146 Timehri. 
Yellow Fever :—By the brilliant discovery of the fact that this fever is con- 
veyed solely by the bite of the Stegomyia mosquito, Yellow Fever to-day ranks 
as an absolutely preventable disease. 
So easily indeed can it be prevented that given a single case, diagnosed from 
the onset, there should be no further cases taking place, if the proper preventive 
measures have been thoroughly carried out. 
As most people know, these measures consist in proper isolation of the patient 
in a mosquito-proof room, or even under a netting, and the thorough fumigation 
of the premises so as to destroy all Stegomyia mosquitos which may happen to 
be about. 
The great drawback to a sufficiently thorough treatment of the patient and 
his surroundings, is the fact of the very great difficulty in an early diagnosis of 
the first case. 
Strange asit may appear to be, it is a fact that contrary to what obtains in most 
other preventable diseases, we know much more about the prevention of this 
disease than we do of the disease itself, at any rate so far as the earliest clinical 
symptoms are concerned. 
At the present time, a very interesting discussion at the Society of Tropical 
Medicine and Hygiene in London, is taking place. The discussion was opened 
by our old friend Sir Rubert Boyce , who maintains that Yellow Fever is endemic 
in West Africa. Similarly a French Commission sent out to Martinique, last 
year or the year before, came to a like conclusion with regard to this island. 
They held that mild cases were occurring there the greater part of each year, 
but they were only called Yellow Fever when pronounced symptoms, such as 
black vomit, etc., were present. 
All the speakers at the discussion on Sir Rubert Boyce’s paper were agreed as 
to the very great difficulty in diagnosing between Bilious Remittent Fever and 
mild cases of Yellow Fever. Sir Rubert inclined to the view that the majority of 
cases diagnosed as Bilious Remittent or “ Inflammatory ’’ Fever were really 
cases of Yellow Fever, but they were only styled so when the pronounced symp- 
toms were present. And it is just these mild or quite unrecognised cases which 
start an epidemic. 
I have been told that given a doubtful case, the diagnosis will be established 
in the course of a few days or weeks, according as to whether pronounced cases 
will follow or not. This is quite a fallacious argument. As I have said before a 
recognised case should not nowadays be followed by others. Furthermore the 
great difficulty of diagnosis between Bilious Remittent Fever and Yellow Fever 
being well established ; I maintain that it is the duty of every medical man nowa- 
days to treat any suspicious or doubtful case as though it were a genuine case of 
Yellow Fever. The reason is obvious, because it is the first few days which are 
so dangerous in a case of Yellow Fever, these being the days when the 
Stegomyia mosquito becomes infected and so capable of spreading the disease : 
and therefore no time should be lost in making up one’s mind as to whether the 
