Thursday, November 12, 2015

Medical advances against diseases caused by parasites; need for follow-up

India should be grateful to scientists and medical doctors who have improved our abilities to control common diseases that are caused by parasites. This is the country in which the cause of malaria was discovered in 1897, leading to an early Nobel Prize being given to Ronald Ross (see http://www.cdc.gov/malaria/about/history/ross.html ). This year, three researchers have been honoured with the Nobel Prize for physiology or medicine for their work on diseases caused by parasites.

QUOTE
The Nobel Prize in Physiology or Medicine 2015 was divided, one half jointly to William C. Campbell and Satoshi ┼îmura "for their discoveries concerning a novel therapy against infections caused by roundworm parasites" and the other half to Youyou Tu "for her discoveries concerning a novel therapy against Malaria".
UNQUOTE
Early work (1978) at the  Kitasato Institute and later work at the Merck Sharp and Dohme Research Laboratories has led to the discovery of the Avermectin family of drugs. The story of the Chinese work against Malaria needs a separate story of its own.

For those of us living in developing countries, the Avermectin family of drugs coming out of the work by Campbell and Omura might turn to be very valuable. Their discovery is a big step forward in our fight against disease. These drugs kill invertebrates even in small concentrations, but are basically non-poisonous to vertebrates like us. Therefore, when you take the medicine to kill off worms in your digestive tract, mosquitoes that bite you could be killed by the small amount of drug in the blood they drink from your body! Visit  http://www.malariajournal.com/content/12/1/153 and  https://en.wikipedia.org/wiki/Ivermectin 

I have also read speculation that such medicines might kill the mosquitoes that spread Dengue; (Dengue is not caused by a parasite, but by viruses spread by Aedes mosquitoes). Drugs like Ivermectin might even kill bed bugs and lice as well! I remember a documentary in which the German submariners during the II World War fight the lice menace very hard! Typhus was a big threat to them!

Many manufacturers in India sell Ivermectin in retail, for something like Rs 10 per dose.

Going forward, there is need to carry out research to investigate many possibilities. I would guess that cattle must be getting poorer quality drinking water as compared to people! Anti-parasite drugs might be useful in protecting them against disease causing worms ( http://www.farmanimalhealth.co.uk/cattle-worms ). Another possibility is that we could develop relatively safer pesticides out of the Avermectin family of drugs. These would be useful in controlling common pests such as flies and cockroaches.

Sometimes, new drugs have significant social impact. The discovery of antibiotics, starting with the work of Alexander Fleming, contributed in a significant way to coping with the widow remarriage problem caused by social prejudices. Antibiotics reduced untimely deaths in India, thereby vastly reducing the number of young women losing their husbands; widow remarriage was no longer such a major problem! The victory of medical research against diseases caused by parasites and mosquitoes could have a similar effect. It could add a few years to life expectancy in developing countries; in any case, it would reduce a lot of suffering.

New tools are now becoming available to reduce the very high incidence of malnutrition among young children in India. WHO believes that de-worming can help children suffering from malnutrition. Newspapers frequently report that a high percentage of Indian children are underweight. India has taken a major initiative to free millions of children from parasitic worms. Visit http://www.ft.com/cms/s/0/b72d6a64-b038-11e4-a2cc-00144feab7de.html#axzz3rCnUC0WK

I will end this blog post with a question. India has an impressive number of national laboratories to carry out scientific research, but there has been no national laboratory so far for carrying out research on “tropical diseases”. Why? Is it because the millions who suffer most from them are the voiceless poor? If you are poor and lack good medical care, Dengue could pose a big risk to you; even filariasis or scabies can make your life miserable.  

A search shows that as of February 2015, the proposal to set up such a lab was awaiting the Union Health Ministry's nod! Visit
http://timesofindia.indiatimes.com/city/patna/Tropical-Disease-Research-Centre-to-be-opened-soon/articleshow/46328206.cms  It is not clear if the proposed Centre will have the resources of a national lab as and when it gets the nod.

Two other institutes are relevant in this context, even if they are small:
Ross was in Secunderabad at the time he succeeded in identifying the malaria parasite in a mosquito; it is appropriate that these two institutions are fairly close to Secunderabad.


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1 comment:

Srinivasan Ramani said...

Abamectin is in use as an agricultural pesticide. It can be used in a very low dose and is biodegradable in the environment.