A Brazilian investigation links parasite and illness

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.

The young patient was the first documented human case of the disease later named after Chagas.

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.

The 11 January trial should not be confused with the more effective purified extract given on 23 January.