Reviewed by Prof. N.A. de S. Amaratunga PhD, DSc

Prof. Nimal Senanayake (NS) professor emeritus, eminent neurologist and creative writer and producer of drama and films, continuing his commitment to write in Sinhala on important health issues for public education, has published the seventeenth in the series and the chosen subject is the deadly Rabies of which the public awareness could be insufficient from the point of view of prevention and treatment to prevent death. Prevention of  onset of the disease is not difficult if treatment is instituted soon after a dog bite or bite by other animals like bats carrying the virus. NS deals with these aspects adequately and in simple prose in his little book of 165 pages.

NS showing his proclivity to drama and suspense starts in dramatic fashion, bringing in bats rather than dogs to beigin his story describing cases of rabies in Texas 1951, Florida 1953 and Pennsylvania 1953, all due to attacks from the sky as it were, all bitten by flying bats coming down and biting without any provocation. All these bats were not blood sucking vampire bats but apparently harmless insectivora. NS’s intention clearly is not just drama but to draw the attention of the reader to the strong possibility of bats developing as vectors of deadly viruses as was the case with Corona and several other virus diseases which NS has written about. NS has mentioned that Rabies following bat bite had occured in Sri Lanka too.

NS then embarks upon a very interesting journey through history starting with  Diana the Roman Goddess of Wilderness and the Hunt and traces back the history of Rabies to 4000 years. He mentions great philosophers Democritus (500 BCE), and Aristotle (384 – 322 BCE) and the father of medicine Hipocrates who had written about disease due to animal bites. Greek physician Galen (129 – 200 CE) had recorded the natural history of rabies and also treatment measures including wound care some of which are still valid. NS has commented on Arabian writtings on rabies which is noteworthy as early development of medicine happened in the Arabian civilisation.

After history NS switches over to his usual practice adopted throughout this series where he asks critical questions and gives lengthy explanations. These questions are those that may arise in the minds of science writers, students, patients and ordinary people. They are designed to bring out the most important information that these categories must know about rabies and also lively anecdotes. This is a very effective and efficient method of conveying the knowledge with brevity and clarity, that the author has developed with his vast experience of teaching and practice of medicine.

Begining with the virology of rabies with a description of the rabies virus the author covers the entirety of all aspects of the disease. He connects up the physiology of the virus with the pathogenesis of the disease, how the virus enters the tissues of the human body, proliferates and then gains access to the nervous system through the peripheral nerves. What happens in the brain when the virus reaches it and affects the brain stem, limbic system etc. would be of particular interest to the medical students.

How the author looks at every aspect is exemplified when a question is asked whether the person who attends to the wounds of the patient could contract the infection and the explanation that follows showing how it could happen. Then the author explains why and how rabies is known as hydro-phobia, the horrendous result that ensues when the extremely thirsty patient attempts to take some water into the mouth and try to swallow it is the reason that causes severe fear of water in the mind of the patient. The physiological basis for this undue fear of water according to the author is ‘conditioned reflex’ and this is illustrated with the famous experiment by Pavlov and his dog. Similarly the patient is horrified of the wind blowing against his body which like water causes severe shivering and muscle contraction. A comprehansive description of the possible animals that could be a vector for rabies is given and also how careful people should be about their pets and the danger of being suddenly attacked by these animals who may appear to be harmless is vividly described.

Though these symptoms are seen in the advanced state the early symptoms could be similar to those of common cold except that there could be radiating numbness at the site of the wound. The wrong beliefs that the patient may bark like a dog or even bite others has no basis and the origin of these beliefs are explained. But the caregivers must be careful not to get contaminated by salivary secretions of the patient even on a minor wound or scratch on their skin.

The tragedy of the situation is that when the patient is not subject to severe muscle contraction and shivering he could be in his proper senses and he realises that he is facing a horrendous death. This state is really pathetic for everybody near and dear to the patient. Physio-pathological explanations of the often mysterious fearful clinical picture would be very useful to medical students. These fearful clinical features could be to some degree controlled with pain killers and sedatives. Apart from the nervous systems other organs also may be invaded via the nerves and consequently heart failure and pneumonia could result. Merciful death would arrive with the patient going into coma due to the development of encephalitis which is not any different from other types of encephalitis.

After this comprehensive discussion on all the importanr aspects of rabies the author talks about a rare type of rabies called paralytic rabies which is due to the spinal cord and the medulla oblongata being affected instead of the brain and brain stem. This condition is also known as the dumb or silent rabies as there is no violent spasms but a paralysis of limbs and other muscles. Yet slow death cannot be avoided. This type of rabies is more common with bat bites and there had been an outbreak of it of epidemic proportion in Trinidad in 1929 – 1931 period. Health authorities thought it was an outbreak of polio or botulism poisoning.

Author goes into details of diagnosis and draws our attention to the fact that the animal bite incident may even have been forgotten as onset of symptoms could be delayed. This makes diagnosis difficult and this is made worse by the fact that there may be several other conditions that may initially exhibit similar clinical features. NS with his usual thoroughness mentions that sometimes a person who has been bitten by a dog may undergo immense mental stress and go into hysteria which may simulate rabies!

NS gives a comprehensive description of tetanus which is one of the conditions that need to be differentiated in the diagnosis of rabies. Moreover tetanus could occure following bites by dogs and other animals who carry the bacterium that causes tetanus. In tetanus the bacteria do not travel upto the nervous system but the toxin it produces while proliferating in the depth of a wound could travel along nerves and effect the central nervous system. Spasms of muscles could result in a similar clinical picture to that of rabies though there are important differences that may help the doctor to suspect rabies. These differences are lucidly described by the author and illustrated with clear colour pictures which is a striking feature throughout the book which complements the text and adds value to the work. The fact that if adequate treatment is provided in good time tetanus could be fully cured which is not the case with rabies which needs to be nipped in the bud if it is to be cured is emphasized.

NS mentions botulinum toxin poisoning which is another condition that could mimic rabies. What is important to ordinary reader here is the fact that contaminated food, specially tinned fish that has gone bad could contain the toxin due to Clostridium Botulinum contamination. NS does not forget to tell us how to detect the possibility of such contamination by an examination of the can of fish which would appear to be swollen and the fish would be blackish in colour. Other diseases that the author mentions which may be clinically similar to rabies are  encephalitis caused by malaria, delerium tremens and poisoning by certain locally found wild fruits like goda kaduru” and attana” and also ganja” which children may unknowingly consume.  

Then the author deals with the tests that could be carried out to confirm the diagnosis particularly in the animal that had bitten the patient so that treatment could be started early to prevent death. He has a story to tell about the development of these tests and also the vaccines. He gives detailed account of how Frenchman Louis Pasteur succeded in discovering  anthrax causing bacteria in cattle and attempts at developing a vaccine against anthrax and also against rabies. Description of Pasteur’s attempt to experiment the rabies vaccine he had developed on a human being is full of drama and suspense. Scientific detail which could be boring is embelished with human drama which is a feature of NS’s writings that make them so readable. Author has written several pages on Louis Pasteur in order to emphasize  the great importance of the ground breaking discoveries he had made which eventually helped mankind to combat many killer diseases caused by micro-organisms. The description of how Pasteur risks his life when he sucked into a tube saliva from a rabid dog is fascinating.

Next NS deals with the attempt at attenuation of the virus by Irish physician Sir David Semple (1856 – 1937) The attenuated virus could be used as the vaccine as it could initiate the development of immunity against the viral infection. Greater success was achieved by the efforts of Polish physician Hillary Koprowski (1960 -2013) and American bacteriologist Herald Cox (1907 – 1986) who used new methods to lessen the virulence of the virus. Methods of producing safe vaccines which may not have the complications of ealier varieties have taken vast stides with the development of DNA technology.

Finally NS writes about prevention and treatment of rabies which is of vital importance as about 55000 die worldwide annually mainly due to ignorence, negligence and lack of facilities for vaccination. What should be done after being bitten by an animal which could be a vector of rabies is clearly described. The use of Rabies Immunoglobulin (RIG) and Anti-rabies Vaccine (ARV) and their mode of action is given in detail. This section is very important for the student as well as lay persons. The final chaptor on animal management from the point of view of rabies prevention would be very useful for everybody, specially people who keep pets, animal lovers and animal farm keepers.

Prof. Nimal Senanayake has produced yet again a compact little book full of knowledge important for everybody written in beautiful Sinhala prose like a story, simplifying complex matters and vividly emphasizing where emphasis is necessary. This excellent piece of work would be of use to ordinary people, medical students, post graduates, animal farmers, and doctors who practice bread and butter medicine every where in the country.