The American Journal of Tropical Medicine and Hygiene - Volume s1-22, Issue 2, March 1942

Invasion of the myocardium of an eleven year old Panamanian child with Sarcosporidia is reported. This is the twelfth reported case of sarcosporidiosis, the fourth with cardiac involvement and the second from the Isthmus of Panama.

The clinical picture of tropical neurasthenia is discussed and its diagnosis and treatment are outlined. Its similarity is shown to hypo-adrenia, or clinical adrenal deficiency, in temperate climates, whose etiology is associated with adrenal exhaustion from congenital or environmental causes. In the tropics, consideration of these same factors may lead to adequate prevention or cure, in at least one category of this disease. Unsolved questions are proposed whose solution is justified by the incidence and importance of tropical neurasthenia.

The true efficiency of a single iodine- or hematoxylin-stained fecal film for the detection of Endamoeba histolytica infections was less than one in five, and ten examinations had to be made to make a negative result reasonably reliable. By a combination of one of these technics with zinc sulphate centrifugal floatation about one out of three or four infections was detected in a single examination, while five examinations provided a probability of 70 to 90 per cent.

The efficiency of the iodine- or hematoxylin-stained film for the non-pathogenic protozoa was one in four, and five examinations detected about 80 per cent. However, when one of these two technics was combined with zinc sulphate centrifugal floatation, the probability was about one in two, while three examinations detected more than 80 per cent.

Thus, the use of the zinc sulphate centrifugal floatation technic in combination with the direct fecal film examination provides greater reliability and ease of detecting intestinal protozoa with fewer specimens than does either of the non-concentration technics.

• 1.  Twenty-six species of bacteria (41 strains) were tested with regard to their ability to cause excystation and growth of E. histolytica in vitro. A heterogeneous group of 14 species of bacteria were found capable of doing so when each was cultured with sterile cysts. The bacteria having the property of inducing excystation and multiplication were Leptotrichia buccalis, Clostridium perfringens, Staphylococcus aureus, Salmonella schottmuelleri, Streptococcus hemolyticus, Str. faecalis, Str. viridans, Bacillus subtilis, B. mesentericus, Actinomyces muris, Aplanobacter stewartii, Bacterium coronofaciens, Serratia marcescens and Neisseria catarrhalis. Some of the intestinal bacteria such as Alcaligenes faecalis could not initiate growth of amoebae from cysts. Three species of yeasts also failed to induce excystation.
• 2.  The growth relationships of the amoebae to the bacteria were determined. During the most active period of multiplication of the amoebae the bacteria were sharply reduced in number and were ingested by the amoebae.
• 3.  The effect of a mixed bacterial flora was studied. Growth was greatly stimulated in some cases when a second or third species was added to an amoeba culture already growing with one species of bacterium.
• 4.  Encystation was produced when Cl. perfringens, a bacterium uniformly present in the human colon, was added to cultures containing one or two other species of bacteria. Cultures containing Cl. perfringens, Str. hemolyticus and Lepto. buccalis or Cl. perfringens and Str. hemolyticus were particularly good cyst producers. Such cultures were uniformly rich in trophozoites but the cysts varied from 5 to 40 per cent.
• 5.  It is felt that the bacteria play a significant role in the excystation, multiplication and encystation of E. histolytica and studies of the bacterial action may lead to a knowledge of the conditions necessary to cultivate E. histolytica without bacteria.

• 1.  The use of the culture method in the diagnosis of amebiasis was evaluated on the basis of personal observations. It was found that its value seemed to us the most significant one in dealing with carriers with a small number of cysts in the stools.
• 2.  It is suggested, therefore, that the culture method may be added to the routine examination of stools as an aid in diagnosing infection with Endamoeba histolytica. It serves as a means of increasing the percentage of positives when jointly employed with other methods and also of checking all the negatives otherwise obtained.

With the kind cooperation of Mr. Rollin H. Baker of the Texas State Game, Fish and Oyster Commission, I had an opportunity to examine a series of 15 raccoons, Procyon lotor lotor, from East Texas. Nine of these were trapped during the month of December, three were obtained in May, and three more in September. Guinea worms were found in six of the nine raccoons examined in the winter, but none were found in those examined in May or September. The worms were never found elsewhere than in the feet; in every instance, they were present in one or both hind feet. Two raccoons also had specimens in one of the front feet, but in one of these cases the worms were dead and partly calcified. The number of worms in a foot varied from one to four.

Inquiry among the trappers in East Texas elicited the information that “worms in the feet” of raccoons is well known to them, and is of very common occurrence.

The case herewith recorded represents the twenty-second instance of human myiasis by larvae of the family Syrphidae to be recorded in the literature In this instance the offending parasite was a member of the genus Eristalis, probably E. tenax. In addition to the form vomited before the patient was seen, seven larvae were expelled following anthelmintic therapy. Because of a complicating condition (bronchitis), it is not clear which, if any, of the child's symptoms can be attributed to the parasitic infestation.

The cases of human myiasis by syrphid larvae recorded in the literature since 1918 have been collected.

Six birds infected with Plasmodium vaughani were used to study periodicity in the asexual cycle, and in four of them variations in the proportion of reticulocytes and the relative numbers of parasites occurring in reticulocytes at different times were determined. The process of division of the parasite was also investigated. The following conclusions may be drawn:

• 1.  The length of the asexual cycle is 24 hours, with the height of segmentation occurring in the morning. The cycle is not very clearly marked however, and synchronicity is not great. There are variations in different birds, and even in the same bird at different times.
• 2.  On the whole it appears that this species resembles many of the other species of malaria in the tendency of the parasites to invade reticulocytes. But this tendency is less marked than in most of these other species.
• 3.  The proportion of reticulocytes to the total number of erythrocytes varies considerably from time to time both in the same bird, and in different birds, but these variations do not seem to be very consistent or regular. And it does not appear that the periodicity of the parasite bears any direct relationship to periodic changes in the number of reticulocytes, or that variations in the proportion of infected reticulocytes necessarily depend on the number of such red cells available.
• 4.  Division in Plasmodium vaughani appears to occur in three ways: by repeated binary fission of the chromatin, with eventual splitting of the cytoplasm, by the splitting of an elongate parasite into merozoites having a bead-like arrangement, or by the similar breaking-up of a ring-shaped form, with a resulting ring of merozoites.
• 5.  Attempts to transmit infection with this species by Culex pipiens indicate that if this mosquito ever acts as a vector in nature, it must do so very rarely.

A book dealing with human malaria—the eighth collection of articles on matters of public health published by the American Association for the Advancement of Science. In it is to be found a systematic, comprehensive and authoritative discussion of the problems of malaria as they are encountered in North America and the Caribbean region.

It is a compilation of forty-four contributions by as many authors with a foreword by the Editor. There are twenty-eight pages of bibliography, also maps, charts, graphs, tables and half-tones, all of distinct informative value. It is a history of the results of intensive thought and work and it points out promising avenues of study and attack. It bears upon the questions of the parasites and their vectors, epidemiology, symptomatology, pathology, immunity, treatment, and control and eradication.

The Publication Committee, Boyd, Soule, Coggeshall, Craig, Taliaferro and Williams, Jr., lent not only guidance in its preparation but added individual contributions.

This work is a review of the subject of immunity against parasites and is intended for the student, the trained investigator, the practicing physician and the veterinarian. In the introduction the author states that he has adopted the classical work of Taliaferro, entitled “The Immunology of Parasitic Infections,” published in 1929, as a point of departure for his book and thus he has reviewed the subject and the contributions which have pertained to it from that date only. The book may thus be considered as a supplement to the book by Taliaferro, bringing the subject up-to-date.

A careful perusal of this work demonstrates that the author has fulfilled his task in an excellent manner and all who are interested in the subject will find here condensed in a practical manner all of the important literature relating to immunity in parasitic diseases. It will prove of great value to all interested in the subject of immunity and especially to research workers, to whom it will be indispensable.

This is a comprehensive treatise upon all of the aspects of the toxemias of pregnancy, from both the scientific and clinical stand-points. The work includes a thorough discussion of the physicochemical, physiological, and pathological features of these toxemias as well as the influence of the endocrines. The clinical portions of the work treat fully the various toxemias in their clinical manifestations and especially valuable are the chapters upon hypertensive disease in pregnancy as distinguished from pre-eclampsia, eclampsia and chronic disease of the kidneys. The chapter upon treatment is particularly interesting and presents not only present day treatment but an historical resume of the treatment of eclampsia. There is also an excellent chapter upon pre-natal care. In regard to the latter, the author stresses the fact that the incidence of these toxemias may be cut down but not completely eliminated by pre-natal care.

This book is a valuable contribution to the subject and gives a broad view of past work upon the toxemias of pregnancy and a thorough knowledge of the work being done at the present time.