Medical The worst disease ever in human history

AI Thread Summary
The discussion centers on identifying the worst disease in human history, with participants highlighting malaria as a leading contender due to its historical death toll, killing approximately 1 million annually. The 1918 influenza pandemic is noted for its unprecedented impact, claiming more lives in a single year than the Black Death did over a decade. Smallpox is also mentioned for its devastating effects on indigenous populations in the Americas and its historical significance. The conversation touches on addiction, debating whether it should be classified as a disease, with some arguing it has a neurological basis while others view it as a behavioral disorder. Ultimately, the discussion reflects on the complexity of defining diseases and their impacts on human health.
Jin S Zhang
Messages
20
Reaction score
0
WHat is the worst and formidable disease ever in human history? Why?
 
Biology news on Phys.org
In terms of total integral number killed over history it's probably malaria.
In number killed in one outbreak it's the 1918 Flu epidemic.
 
Addiction

As near as I can tell, malaria kills about 1 million people a year; alcohol kills about 1.8 million; tobacco kills about 4 million each year, worldwide.
 
1918 influenza


-killed more people in 1 year than black death was able to over 10 years
-killed more people in 1 year than the total amount of people combined to date that have died from AIDS
-infected over 1 billion people
-depressed the average lifespan age in American by something like 10 years
 
I'm no expert on this subject but I would say smallpox. It killed 90% of the indigenous people in North and South America after Columbus arrived. Plus many people in Europe, Asia and Africa.
 
Ivan Seeking said:
Addiction

As near as I can tell, malaria kills about 1 million people a year; alcohol kills about 1.8 million; tobacco kills about 4 million each year, worldwide.

You are so funny.
 
What is funny about that? In the US, at least, addiction is considered to be a disease.
 
If you limit it to communicable diseases rather than old age or malnutrition then most diseases are fairly modern in evolutionary terms.
Smallpox,TB,measles etc are transferred from animals and only appeared in humans when we started living with herds of domesticated livestock say 10,000 years ago.
Widespread plagues need large concentrations of people living together and long distance trade so only got going 1000 years ago.
For the first 1-2 million years of human history it was only something flying out of the jungle and biting you that really mattered,
 
Last edited:
mqb is talking about density-dependent disease transmission. TB is a good example of this. There have been major outbreaks of DD diseases documented way back before Roman times. An excellent work meant for non-scientists is 'Guns, Germs, and Steel' by Jared Diamond. An old book 'Rats lice and History' by Hans Zinsser raised a lot of the questions in this area of enquiry. And has more epidemiological discussion.
 
  • #10
Ivan Seeking said:
What is funny about that? In the US, at least, addiction is considered to be a disease.

I suspect the OP is referring to infectious disease (i.e. caused by a pathogen), rather than disorders, which technically aren't disease, but are still medical conditions. In common usage, the two are often used synonymously, but in medicine, disease would mean something different from a disorder. The OP will need to clarify on that point.
 
  • #11
Birth.

It has a 100% fatality rate.
 
  • #12
I don't mind dying of birth.
 
  • #13
I heard the worst diseases are heamorrhoids and ebola.
 
Last edited by a moderator:
  • #14
lol. There is some serious religion/atheist bashing going on which I personally find quite amusing. I'm not going to get involved in it, since the original question was not "which has killed more people... religion or lack of religion".

With respect to the original question, could genetic diseases/abnormalities not be the largest single killer of humans? I know that they generally only affect a tiny proportion of humans, but given how long they have been around, it may be a contender
 
Last edited:
  • #15
Removed off topic religious discussions.
 
  • #16
Moonbear said:
I suspect the OP is referring to infectious disease (i.e. caused by a pathogen), rather than disorders, which technically aren't disease, but are still medical conditions. In common usage, the two are often used synonymously, but in medicine, disease would mean something different from a disorder. The OP will need to clarify on that point.

I knew that this wasn't just a casual reference so I checked. It seems that the National Institute on Drug Abuse are the ones who promoted the idea that addiction is a disease of the brain - I think along the lines of a genetic disease. But that idea is losing favor.

...As a psychiatrist who treats heroin addicts and a psychologist long interested in the philosophical meaning of disease, we have chafed at the "brain disease" rhetoric since it was first promulgated by NIDA in 1995. Granted, the rationale behind it is well-intentioned. Nevertheless, we believe that the brain disease concept is bad for the public's mental health literacy.[continued]
http://www.slate.com/id/2171131/nav/tap3/

Also, this, which is a reply to the article above:
This clueless pair doesn't argue that the neurochemistry of an addict's brain is no different from that of a non-addict. They can't, because it demonstrably is. Instead, they offer gems of wisdom like this:

"Characterizing addiction as a brain disease misappropriates language more properly used to describe conditions such as multiple sclerosis or schizophrenia—afflictions that are neither brought on by sufferers themselves nor modifiable by their desire to be well."

This presumes that there's no underlying neurological basis that predisposes someone to addiction. Those who actually know something about it know this is a false presumption. Addiction, as Satel and Lilienfeld have somehow failed to learn, is not simply the behavior of abusing drugs—if it were, then all of the college students who drink too much would be alcoholics. Most aren't; they grow out of it.

Addiction is actually a disorder in which the brain's reward system is conditioned to value the reward of getting high over pretty much anything else. It's a disorder, in other words, in which the brain is malfunctioning. [continued]
http://time-blog.com/eye_on_science/2007/07/addiction_is_not_a_disease.html

In the end it seems that this is a political issue as much as a medical one.

Again, from the first link:
A new bill sponsored by Sen. Joe Biden, D-Del., would change the name of the National Institute on Drug Abuse to the National Institute on Diseases of Addiction and change the name of the National Institute on Alcohol Abuse and Alcoholism to the National Institute on Alcohol Disorders and Health. Called the Recognizing Addiction As a Disease Act of 2007, it explains, "The pejorative term 'abuse' used in connection with diseases of addiction has the adverse effect of increasing social stigma and personal shame, both of which are so often barriers to an individual's decision to seek treatment." Addiction should be known as a brain disease, the bill proclaims, "because drugs change the brain's structure and manner in which it functions. These brain changes can be long lasting, and can lead to the harmful behaviors seen in people who abuse drugs."

Is diabetes a disease or a disorder?
 
Last edited:
  • #17
If we are to limit ourselves only to those lethal pandemics that political correctness has allowed to define as such, tuberculosis is as far as I know of still the major killer.

But mental diseases are far more prevalent, and cause numerous deaths every year.
 
Last edited:
  • #18
Ivan Seeking said:
I knew that this wasn't just a casual reference so I checked. It seems that the National Institute on Drug Abuse are the ones who promoted the idea that addiction is a disease of the brain - I think along the lines of a genetic disease. But that idea is losing favor.


http://www.slate.com/id/2171131/nav/tap3/

Also, this, which is a reply to the article above:

http://time-blog.com/eye_on_science/2007/07/addiction_is_not_a_disease.html

In the end it seems that this is a political issue as much as a medical one.

Again, from the first link:


Is diabetes a disease or a disorder?

While NIDA may have influenced this official recognition, alcoholism, has long been considered a disease in many quarters and research based on this assumption has produced some very interesting findings, not the least of which that it is subject to greater genetic influence than say, most cardiovascular disease and diabetes. Addiction is one of the few illnesses I know of where victims are so often incapable of seeling and/or using treatment to their advantage. Certainly, not the only one as heart disease, diabetes, obesity and many forms of psychiatric illness seem to share in common this odd inability to modify behavior for ones benefit.

In terms of the morbidity and mortality, it does rank near the top, to say nothing of lost productivity and the damage done to others, both directly (1/2 of all violent crimes inclusding homicide I believe are committed under the influence) and indirectly. Curiously the amount of money spent on treatment and resesrch pales in comparison to more glamorous diseases such as cardiovascular--when I last taught medical students on the subject, the outlays were something like 50:1 in favor of the latter.

Despite the destigmatization that has occurred over the last 20 or so years, there is still a belief, both among the general public as well as health care professionals that the illness is self-inflicted. Yet in all my years of treating addicts I have not met one who chose to become one.
 
  • #19
Smoking is still the #1 leading cause of preventable death world wide. Not obesity, not alcholism, not AIDS, not malaria, not TB, not obesity. SMOKING STILL #1.
Stupid.
The top 3 killers worldwide are

1.) heart disease
2.) stroke
3.) lung cancer.

Smoking contributes to ALL 3 of the top 3 killers worldwide.
 
Last edited:
  • #20
According to the WHO - top 10 causes of death:

Developed countries:
Ischaemic heart disease 3,512,000
Stroke 3,346,000
Chronic obstructive pulmonary disease 1,829,000
Lower respiratory infections 1,180,000
Lung cancer 938,000
Car accident 669,000
Stomach cancer 657,000
High blood pressure 635,000
Tuberculosis 571,000
Suicide 499,000


3rd world:
HIV-AIDS 2,678,000
Lower respiratory infections 2,643,000
Ischaemic heart disease 2,484,000
Diarrhea 1,793,000
Cerebrovascular disease 1,381,000
Childhood diseases 1,217,000
Malaria 1,103,000
Tuberculosis 1,021,000
Chronic obstructive pulmonary disease 748,000
Measles 674,000


A bit arguable, since diarrhea is a symptom not a disease and it's a bit arbitrary how you split heart disease.
In the developed world it would seem that if you stay away from cigs, fast-food and SUVs you will be OK.
Many of these disease are newcomers or are a result of a more modern lifestyle. Evidence from the number of mutations in the genome to counter it suggests that throughout human evolution malaria has been the big one, upto a couple of hundred years ago it was still one of the biggest killers in Europe. Some estimates suggest that half of all humans who ever lived contracted it!
 
Last edited:
  • #21
mgb_phys said:
According to the WHO - top 10 causes of death:

Developed countries:
Ischaemic heart disease 3,512,000
Stroke 3,346,000
Chronic obstructive pulmonary disease 1,829,000
Lower respiratory infections 1,180,000
Lung cancer 938,000

Car accident 669,000
Stomach cancer 657,000
High blood pressure 635,000
Tuberculosis 571,000
Suicide 499,000


3rd world:
HIV-AIDS 2,678,000
Lower respiratory infections 2,643,000
Ischaemic heart disease 2,484,000

Diarrhea 1,793,000
Cerebrovascular disease 1,381,000
Childhood diseases 1,217,000
Malaria 1,103,000
Tuberculosis 1,021,000
Chronic obstructive pulmonary disease 748,000
Measles 674,000



And all of those have an extremely good chance of having smoking as their hidden cause.
 
  • #22
gravenewworld said:
Smoking is still the #1 leading cause of preventable death world wide. Not obesity, not alcholism, not AIDS, not malaria, not TB, not obesity. SMOKING STILL #1.



Stupid.



The top 3 killers worldwide are

1.) heart disease
2.) stroke
3.) lung cancer.

Smoking contributes to ALL 3 of the top 3 killers worldwide.

What is the problem with this.. We are running into some critical overpopulation problems now, what's the problem?
 
  • #23
henxan said:
What is the problem with this.. We are running into some critical overpopulation problems now, what's the problem?

PREVENTABLE death. It costs everyone money when it shouldn't.
 
  • #24
gravenewworld said:
Smoking is still the #1 leading cause of preventable death world wide. Not obesity, not alcholism, not AIDS, not malaria, not TB, not obesity. SMOKING STILL #1.

I don't know about that obesity thing.
I read a comment in a research article that being 10lbs overweight was equivalent to smoking a pack of cigarettes a day in terms of health risk.

Last I checked the insurance companies docked you 5 years off your life expectancy.
So in terms of years of life lost it doesn't seem to be a big deal compared to something like malaria where children tend to be the victim.
 
  • #25
NoTime said:
I don't know about that obesity thing.
I read a comment in a research article that being 10lbs overweight was equivalent to smoking a pack of cigarettes a day in terms of health risk.

Last I checked the insurance companies docked you 5 years off your life expectancy.
So in terms of years of life lost it doesn't seem to be a big deal compared to something like malaria where children tend to be the victim.

There are numerous sources out there that claim smoking is the #1 leading cause of preventable death in the world. You can simply search google to find a ton. Here in the US, obesity is approaching #1 status as the leading killer because Americans in general smoke less than a lot of countries in the world per capita wise. However, consider places like Japan where obesity isn't that much of a problem. Almost 2/3 of Japanese men smoke :bugeye:. In China it is estimated that 350 million people smoke :bugeye:. Smoking rates have dramatically risen in Asian countries. By 2020 WHO predicts that smoking will kill 10 million people per year world wide. Obesity is a problem among industrialized nations, however, you will find smokers EVERYWHERE. Smoking is still king when it comes to killing and will remain in the top spot for years to come.
 
Last edited:
  • #26
gravenewworld said:
PREVENTABLE death. It costs everyone money when it shouldn't.

It costs everyone a lot of money? What is this, youre a greedy bastard?

Well, firstly, I would like to point out that you have what could be misinterpreted arrogant attitude. Then what I am going to say probably will please you!

Actually Poland did a research on this subject, and wouldn't you know it, its actually good for the economy! People die earlier, ergo less expenses for treatment the elderly. This actually by a great deal outweighs the negative consequences you mentioned. Another extremely positive factor is the relative high taxes being put on tobacco sales. This depends on the individual countries, but for instance for Norway, which I come from, have put taxes in the range of several hundreds of percent on the tobacco.

Therefore, as a conclusion, there is no economic negative aspect to tobacco. If one is to state a reason for banning tobacco, it would be on a basis of telling people of how they should live their life. Like in a communistic system. Is that ok?
 
  • #27
henxan said:
It costs everyone a lot of money? What is this, youre a greedy bastard?

LOL, so what is better spending tons of filthy lucre on treating PREVENTABLE DISEASES or spending all of that money on AIDS research?

Well, firstly, I would like to point out that you have what could be misinterpreted arrogant attitude.
So I have been told.

ctually Poland did a research on this subject, and wouldn't you know it, its actually good for the economy! People die earlier, ergo less expenses for treatment the elderly. This actually by a great deal outweighs the negative consequences you mentioned. Another extremely positive factor is the relative high taxes being put on tobacco sales. This depends on the individual countries, but for instance for Norway, which I come from, have put taxes in the range of several hundreds of percent on the tobacco.
You know what is also good for the economy? Consuming as much as possible. I guess we should continue to consume as much as possible regardless of the disastrous effects it may have on the environment.

Also please link to the Polish study. From what you have described the Polish study seems to have only examined costs of treating smoking illnesses vs. cost of elderly care. If you are going to talk economics then start thinking like an economist. Smoking also has costs from lost productivity. You can not simply ignore that HUGE point and must factor it into how much smoking really economically costs.

Therefore, as a conclusion, there is no economic negative aspect to tobacco. If one is to state a reason for banning tobacco, it would be on a basis of telling people of how they should live their life. Like in a communistic system. Is that ok?
Where did I ever mention the word 'ban' ? Get a friggin clue dude.
 
  • #28
Cars is apparently the correct answer. (In the good old USofA at least)
Most of the modern diseases affect mostly older people who would not have been alive at their age a couple of hundred years ago. So healthcare, media, and general societal hysteria might come in as a good second, third and fourth as most deadly diseases.

http://www.disastercenter.com/cdc/

Odd. The music playing in the background where I'm at is http://www.youtube.com/watch?v=xFObRusJt24"

I always knock on wood when I hear that song.
 
Last edited by a moderator:
  • #29
gravenewworld said:
LOL, so what is better spending tons of filthy lucre on treating PREVENTABLE DISEASES or spending all of that money on AIDS research?

Lol. Preventable?
You could eliminate AIDS if everyone stopped having sex.
As an added benefit this would solve all enviromental problems in about 60 years.

You could solve the malaria problem just by moving all people out of the tropics.

PS: While I don't have any handy links I've seen other studies that indicate smokers die cheaper.
 
  • #30
OmCheeto said:
Most of the modern diseases affect mostly older people who would not have been alive at their age a couple of hundred years ago.

You don't have to go back that far. IIRC the life expectancy in the USA in 1900 was 45 and probably remains in that neighborhood for a lot of the world currently.

Personally I'd pick poverty.
 
  • #31
NoTime said:
Lol. Preventable?
You could eliminate AIDS if everyone stopped having sex.
As an added benefit this would solve all enviromental problems in about 60 years.

You could solve the malaria problem just by moving all people out of the tropics.
No AIDS is still transferable from non sexual contact.
PS: While I don't have any handy links I've seen other studies that indicate smokers die cheaper.
You should read this book then that was published by MIT
http://books.google.com/books?id=J4...oi=print&ct=title&cad=one-book-with-thumbnail

There are 100s of studies out there that have tried to determine the net cost of smoking to society, however, most of them only concentrate on one thing such as medical costs vs. savings in shorter lifespan while ignoring many other costs attributed with smoking like lost productivity.

In that book Sloan (Duke Economist) conducted one of the most recent and comprehensive studies of the net cost of smoking and concludes that even if you factor in the shorter lifespans of smokers, smoking still places an economic burden on the rest of society. Sure smokers pay cigarette taxes, but they earn less over their lifetime (because of the more time they need off etc.) thus leading to less taxes paid into things like income taxes.

Read the book.

You could solve the malaria problem just by moving all people out of the tropics.
Even though Malaria in the US is rare (and considered to be eradicated in the US) there are still reported cases of Malaria infections from people who didn't even travel outside of the US.

http://www.cdc.gov/malaria/features/surveillance.htm

Also moving 4 billion people from tropical climates or sub saharan Africa in order to avoid malaria IS NOT REALISTIC.
 
Last edited by a moderator:
  • #32
In case people have forgotten, please click on the link to https://www.physicsforums.com/showthread.php?t=5374". You are also welcome to use the REPORT button if you believe a post is out of line. If you choose to IGNORE all that, then a bunch of you will be forced to go find a life elsewhere away from PF.

Zz.
 
Last edited by a moderator:
  • #33
Zz has it exactly. You guys are arguing ad hominem - not critiquing data or data gathering procedures. That is a fast path to getting a horizontal line thru your username.
 
  • #34
Yeah, I see that I went a bit over the border there.. Well, now I know where the limit is set, and Ill try to refrain from passing it in the future :)..
 
  • #35
Gravenworld:

I must apologize, because the study was not made in Poland, but in the Czech Republic ;).. you know, there's always problems sorting out between those countries.
Another error I made was stating that the study was financed by the State. This is not factual, and came as a result of hearing the news on radio several years ago, and everything did not stick ;)..

Well, here is your link:http://www.mindfully.org/Industry/Philip-Morris-Czech-Study.htm"

Though provisioned by Philip Morris, the data should be easily verified!.. Let me hear back when you get to read through it ;)
 
Last edited by a moderator:
  • #36
IMO this discussion underscores Ivan's original point about addiction. Nicotine while not producing euphoria has the curious property of being among the most addictive substances known to man. The leader tho by quite a stretch in terms of addiction worldwide remains caffeine.
 
  • #37
gravenewworld said:
And all of those have an extremely good chance of having smoking as their hidden cause.

Stomach cancer, high blood pressure and cerebrovascular disease could also have smoking as their hidden cause.
 
  • #38
This list of the http://healthlifeandstuff.com/2009/11/the-10-worst-diseases-ever/" says Bubonic plague is the worst, as it killed 1/3 people in Europe at one point.
 
Last edited by a moderator:
  • #39
rainbow93 said:
This list of the http://healthlifeandstuff.com/2009/11/the-10-worst-diseases-ever/" says Bubonic plague is the worst, as it killed 1/3 people in Europe at one point.

Yes but the population then wasn't that big so it may have only killed 10M people.
So a disease today that kills 1% of the 6Bn population is a bigger killer.
Alternatively a disease like malaria that killed a large proportion of people every year for the last million years is also a contender.
 
Last edited by a moderator:
  • #40
wildman said:
I'm no expert on this subject but I would say smallpox. It killed 90% of the indigenous people in North and South America after Columbus arrived. Plus many people in Europe, Asia and Africa.

I would have said Bubonic Plague, but smallpox seems to have caused more damage.
 
  • #41
mgb_phys said:
Alternatively a disease like malaria that killed a large proportion of people every year for the last million years is also a contender.

I wasn't aware malaria has been around for the last million years. Source please. The History of Malaria, an Ancient Disease implies early mention of malaria in 2700BC.
http://www.cdc.gov/malaria/history/index.htm

As far as today goes' ischemic heart disease kills over 6 million individuals each year and is projected by the World Health Organization to be the greatest single-disease cause of death worldwide' according to Duke Clinical Research Institute.
Dis Markers. 2009;26(5-6):265-71.

Prognostic biomarkers in individuals with prevalent coronary heart disease.

Halim SA, Newby LK.

Duke Clinical Research Institute, Duke University Medical Center, Durham, NC 27715-7969, USA.
Coronary disease is the leading killer of individuals worldwide and a leading cause of healthcare expenditure. On a global scale, ischemic heart disease kills over 6 million individuals each year and is projected by the World Health Organization to be the greatest single-disease cause of death worldwide by an increasing margin into 2030. Nearly 17 million Americans (7.6% of the population) have prevalent coronary heart disease, 8 million of whom have had a prior myocardial infarction. It is estimated that in 2009, 550,000 will die from coronary heart disease in the United States and that the direct and indirect costs from treating coronary heart disease will exceed $165 billion. Although patients with known coronary artery disease are among the highest risk patients for future cardiac events, not all patients with coronary disease will have an ischemic event (first or recurrent). Determining which of these patients will have an ischemic event is critical to the concept of personalized cardiovascular care. Increasingly, biomarkers that can be readily assayed from blood or other body fluids will be critical to risk stratification and effective application of secondary prevention strategies, just as they have played an increasingly prominent role in risk stratification of acute coronary syndrome patients.
http://www.ncbi.nlm.nih.gov/sites/e...ez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
 
  • #42
Impressive numbers, but still a drop in the bucket compared to addictive disease, which obviously causes a lot of heart disease. I couldn't easily locate US stats but here are some from Canada which in the year in question had a population of about 23 million. From the: Journal of Public Health, Vol. 89, Issue 3 385-390, Copyright © 1999 by American Public Health Association
This Article




Morbidity and mortality attributable to alcohol, tobacco, and illicit drug use in Canada.

E Single, L Robson, J Rehm, X Xie and X Xi

Canadian Centre on Substance Abuse, University of Toronto, Ontario, Canada.


OBJECTIVES: This study estimated morbidity and mortality attributable to substance abuse in Canada. METHODS: Pooled estimates of relative risk were used to calculate etiologic fractions by age, gender, and province for 91 causes of disease or death attributable to alcohol, tobacco, or illicit drugs. RESULTS: There were 33,498 deaths and 208,095 hospitalizations attributed to tobacco, 6701 deaths and 86,076 hospitalizations due to alcohol, and 732 deaths and 7095 hospitalizations due to illicit drugs in 1992. CONCLUSIONS: Substance abuse exacts a considerable toll on Canadian society in terms of morbidity and mortality, accounting for 21% of deaths, 23% of years of potential life lost, and 8% of hospitalizations.
One stat I did find re the USA, 500 billion per annum direct and indirect costs, and that for EtOH alone!
 
  • #43
ViewsofMars said:
I wasn't aware malaria has been around for the last million years. Source please. The History of Malaria, an Ancient Disease implies early mention of malaria in 2700BC.
The malaria parasite is old, the family is possibly older than mosquitoes. It also infects a lot of other primates so it's a fair bet it infected early man as well.

It also infects people on the african savanna, most more modern epidemic disease are water borne or transmitted from domesticated animals so need the start of cities to become a problem. Malaria was always present for as long as you care to define people as people.

It probably wasn't mentioned before the invention of writing and civilization in the 3rd millennia BC for the same reason that nothing else is!
 
  • #44
mgb_phys said:
The malaria parasite is old, the family is possibly older than mosquitoes. It also infects a lot of other primates so it's a fair bet it infected early man as well.

It also infects people on the african savanna, most more modern epidemic disease are water borne or transmitted from domesticated animals so need the start of cities to become a problem. Malaria was always present for as long as you care to define people as people.

It probably wasn't mentioned before the invention of writing and civilization in the 3rd millennia BC for the same reason that nothing else is!

Well, I went exploring and found an absolutely incrediable website that pertains to nearly every aspect of "Malaria - History, Aetiology, Pathophysiology, Clinical Features, Diagnosis, Treatment, Complications And Control Of Malaria" by Dr. B.S. Kakkilaya. I highly recommend his educational website for those who wish to learn about Malaria.

History of Malaria Parasite And Its Global Spread


Time Line For Origin of Malaria

Half a billion years ago
Existence of pre-parasitic ancestor

150 million to 200 million years ago
Early Dipterans, ancestors of mosquitoes, appear

130 million years ago
Two-host life cycle in Dipterans and vertebrates evolves

130 million years ago
Divergence of the bird and mammalian malaria parasites

100 million years ago
Lineage of P. malariae, P. ovale, and P. vivax diverges

~5 million years ago
P. falciparum evolves

2-3 million years ago
Divergence of P. vivax from P. cynomolgi

4000-10000 years ago
Lethal strain of P. falciparum appears

4000-5000 years ago
Anophelines in Africa develop highly anthropophilic habits

Man and Malaria seem to have evolved together. It is believed that most, if not all, of today's populations of human malaria may have had their origin in West Africa (P. falciparum) and West and Central Africa (P. vivax) on the basis of the presence of homozygous alleles for hemoglobin C and RBC Duffy negativity that confer protection against P. falciparum and P. vivax respectively.

The ancestors of the malaria parasites have probably existed at least half a billion years ago. Molecular genetic evidence strongly suggests that the pre-parasitic ancestor for malaria parasite was a choroplast-containing, free-living protozoan which became adapted to live in the gut of a group of aquatic invertebrates. This single-celled organism probably had obligate sexual reproduction, within the midgut lumen of a host species. At some relatively early stage in their evolution, these "premalaria parasites" acquired an asexual, intracellular form of reproduction called schizogony and with this, the parasites greatly increased their proliferative potential. (This schizogony in the RBCs of humans causes the clinical manifestations of malaria). Among the invertebrates to which the ancestors of the malaria parasites became adapted were probably aquatic insect larvae, including those of early Dipterans, the taxonomic order to which mosquitoes and other blood-sucking flies belong. These insects first appeared around 150 million to 200 million years ago. During or following this period, certain lines of the ancestral malaria parasites achieved two-host life cycles which were adapted to the blood-feeding habits of the insect hosts. In the 150 million years since the appearance of the early Diptera, many different lines of malaria and malaria-like parasites evolved and radiated. The malaria parasites of humans evolved on this line with alternate cycles between human and the blood-feeding female Anopheles mosquito hosts. Fossil mosquitoes have been found in geological strata 30 million years old.

P. falciparum is found to be very closely related to a malaria parasites of chimpanzees, P. reichenowi and these two are more closely related to the malaria parasites of birds than to those of other mammals. The lineage of these parasites possibly occurred around 130 million years ago, nearly about the same time as the origin of the two-host life cycle involving blood-feeding Dipterans and land vertebrates. The separation of the lines that led to P. falciparum and P. reichenowi probably occurred only 4 million to 10 million years ago, overlapping the period in which the human line diverged from that of the African great apes. The modern, lethal strains of P. falciparum probably emerged about 4,000 years ago, after agriculture took roots in Africa.

P. malariae, P. ovale, and P. vivax diverged over 100 million years ago along the lineage of the mammalian malaria parasites. P. ovale is the the sole known surviving representative of its line and causes infection only in humans. P. malariae was a parasite of the ancestor of both humans and African great apes and had the ability to parasitize and cross-infect both host lineages as they diverged around five million years ago. P. malariae is found as a natural parasite of chimpanzees in West Africa and P. brazilianum that infects New World monkeys in Central and South America is morphologically indistinguishable from P. malariae. P. malariae, like P. ovale, is the only confirmed and extant representative of its line. P. vivax belongs to a group of malaria parasites like P. cynomolgi, that infect monkeys. The time of divergence of P. vivax from P. cynomolgi is put at 2-3 million years ago.

End of the last glacial period and warmer global climate heralded the beginnings of agriculture about 10000 years ago. It is argued that the entry of agricultural practice into Africa was pivotal to the subsequent evolution and history of human malaria. The Neolithic agrarian revolution, which is believed to have begun about 8,000 years ago in the "Fertile Crescent," southern Turkey and northeastern Iraq, reached the western and Central Africa around 4,000 to 5,000 years ago. This led to the adaptations in the Anopheles vectors of human malaria. The human populations in sub-Saharan Africa changed from a low-density and mobile hunting and gathering life-style to communal living in settlements cleared in the tropical forest. This new, man-made environment led to an increase in the numbers and densities of humans on the one hand and generated numerous small water collections close to the human habitations on the other. This led to an increase in the mosquito population and the mosquitoes in turn had large, stable, and accessible sources of blood in the human population, leading to very high anthropophily and great efficiency of the vectors of African malaria. Even though the practice of agriculture had developed throughout the tropics and subtropics of Asia and the Middle East up to several thousand years before those in Africa, simultaneous animal domestication in Asia probably prevented the mosquitoes from developing exclusive anthropophilic habits. In most parts of the world, the anthropophilic index (the probability of a blood meal being on a human) of the vectors of malaria is much less than 50% and often less than 10 to 20%, but in sub-Saharan Africa, it is 80 to almost 100%. This is probably the most important single factor responsible for the stability and intensity of malaria transmission in tropical Africa today.
http://www.malariasite.com/malaria/history_parasite.htm


It probably wasn't mentioned before the invention of writing and civilization in the 3rd millennia BC for the same reason that nothing else is!

You might enjoy reading "Malaria In Ancient Literature."
http://www.malariasite.com/malaria/history_literature.htm

Thanks,

Mars
 
Last edited by a moderator:
  • #45
well quite the discussion on noninfectious .. ugh... conditions or behaviors..
i would have to agree with the flu of 1918
but i would like to expand on what is the worse on the human condition
i/e the person?

rabbies ? leper loosing parts of his body?
loosing your mind or un-tolerable pain from parasitic infections?

yes.. that is a good expanshon of the OP's question
what is the worse or most horrible
Infectious disease on the person ...?
 
  • #46
The Op's question never said word one about infectious etiology. I trust from your comments that you don't see addiction as a disease. You may not have enough information: the genetic contribution (at least with alcohol) is greater than both cardiovascular disease or Type II diabetes (which are felt to be highy inheritable diseases and also contain behavioral components). The course of the illness is uniform across cutures and and from what we can tell, time course. Not an infectious disease (role modeling and parental habits are of less prognostic importance than the history of the biologic parents, even in cases of adoption at birth), but a disease by every criteria.
 
  • #47
It seems reasonable to consider only those diseases which are likely to cause severe disability or death of a young person. Neither smoking, nor alcohol addiction, nor obesity fit this criterion. Smoking will make you more likely to die of lung cancer when you're 70 (instead of living till 80 just to have your consciousness wiped by Alzheimers). Excessive consumption of alcohol can result in stomach cancer or cirrhosis of liver, but once again not till you're into your retirement years.

We should not consider diseases that primarily kill infants and the elderly (such as most types of flu), and we should adjust for the population of the world (75 million killed by the 1918 flu pandemic in the population of 2 billion represent smaller impact on human society than 75 million killed by the 14th century plague pandemic in the population of 400 million).

From this perspective, it's probably a three-way tie between plague, smallpox and tuberculosis.
 
  • #48
I would agree if you considered all generations equally important--i.e that the population was roughly constant with roughly the same proportion of individuals surviving childhood.

But if you look at total numbers afflicted, than I would disagree.

fig-humans.jpg



A rather sobering reminder that population numbers were virtually flat until say 1500 a.d. at which time sufficient numbers were living plenty long enough to suffer the ravages of addictive illness. BTW I have seen several die under the age of 30 to cardiomyopathy and cirrhosis, but recognize that most of these illnesses have their largest impact in middle age.
 
  • #49
denverdoc said:
population numbers were virtually flat
:confused:
 
  • #50
From the perspective that H. sapiens is probably about 200,000 years old, yes. So the classic 30 foot graph with a spike on the end is a better representation than the one shown.
 
Back
Top