Sir: In his paper on Ronald Ross' laboratory in Calcutta, ¹ Agneish Dutta states: ‘With another scientist, Patrick Manson (1844–1922) Laveran found that that Filariasis (sic) (a tropical and parasitic disease caused by nematode worms) grew in the mosquito stomach and related this to the transmission of Plasmodium via the mosquito’. Manson discovered Filaria in a Culex mosquito stomach and published his findings in 1887 ² whilst Marie Phisalix in her biography of Laveran with its exhaustive bibliography ³ wrote: ‘Il communiqué en 1893 à la Société médicale des Hôpitaux un cas de filariose qui est interessant au point de vue du diagnostic de paludisme … Laveran fit l'examen du sang, mais au lieu des hématozoaires du paludisme il trouve des embryons de filaries’. ^4,5

Mme Phisalix also refers to a publication on a case of infection with F. loa reported to the Société de Pathologie Exotique in 1916. ⁶

Sir Ronald Ross refers in his autobiography ⁷ to Laveran's conjecture that mosquitoes might carry malaria as they did in filariasis, which would imply that Laveran knew of Manson's work although he does not mention Manson by name. Like Manson he thinks that mosquitoes might infect drinking water with Filaria when they die. ⁸

I feel that these papers hardly imply that Laveran discovered Filaria in a mosquito's stomach alongside Manson.