Damming river decreases snail linked disease in China

Schistosomiasis affects over 200 million people worldwide, but you have probably never heard of it.

One reason might be because it makes people weak, but doesn't kill a lot of people quickly in a dramatic fasion.

from SciDaily:

After they built the three Gorges dam in China, the number of snails decreased, as did the rate of snail related schistosomiasis.

Following the opening of the dam, they found, the volume of annual runoff into Dongting Lake declined by 20.85% and the sediment volume discharged into the lake declined by 73.9%. In turn, the mean density of living snails decreased by 94.35% and human rates of schistosomiasis decreased from 3.38% in 2003 to 0.44% in 2015, a reduction of 86.98%. The researchers hypothesize that low water levels in the summer and high levels in the winter led the lake to become an unsuitable environment for snails.

Rice growing in paddies requires a lot of contact with muddy water, so did people catch the disease from planting rice in the mud, or because they washed in the river water? One is curious.

this article suggests that growing rice in paddies in Uganda (and fishing with baskets) has increased the intestinal type of parasite. article is from 1994

In Eastern Uganda, paddy-rice growing, which has only become popular in recent years, seems to be associated with the emergence of schistosomiasis mansoni as a new problem in public health. 

the article suggests the farmers should wear boots, which gave me an LOL moment: the boots would sink into the thick mud. That is why we use handtractors or waterbuffalo instead of regular tractors in our rice fields.

this is a slightly different parasite than what we saw in Afro, but it makes me wonder if a similar drop was seen after other dams were built..

1975 article on the Aswan dam (Egypt).

An increase in the prevalence of schistomiasis in Egypt, as a result of the Aswan High Dam, has for long time been predicted because of reclamation of land and conversion of annual flooding (basin irrigation) into perennial irrigation in Upper Egypt.

Two aspects, neglected in the predictions, have been investigated in the present study, and these are: the ecological changes, relevant to the transmission of the disease, in the Nile itself, and those in irrigation canals and drains in areas which had been under perennial irrigation before the constriction of the dam.

The findings indicate that the Nile, at least in the Delta, has become a favorite habitat for breeding of the snail hosts of both urinary and intestinal schistosomiasis, a center for human activities and evidently for transmission, and that irrigation canals and drains now harbor throughout the year undisturbed and stable populations of these snail hosts.

This has resulted from the elimination in these canals, of the so-called 'winter closure', because it is no more needed. Before the dam the closure was enforced for about 40 days, during which the canals were closed and dried up, and the silt deposited on their beds during the Nile flood dredged out together with the snails and aquatic weeds.

translation: The irrigation canals no longer dry up so there are more snails.

here is a 1979 Lancet reference that compared the population data with data from 1935 and found the urinary parasite decreased but the intestinal form (that can affect the liver) increased quite a bit.

The prevalence of Schistosoma mansoni infection had increased from 3.2% to 73%, whereas S. haematobium infection, which had been very common in 1935 (74%), had almost disappeared (2.2%).

So what about other areas of Africa? we had quite a few small irrigation dams in Zimbabwe (the veldt is dry and with irrigation you can grow two crops a year).

But  ppeople tended to get the urinary type infection from swimming or bathing or washing things in the rivers so changes could also be from digging wells to supply water..

Here is a study in Senagal, Zambia and Mali (sub saharan Africa).

Recent ecological changes caused by the construction of dams at Diama and Mananatali on the Senegal River, such as reduction in salinity, more stable water flow, creation of irrigation canals and development and extension of rice culture, have contributed towards the occurrence of new outbreaks of both intestinal and urinary schistosomiasis in the Senegal River Basin

 In Mali, the four main areas of high prevalence of S. haematobium are Office du Niger (irrigation areas), Bandiagara (small dams), Selingué (dam areas) and Baguineda (irrigation areas). Apart from the Office du Niger, S. mansoni infections are rare.

again, one wonders if the infection is caught during planting/weeding in rice paddies (or in mud) or just from bathing or contact with the water from the canals.

The entire article is not available.

finally, the Uganda article notes that the rice growing was a new project.

In more recent years, China (and Saudi) are buying up land in Africa for agriculture. Will this include rice growing and increase intestinal schisosomiasis?

related article: Chinese returnees are bringing back the intestinal and urinary forms to their native country.

heh. the article blames climate change.

but it does show that globalization can spread diseases that are "below the fold" and pretty well ignored by the world.

nor is this a new problem:
here is an article about the British soldiers getting infected during the Boer war and the Yanks getting infeccted in the Philippines during World War II.

prevention was the key:

3. * * *. The following precautions will be observed: (a) All water used by troops will be obtained from approved water points * * *. This is meant to include water used for drinking, bathing, laundry, and washing of vehicles or floors. (b) Wading, bathing, and washing of clothing by troops in any fresh water river, swamp, pond, or rice field is prohibited * * *.

a report on the problem in the Philippines: and it is worse in the southern regions.

Schistosomiasis japonica has a long history in the Philippines. In 1975, 24 endemic provinces were identified in the northern, central, and southern islands of the Philippines. More than five million people were at risk, with approximately one million infected. In 2003, new foci of infection were found in two provinces in the north and central areas. For the past 30 years, human mass drug administration (MDA), utilizing the drug praziquantel, has been the mainstay of control in the country. Recent studies have shown that the schistosomiasis prevalence ranges from 1% to 50% within different endemic zones. Severe end-organ morbidity is still present in many endemic areas, particularly in remote villages with poor treatment coverage. Moreover, subtle morbidities such as growth retardation, malnutrition, anemia, and poor cognitive function in infected children persist.

There is now strong evidence that large mammals (e.g. water buffaloes, cattle) contribute significantly to disease transmission, complicating control efforts. Given the zoonotic nature of schistosomiasis in the Philippines, it is evident that the incidence, prevalence, and morbidity of the disease will not be controlled by MDA alone. There is a need for innovative cost-effective strategies to control schistosomiasis in the long term.

so in the Asian parasite, water buffalo are part of the problem...discussion here.

hmm... wonder if anyone has done a study comparing areas tat use waterbuffalo vs handplows.

JAMA: Racism in medicine?

Poverty kills... or maybe racism kills. JAMA explains why black babies have a higher death rate but notes it is going down.

A lot of the deaths are related to maternal complications or prematurity.

 No comparisons of black children with immigrants (including immigrants from Africa or the West Indies)  or Hispanics, so we don't know if it is racism per se, or poverty, or the barriers to access medical care.

and if it is an access problem, we don't know if it is urban (where long lines in huge clinics where you see the doc of the day discourage folks) or if it is rural (where no docs at all).

Yes there is racism in medicine: I saw a lot when I worked for the IHS.

There are also programs to recruit docs for inner city and rural "underserved areas"... alas like the IHS often it is short term stuff, and the worst one was where they subsidized you for two years then you were on your own (and left with huge numbers of patients who didn't or couldn't pay their bills, or waiting for months to get paid a pittance for Medicaid, provided they didn't turn you down for not dotting your "i's" or crossing your "t's" correctly... hmm.. wonder if Obamacare improved this).


The dirty little secret behind high childhood mortality in the black community is Sickle cell disease, which if it hit cute blond kids would have TV marathons raising money for a cure.

However, Sickle cell disease usually doesn't kick in for a couple months after birth (when the fetal Hemoglobin is replaced with adult hemoglobin).

But I wonder about things like high blood pressure complicating the mix.

Heartburn medicine hysteria: Garbage in garbage out again.

Awhile back I linked to a study why GP's and other ordinary docs don't follow "expert" advice, and although I am still trying to find the original article, this study that is in all the newspapers is an example why.
Heartburn medicine causes a 25 percent higher death rate, cries the headlines.

Uh, what from? And what is the actual numbers you are talking about?

from lots of different diseases, a fact that suggests that maybe it's not the medication:

roton pump inhibitors or PPIs, have been tied to a wide range of side effects including fractures, dementia, heart disease, pneumonia and kidney disease, the study's senior author Dr. Ziyad Al-Aly of Washington University School of Medicine in St. Louis told Reuters Health in a telephone interview.

so they compared groups of people with severe heartburn with those who don't have heartburn.

 They also compared PPI users and non-users within a group of nearly 3.3 million people, and PPI versus no PPI and no H2 blockers among about 2.9 million people.

ah, but what causes heartburn?

People who smoke (more heart attacks).

People who take NSAIS like motrin or advil (more fractures from falls in arthritic patients)

People who drink (more heart attacks, more falls with fractures)

People with Gastroesophogeal reflux (who have an increase rate of pneumonia from aspiration, and who tend to be obese and often diabetic or elderly)

and don't forget that many diabetics and pre diabetics are obese and have reflux

and then there is the problem of "heartburn": Sometimes "heartburn" is not from acid reflux, but angina, i.e. a symptom of heart disease.

the dirty little secret is that this relieves symptoms a lot better than earlier medicines like H2blockers or antacids.

and as I said before: one reason that we family docs don't always obey the elite studies is that we deal with real patients.

Here is the elite answer to not using the medicine:

When a person has heartburn or reflux, he added, possible root causes like obesity, poor diet or smoking should be addressed first. "Any intake or use of PPIs should be under the watchful and vigilant eye of a physician, for the smallest dose that's effective and the shortest period of time," he said.

right.

As if we didn't already try these things already. But trying to get people to do these things in the real world is hard

And if you think people have nothing better to do than see their doctors all the time, you are wrong. Believe me, make these drugs hard to get and you will have  grannies buying and selling them on the street to make money, the way our elderly arthritic patients used to do with their tylenol 3's.

can you say "garbage in/garbage out" Children?

I'm not saying that this shouldn't be a "headsup" to oversue of the medicine, but you know that chronic reflux does have it's own side effects aside from pain:

Complications may include: Worsening of asthma A change in the lining of the esophagus that can increase the risk of cancer (Barrett esophagus) Bronchospasm (irritation and spasm of the airways due to acid) Chronic cough or hoarseness Dental problems Ulcer in the esophagus Stricture (a narrowing of the esophagus due to scarring)

finally, patients like the drug because it means they can eat stuff they usually had to avoid (spicy foods).
In my case I mainly take the medicine when I use NSAIDs for my aches and pains (osteoarthritis).

Now, since NSAIDs also affect the kidneys and heart by fluid retention etc should I stop using them too? And stop exercizing, and fall down a lot more due to stiffness?

Medicines all have side effects. Use them wisely but don't panic over scare articles.

---cross posted from my other blog.

There are no good choices

the idea that one needs to make decisions based on quality of life is a slippery slope that quickly degenerates into seeing anyone who is imperfect as "life unworthy of life", to use the Nazi terminology.

I haven't been following the story of an infant who the doctors and the imperial courts have decided should die, but GetReligion (a blog that examines the journalistic handling of religious issues) has a summary of the dangerous legal precdent behind the story: they quote from the nytimes story:

Judges in the case have acknowledged that the case highlights differences in law and medicine – and an American willingness to try anything, however unlikely the possibility of success – but have held that prolonging the infant’s life would be inhumane and unreasonable.

it's not the money (the parents have raised the money for treatment).

it's not the ethics or religious reason (under Catholic ethics, removing extraordinary treatment is optional, nor is it necessary to use treatment that only will prolong dying, but it also means the patient or his family have the ethical option to do everything possible for the child).

This is not about ethics: It's about who decides your life is useless so you are better off dead. It's about the docs deciding the kid's quality of life is not good enough for them, so they are removing treatment to end the life.

So the courts sided with the doctors and (unlike other "futile care" cases in the US) have denied the parents the right to find an alternative place to care for the child, either in another hospital or even letting them take him home to be cared for so he can die in a loving environment...

But is the case "hopeless"? For in this case, they are denying permission to take the child to the USA where there is a possible treatment that will help their child.

Arturito has a similar mitochondrial depletion syndrome to Charlie and was the first person in the United States to receive the experimental and pioneering nucleoside therapy. It’s the same therapy Charlie’s parents, Connie Yates and Chris Gard, are fighting for their son to receive. Yesterday, a High Court judge agreed with doctors at Great Ormond St Hospital that Charlie should not have the treatment and should be allowed to “die with dignity

Ah yes: Dignity at all costs, never mind the alternatives are available.

This reminds one of the Terri Schiavo case, where the parents were not allowed to take her home and care for her there, because in both cases the decision is that the person's quality of life is bad, so they are better off dead.

From GR:

Thus, government officials and doctors are defending tiny Charlie's right to choose death over suffering through further medical treatments? Did I read that right? That appears to be the bottom line, in mainstream news reports about the case.

Now, if journalists are open to digging deeper into the religious elements of this case, I would recommend them reading a First Things essay by conservative Wesley J. Smith, author of "Culture of Death: The Age of 'Do Harm' Medicine."

wikipedia page 

Augusto Odone, call your office.

Bubonic plague in the Bronze age?

mp3

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BBC LINK (2015...guess I missed it back then).

Nature article here. also 2015.



I was aware that the Justinian plague was P.Pestis but not that it went this far back.

On the other hand, the plague that destroyed the Hittites (brought back with Egyptian POW's) might have been Bubonic plague, so did it have anything to do with the collapse of the Bronze age?

And of course, all those "hemorrhoids" or "boils" in the Philistines when they stole the Arc of the covenant (in the iron age, a couple hundred years later) does sound like the bubos of the plague.

from nature:

But the analysis revealed that plague might have been less transmissible in the early Bronze Age. The six oldest Bronze Age strains lacked a gene called ymt that helps Y. pestis to colonize the guts of fleas, which serve as an important intermediary. In outbreaks of bubonic plague, infected fleas (often travelling on rodents) transmit the bacteria to humans living nearby. Without fleas as a go-between, Y. pestis spreads much less efficiently through blood (where it is known as septicaemic plague) or saliva droplets (pneumonic plague). An early Iron Age skeleton from Armenia dated to around 1000 bcwas infected with Y. pestis that harboured ymt as well as another mutation linked to flea-aided transmission.
Wyndham Lathem, a microbiologist at Northwestern University’s Feinberg School of Medicine in Chicago, Illinois, says that in the absence of ymt, Bronze Age plague victims would have probably contracted pneumonic plague, as opposed to the bubonic form. All the Bronze Age strains also contained another virulence gene, pla, which Lathem's team has shown is important in infecting the lung⁶.

Plague may have been less transmissible without fleas, but it would have been no less deadly. More than 90% of untreated cases of pneumonic plague are fatal.

credit: Nature

but since pulmonic plague is rapidly fatal, one has to wonder how it spread (discussed in the podcast).


Ancient Egypt plauge article from nat geo.


but how ancient? This grave with plague victims only goes back to 300 BC.


an article on the ten diseases plaguing the ancient world.

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update: Good article here discusses the genes for transmission.

And this is new to me: Gastroenteritis from eating meat contaminated by the Pestis germ.

How to control a parasite

Elephantiasis is a disease where the filaria worm blocks the lymph node and you end up with a huge leg (and/or scrotum). WIKIPEDIA ARTICLE.

This Science daily article discusses how Cameroon is trying to control this disabling disease: by giving a yearly dose of the anti parasite drug.

the infection rate is now so low that the country is considering stopping the program.

another mosquito based disease.

we used to see people with itchy nodules and would biopsy the nodules to check for this, although there is also a blood test.

I can't remember the name of the medicine used to treat the disease back then, but this article discusses the present day treatment.



You can also kill the parasite by using tetracycline, which kills a bacteria that the worm needs to live.

however, surgery is required for the damage.