World Zoonoses Day-July6

World Zoonoses Day-July 6

A zoonosis is a disease that is transmitted from animals to man. The most talked of these days are leptospirosis, and "mad cow disease" (not prevalent in India), but by far the deadliest of all is rabies.

It is essential to have oneself and one's pets vaccinated against these diseases. All food animals need to also be regularly vaccinated, or their meat would not be fit for consumption. However, most people have a rather casual attitude towards vaccination, some even fear it. World Zoonoses Day is celebrated on July 6 every year to bring the problem into people's consciousness, and remind them to take action.

Zoonotic diseases are infectious diseases that are naturally transmitted between vertebrate animals and humans. India being an agricultural country, more than 80 per cent of the rural population lives in close association with animals. Thus, the chances of transmission of such diseases are high. More than 60 per cent of newly identified infectious agents affecting humans are zoonotic infections, the latest World Health Organisation (WHO) reports show. What is alarming is that India, with 1.4 million cases reported across 13 States and 10 districts, is becoming a hot spot for zoonotic diseases.

With 20 cases of H1N1infections registered in the State recently, the need to create effective awareness among the public about preventive care against zoonotic diseases gains importance.

“While most of the people are aware of diseases such as rabies, they are less aware of emerging zoonotic diseases that can have a potentially serious impact on human health. Thus, prevalence of diseases such as Avian influenza, Bovine Spongiform Encephalitis (BSE) and the Nipah virus are not well-mapped out. Also people are not aware of the re-emergence of certain zoonotic diseases,” K. Vijaykumar, Head of Community Medicine, Government Medical College, said.

This day is the anniversary of the invention of Rabies vaccine by the great scientist Louis Pasteur

Born : December 27, 1822 Dole, Jura, Franche-Comté, France

Died :September 28, 1895 (aged 72)
Nationality  :French

Fields Chemistry ,Microbiology

Signature

Louis Pasteur (December 27, 1822 – September 28, 1895) was a French chemist and microbiologist born in Dole. He is remembered for his remarkable breakthroughs in the causes and preventions of diseases. His discoveries reduced mortality from puerperal fever, and he created the first vaccine for rabies and anthrax. His experiments supported the germ theory of disease. He was best known to the general public for inventing a method to stop milk and wine from causing sickness, a process that came to be called pasteurization. He is regarded as one of the three main founders of microbiology, together with Ferdinand Cohn and Robert Koch. Pasteur also made many discoveries in the field of chemistry, most notably the molecular basis for the asymmetry of certain crystals. His body lies beneath the Institute Pasteur in Paris in a spectacular vault covered in depictions of his accomplishments in Byzantine mosaics.

The house in which Pasteur was born, Dole

Immunology and vaccination

Pasteur's later work on diseases included work on chicken cholera. During this work, a culture of the responsible bacteria had spoiled and failed to induce the disease in some chickens he was infecting with the disease. Upon reusing these healthy chickens, Pasteur discovered that he could not infect them, even with fresh bacteria; the weakened bacteria had caused the chickens to become immune to the disease, even though they had caused only mild symptoms.
His assistant Charles Chamberland (of French origin) had been instructed to inoculate the chickens after Pasteur went on holiday. Chamberland failed to do this, but instead went on holiday himself. On his return, the month-old cultures made the chickens unwell, but instead of the infection's being fatal, as it usually was, the chickens recovered completely. Chamberland assumed an error had been made, and wanted to discard the apparently faulty culture when Pasteur stopped him. Pasteur guessed the recovered animals now might be immune to the disease, as were the animals at Eure-et-Loir that had recovered from anthrax.
In the 1870s, he applied this immunization method to anthrax, which affected cattle, and aroused interest in combating other diseases.

Louis Pasteur in his laboratory,  in 1885

Pasteur publicly claimed he had made the anthrax vaccine by exposing the bacillus to oxygen. His laboratory notebooks, now in the Bibliothèque Nationale in Paris, in fact show Pasteur used the method of rival Jean-Joseph-Henri Toussaint, a Toulouse veterinary surgeon, to create the anthrax vaccine. This method used the oxidizing agent potassium dichromate. Pasteur's oxygen method did eventually produce a vaccine but only after he had been awarded a patent on the production of an anthrax vaccine.
The notion of a weak form of a disease causing immunity to the virulent version was not new; this had been known for a long time for smallpox. Inoculation with smallpox was known to result in far less scarring, and greatly reduced mortality, in comparison with the naturally acquired disease. Edward Jenner had also discovered vaccination, using cowpox to give cross-immunity to smallpox (in 1796), and by Pasteur's time this had generally replaced the use of actual smallpox material in inoculation. The difference between smallpox vaccination and anthrax or chicken cholera vaccination was that the weakened form of the latter two disease organisms had been generated artificially, and so a naturally weak form of the disease organism did not need to be found.
This discovery revolutionized work in infectious diseases, and Pasteur gave these artificially weakened diseases the generic name of vaccines, in honour of Jenner's discovery. Pasteur produced the first vaccine for rabies by growing the virus in rabbits, and then weakening it by drying the affected nerve tissue.
The rabies vaccine was initially created by Emile Roux, a French doctor and a colleague of Pasteur who had been working with a killed vaccine produced by desiccating the spinal cords of infected rabbits. The vaccine had been tested only on eleven dogs before its first human trial.
.This vaccine was first used on 9-year old Joseph Meister, on July 6, 1885, after the boy was badly mauled by a rabid dog. This was done at some personal risk for Pasteur, since he was not a licensed physician and could have faced prosecution for treating the boy. After consulting with colleagues, Pasteur decided to go ahead with the treatment. Meister did not contract the disease. It is sometimes said that Pasteur saved the boy's life; but this cannot be maintained with certainty, since the risk of contracting rabies after such an exposure is estimated at around 15%. Nonetheless, Pasteur was hailed as a hero and the legal matter was not pursued. The treatment's success laid the foundations for the manufacture of many other vaccines. The first of the Pasteur Institutes was also built on the basis of this achievement.


We gave informations to the students to make posters and write-ups

ഈ അന്താരാഷ്ട്രരസതന്ത്ര വര്‍ഷത്തില്‍  ലൂയി പാസ്റററെ നന്ദിയോടെ സ്മരിക്കാം