Giovanni Battista Grassi

Giovanni Battista Grassi bigraphy, stories - Italian zoologist

Giovanni Battista Grassi : biography

27 March1854 – 4 May 1925

Giovanni Battista Grassi (27 March1854 – 4 May 1925) was an Italian physician and zoologist, most well-known for his pioneering works on parasitology, especially on malariology. He also worked on the embryological development of honey bees, on heminth parasites, the vine parasite phylloxera, on migrations and metamorphosis in eels, and on termites. He was the first to describe and establish the life cycle of the human malarial parasite, Plasmodium falciparum, and discovered that only female anopheline mosquitoes are capable of transmitting the disease.


The 1902 Nobel Prize

The 1902 Nobel Prize in Physiology or Medicine was awarded to Ronald Ross basically for his discovery of the life cycle of malarial parasite (or as the Nobel citation goes: for his work on malaria, by which he has shown how it enters the organism…). That was where the dispute ignited which lasted till today. Grassi was the first to suggest that there must be some developmental stage of Plasmodium in the white blood cells. In 1897, independent of Ross, he, along with his Italian associates, had established the developmental stages of malaria parasites in anopheline mosquitoes; and they described the complete life cycles of P. falciparum, P. vivax and P. malariae the following year. When the Nobel nomination was called, a modest and self-centered man, Grassi started to have a fiery polemic over priority with a militant Major Ross, which was further exacerbated by the interference of Robert Koch. The initial opinion of the Nobel Committee was that the prize should be shared between Ross and Grassi. Then Ross made a defamatory campaign accusing Grassi of deliberate fraud. The weight of favour ultimately fell on Ross, largely upon the influences of Koch, the appointed "neutral arbitrator" in the committee; as reported, "Koch threw the full weight of his considerable authority in insisting that Grassi did not deserve the honor" (Koch was quite disgraced in 1898 when Grassi pointed out flaws in his methodology on malarial research). Hence, the verdict. The indelible irony was that Ross was definitely the first to show that malarial parasite was transmitted by the bite of infected mosquitoes, in his case the avian Plasmodium relictum. But Grassi’s work was much more directly relevant to human health as he demonstrated that human malarial parasites were incriminated only by female Anopheles (Interestingly, Ross never identified the mosquito species, being not a zoologist, "grey mosquito with dappled wings" was all that he could offer). Indeed it was Grassi who identified the species correctly, and in 1898 who first established the complete life cycle of P. falciparum, the first human malarial parasite for which the entire cycle was determined. By today’s standard, they should have undoubtedly shared the Nobel.

Grassi’s law

Grassi had developed a dogma that "there is no malaria without Anopheles" or simply, "anophelism without malaria". This was dubbed the "Grassi’s Law", which is formulated as: infected man + anopheles mosquitoes = malaria. Although the equation is straightforwardly correct, the reverse implication is not so. In many areas, he himself had noted that where anopheline vectors were abundant, malaria was not at all prevalent, and sometimes absent. This caused a little problem in understanding malaria epidemiology for some time. In fact, in 1919 he identified three typical malaria prevalent localities, but which were not affected by malaria in the same way, such as the gardens of Schito near Naples, Massarosa in Tuscany, and Alberone in Lombardia. In 1921, after repeated assessment, he concluded with the assumption of the existence of races of Anopheles, that there were morphologically indistinguishable mosquitoes that do not bite humans, and that therefore did not play a role as vectors. The enigma was solved in 1925, a year after his death, by his pupil Falleroni, who demonstrated that there are six cryptic species of which only four bite humans and transmit malaria.