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present in the Mexican Republic and in the Isthmus, and although the date 
of origin of the very severe outbreak of Yellow fever in Spanish Honduras 
and Guatemala is put down as occurring in the month of May, or even later, 
there is the possibility that infection was present in both countries at a much 
earlier date, and that, therefore, the disease might have also been introduced 
from either of these countries. Admittedly it is a very difficult matter to trace 
the source of infection, but we may venture to surmise that it was introduced 
very early in the year by way of the shipping, at a time when it was not 
expected, and quarantine supervision not so severe as it would have been had 
the danger been realised. The outbreak demonstrates the necessity of con- 
stant quarantine supervision in the Yellow bever Zone, and of putting the city 
in such a sanitary state that it will in future be impossible for Yellow fever to 
spread. There appears to be little doubt that by June there was very general 
infection of the mosquitoes throughout Belize, for cases occurred scattered both 
in the north and south portions of the town. After June the disease dies down, 
not in my opinion from the anti-mosquito measures which were taken, which 
were not sufficient to appreciably reduce the number of the Stegomyw , as will 
be shown later on, but from the absence ol the arrival of fresh susceptible 
non-immunes. The remarkable instance of the crew of the S.S. “ Whitehall,” 
who arrived on the nth May in Belize, and who began to show suspicious 
symptoms on the 17th, shows that if we accept them as cases of Yellow fever, and 
there seems little reason to doubt their genuineness, that new arrivals very soon 
contracted the disease. 
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