Tag Archives: disease

flesh eating bacteria: worry or not worry?

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If you are one of the people who gets flesh eating bacteria, it is horrible. This article is about a person who got a minor scrape in the Gulf of Mexico, lost her leg, and was lucky to live. But here are the numbers:

Cases of V. vulnificus are rare. Between 150 and 200 are reported to the Centers for Disease Control and Prevention every year, with about 20% resulting in death. Most are in states along the Gulf of Mexico, but, in 2019, 7% were on the Pacific Coast. Florida averages about 37 cases and 10 deaths a year.

But a rise in cases nationally and the spread of the disease to states farther north — into coastal communities in states such as Connecticut, New York, and North Carolina — have heightened concerns about the bacterium, which can result in amputations or extensive removal of tissue even in those who survive its infections. And warmer coastal waters caused by climate change, combined with a growing population of older adults, may result in infections doubling by 2060, a study in Scientific Reports warned earlier this year.

Alternet, orignally in Tampa Bay Times

My heart certainly goes out to this person, the other 149-199 people per year who get this, and the other 299 to 399 per year who may get it by 2060. I am going to continuing worrying most about things that kill tens or hundreds of thousands of people each year. And I am going to keep in mind that being so fearful of the outside world I become a couch potato would also be very risky for my health.

what epidemiologists, virologists, and immunologists are doing

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This STAT article surveys not what they recommend to others, but what they are actually doing. The sample size is 34, so I am not sure this qualifies as a scientific survey. But to summarize, they are ALL getting the bivalent booster. Almost all are wearing masks when they go shopping. Most are eating indoors and attending family gatherings, but they are testing first. Most are letting their children and grandchildren engage in more or less normal activities, but requiring or encouraging them to wear masks.

So, it seems at least this group of people with scientific/medical knowledge about Covid-19 are being more conservative than the public at large.

zoonotic diseases

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This article in France24 draws a link between habitat loss, climate change, and zoonotic diseases.

“Deforestation reduces biodiversity: we lose animals that naturally regulate viruses, which allows them to spread more easily,” he told AFP…

As animals flee their warming natural habitats they will meet other species for the first time — potentially infecting them with some of the 10,000 zoonotic viruses believed to be “circulating silently” among wild mammals, mostly in tropical forests, the study said.

Greg Albery, a disease ecologist at Georgetown University who co-authored the study, told AFP that “the host-pathogen network is about to change substantially”.

France24

I don’t quite get the logic of the first sentence – how do animals “naturally regulate viruses”? I can see the logic that some animals would limit the spread of viruses they are infected with based on their behavior. If they start moving around more, whether because their habitats are becoming smaller and more fragmented, because their ranges are shifting as the climate changes (although this seems like a much slower process to me), they will potentially interact more with other wild animals, with domestic animals, and with humans.

So solutions could be to protect natural habitats and keep cities from sprawling into them, shift more to vegetarian diets for people and/or keep livestock indoors (maybe not so great for the livestock).

May 2021 in Review

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Most frightening and/or depressing story: The Colorado River basin is drying out.

Most hopeful story: An effective vaccine for malaria may be on the way. Malaria kills more children in Africa every year than Covid-19 killed people of all ages in Africa during the worst year of the pandemic. And malaria has been killing children every year for centuries and will continue long after Covid-19 is gone unless something is done.

Most interesting story, that was not particularly frightening or hopeful, or perhaps was a mixture of both: I learned about Lawrence Kohlberg, who had some ideas on the use of moral dilemmas in education.

social insects and disease

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This article in Wired says social insects like ants and bees have a variety of behaviors that reduce pathogen spread in their crowded colonies. They range from obvious ones like keeping the nest clean and keeping waste outside, to forms of social distancing where they reduce the number of other individuals they are interacting with. Some species also swap body fluids intentionally to spread antibodies, which reminds me of the old stories where mom puts all the kids in bed with the first one to catch the mumps or chicken pox.

I’ve always found ants interesting because there are enormous numbers of them, rivaling or exceeding human biomass, they build cities and transportation systems and hunt and gather and farm and fight each other, and yet they don’t negatively impact the environment. They are the environment and nobody ever asks whether their population or their consumption patterns exceeds the planet’s carrying capacity. They also adapt just fine to all kinds of novel and damaged ecosystems that we are creating.

new hope in the fight against AIDS

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From Bloomberg: New drugs mean not only that AIDS can be effectively managed in people that already have it, but that the risk of transmission can now be very low in people taking the drugs. Some drugs even have a strong protective effect for people who have not been exposed but are considered at risk of exposure. According to this article, eradication of the disease now seems possible for the first time.

life expectancy in ancient societies

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This article says life expectancy in ancient societies may not be as low as people tend to think. Many people are probably aware that child mortality brings down the average, but something I never thought about is how hard it is to measure the upper limit for populations that existed before any type of written records. There are people who specialize in digging up graves and doing exactly this, which seems a bit macabre.

We are all able to instinctively label people as ‘young’, ‘middle-aged’ or ‘old’ based on appearance and the situations in which we encounter them. Similarly, biological anthropologists use the skeleton rather than, say, hair and wrinkles. We term this ‘biological age’ as our judgment is based on the physical (and mental) conditions that we see before us, which relate to the biological realities of that person. These will not always correlate with an accurate calendar age, as people are all, well, different. Their appearance and abilities will be related to their genetics, lifestyle, health, attitudes, activity, diet, wealth and a multitude of other factors. These differences will accumulate as the years increase, meaning that once a person reaches the age of about 40 or 50, the differences are too great to allow any one-size-fits-all accuracy in the determination of the calendar age, whether it is done by eye on a living person or by the peer-preferred method of skeletal ageing. The result of this is that those older than middle age are frequently given an open-ended age estimation, like 40+ or 50+ years, meaning that they could be anywhere between forty and a hundred and four, or thereabouts.

The very term ‘average age at death’ also contributes to the myth. High infant mortality brings down the average at one end of the age spectrum, and open-ended categories such as ‘40+’ or ‘50+ years’ keep it low at the other. We know that in 2015 the average life expectancy at birth ranged from 50 years in Sierra Leone to 84 years in Japan, and these differences are related to early deaths rather than differences in total lifespan. A better method of estimating lifespan is to look at life expectancy only at adulthood, which takes infant mortality out of the equation; however, the inability to estimate age beyond about 50 years still keeps the average lower than it should be.

Archaeologists’ age estimates, therefore, have been squeezed at both ends of the age spectrum, with the result that individuals who have lived their full lifespan are rendered ‘invisible’. This means that we have been unable to fully understand societies in the distant past. In the literate past, functioning older individuals were mostly not treated much differently from the general adult population, but without archaeological identification of the invisible elderly, we cannot say whether this was the case in non-literate societies.

infectious disease

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The Royal Society says that the annual number of disease outbreaks and types of diseases causing them have both increased since 1980, although the fraction of the population affected has actually decreased. I assume this last trend has to do with population growth. I am not sure this should be comforting. If there are more outbreaks and more different types, it seems like there would be more potential for something really bad to emerge and then get out of control. But this article isn’t really about that, it’s just a presentation of the data.

Our analyses indicate that the total number of outbreaks and richness of causal diseases have each increased globally since 1980 (figure 1a). Bacteria and viruses represented 70% of the 215 diseases in our dataset and caused 88% of outbreaks over time. Sixty-five per cent of diseases in our dataset were zoonoses that collectively caused 56% of outbreaks (compared to 44% of outbreaks caused by human-specific diseases). Non-vector transmitted pathogens were more common (74% of diseases) and caused more outbreaks (87%) than vector transmitted pathogens (table 1). Salmonellosis caused the most outbreaks of any disease in the dataset (855 outbreaks reported since 1980). However, viral gastroenteritis (typically caused by norovirus) was responsible for the greatest number of recorded cases: more than 15 million globally since 1980.

It’s interesting how we tend to be less afraid of diseases that are more common and more afraid of ones that are less common, even though a given person would be more likely to suffer from a common disease. Of course, this analysis doesn’t take into account the severity of the disease and suffering caused, which should certainly be a factor in what kinds of controls and research we invest our efforts and money in.