MALARIA, MOSQUITOES AND THE ESSEX MARSHES 47
Towards the end of the 19th century, historians record, and
statisticians confirm, that there was a remarkable fall in the inci-
dence of malaria, especially in Essex and Kent. The Registrar
General's figures for Essex for the ten-year period, 1871-1880,
show that there were 62 cases, and during the next ten years,
only 28.
In the last few years of the 19th century, the great puzzle
regarding the cause of malaria and its mode of transmission was
solved. A number of workers, notably Laveran, had done re-
search on these problems, but it was in 1894 that Dr. (later Sir)
Patrick Manson put forward the mosquito-malaria theory. This
theory he communicated to Major (later Sir) Ronald Ross and
within three or four years Ross, inspired and guided by Manson
had proved the theory correct. The story of these years is told
in Ross's Memoirs—a story full of excitement, adventure, set-
backs and 'administrative barbarism'—but ultimate success. One
incident seems worth recalling. Ross wrote, ". . . . in November
(1894), I called upon him (Dr. Manson) again and found him just
starting off for the Seamen's Hospital. I went with him and re-
member distinctly that as we were walking along Oxford Street
at about 2.30 p.m. he said to me, 'Do you know, I have formed
the theory that mosquitoes carry malaria just as they carry
Filariae'." The point of interest is that the Seamen's Hospital
where Manson worked and Ross visited, was the one at the
Royal Albert Dock, within our own county and only a mile or so
away from the Club's headquarters. The results of these re-
searches were slow to be accepted—even by some medicals and
other men of science.
When malaria came again into significance during the First
World War (when large numbers of troops were serving in
malaria-infected areas), there was, thanks to the work of Ross and
others, a wealth of knowledge to draw upon. The disease jumped
into importance in England itself in 1917. when ships arriving
in the Port of London from Dakar during the late summer were
found to be carrying considerable numbers of crew infected with
malaria. Then there was the effect of the repatriation of services
personnel. During the summer of 1916, following a severe epi-
demic of malaria among troops in Salonika, large numbers of
persistently relapsing cases were sent home, and special camps
were erected for them in various parts of the country. Where the
Anopheles density was high, it was not surprising that by the
summer of 1917, from this reservoir of infection, cases of malaria
occurred among the civilian population, as well as among service
personnel in nearby camps who had not been overseas. The
repatriation was associated with a high incidence of imported
malaria in the country as a whole, but only in the Thames
estuary did this imported infection produce a marked rise in
indigenous malaria. Immediately after the War, there were
some six hundred cases of indigenous malaria, and ninety per
cent. of these were in our coastal districts of the south and south-