The American Journal of Tropical Medicine and Hygiene - Volume s1-28, Issue 2, March 1948

• 1.  Ectopic lesions in schistosomiasis are definied as those produced by immature or mature stages of schistosomes outside the portal-caval venous blood channels with their extension into the pulmonary arterioles. The lesions occasioned by the migration of young worms have been studied critically in experimental hosts but are not histologically described for man.
• 2.  Interpretation of the lesions produced by schistosomes in man or other definitive hosts requires background information on the usual route of migration of the larvae from the site of their entry into the body to their arrival in the intrahepatic portal vessel, the growth of the worms in this location, their subsequent passage against the venous blood current to the mesenteric venous radicles or vesical plexus where they mature and oviposition takes place, and finally the local and systemic tissue reactions to the presence of the worms in the body.
• 3.  Tabulation of published and other case histories of ectopic schistosomiasis, based on autopsy, biopsy, surgical intervention and substantial clinical data indicates that there are not less than 82 known cases with 86 separate sites where these lesions have been located. Twenty-one cases with 23 lesion sites are attributed to Schistosoma haematobium; 12 cases with 12 lesion sites, to S. mansoni, and 49 cases with 51 lesion sites, to S. japonicum. A majority of reported ectopic lesions in S. haematobium infection have occurred outside the brain and its blood vessels; a significant preponderance of those in S. japonicum infection have been in the brain, while those in S. mansoni infection are too few to show any significant anatomical predilection.
• 4.  The tissue reaction to schistosome eggs which escape from blood vessels nto perivascular tissues is an acute inflammatory one in which histiocytes, epithelioid cells, giant cells, eosinophils, plasma cells and fibrocytes attempt to wall off the invading foreign body, with the eventual production of a pseudotubercle around each egg as a center. Nest of eggs were typically found within relatively circumscribed areas, so that each lesion consists of an aggregate of pseudo-tubercles forming a granuloma that varies in size from a pinhead to an orange. The smallest ectopic lesions have been found in the conjunctivae, the largest ones have occurred in the brain.
• 5.  From the time of entry of the metacercariae of the human schistosomes into the cutaneous venules, following exposure to infection, the worms are characteristically intravascular in their location. There are several records of ectopic location of the adult worms, one in the middle cerebral vein, one in the ophthalmic vein, one in a coronary artery, and larger numbers from gastric, splenic, esophageal, hepatic and renal veins of heavily infected experimental animals. In no instance is there any evidence of local tissue reaction to the presence of the worms.
• 6.  Five separate theories have been adduced to account for ectopic lesions in schistosomiasis: (1) Metacercariae develop to adult worms, with subsequent oviposition, at or near the sites of penetration into the skin or mucous membrane; (2) a patent forament ovale would provide a direct route from the inferior caval veins into the systemic circulation; (3) eggs may escape through the pulmonary capillaries and be deposited in distant arterioles; (4) adult worms may travel against venous blood flow into collateral vessels and on reaching the end venules deposit their eggs, and (5) the vertebral venous system provides a natural, valveless intercommunicating channel from portal and caval veins to all parts of the body, without need of embolic filtration of eggs or the migration of adult worms against blood flow or valves.
  
  The first theory is contrary to all critical studies on the development of schistosomes in the body of the definitive host. The second theory predicates a highly improbable combination of circumstances but might possibly explain the presence of a male worm discovered in a branch of the coronary artery. The third theory is discounted by the characteristic disposition of eggs in nests or aggregates, and tissue reaction around venules rather than arterioles. The fourth theory provides a rational explanation in case the worms migrate against venous blood flow into valveless veins. The fifth theory provides an adequate basis for all but one of the ectopic lesions which have been described.
• 7.  Ectopic lesions in schistosomiasis are not rare, although the cases described are few compared with the millions of cases of intestinal and vesical schistosomiasis. It is significant that during the period 1942–1947 more ectopic cases were reported than from 1889 through 1941, and that autopsy diagnosis has declined while diagnosis by biopsy and surgical removal of the lesion has increased.
• 8.  Ectopic lesions in schistosomiasis, particularly those involving the central nervous system, may be anticipated even several years after intestinal or vesical symptoms have disappeared; moreover, these lesions may develop without a previous clinical history or diagnosis of the disease.
• 9.  Chemotherapy is essential for all cases of schistosomiasis diagnosed by ectopic lesions, to prevent additional ectopic complications, even though there may have been no history or diagnosis of abdominal schistosomiasis. The present drug of choice is potassium antiomony tartrate, administered intravenously in a one-half per cent solution on alternate days for approximately four weeks.

It is fitting to introduce this Presidential address with a declaration of deep appreciation of the honor you have bestowed upon me by electing me to the Presidency of the American Academy of Tropical Medicine. The motive behind this action was, I like to believe, not only to single out one who has lived in the tropics and become seriously interested in its health problems but as well to do honor to the organization he directs, the International Health Division of The Rockefeller Foundation, whose work in tropical medicine has brought new luster to the many distinguished achievements of others in that field.

I wish to acknowledge my gratitude to the Vice-President of the American Academy of Tropical Medicine, Dr. George C. Shattuck, for his kindness in acting in my stead during this 14th annual meeting of the Academy and to extend sincere thanks to the Secretary, Dr. Ernest Carroll Faust, for his willingness to read this address.

Experiments to test the possibility of area-control of Phlebotomus with residual DDT were carried out in Peru, 1945 to 1947.

• 1.  The results furnish additional support for the effectiveness of house spraying in protecting persons indoors.
• 2.  Treatment of stone walls (the principal outdoor shelters and breeding places) produced marked reduction of sandflies.
• 3.  Treatment of stone walls combined with house spraying reduced sandflies to an extremely low level. This effect still persisted after twelve to nineteen months.
• 4.  The results were sharply localized within the sprayed areas, sandflies occurring in normal abundance in houses or caves 75 to 200 yards distant.
• 5.  Practical control programs in camps of two large construction projects gave an extremely high degree of sandfly control, followed by the virtual cessation of new cases of cutaneous leishmaniasis or bartonellosis.
• 6.  Analysis of the results in terms of the habits and life-history of Phlebotomus supports the possibility of achieving practical control by methods applicable to many of the Phlebotomus regions of the world.

• a.  Their flight habits make sandflies vulnerable to residual DDT throughout their adult life.
• b.  The long life-cycle delays the recovery of a depleted sandfly population.

• 1.  Three hundred and sixteen neotropical rodents, belonging to twenty different species, were tested against several strains of yellow fever virus.
• 2.  Coendou prehensilis, C. paraguayensis, Dasyprocta aguti, D. aguti maraxica, D. azarae aurea, Akodon arviculoides and Sylvilagus brasiliensis were found to be resistant to all strains of virus used. None circulated virus and, in general, the immunity response was poor.
• 3.  Among the rodents belonging to the genera of Cercomys, Euryzygomatomys, Cavia, Nectomys and Oxymycterus only a small percentage circulated traces of virus.
• 4.  Of the three species of Proëchimys tested, one, P. cayennensis roberti, was found to be resistant to the virus. Individuals of P. iheringi circulated virus, in traces, after the inoculation of the Asibi strain but were resistant to two jungle strains (J.Z. and O.C.). However, rodents belonging to the species P. dimidiatus circulated virus when infected with any one of these three strains. In general circulating virus was present only in small amounts and persisted for only 1 or 2 days in the blood stream. However, occasional individuals circulated virus for longer periods.
• 5.  Of the three species of Oryzomys tested, one (O. laticeps) circulated more virus than the other two (Oryzomys sp. and O. intermedius), both of which showed only traces of virus in the blood stream after inoculation.
• 6.  Sciurus ingrami was found to circulate virus after inoculation with the Asibi and the J. Z. strains, but not after inoculation with the O. C. strain. However, all the animals inoculated with the O. C. strain developed antibodies.
• 7.  Cuniculus paca was the only species tested of which all the surviving animals circulated virus and developed neutralizing antibodies.
• 8.  Of eight species tested against the French neurotropic strain only one, Nectomys squamipes, was found to be susceptible.

• 1.  Transmissions of infection with yellow fever virus were obtained in the laboratory by bite of Haemagogus capricornii Lutz, the identity of which was established through the examination of the terminalia of male offspring secured from the infecting females.
• 2.  The capacity of a given insect to transmit infection by bite was not constant.

• 1.  A discussion of the potential vectors of dengue in the South Pacific is given.
• 2.  From epidemiological evidence gathered over a period of two years' observations, Aedes aegypti appears paramount as the common vector of dengue on New Caledonia, in the New Hebrides, and throughout the Solomon Islands.
• 3.  Dengue appeared only on those bases in the South Pacific wherever Aedes aegypti was known to exist before military occupation.
• 4.  The island form of Aedes hebrideus found in the New Hebrides does not appear to be a vector of dengue in nature under normal conditions.

• 1.  During the campaign in Okinawa, the incidence of infection with Isospora hominis as determined in hospitalized patients exceeded 0.75 per cent.
• 2.  In five patients studied intensively, no symptoms could be ascribed to the Isospora infection, although in some of these the cysts were present in large numbers. The stools were usually negative to the guaiac test and there was evidence that eosinophilia was associated with the usually concomitant ancylostomiasis rather than with the isospora.
• 3.  The infection seemed to be self-limited, although we have observed it to persist for as long as 38 days despite therapy.
• 4.  There is not a dramatic response to treatment with tetrachlorethylene carbarsone, or quinine, and infection can probably take place and continue during atabrine prophylaxis.
• 5.  At a temperature of 27–31°C. mature sporocysts were observed to develop from unsegmented oocysts within 48 hours.
• 6.  Unsegmented oocysts were demonstrated in the upper jejunum in material obtained by Miller-Abbott tube, but no intracellular forms were observed.
• 7.  Long persistence of large numbers, and the fact that the oocysts are usually passed in an unsegmented stage, suggest that Isospora hominis is a parasite rather than merely a passenger through the gastro-intestinal tract.

An autopsy protocol of a native East Indian dying with Kala-Azar in America is described. The hazard inherent with splenic puncture is illustrated. Sternal puncture makes the former procedure unnecessary. Ordinary hematoxylin-eosin stain on formalin fixed tissue permits illustration of the Leishman-Donovan bodies. A “clasmatocyte tissue” response is the underlying pathologic response to the parasite even though parasites cannot be readily demonstrated in the cell. In addition to splenomegaly and hepatomegaly, bronchopneumonia, ulceration of the bowel and brain tissue changes were found.

A new reaction for the diagnosis of Kala-azar is described and its results are presented and compared with those of the classic formic aldehyde reaction of Napier.

Against E. histolytica infection in kittens Diodoquin, Vioform, Chiniofon, and Carbarsone were variably efficient using dosages comparable to those recommended for human infections. Emetine was totally ineffective under the same conditions. One kitten that relapsed repeatedly was discussed.

Atabrine is fungicidal in vitro at concentrations of 25 to 50 mgm. per cent and fungistatic at 3 to 25 mgm. per cent for C. neoformans. Toxic reactions are obtained with much lower plasma or tissue concentrations. Atabrine is, therefore, of little therapeutic value in cryptococcus infections.

A patient at this hospital, who was a veteran of 3 years' service in the South West Pacific, proved to have ova of Strongyloides in the stool. He was admitted to the hospital on March 12, 1947 with pain low in the right side of the chest, fever, and chills. Since discharge from the service in October 1945 he had suffered from frequent episodes of chills, fever, and malaise which he assumed to be malaria and treated with atabrine. In the hospital a diagnosis of amebic hepatitis was made. Treatment with emetine, followed by diodoquin, resulted in clinical and parasitological cure of the amebic infection. It is felt that the patient exhibited no symptoms attributable to the Strongyloides infection which was found incidental to his principal complaint. While there was an initial leucocyte count of 14,000 per cu. mm., which decreased to normal limits after treatment of the amebiasis, the eosinophile count did not exceed 3 per cent.

In a field study in South Carolina, Anopheles quadrimaculatus mosquitoes were applied to native cases of malaria in Negroes to determine the infectivity of such malaria cases.

Of 142 feedings upon Plasmodium falciparum patients, 21 showed infections. Of 12,606 mosquitoes dissected, 2.5 per cent were infected. These infections developed normally in the mosquito and in one out of two trials transmission was successful.

The majority of the mosquito infections occurred during the months of October through January. Mosquitoes kept at outside temperatures during October and November became infected.

One patient remained infective to mosquitoes over an 8-month period.

Of the 25 patients showing gametocytes, 64 per cent infected mosquitoes. The gametocyte densities resulting in infections were relatively low, none being over 90 per cmm. Thirteen of the infections resulted when the gametocytes were fewer than 10 per cmm.

Patients with asymptomatic parasitemias infected mosquitoes at about the same rate as did those who were symptomatic. As the asymptomatic group is considerably larger than the other, it is concluded that the former is mainly responsible for the transmission of malaria.

There were 14 feedings upon P. malariae. Four cases showed gametocytes of a low density at feeding and three lots of mosquitoes were infected. Of 586 mosquitoes dissected, 1.7 per cent were infected.

Of nine feedings upon P. vivax, none became infected nor were gametocytes present.

It is concluded that the patient with an asymptomatic parasitemia, usually with a relatively low gametocyte density, is the important factor in the transmission and maintenance of P. falciparum and P. malariae malaria in the area studied.

Murine typhus is reported for the first time on the Isthmus of Panama.

The epidemiological study of the cases diagnosed in the present outbreak of murine typhus showed that the focal point of the infection was the storeroom of one of the patients where were found dead rats shortly before the first human case had been diagnosed.

The study of the clinical form of the disease as observed in this outbreak of murine typhus showed that it reproduced, in every aspect, the clinical findings reported in well known text-books.

All adult anopheline resting places in a sixteen square mile area were sprayed with a five per cent emulsion of DDT in July and August of 1946 for the purpose of evaluating the effect on the gross anopheline populations.

The subsequent reduction in anophelines seems to warrant further consideration of this means of malaria control. Following treatment, only one anopheline could be found within the sprayed shelters. Larval populations, by comparison with untreated areas, were reduced 89.1 per cent. Other areas under study during the period of the experiment showed no tendency towards a concomitant natural reduction in anopheline populations.

The 43rd annual meeting of the American Society of Tropical Medicine was held in conjunction with the 30th annual meeting of the National Malaria Society and the 14th annual meeting of the American Academy of Tropical Medicine December 2, 3 and 4, 1947. The headquarters for the joint meeting was the Atlanta Biltmore Hotel, Atlanta, Georgia.

Registration opened at 2:00 p.m. on Monday December 1, 1947. Hospitality sessions were held from 5:00 to 7:00 p.m. on Monday December 1, Tuesday December 2 and Wednesday December 3. Scientific sessions of the Society were held from 2:00 to 5:00 p.m. on Tuesday December 2nd; at which time the Bailey K. Ashford Award was presented by Dr. R. A. Lambert to Dr. Jose Oliver Gonzalez. A Session was held from 2:00 to 5:00 p.m. on Wednesday December 3, at which time a symposium on the virus diseases was presented by invited contributors upon the invitation of the American Society of Tropical Medicine.

The main objective of the author of this compact though comprehensive and richly informative text-book on leprosy is to furnish general practitioners as well as specialists in the tropics, a practical guide on all phases of the subject of leprosy. A glance at the contents impresses one with the scope of the book and makes one wonder how the author ever managed to contract and condense the subject matter into this comparatively thin volume of 283 pages.

The author has succeeded very well in his purpose of presenting a practical viewpoint on some aspects of his subject. On other aspects, specifically chapters IV and VIII, covering the pathology, atypical lesions, and the development of lesions, a highly theoretical approach is, it would seem, beyond the scope of the average physician. On the other hand, these subjects are rather controversial elements among specialists. Here the practical approach has fallen down.

This revised edition has been enlarged to include the newer work in nutrition. It comprises twenty nine chapters and twenty one appendices. The initial chapters are devoted to the physiology and chemistry of the basic food elements. The ensuing five chapters deal with the vitamins in relation to diet and human nutrition. Following a good historical review and general statement the individual vitamins are treated separately under the headings: chemistry, storage in the body, deficiency in animals and man, unitage, human requirements, and the effects of storage and cooking. Each section is closed with a list of food sources for the particular vitamin giving the unit content per one hundred grams and per ounce of the source.

Succeeding chapters deal with foods of vegetable origin, foods of animal origin, diets, and public health activities in relation to nutrition including techniques of diet surveys.

In reviewing this book one should be guided by the aim of the contributors in the production of the work. As stated in the Preface “this book does not claim to be more than a series of miscellaneous memoranda arranged in alphabetical order” and “our present aim has been to give medical officers something that can be more easily carried around than a textbook and yet offer in concise form the essential of the more important diseases of the tropics. This volume is intended as a companion, not as a rival, to the standard works.”

Viewed from this stand-point, the volume well fulfils its mission and can be recommended to medical officers as a safe guide in the study and treatment of the diseases of tropical and subtropical regions. The names of the contributors are not given but the discussions of the various diseases are uniform in excellence with the exception of one or two subjects mentioned below.

If the first edition of Buxton's “The Louse” received acclaim as a uniquely thorough work in medical entomology, the second edition must leave its reviewers at a loss for adequately descriptive priase. Here we find the author no less enthusiastic about his subject, and despite the monotony that one would suspect to be attendant upon the lives of lice, one follows the newly-gathered information with increasing fascination.

It would appear that World War II did nothing to halt British investigators in their researches in the biology of lice. Whereas it might seem that during such emergencies one would more wisely concentrate on preventive or control measures, it is clear that new information on the sensory organs in the antennae of lice was of value in enabling the investigators to appraise the mechanisms by which some of teh new insecticides exerted their effects.

Note: Books received for editorial consideration will be intermittently listed. This acknowledgment must be regarded as an adequate expression of appreciation for the courtesy of the author or publisher. Selections will be made for review in the interest of our readers.

George E. Burch and Paul Reaser. A Primer of Cardiology. 272 pp. Frntspc. and 203 illus. Lea & Febiger, Philadelphia, 1947.

Emmanuel Goldberger. Unipolar Lead Electrocardiography. 182 pp., 88 illus. Lea & Febiger, Philadelphia, 1947.

Philip Lewin. The Foot and Ankle: Their Injuries, Diseases, Deformities and Disabilities. Line drawings by Harold Laufman. Third Ed. Rev. 847 pp., 389 llus. Lea & Febiger, Philadelphia, 1947.

William Lincoln Ballenger, Howard Charles Ballenger assisted by John Jacob Ballenger. Diseases of the Nose, Throat and Ear. Ninth Ed. Rev. 993 pp., 16 plates and 597 illus. Lea & Febiger, Philadelphia, 1947.

Jose Lima Pedreira de Freitas. Contribuçäo para o estudo do diagnostico da molestia de Chagas por processos de laboratório.

A committe has recently been established in Paris to celebrate the scientific jubilee of Professor E. Brumpt, who after more than forty-five years of teaching and scientific research in parasitology has justly acquired a worldwide fame. It appears that to perpetuate the memory of this master, the best means will be to create a foundation, the income of which will be regularly utilized in the form of a prize. Naturally the frequency and amount of the award will depend on the sum which is accumulated. Contributions should be sent to the Secretary General of the Committee, Professor Lavier, Faculté de Medecine de Paris, 12, Avenue de l'Observatoire, Paris VI, as the faculty of medicine has been made responsible for the award of the prize. The prize, to be called Emile Brumpt will be awarded to the authors of the most important works on parasitology or tropical pathology, either human or veterinary, without distinction of nationality.