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CHAPT E R I X. 
THE SHIPPING TRADE OF BELIZE AND THE 
RELATIONSHIP OF TRADE ROUTES TO THE DISTRIBUTION 
OF YELLOW FEVER. 
In 1903, Sir Patrick Manson 1 2 drew attention to the risk of introducing 
Yellow fever into Asia by making and working the Panama Canal. He 
pointed out how disease followed the lines of commercial maritime travel, and 
the danger which would exist of transmitting infected mosquitoes.' 2 3 There 
is abundant proof in the past, in the days of the sailing ships, of the 
transference of Yellow fever from endemic foci in the West Indies, South 
and Central America, both to Southern Europe and to North America, 
where the fever spread over a smaller or larger area of infectible territory 
when the conditions of temperature and moisture were favourable to the life 
and development of the Stegomyia fasciata. 
Spain was terribly ravaged by it in the early part of the 19th Century, 
the infection being brought from the Spanish Colonies in ships harbouring 
infected Stegomyia and breeding fresh supplies. In the same way Portugal 
was infected from Brazil, and Gibraltar also became infected. In France 
and in England ships have carried both infected mosquitoes, and cases of 
Yellow fever which developed on board, to their shores, but diffusion has 
not occurred. The history of the outbreaks of Yellow fever in Europe 
marks the period of active Colonial development and military expeditions to 
Yellow fever countries. 
Since 1870, however, there has been a marked diminution in the number 
of Yellow fever patients brought to Europe, and this is attributed to improved 
ships’ hygiene, and to the substitution of steam for sail. The risk of the 
transportation of mosquitoes for long distances by ships is becoming less. 
Nevertheless, there is a possibility, and I have considered it of interest to 
record some of the most recent evidence bearing upon the subject. 
Transference of Mosquitoes bv Ships. 
It is well known that it is often impossible to sleep on board ships 
without nets, when moored alongside wharfs, or standing off a small distance 
from shore, or whilst moored in certain rivers. In New' Orleans ships alongside 
the wharf become severely invaded at times. Depending upon the season of 
the year, and the temperature, mosquitoes on board may be transferred 
considerable distances, especially in those places on the ship which are kept 
warm and free from draught. The common places described are the galley, 
stuffy berths, forecastle and holds. 
1 Paper read before the Epidemiological Society, 1903. 
2 Yellow fever in France, Italy, Great Britain and Austria, Yellow fever Institutes Bulletin, 
No. 8, 1902, also Bulletins 1-7, 1902. 
*Mous/i]ues et Fiivre Jaune — Cnantemesse et Borel, Paris, 1905. 
