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Year : 2021 | Volume
: 11 | Issue : 1 | Page : 16--18
The forgotten malariologist: Giovanni Battista Grassi (1854–1925)
Department of Microbiology, Sri Venkateswara Institute of Medical Sciences and Sri Padmavathi Medical College (Women), Tirupati, Andhra Pradesh, India
Department of Microbiology, Sri Venkateswara Institute of Medical Sciences and Sri Padmavathi Medical College (Women), Tirupati, Andhra Pradesh
The discovery of the mosquito as a vector for malaria parasite was an important discovery at the turn of the 19th century for which Sir Ronald Ross received the Nobel Prize in 1902. Battista Grassi, an Italian physician and a zoologist is also credited with this discovery and he described the species of the mosquito and proved the transmission in healthy human volunteer. Although we remember his name only in this context, he also made numerous other discoveries spanning the fields of protozoology, helminthology, entomology, and zoology.
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Chaudhury A. The forgotten malariologist: Giovanni Battista Grassi (1854–1925).Trop Parasitol 2021;11:16-18
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Chaudhury A. The forgotten malariologist: Giovanni Battista Grassi (1854–1925). Trop Parasitol [serial online] 2021 [cited 2022 May 25 ];11:16-18
Available from: https://www.tropicalparasitology.org/text.asp?2021/11/1/16/315927
The 19th century Europe was an exciting continent of scientific discoveries and this era marked the beginning of Microbiology. Parasitology has for long been the domain of zoology and discovery of many pathogenic helminths and protozoa predated the discovery of bacteria. However, newer discoveries were continuously being made spurred by the scientific works of Europeans in their colonies in Asia and Africa which were and still remain the hotbed of tropical parasitic diseases. This article is a brief biographical sketch of an Italian physician and a zoologist whose name remains entwined with Ronald Ross in the field of malaria and which has overshadowed his numerous discoveries in helminthology, apart from entomology and zoology.
Life and Career
Giovanni Battista Grassi was born in a village near Milan in Italy on March 27, 1854. His formative years were spent in natural, rural surroundings. He enrolled as a medical student in the famous University of Pavia where, among others, the cellular physiologist Golgi was one of the faculties. After earning MD degree in 1878, he turned his attention to zoology and got trained in Germany at the universities of Heidelberg and Wurzburg under the guidance of Otto Butichili, the protozoologist. At the age of 29, in 1883, he was appointed as professor of zoology at the University of Catania in Italy. In 1895, he was made the chair of comparative anatomy in the University Regia at Rome where he spent the remaining period of his active scientific life till his demise in 1925. During his lifetime, Grassi worked and made valuable contribution in the fields of protozoology, helminthology, and entomology, but his lasting interest remained zoology.
Studies on Helminths and Protozoa
While still a medical student, he started his independent investigation on the etiology of anemia in the cats, and in 1878, he published a paper describing Ancylostoma balsami (caninum) in the intestine of the cats. He observed the eggs of the nematode parasite and later studied the human pathogen Ancylostoma duodenale. He established a rapid method of detecting the eggs in the feces as a diagnostic method to prove the presence of the helminth in the intestine. Later, he made important discoveries regarding Ascaris lumbricoides and showed that ingestion of the eggs resulted in human infection. In Hymenolepis nana, he proved that no intermediate loss is needed and life cycle is completed in a single host, while another species Hymenolepis diminuta requires two host. Filaria inermis, which is a parasite of human as well as of the equine species, was first described by him and he studied the transmission of filaria by mosquitoes. Grassi showed that the dog flea is the intermediate host for Dipylidium caninum and he also established the intermediate hosts of various tapeworms of veterinary importance.
Between 1879 and 1882, he was also engaged in the study of human intestinal protozoan parasites. That Entamoeba coli is a gut comensal was first enunciated by him. He published a detailed description of the protozoan parasites present in termites and their importance in the food assimilation in the termites.
Studies in Entomology and Zoology
Grassi made some important contribution in the field of entomology. His work on Thysanura was instrumental in establishing it as the most primitive order of insects. His seminal works on the description of 21 new termite species, the development of the termite community, and his monograph on the same earned him the Darwin Medal of the Royal Society. He published a number of studies on sandfly, housefly, arachnids, honey bees, and the mosquito. He made the important observation that housefly can consume the ova of some helminth parasites and these are not destroyed in the housefly gut and excretion of these ova with the feces can help in the spread of these parasites.
The marine metazoa of the order Chaetognatha was a subject of special interest to him. He described 14 species of this marine animal and in 1883 his monograph on Chaetognatha was published by the Naples Zoological Station and he showed that these are not morphologically similar to the molluscs and coelenterates. He also published a monograph on the vertebral column and respiratory system of fish in the same year. His other major works in zoology were concerned with the metamorphoses of eels and advocated the use of larvivorous fish as a means of destroying mosquito larva. In 1922 he first introduced Gambusia fish into Italy for this purpose.
Contribution to Malariology and the Controversy
Notwithstanding the vast contribution of Grassi in different biological fields, the one subject in which his name stands out and is remembered among medical parasitologists is his contribution to malaria and its parasite. His name also stands out regarding the lasting controversy over the discovery of the malaria parasite cycle in the anopheles mosquito, for which he was an equal contender with Ronald Ross who won the Nobel Prize for this work.
Grassi started his studies on malaria in 1888 and collaborated with the physician Ricardo Feletti and together they studied the malaria cycles in various species of birds. They described two such parasites Lavereria dasilevsky and Hoemameba praecox. They proposed the names of two human malaria parasites which are presently known as Plasmodium vivax and Plasmodium malariae.
In 1895, when he came to Rome, it was the hypothesis among the Roman malaria experts that the parasite is transmitted by a blood-sucking insect whose identity was unknown at that time. From the point of a zoologist, Grassi selected three mosquitoes as suspects: Anopheles claviger and two Culex species. Along with Bignami and Bastianelli, Grassi announced to the Lincei Academy on November 6, 1898 that he had infected a healthy volunteer by exposing him to the bite of these mosquitoes, and on December 4, 1898, a report was read in the academic session of the Lincei Academy that a healthy man in a nonmalarious area had contracted malaria after being bitten by an experimentally infected A. claviger., The entire developmental cycle of the malaria parasite in the Anopheles host were described on December 22 in the same year.
In this regard, if we look at the contribution of Ronald Ross, we find that in 1897, during his studies on bird malaria, he described oocysts of the parasite in the stomach walls of an unclassified mosquito which he called “a grey mosquito” and a “dappled winged mosquito” which he thought is probably a Culex., In 1899 his publication on Annales de “l” Institut Pasteur mentions the insect responsible for the malaria transmission as “moustique d' une novella espece.” Unlike Grassi, Ross was not trained as a Zoologist and he completely lacked the knowledge of systematic zoology. The credit for actually identifying the species of mosquito and actual transmission in human volunteer should go to Grassi since Ross was unable to identify the mosquito and he had extrapolated his hypothesis from studies in malaria of birds. Ross was already aware of the studies being conducted at Rome through the reports being sent to him by E. Charles who was a guest at Grassi's laboratory, being sent there by no other person than Sir Patrick Manson with whom Ross had a close scientific association.
Immediately after these independent findings by Ross and Grassi, Ross began a defamatory campaign in order to claim priority in the discovery of malaria transmission mechanism resulting finally in the award of the Noble Prize to him in 1902. In 1900, Grassi published one of his most important work “Studi di uno Zoologo sulla Malaria” (A Zoologist study in malaria).
The Later Years
Disappointed over the Noble Prize controversy, Grassi turned his attention away and dedicated to matters related to phosphoric necrosis and alpine goiter and also in entomology. However, in 1918 he renewed his interest in the study of malaria which had resurged subsequent to the First World War. The mortality due to malaria in Italy had decreased from 600/million in 1898 to <50 in 1915 due to the recent discovery of the vector and protective measures against mosquitoes together with free distribution of quinine. But in 1919, the mortality had again risen to 320/million. Grassi again concentrated on the enigma of “Anophelism without malaria”. He identified three areas in Italy which were free of malaria but populated by Anopheles maculipennis. He proposed that there may be a certain race of Anopheles mosquito which do not bite man. Although he could not prove his hypothesis, only 1 year after his death, one of his students, Felleroni, in 1926 showed that there were six species of Anopheles in the maculipennis complex of which only two are anthrophilic while the rest bite only animals and are zoophilic. This emphasizes the importance of exact identification and classification of vectors which is important in the control of vector borne diseases. Grassi continued with his teaching and research works at the university till his death on May 4, 1925 at the age of 71.
In the end analysis, it may be said that both Ross and Grassi approached the same problem albeit in different manners. Grassi applied his Zoological knowledge which is experimental and systematic while that of Ross was more of an empirical nature and a deductive one. The precise identification of the species is the cornerstone of any Zoological study. Grassi could identify the vector as Anopheles instead of naming it merely as “grey mosquito” or “dappled merged mosquito”, the terms used by Ross. Moreover, the experiments conducted by Grassi using human volunteers need special appreciation since he used laboratory-grown mosquitoes; selected the patients of malaria which were bitten by these mosquitoes; and in the last step used these infected mosquitoes to bite a healthy human volunteer. It was pure science and not an intuitive empirical finding. However, at the end, we can only say that both deserved equal appreciation and equal merit should be given to both Batista Grassi and Ronald Ross.,
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Conflicts of interest
There are no conflicts of interest.
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