August 22, 1967
Dear Paulo:
Greetings from Juliet and me to you and your family.
The most immediate reason for this note is the news of the reinfestation of Belem do Para with Aedes aegypti.  This reinfestation has been believed imminent for several years, ever since the full scale reinfestation of French Guiana and Guyana.  The situation is particularly disturbing since I learned some months ago that Dr. Germano Faria, the head of DNERU, had expressed himself as not especially concerned over the threat of reinfestation with Aedes aegypti since the threat of yellow fever could be readily handled by vaccination.
I would point out that Belem lies at the mouth of the Amazon and can readily become a distributing center for Aedes aegypti to the Amazon Valley and to the coast of Brazil.
Historically, unrecognized yellow fever was shown to be present in Belem in May 1930 when the routine collection of liver tissue from individuals dying after less than ten days illness revealed a positive on the third liver collected.  This was almost a year after the last recognized case and a month before the local profession reported the disease.
As you know, Belem has an ideal climate for Aedes aegypti.  Eradication was attained only after the ships engaged in river traffic installed special tubulation which permitted oiling of the bilge water from the upper deck.
The reinfestation of Belem after a period of thirty years of freedom from this mosquito is, I believe, an event of such importance that a full investigation and local eradication effort is indicated.  Also, I would insist that pressure be put on the Government authorities to make a major issue of this reinfestation at the Directing Council meeting in Port-of-Spain, Trinidad, at the end of September.
It must be remembered that the campaign for the eradication of Aedes aegypti in the Western Hemisphere was initiated by action of the Brazilian delegation at the first Directing Council in 1947.  The Brazilian resolution was based on the need to prevent reinfestation across international borders.
This objective of Brazil was reached many years ago with the eradication of aegypti from all the South American countries excepting Venezuela and Dutch Guiana and the Cucuta area of Colombia.  The failure to clean up the Caribbean has resulted in reinfestations of Guyana and French Guiana and repeated reinfestations of Trinidad in recent years.  (Further to the north and west, El Salvador was found reinfested in 1965, and Mexico has had minor reinfestations in 1965 and 1967.)
The United States is working on the problem in Puerto Rico, the Virgin Islands, and some of the infested area in the United States.
It is important that the countries which have eradicated Aedes Aegypti join together in insisting that the infested areas in Western Hemisphere be cleared before they all become reinfested.
It should be remembered that the Brazilian report of the eradication effort submitted to the Pan American Sanitary Conference in l958 showed 617,000,000 house visits between 1931 and 1958 when eradication was finally certified.  Today the increased urbanization of Brazil, the increased facility of transportation in the interior, and the great increase in disposable throw-away containers, including used automobile tires, would all increase greatly the difficulties and coat of any future eradication effort.
It must be remembered that Brazil has a great reservoir of jungle yellow fever virus which has been shown to invade from time to time all of the Brazilian states excepting only Ceara, Rio Grande do Sul, Pernambuco, Alagoas, and Sergipe.  In recent years fatal cases have occurred from Roraima in the north to Rio Grande do Sul in the south.
I am writing you at such length and reminding you of things you already know because I believe the matter is of such importance that you should stimulate what activity you can through professional contacts, and Augusto should do the same through business and political contacts he may have.  It is especially important that Brazil move immediately to eliminate this reinfestation and at the same time use every means to get the support of other countries now free of aegypti to insist on the completion of eradication of Aedes aegypti in those countries which have not met their international obligation in this matter.
Cordially yours,
Fred L. Soper