Abstract
The past few years have offered me a number of opportunities to conduct malarial surveys on labor forces in rural locations along the Caribbean coast of Central America and I have been surprised at the relatively low index of “gamete carriers” that a single thick blood film examination has revealed. I have never made a routine practice of examining all cases of malarial fever at the time of discharge from the hospital, but on numerous occasions such examinations have been made and frequently they disclosed patients that were carrying abundant gametes. I have not been able to find, in the literature at hand, very much in the way of actually recorded data on this subject. During the past six months it has been my duty to make some field surveys for malaria in seven different countries and I have taken the opportunity, so far as it presented itself, to examine as many treated cases of malaria as I could collect in the last day or so of my stay in various port towns.