April/13/l927. Some thoughts that came to me this morning.
Is It Possible To Exterminate Aedes Aegypti In Limited Control Areas?
Has Extermination Ever Been Attempted?
Is It Feasible to Investigate The Problem In Bahia?
Not knowing the answers to the first two questions above, I can only think that it is worth some little investigation in Bahia,
because great economies might result.
The following thoughts came to as a course of investigation to follow:-
1. Keep a daily list of each "foco" found, with zone number, name of street and number, and type of container in which
found, and, if possible, whether large or small.
2. Select an appropriate area for which we have completely detailed maps. About ten zones in the contested central district
might suffice -- the present 4th District and a few adjoining zones.
3. Make a spot map of all "focos" found, using a different colored pin for each week, for a month: this to constitute
a working basis before any control measures be undertaken.
4. Determine from this map if there is any sort of focal distribution. If so attempt to eliminate it.
5. Develop, if possible, the use of something to kill eggs on the sides of containers in which breeding has been found. Perhaps
creoline or kerosene would kill these eggs.
6. Personal investigator of all houses with aedes "focos" during the experimental period.
7. The possibility of measures against adults in houses where breeding has been found, might warrant attention. There is
the bare possibility, that by a judicious combination of chiefly antilarval measures, and secondarily, specialized anti-adult
measures, extinction in a limited and carefully watched zone might be achieved.
8. Should extinction be achieved in any given area, a barrage of the most intense control to be thrown around the area, or
else the area of extinction to be enlarged. The recent work of Dunn with tree hole breeding in Africa to be kept in mind.
9. If extinction be achieved in an area, then have monthly inspections, preferably by the brigade system. This is the place
where the economy would come in. It would make the labor costs in the zone about one fourth of what they are with the current
This may seem a bit wild, but it does not seem to me to be any more of a departure from the reasonable than was the first
attempt to control yellow fever by antilarval measures alone. It seems to me to be worth investigation.
The above outline of investigation involves almost no new procedures. With the exception of the visits to houses in which
are found the "focos", it, does not involve anything not now being done in Bahia. Furthermore, in Recife, such visits
are now being made.
I have pondered considerably over the budgeting of the expenses of the yellow fever control operations. I have come to the
conclusion that almost all the expenses can be budgeted. However, it seems advisable to leave some of the control operations
outside of a budget, or perhaps, in a very elastic one.
The important thing is, it seems to me, that fully 90% of the expenses can be budgeted, in somewhat the following manner.
1. Only places where service is to be continuously in operation for a period of six months to come under the regular budgets.
This would include only the stations of permanent control.
2. Each station to have a budget with similar item numbers, the amounts to vary, of course, with each station. Both the
total amount and the proportionate amounts of the various items.
3. The Rio office to charge each station, of course, for supplies and for shipping charges, but these not to come within,
the station budgets, special arrangement being made in Rio for them.
4. Each station budget to be in two parts, the first to include expenses for control in the city proper, and the second to
cover expenses in the permanent interior stations. For this last, three or four items would seem to be sufficient.
5. This would necessitate, if the system were put into effect on July 1, 1927 but five budgets, for Bahia, Recife, Parahyba
and Campina Grande, Netel, and Fortaleza, respectively, each with its respective interior stations.
6. Temporary control measures could then be financed by special grants for temporary work in the various other places indicated
from time to time.
The above system does not seem to me to be unduly complicated. It would put each station on not more than two budgets, and
most of them would be on one most of the time.
It is perfectly obvious and well known that by far the larger part of the expenditures occur now in the city of Bahia with
its surrounding zone of secondary cities, in Recife, Parahyba and Campina Grande, in Natal, and in Fortaleza. These are the
permanent stations where control measures and therefore costs are relatively stabilized. The only thing that seems liable
to happen is a reduction in costs. The budgets should allow for some expansion, of course.
Perhaps, in my ignorance of the entire working of budgets, including their course in and thru the home office, this plan has
insuperable and dangerous technical difficulties. The thought occurs to me that perhaps these budgets could be arranged within
the yellow fever budget for this year, and give a basis for the budgets and appropriations next year.
As I read over this memorandum it seems as if the tone were authoritative. It is not meant to be such, but in the light of
my understanding of the situation, which is only partial, the thing seems feasible.
[Handwritten note:] April 26, 1927
When I returned to Balia, I found that Dr. Henry had made all preparations to put the above measures into effect, having come
to the same conclusions.