Berenice enters the history of tropical medicine

While working in British-ruled India, he observed pigmented structures in the dissected mosquito.

The discovery helped establish the role of mosquitoes in malaria transmission; the full life cycle was clarified through later work.

The date later became World Mosquito Day, commemorating a result reached in India rather than Britain.

The work depended on Indian settings, patients and assistants, although standard retellings often focus almost entirely on Ross.

In Lassance, he found the parasite now called Trypanosoma cruzi in the blood of two-year-old Berenice.

Chagas connected a parasitic organism, an insect vector and a human case in his research.

The 14 April diagnosis preceded later research into the diverse long-term effects of Chagas disease.

The fourteen-year-old patient was given a first pancreatic extract injection in Toronto.

The initial extract had only limited effect and caused a local reaction; a successful improved treatment followed later.

Leonard Thompson was the first human recipient in this Toronto research program.