The American Journal of Tropical Medicine and Hygiene - Volume s1-10, Issue 6, November 1930

The present work has involved the use of a total of 250 birds, of which 154 have been included in the experimental series. One third of the latter number were given quinine, one third plasmochin, and one third served as controls. Five strains of avian malaria have been used: one strain of Plasmodium elongatum, one of Plasmodium cathemerium, and three of Plasmodium praecox. One of the latter came from Germany, one from New York, and the third from Virginia. This last was originally described by Hartman as Plasmodium inconstans.

The conditions of the experiment have been made as uniform as possible, so that such differences as might seem to appear could be justly laid to differences in the treatment or in the strain of malaria. Equivalent inocula of parasites have been used for all the birds in any given series, and in most of the cases the dosage has been varied with the weight of the bird. The duration of treatment was fourteen days in all cases, except for five series of six birds each infected with Plasmodium praecox (type strain). Ten of these birds were given quinine and ten others plasmochin. In each instance two birds died during treatment—probably as the result of it—but treatment of the others was continued for eight weeks in the case of those receiving quinine and for seven with those receiving plasmochin. The latter were treated for a shorter time because subinoculations made at the end of the first month proved negative, except in 1 case, and it was thought that sterilization had been accomplished. The single case which gave a positive result was treated for another week.

The results justify the following conclusions:

• 1.  The different strains of Plasmodium praecox react to treatment in essentially the same way for either plasmochin or quinine, but the three species show marked differences. Apparently they stand in the following order, the most susceptible being at the head of the list:

  Quinine	Plasmochin
  1. Plasmodium praecoz	1. Plasmodium elongatum
  2. Plasmodium cathemerium	2. Plasmodium praecox
  3. Plasmodium elongatum	3. Plasmodium cathemerium

  Plasmodium cathemerium and Plasmodium praecox, the two species which resemble each other most morphologically, also differ least in their susceptibility to treatment.
• 2.  There is no evidence that the gametocytes of any of the three species are more resistant to the action of plasmochin and quinine than are the asexual stages. What differences there may be seem to be of the reverse sort. Thus it appears that the avian malarias differ in this respect from the malarial fevers of man. This finding is opposed to that of Kopenaris (1911) who used quinine in experiments with bird malaria.
• 3.  Treatment during the incubation period is considerably more effective than that started during the acute stage. Treatment with plasmochin for two weeks will often entirely prevent infection with Plasmodium praecox when started the day after inoculation, but if postponed until parasites appear in the peripheral blood seven or eight weeks of treatment is seldom sufficient to cause complete recovery.
• 4.  A system of treatment comparable to the Bass system recommended for human malaria was followed with Plasmodium praecox infections of birds, but in only 1 case was sterilization attained. This occurred in one of the plasmochin-treated birds. Quinine, although administered to eight birds for an equal number of weeks, failed to prevent relapse or cause sterilization in a single case.
• 5.  Sterilization can apparently be regularly produced by plasmochin when used against Plasmodium elongatum, and it does not matter whether treatment is commenced the day after inoculation or postponed until parasites are demonstrable in the blood. Fourteen cases in all have been cured in this way. Quinine seems to be relatively ineffective against this species but it did prevent infection in one bird out of six. In no case was sterilization obtained in infections of Plasmodium cathemerium.
• 6.  Except in cases infected with Plasmodium cathemerium freedom from relapse during the first month after treatment proved an almost sure indication of sterilization.
• 7.  Birds which have been sterilized by the use of quinine or plasmochin were as susceptible to reinfection as if they had never been infected to begin with, or had recovered naturally.
• 8.  Plasmochin is uniformly superior to quinine in the treatment of bird malaria, but the degree of superiority differs with the species of parasite responsible for the infection. Roehl (1926) estimated that it was sixty times as effective as quinine, but it is also more than six times as toxic to the host. Even when this allowance is made for the difference in toxicity it does not seem to be nearly as much better than quinine as Roehl believed, except in the case of Plasmodium elongatum. Roehl did not work with this species however.
• 9.  Increasing the dose to the limit tolerated by the bird does not seem to add greatly to the efficacy of either of these drugs.
• 10.  Relapses occurring after treatment are usually considerably milder than untreated acute attacks.
• 11.  Chronic infections of Plasmodium praecox differ very much in the individual parasite levels established, and previous treatment has no effect on them.
• 12.  Plasmochin is able to reduce the parasite level to a point lower than quinine can when used against Plasmodium praecox, and in both cases the level is forced below that established in untreated chronic infections. That this difference exists is shown by the fact that the blood of quinine-treated cases remains infective when inoculated into clean birds, whereas in most cases that of birds being treated with plasmochin is not.

• 1.  Guinea pigs actively immunized against the Boston strain of L. icterohaemorrhagiae are immune against Type A of the Akiyami strain of leptospira.
• 2.  Guinea pigs actively immunized against Type A of the Akiyami strain of leptospira are immune against the Boston strain of L. icterohaemorrhagiae.
• 3.  These two strains are indistinguishable by the cross immunity tests.

Since the discovery by Stokes, Bauer, and Hudson (1) that yellow fever may be transmitted to monkeys, laboratories for further studies of the disease have been established in various parts of the world. In many of these places accidental infections have occurred which have been mentioned only casually in published reports.

It has been suggested to us that a fuller account of some of the infections might be appreciated by other laboratory workers and by the medical profession. We have prepared, therefore, a résumé of the histories of four cases among Americans, in Bahia, Brazil; at least three of the patients unquestionably were infected in the laboratory. As far as we know, none of the Brazilian personnel has become infected.

It would be of value to know how each laboratory infection is acquired and the strain of virus that is responsible. On these points exact data are usually not obtainable.

The observations described indicate that heavily contaminated drinking water is the principal source of intestinal infections in the vicinity of Dzitas and of Chichen Itza. What is true of this region is, probably, equally true for other small Yucatecan communities and for all the Indian villages. Other evidence points unmistakably to drinking water as a very serious source of danger in Merida and in other cities in Yucatan. That there is an extremely high mortality from intestinal infections in Merida has been demonstrated (table 1) by Hoffman (1). Further statistical data will be presented in the Report of our Expedition (2).

That safe municipal water supplies are urgently needed by the cities in Yucatan is beyond question.

It is believed that in the smaller Yucatecan communities and in the Indian villages much could be done to reduce the deathrate and to improve the health if the people could be taught the dangers of contaminated water, the importance of cleanliness of water-containers, and the protection offered by boiling. To prevent the contamination of wells would require a complete change in the habits of the people and an expenditure of effort and of money which could hardly be expected of the general population in the near future.

The difficulties attendant upon the differential diagnosis of sprue and pernicious anemia are well known to those called upon to treat the two conditions. In some cases it is impossible to distinguish between them and this has led some clinicians to regard them as the same disease. Christian (1) has suggested that they are one and the same disease and that sprue may develop into pernicious anemia. Wood (2) has added support to this idea by finding Monilia psilosis in cases of pernicious anemia, which yeasts are regarded by Ashford as the causative organism of sprue. Baumgartner (3) disagrees and thinks that they are two distinct diseases but states that some cases “probably cannot be correctly diagnosed, at least by methods now available.” This disagreement has been under discussion in the literature for years; the diagnosis of the two conditions meanwhile becomes constantly more complex.

Contrary to popular belief syphilis still presents many unknown aspects. It is true that dependable methods are available for the diagnosis of the early case and of a certain proportion of otherwise obscure late cases; that the mode of transmission is known; that methods of treatment can be applied which will temporarily sterilize and permanently arrest or cure a high proportion of early cases; but the fact remains that the application of present knowledge has not brought this disease under control. It remains as one of the two or three most important diseases from the public health standpoint.

Against this background of present knowledge should be sketched some of the unknown factors in order to get a true perspective of the syphilis problem. For purposes of discussion these factors may be grouped into: (a) The problem of the growth and biology of the infecting organism; (b) the reactions of the body resulting from the infection; (c) diagnosis and treatment of the disease; (b) public health, epidemiological, and sociological problems.

This is the first of the projected nine volumes of the system of bacteriology being published by the Medical Research Council, of England, several volumes of which have already been reviewed in this Journal. The present volume considers general questions relating to the subject of bacteriology and the contributors are Andrewes, Arkwright, Barnard, Browning, Bulloch, Chick, Gardner, Harden, McCombie, McLeod, St. John-Brooks, Slator and Thornton. The subjects considered are History, Morphology, Physics of the Bacterial Cell, Growth and Reproduction, Disinfection, Metabolism, Bacterial Respiration, Nomenclature and Classification, and Variation. Every one of these subjects is well discussed, and it is difficult to select those chapters of most interest and importance, but it may be stated that the chapters upon the history of bacteriology, by Bulloch; the metabolism of bacteria, by Harden; and variation in bacteria, by Arkwright, are especially well done and of great interest and value.

A very interesting and well written presentation of the accomplishments of sanitation and Public Health, written for the lay reader.

In a work of this kind accuracy is a prime requisite, but this book is full of misleading statements. Historians no longer accept the statement (p. 23) that Columbusand his men acquired syphilis from America. That typhoid fever is now almost non-existent in our country (p. 88) is almost as gross an exaggeration as the reputed death of Mark Twain that occurred during his life. It is surprising to find the elimination of scurvy attributed solely to Captain Cook (p. 60). Dengue occurs constantly in spite of the declaration (p. 191) that it is vanquished, and the scientific work done on this subject, as well as the eradication of beriberi from the Philippine Scouts (p. 263) resulted from the labors of many men rather than single individuals.

The subject of protozoology is rapidly increasing in importance to the public health officer, physician, and medical scientist, with the rapid advances that are being made in our knowledge of the parasitic protozoa of man and animals, and with our better realization of the relation many of these protozoan organisms bear to human health and prosperity. The editors of this work have endeavored to bring together information of value to students and investigators in protozoology that is scattered in various journals and other publications having to do with methods of research and problems which are still unsolved in this fascinating branch of zoology. The work is written by specialists in the various fields of protozoology and contains a vast amount of information which will undoubtedly prove of great value in future research in protozoology.

The American Society of Tropical Medicine was established March 9, 1903. It has been chartered as a perpetual corporation by the State of Pennsylvania. It is one of the component organizations of the Congress of American Physicians and Surgeons. Its purpose is to advance the knowledge of tropical diseases by encouraging original research by its members and others; collecting and recording facts ascertained by such researches, and disseminating information thereof by discussion among its members and by the publications of papers read before the Society. The affairs of the Society are administered by a Council of five, a President and a Secretary, elected by the Society. Any regular physician or scientist interested in the study of tropical diseases is eligible for Active Membership. Candidates for membership are elected by ballot at the annual meeting upon recommendation by the Council. The dues are fixed each year by the Council but cannot be increased beyond $5.00 without approval by the Society at its annual meeting.