INTERVIEW WITH THE EDITOR OF TROPICAL PARASITOLOGY

This is the e-mail interview of mine by the Editor of Tropical Parasitology where I have been able to express my views on Parasitic Diseases in India

FACE TO FACE WITH DR MC AGRAWAL

Dr Mahesh Chandra Agrawal , born on 2^nd January,19943 at Firozabad,UP ,obtained university Gold Medals in BVSc & AH, MVSc (Parasitology) being stood first in Jawaharlal Nehru Krishi Vishwa Vidyalaya ,Jabalpur ,MP .He completed his Ph.D. program from JNKVV under ICAR senior fellowship. His main research interests have been schistosomes and schistosomiasis and has been awarded Gold Medals etc by various societies for his outstanding achievements. He was awarded National Fellowship by ICAR, New Delhi (1995-2000) to work on schistosomiasis which happened first in JNKVV and first in Parasitology and after retirement in 2005 he was awarded Emeritus Scientist award of ICAR to work on control of schistosomiasis under field conditions . He is elected fellow of National Academy of Veterinary Sciences, Indian Association for Advancement of Veterinary Parasitology ,Zoological Society of India. Recently his book “Schistosomes and schistosomiasis in South Asia (ISBN 9788132205388) has been published by Springer India Pvt Ltd, New Delhi. Presently, he is busy in writing  a book “Research As Career” for research scholars in Parasitology. In 2012, Prof MC Agrawal has delivered Dr SC Parija oration award of Indian Academy of Tropical Parasitology at Shri Auribindo Medical Institute ,Indore.

1.Parasitic diseases have long been branded as the diseases of developing and the under-developed countries .You have been one of the pioneers in parasitic research in India. Over the period of your long career ,have you noticed  any gross change in trend of these diseases ?

Yes! A great change in trend of these diseases is observed over the time. I think there are two reasons for this. One is the spread of our knowledge on the subject hence we become more aware about existence of diseases  in our location. Second might be the change in environment , irrigation facilities, deforestation ,husbandry practices ,change in vector population etc  that might have contributed in spreading these diseases to new locations .

 2.How has research in microbiology and Parasitology changed in past years in terms of technicality and quality? Are the current studies better designed and better funded than those of yester years ?

There is a tremendous change observed in research pattern of yester year and of present day. When I joined my research career in Parasitology, that was the era dominated by reporting of occurrence or  morphology description  or  life cycle of the parasite. It was fascinating to record a parasite in any unusual host or at unusual location.  However, this was also the period of realization that time is changing and persons were shifting to fields like epidemiology, environment, pathology, biochemistry, immunology, chemotherapy of parasitic diseases (till that time biotechnology has not emerged). Present research is better designed and funded than yester years.

3.How would you assess the present scenario in tropical Parasitology research in India ? Are the Indian laboratories well equipped in performing newer molecular, genomic and proteomic studies in par with the west ?

In my opinion, the present scenario of research in tropical Parasitology in India is not good . We have failed to attract talents in Parasitology and as such research on parasites in zoology departments is diminishing or rather finished  ; neither there is any Master’s program in Parasitology in any zoology department in India nor there is any demand from students. So is the case with Medical faculty .This is all because we have failed to create job opportunities for our young talents in this field.

The contrast to west may be assessed by the fact that many European colleges, where parasitic diseases is not the problem, are running successfully Master’s and Doctorate programs in Parasitology with international research projects . Our laboratories are not as equipped as west for research on tropical Parasitology. But this will be a costly proposition hence I will suggest to have more national and international collaborations for obtaining better results at lower costs .

4. Which parasitic diseases in India you think would benefit most from research and which of the diseases need more attention on research ?

Obviously , the parasitic diseases which are affecting larger population or more animal species need our attention most. We may give our priority to those parasitic diseases which are affecting our tribal population, below poverty line persons ; or parasitic diseases of swine ,sheep ,goat as they are maintained by most poor people.

However, one fact should always be remembered while dealing parasites. They are having complex life cycle , having greatest capacity of modifications as per circumstances ( inheriting sexual life cycle passes this quality due to cross transfer of genes) and its difficult to eliminate them without studying their complexities ; mosquito is the best example which is surviving from thousands of years and have withstood well to all our insecticides and other scientific efforts to eliminate this enemy of human life.

Again change of environmental conditions , local fauna and human activities are leading to emergence of new parasitic problems or some old one may emerge as more problematic hence we should continuously remain watch full on emerging parasitic diseases as well.

5. Are the diseases which are branded as neglected tropical diseases really neglected in India ?

To get the answer of this question, it’s better to examine what the government has done to control these neglected diseases?  There are three fronts- education ,policy decisions and execution side. The education of parasitology is imparted in three faculties-zoology, veterinary and medical . Parasitology has completely been ignored now in zoology departments and no zoology department in India is offering MSc or Ph.D in Parasitology. No state medical colleges are having separate department of Parasitology but it’s a small and neglected part of department of Pathology .Veterinary colleges are having separate departments of Parasitology but the faculty positions are curtailed. No job opportunity is created in this discipline in any of three faculties to attract the talents.

I am not aware if important policy decisions either by planning commission or at government level  have been made along with implementation program to control parasitic diseases in the country ,leaving aside malaria. There is no scientific panel  who may advise the government/departments on important parasitic diseases and how they may be dealt in the country. Neither public health department nor animal husbandry department  has created subject specialist posts on parasitic diseases to control the infections. The parasitic diseases are tackled by either a veterinarian or medical officer with no superior post of  parasitologist in either department.

These facts reflect how parasitic diseases are neglected in the tropical country like India. To avert the situation there is a need of a National Institute of Parasitology (more details given in “The Para Sight issue 2 of IAAVP or see my blog )  which can monitory parasitic diseases of the country.

6. Veterinary Parasitology is a highly neglected field in our country. Considering the large zoonotic reservoir in India, what do you think on the effectiveness of control of parasitic zoonosis in India ?

You are right in saying that parasitic diseases of animals in India have completely been neglected.  Perhaps this is on the notion that they do not cause animal death hence harm to animal industry is minimum. However, sincere  efforts of Parasitologists have conclusively demonstrated that parasitic diseases are not only causing debility or production losses but are also responsible for causing slow ,steady death of animals, one by one, without confirming diagnosis hence specific treatment resulting in wiping of almost whole flock within a short period ; this has been demonstrated well in ovine haemonchosis as well as in ovine schistosomiasis . This neglect is again despite that parasitic diseases neither have any vaccine to control nor have specific drugs like antibiotics for effective cure.

Parasitic zoonosis has two main components- medical and veterinary. How we can effectively control them when both are working wide apart . There is no body which can collaborate  the efforts of the two or any organization which may formulate working plan and combine the work for more efficient results. Earlier, attempts were made to start degrees in Veterinary Public Health but absence of creating posts and a common strategy distracted the concerned persons.

As zoonotic diseases, viral ,bacterial, fungal, protozoan ,helminths make a large part of infectious diseases, it may be better to formulate a separate entity at government level which may deal all these zoonotic diseases by incorporating subject matter specialists of each discipline.

7. Can you share some of your interesting observations of animal infections rarely infesting humans ?

During teaching course of parasitic zoonosis to postgraduate students, I asked the PG students to examine stools of  hostel students for parasitic infections. These hostellers  were found positive for Hymenolepis eggs ; it was later observed that the flour is mixed with positive rat faeces resulting in such infections. Some students ,having rural back ground, were positive for hookworm infection. This simple work showed how parasitic infections may reflect back ground history of any one .  

8.Commending your authorship in various literary materials on helminthes in India, kindly shed some light on the burden of helminthes in our country, comparing the urban ,rural and the tribal population.

As parasitic disease is the cumulative effect of social status , economic activities, nutritional status, behavioral differences and environment  of human population ,so it will naturally differ as per these parameters. Urban group is in advantage stage as it has created conditions where exposure to parasitic stages become minimum hence malaria has remained ,perhaps, the only main problem of this elite group . However, urban population ,particularly, slum dwellers are facing some more problems like amoebiasis. Another problem arising is because of street dogs and their scattering faecal material which is responsible for serious zoonotic diseases like hydotidosis ,cysticercosis, toxocariasis or visceral larval migrans (not mentioning rabies as being a viral problem).

Rural population facing great problems and you may encounter all the parasitic problems ,referred in our text books but severity of problem may differ as per above factors. Thus hookworms ,causative agent for anaemia, are causing havoc to rural pregnant woman and malnourished children . Filariasis, visceral larva migranes , cercarial dermatitis, hydatidosis, cysticercosis, are increasing health problems of rural population and its difficult to escape from these infections due to existing environmental conditions.

Though we have started talking separately about tribal health, it appears ,in my opinion, of little value. Are we knowledgeable about their health problems or infectious diseases common in them ? How many books/publications have come out dealing with tribal health in India ?   .Can be make a generalized statement for the infections for all the tribes , existing in the country, with so much diversity ? ; have we started accumulating data about tribal diseases ? ; have we made epidemiological studies comparing tribal differences ,responsible for particular ailment ?. When we talk about tribes, we have to separate them in various  categories (e.g education ,food habits, occupation, environment ,living in isolation ) to draw fruitful results.

I am aware about the Regional Medical Research Center on Tribal Health, operating at Jabalpur ,Madhya Pradesh. They are working on malaria, tuberculosis, florosis etc but not sure if they are collecting data on general tribal infections and all the details , thereof . As my state, Madhya Pradesh, is possessing large tribal population, I am aware that our remote tribal populace is averse of contacting modern Allopathic doctors and still depend on their home healer or “Ojha” or Gunnia”. Therefore, we have to work much more for knowing their specific  health problems and solutions which may be accepted by them. Their close association with their animals like swine ,dog ,poultry  exposes them more to zoonotic diseases. Moreover, they are still more close to forest ,therefore, infections like schistosomiasis, paragonimiasis, trichinellosis , angiostrongylosis etc can attack them with more probability.

Though I am not loaded with the data, I presume that our tribal population is more severely affected with parasitic infections, looking to their social behavior ,education,  economic conditions, nutritional status, bad surroundings;  moreover, a simple ailment, curable with the help of modern medicine (e.g. hookworm infection) may be dangerous to them due to ignorance and their no reach to the modern medicine.

9. We applaud you for your extensive contribution to research in schistosomiasis. Can you brief us on the magnitude of this problem in India ?

The infection appears a great problem in rural population throughout India but more so where rain fall is high and persons are still depended on tanks, water ponds for their domestic requirements. However, if you will follow western style by searching positive snails in the rivers ,streams , searching egg positive human samples by routine faecal and urine examination, you will ,in all probability, get negative results. This is because the intermediate hosts of Indian schistosomes are present in ponds ,tanks and not in rivers and eggs are extremely difficult to detect in human excreta due to very low egg production. Moreover, the sufferers are generally persons below poverty line like washer man ,fisherman ,cultivators, laborers ,shepherds ,  children, young girls who are most neglected strata of the society. There is another category of possible positive persons- immune-deficient, tuberculosis positive ,malnourished  and alike groups.

The real magnitude of the problem can be judged only when we include above category of persons in our study and start examining them not for schistosome eggs but schistosome antigens in their excreta.

A surveillance work in Assam, Chattisgarh, Madhya Pradesh revealed about 70 % rural population were either showing lesions of cercarial dermatitis or had its history with four passing schistosome antigen in their urine. As cercarial dermatitis is the first stage of human schistosomiasis ,further studies are necessary to assess its full public health impact.

The magnitude is more sever in our domestic animals but here again it depends on rain fall, temperature ,geography,  species , breed, age of animal and husbandry practices ,followed in the places.

Very young animals generally do not suffer because of stall feeding practice while old animals  do not excrete eggs in sufficient number due to thickening of intestinal wall. Cattle is main reservoir host for S.indicum and S.spindale while swine is main reservoir for S.incognitum. Nasal schistosomiasis appears more widely prevalent in India than hitherto considered. This assumption got support by finding Jabalpur like nasal schistosomiasis at other places also where the infection exists symptomless in buffaloes while local cattle appear resistant to the entity.

Schistosomiasis is prevalent in all the states of the country ,affecting mainly ruminants .The infection is not causing only production losses but also outbreaks and heavy mortality ,especially in sheep , but the disturbing fact is that the causative agent is not identified as schistosomes due to faulty diagnostic methods and ailment is wrongly attributed to PPR or alike viral infections. The space is limited for speaking ; all my thoughts and discussions on the topic has been documented in my book “Schistosomes and schistosomiasis in South Asia (ISBN 978-81-322-05388)” which you may follow on the website < www.Springer.com>

10. What are your suggestions and advice to young scientists pursuing their career in Parasitology ?

While doing your Master’s degree , please do not confine only on your thesis problem but imbibe a holistic view of the subject by studying all the aspects of Parasitology. Get mastery at least of the Parasitology text book which is being taught – learn all the important techniques of Parasitology and do not limit only to those related to your thesis work.

When you are doing your doctorate program , critically analyze the research papers , particularly of your research problem , and find out the lacunae in designing their research program. Read critically review articles and advances of Parasitology and see why the author is reaching to particular conclusion and what may be the other possibilities.

While you are starting your research career, restrict yourself only to one topic and devote your whole life to it only as life is very short while problems are fathomless. Be a voracious reader and read more and more about the Parasitologists (e.g. www.drscdutt.com )  and how they worked , may read “After fifty years of research (of Dr SC Dutt)” on my blog www.indianschistosomiasis.blogspot.com .

If you have joined research as a career , please do remember that sky is the limit and this is the field where knowledge is worshiped and you may be remembered years after, for your work , which is not possible in other profession. Do not forget that human civilization has evolved only on the basis of knowledge or research.  

AFTER FIFTY YEARS OF RESEARCH-of Dr S C Dutt

                                         DR MC AGRAWAL 

                FORMER Prof and Head, ICAR  EMERITUS SCIENTIST,
                                   Department of Parasitology

                             

                                          

         

I have read a couplet in recent past, which describes futility of life in following words

bina libas aaye the es  jahan mai, Bas ek kafan kee khatir etna  safar karna pada

(We entered in this world without clothes and traveled  a long journey only for a coffin)

This may be true for most of us who pass their life with no cause but certainly it is not true for persons like late Prof SC Dutt who devoted his whole life for scientific cause. The best testimony  of this is to check ,in present time, the relevance of his research work that was  carried out about fifty years back and his passing away in August,1980. There are two ways to assess, posthumously, the  scientific contributions of a scientist, - first, whether his research work is still cited in research papers and second if further research have supported or nullified his theories or observations; on both accounts he is a winner. I wish to extend the argument with some scientific achievements of Dr Dutt.

The nematode Filariids are known to utilize a mosquito or other blood sucking arthropod as its intermediate host. The filariids, belonging to the family Stephanofilariidae are prevalent in USA, Canada, and South East Asia including India and were first identified in 1933 as an agent for causing dermatitis- mainly in bovines. In India ,Hump-sore is a common skin disease of north-eastern cattle and its etiological agent ,Stephanofilaria assamensis , was identified and described ,first time, by Dr PG Pande  ,IVRI ,Izatnagar in 1936.Nevertheless , life cycle of any Stephanofilaria species remained obscured, though scientists were suspecting various blood sucking arthropods acting as intermediate host for this filariid. To the surprise of all, Dr SC Dutt discovered in 1963 its intermediate host being a Musca species- so far never suspected as an intermediate host for any filariid worm. Scientists were skeptical to this discovery and reluctant to accept the findings; as per general norms, the intermediate host for a filariid must be a blood sucker and Musca does not possess mouthparts enabling the fly to suck blood of the host –rather it is having lapping type mouth parts suitable to lap food material. Dr Dutt incriminated Musca conducens and put a satisfactory explanation for the fly acting as intermediate host. First the filariid is present not beneath the skin but in the skin and its microfilariae are not found in peripheral blood but remains in the skin. The fly has an enlarged chitinized mentum with a pre-stomal tooth and interdental armature (quite different from lapping type mouth parts of Musca domestica, the common house fly) with which it is able to scratch and tear the skin to feed on the serous blood mixed fluid which also contains microfilariae (infective stage for fly) thereby enabling the fly to play its vector role; blood is found an essential prerequisite for oviposition of these flies. This finding was confirmed subsequently by transmission experiments of other workers. Later, in 1970, Dr Dutt incriminated Musca planiceps as the vector for another species of the filariid i.e. Stephanofilaria zaheeri, the causative agent of ear-sore in buffaloes. Even after lapse of so many years of this unique discovery, no worker disputed the finding of M.conducens as intermediate host for S.assamensis or M.planiceps for S.zaheeri nor came out with the results showing any other insect as main intermediate host for the filariid.

The schistosomes or blood-flukes or Bilharzia have been the main field of research for Dr Dutt and he has made many new discoveries on this parasite. In the beginning of his career itself, he made an important discovery that contradicted the than existing hypothesis. As is well known, unlike to other trematodes, the schistosomes are unisexual where male and females are separate individuals, each developing from a single cercaria. While working on life cycle of the blood flukes, scientists found that the snails, the intermediate host where a single miracidium is developing into many cercariae, are regulating sex of the blood flukes by allowing development only of a particular miracidium. In 1930 and onwards, the scientists were working on life cycle of Schistosoma spindale and trying to develop the fluke in experimental animals. However, the animals developed only male S.spindale ; Fairley and associates used good number of guinea pigs  to develop S.spindale but neither its eggs nor females could be observed in any guinea pig prompting Fairley to hypothesize that there are some ‘host factors’ which are preventing development of female S.spindale. This led to  great interest in this discovery and may be visualized by the fact that the prestigious scientific magazine “Lancet” commanded this work in its editorial.

In late fifties, Dr SC Dutt meticulously planned his experiment to check this hypothesis by infecting 24 guinea pigs with different number of S.spindale cercariae (8,000 to 50,000/animal) and sacrificing the animals between 33-153 days post exposure. He provided conclusive evidence of developing females with production of eggs and pseudo-tubercles in the guinea pigs thereby negating the existing hypothesis.  His observations were correct was further proved when in 1990, Dr Anjana Mishra, in her Ph. D. research program  infected albino mouse, albino rats, rabbits and guinea pigs with different doses of S.spindale cercariae and killed them at different time intervals. Interestingly, in these comparative studies, guinea pig emerged as most suitable host for development of S.spindale with highest percentage of fluke development and presence of hundred percent viable eggs, at a time. Therefore, claim of Dr Dutt that guinea pig is developing both sexes has further been strengthened by later research work.

I will like to attract attention on another important problem in late 1960. The etiological agent for nasal granuloma was discovered by Dr Rao MAN in 1933 being a new schistosome species i.e. S.nasale. Though the blood fluke exists  both in cattle and buffalo, it is causing lesions only in cattle while buffalo is maintaining the parasite without any lesions. This led to the possibility of existing two strains or subspecies – one in cattle causing lesions and other in buffaloes without any lesions. Therefore, Dr Dutt decided to solve this problem and conducted cross-transmission experiments in 1968 where cattle were infected with S.nasale of buffalo origin and vice versa. By his experiments, Dr Dutt proved non-existence of two sub-species or strains and its only host species which is responsible for this difference. Subsequent workers confirmed experimentally this finding paving the way to investigate host factors responsible for these differences. The present knowledge also supports the hypothesis of Dr Dutt but with a difference i.e. there appears different geographical strains of S.nasale which is behaving differently – there is one strain in Tamilnadu for which sheep and goats are also susceptible, another strain in Maharashtra where goat is resistant, yet another strain in Jabalpur for which local cattle (but not cross bred cattle) are resistant. All these speculations have been made on epidemiological grounds and biological and biochemical confirmations are still awaited.

There are many other land mark contributions of Dr SC Dutt to the biological sciences and it’s difficult to narrate all of them,here. However, I may mention few of them briefly. Till late fifties, very little was known about Schistosoma indicum though the blood fluke was in lime light because of its resemblance  with Schistosoma haematobium which was found existing in Gimvi village of Ratnagiri district by Gadgil and Shah in 1952. Dr Dutt thoroughly investigated the parasite in association with Dr HD Srivastava including its morphology, life cycle, host susceptibilities that culminated in to publication of an ICAR technical bulletin (34) on Schistosoma indicum. Dr Dutt discovered a new blood fluke (Orientobilharzia dattai) where male was containing many testes ; first the parasite was put ,by them, in the genus Ornithobilharzia but subsequently they created a new genus Orientobilharzia making O.dattai, its type species. The argument put forward was that while Ornithobilharzia contains both avian and mammalian blood flukes, Orientobilharzia possesses exclusively mammalian schistosomes. It may be clarified that the name dattai in the new blood fluke species does not represent Dr SC Dutt  but it was christened in the name of Dr SCA Datta who was the then Director of IVRI, Izatnagar. Interestingly, this new species, unlike to its sister species Orientobilharzia bomfordi ( created by Dr RE Montgomery in 1906 in honor of Dr Bomford but its existence is disputed) , is accepted as a  valid species and occurring in many parts of India. Ironically, there is no further discovery of new schistosome species in India since O.dattai in 1955 and  Dr Dutt’s work remained last taxonomic work for Indian schistosomes though there is dire need of solving many taxonomic problems related to Indian schistosomes.   Another land mark contribution of Dr SC Dutt is about determining intermediate hosts for schistosome species. Prior to his studies, both Indoplanorbis exustus and Lymnaea luteola were incriminated intermediate hosts for S.nasale, S.spindale and S.indicum . By his analytical work , he proved that it is only I.exustus which is intermediate host for all these three Schistosomes exhibiting most restricted host specificity at intermediate level which is in contrast to their final host range. The claim of Dr Dutt still holds true and has been accepted by all scientific fraternity without any exception .

Certainly, this is not a small achievement that even after fifty years there is no one who disputed his findings- further research only supported his observations. A serious thought in this direction should to be given to analyze the reasons responsible for such high quality of research work from late Dr Dutt as it will be  important for our young or emerging scientists . I have witnessed his research persuasions (1970-1974) in the department of Parasitology as his post graduate as well as a Senior Research Assistant  and I have seen this eminent scientist sitting on a steel stool making microscopic studies for hours together which is difficult to follow by most of us. Secondly, he had no hurry to publish his observations , rather he continued to verify his observations by different angles and submitted his research papers only after being satisfied with his observations.