stricken, which is essentially the case.
One of the plants heavily afflicted by Phytophthora in the past 30 plus years has been the cocoa tree, Theobroma cacao, and specifically the cocoa trees planted in western Africa, where most of the world’s cocoa beans are produced. The species of Phytophthora doing the most damage in that period has been Phytophthora megakarya, a disease that blackens the pods which contain the cocoa beans, rendering most of them unfit for consumption. This disease and a virus transmitted by mealybugs called cacao swollen shoot virus (CSSV) in combination have decimated cocoa tree plantations in western Africa in recent decades.
A Venn diagram showing the combination necessary for disease to form. This can apply to humans and animals as well as to plants. Illustration by Earlycj5.
Phytophthora megakarya was introduced from the Americas, where it had long co-existed with the native cocoa trees. The cultivated cocoa trees of western Africa had developed for generations without having to cope with infestations from megakarya, though they had long been contending with Phytophthora palmivora, a less devastating disease for them.
CSSV was native to the forest trees of western Africa, where it did little damage because of long term co-evolution of the trees with the virus. The introduced cocoa trees had no inherited defense against CSSV, resulting in afflicted cocoa trees losing vigor and dying within a few years. Meanwhile, the ants that farmed the mealybugs for their sugary secretions have ensured they continue to live safe from predators by guarding them, even building shelters for them.
Chocolate has grown steadily more expensive, at a rate beyond ordinary inflation, due primarily to shortages of cocoa beans caused by these pathogens. Another reason for chocolate price increases has been related to the salutary shift away from indentured labor on cocoa plantations, making the price more accurately reflect the true cost of production. The cost of production is bound to catch up with any resource as nature asserts itself in one way or another, or in many ways, and imagining that we are immune or insulated from the effects of that assertion is mere hubris and folly. Ultimately, we will pay the price.
— Izzy
“What made eradication possible was a really good vaccine and political support. There was a real incentive to do it. You don’t ask a cow if it wants to be vaccinated. You just do it.” — Ron DeHaven, former CEO of the American Veterinary Medical Association, speaking about the eradication of rinderpest, a cattle disease related to the measles virus.
Rinderpest and smallpox are the only two infectious diseases that have been eradicated around the world. Smallpox is the only disease to be eradicated that infects only people. Eradication of other infectious diseases, like COVID-19 for one, is unlikely because there are alternate hosts in the animal population, and while it may be feasible to vaccinate domesticated animals such as cows to the point of herd immunity, it is unrealistic to think the same can be done for wild animals.
Ruins of the Smallpox Hospital built in the 19th century on Roosevelt Island in New York City. Photo by Flickr user Adam Jones.
Cows have another favorable trait in reaching herd immunity besides being easily available for their shots, which is that they don’t subscribe to bizarre, illogical, and unscientific conspiracy theories egging them on to refuse vaccinations, if that was a possibility for them. Rinderpest, like its cousin infecting humans, the measles virus, is among the most contagious diseases on the planet, and the more contagious a disease is, the higher the percentage of a susceptible population must be vaccinated in order to achieve herd immunity. For measles and rinderpest, that’s over 90 percent.
Smallpox is – was – in the middle of the scale as far as its contagious qualities, but among the deadliest at around 30 percent fatalities. Influenza, with notable exceptions throughout history, such as the 1918-19 Spanish Flu outbreak, is at the lower end of the scale for both contagiousness and deadliness. COVID-19, like the other Severe Acute Respiratory Syndrome (SARS) viruses to which it’s related, is higher up the scale for contagiousness than the annual flu, but it is nowhere near as deadly as smallpox, though deadliness as always is strongly affected by a victim’s socioeconomic circumstances. The poor, as always in any affliction, die in droves, while the better off have access to the best care and are less likely to be infected in the first place.
One by one through the nineteenth and twentieth centuries, diseases that had killed hundreds of millions over thousands of years were brought under control with vaccines and other public health measures, such as better sanitation. There have always been people of skeptical of the effectiveness of vaccines or suspicious of the motives of the medical people, often affiliated in one way or another with a government entity, who administered the vaccines. The difference in then from now is that before about 1980 evidence of a world without vaccines was still readily available to everyone, rich and poor, living in the industrialized northern hemisphere or in the largely agricultural southern hemisphere.
In 1947, when the threat of disfigurement or death from smallpox was still very real to everyone, the citizens of New York City lined up for blocks to receive vaccinations in order to stem a possible outbreak.
Today, people in richer countries no longer see the effects of smallpox at all, and rarely do they see the effects of less disfiguring, less deadly diseases like measles. If COVID-19 were to leave visible scars on those who suffered and survived, instead of just the internal scars it does leave, one wonders if at least some of the people ready to dismiss the seriousness of the disease and the severity of the outbreak would be as obstinate about complying with public health measures.
If there were still children crippled by polio in every neighborhood, would there still be people who are more willing to believe an insane theory about vaccines they read in their Facebook “news” feeds than the scientific fact of once rampaging infections brought to heel in the past two hundred years? No doubt there will always be some hard cases who can’t be reached through reason, no matter what. The amount of the U.S. population vaccinated against COVID-19 is currently about 43 percent, and it needs to be over 70 percent to reach herd immunity. It will be best to cross that threshold before cold weather sets in again, forcing people back indoors. If it’s not, then COVID-19, a disease that will likely never be eradicated, only controlled, could surge once more, making this summer of relative freedom appear in retrospect like a fool’s paradise.
— Vita
It’s no surprise MAGA Mussolini has called the imminent danger of a coronavirus pandemic a hoax, nor is it a surprise his MAGA followers swallowed that lie and called for more. They always do. These developments have become so predictable that they no longer warrant the bother of linking to the news stories about them. All the rest of us can do, those of us who live in the fact-based world, that is, is resist the implementation of damaging policies by those who live in the fantasy world of MAGA hate-based politics.
The Sick Child, an 1893 painting by the American artist J. Bond Francisco (1863-1931).
The great surprise is how well scientists and doctors have done in the past 100 years in restricting another pandemic like the Spanish Flu outbreak of 1918 and 1919, which killed 100 million people around the world. The Spanish Flu came on the heels of the close of World War I, and after it had finally flamed out it had claimed more lives than that most horrific “War to End All Wars”. That was the way the balance had worked throughout history, with battlefield deaths generally being outpaced by the communicable diseases unleashed in the gatherings of large armies and refugees. The later twentieth century holds the dubious distinction of tipping that balance toward human mayhem as the major cause of death in wars.
What is most remarkable about the efficiency of modern science in preventing the kind of communicable disease pandemics which have periodically scourged humanity is that scientists and doctors have done this despite the huge increase in population at the same time worldwide travel has skyrocketed in volume and speed. More people than ever before are moving faster and more frequently from one part of the world to the next, and all the while they are sharing untold numbers of germs both dangerous and mundane with local populations.
In the taking over of the New World by European colonists only two and more centuries ago, those sorts of introductions – though at a slower pace – led to genocidal destruction of the indigenous population through their exposure to an array of unfamiliar diseases. People more often lived in lighter concentrations then than they do now. Travel was certainly far slower, and most people then lived their entire lives in the familiar surroundings of one city or of a handful of farm villages.
The great danger now is the introduction of an unfamiliar permutation of a familiar virus or bacterium. And yet for 100 years the world’s scientific and medical professionals have forestalled the disaster that could easily overtake us if they weren’t vigilant. Calling their sincere efforts a hoax helps no one, and acting on such misinformation would amount to carelessly flipping a lit cigarette butt onto dry brush.
— Vita
The eastern half of the country has received copious rainfall this spring, and in the eastern seaboard states the rainfall has been excessive, leading to flooding in spots like Ellicott City, Maryland. The high rainfall amounts have led to a greater than usual amount of standing water, and because mosquitoes lay their eggs in standing water there is a greater than usual mosquito count in the eastern United States. There was also a mild winter preceding this spring, and that has led to high counts of ticks and other insects. People who want to spend more time outdoors as the weather warms this year must be prepared to either defend themselves or succumb to getting their blood drawn by numerous insects, taking a chance consequently on coping with a disease for which the blood sucking insects are vectors.
There are the usual recommendations from experts to cover up when outdoors in the summer when insects are most active, but it’s awfully tough to take their advice when it’s 90 degrees and the humidity is very high. Long pants tucked into high socks? Long sleeves on shirts? In order to stay comfortable, many people won’t heed that advice. The advice to wear loose fitting, light colored clothes is welcome, however, because in addition to coping with insect attacks that advice helps the wearer cope with hot weather. Above all, in more ways than one, the most important item of clothing in summer is a broad brimmed hat.
An illustration of Tanacetum cinerariifolium from the 1897 edition of Köhler’s Medizinal Pflanzen, a book on medicinal plants by Franz Eugen Köhler.
A good quality broad brimmed hat will serve to ward the sun off a person’s face, neck, and ears, as well as absorb sweat before it runs down from brow into eyes, and in addition will help keep insects away from one’s head. The last statement is based on nothing more than anecdotal evidence, but test it for yourself in the course of wearing a broad brimmed hat for all its other useful qualities. Insects seem reluctant to come up under the broad brim. Is it 100% effective? No, but then very few things are 100% effective in life. Toss away that useless baseball cap and try wearing a broad brimmed hat like a boonie hat. Bucket hats, the diminutive cousins of boonie hats, do not count.
An illustration of Tanacetum coccineum from the 1897 edition of Köhler’s Medizinal Pflanzen, a book on medicinal plants by Franz Eugen Köhler.
For those who would rather resort to what they believe are the more certain results yielded by chemical insect repellents, there are the usual products readily available at most stores. Try not to go overboard. Before buying those clothes soaked in permethrin, consider eating more garlic and onions as a systemic repellent to ooze out of your pores for a day or two at a time, scaring off bugs and people alike. Botanical repellents are generally less effective than their more renowned chemical cousins, but they also leave a lighter footprint on the environment and perhaps on the user.
One product that straddles the border is the permethrin mentioned earlier. Permethrin is derived from flowers related to chrysanthemums, and is not a repellent but an insecticide. When you use permethrin products, insects will land on you and may get an opportunity to suck blood before they die and drop off. A repellent, of course, wards off insects before they land on you. Permethrin is more effective than other botanicals, and is generally safer for the environment and the user than chemical repellents or insecticides. It is used in some flea treatments for dogs. It is not used in flea treatments for cats, however, because it is toxic, even deadly, for cats. People who have both cats and dogs in their homes should keep in mind if they apply permethrin flea treatment to the dogs but not the cats that the permethrin can still adversely affect the cats by secondary contact. For everyone, as tempting as it is to reach for the most highly effective treatment when battling insects which can transmit troubling diseases, or at least cause discomfort, try to maintain perspective so that the treatment doesn’t end up being worse than the affliction.
— Izzy
