The American Journal of Tropical Medicine and Hygiene - Volume 10, Issue 1, 1961

For semi-immune Africans reared in districts of malarial holoendemicity in East Africa, the following single doses of chloroquine phosphate (recorded as base) are effective in the treatment of malaria caused by any species of parasite and appear to achieve radical cure of subtertian malaria: age 0 to 1 year, 19 mg; 1 to 2 years, 37 mg; 3 to 5 years, 75 mg; and 6 years and older, 120 mg. For suppression, the respective dosages are 19 mg, 37 mg, 75 mg, and 75 mg.

The doses used for treatment clear parasitemia, fever and symptoms attributable to malaria as quickly as do larger doses and stimulate less vomiting. They should precede courses of suppressive treatment.

The first of two patients with Plasmodium falciparum infections which failed to respond to chloroquine therapy administered in Colombia, South America, received three further courses of 1.5 g of chloroquine and experienced clinical and parasitic relapses 12 and 8 days, respectively, after the first two courses. Upon the completion of the third course the drug was continued for 14 more days at a dosage of 0.3 g daily. Blood smears remained positive during this period. A 3-day course of quinine sulphate (90 grains) produced negative blood smears, but a parasitic relapse occurred after 17 days. An apparent cure was effected by a 10-day course of quinine.

The second patient experienced a clinical and parasitic relapse approximately 20 days after a first course of chloroquine; and after a second course (2.1 g) followed by a 14-day course of primaquine, a recurrence of parasitemia accompanied by minor symptoms approximately 21 days after the completion of the chloroquine therapy was observed. A 10-day course of quinine produced an apparent cure.

It has been found that the addition of red cells to the CLG and S-F media inhibits the multiplication of the K-9 strain of Entamoeba histolytica. After about 5 days the amebae recover from the inhibitory action of the erythrocytes and grow in a normal fashion when optimum amounts of red cells and amebae are used. During the inhibitory period there is actual destruction of many of the trophozoites originally seeded, suggesting the presence of a toxic material in red cells. E. histolytica strains 103 and 200 showed resistance to the effect of red cells. It was observed that these strains readily hemolyze red cells. This, and their ability to migrate up the sides of the culture tubes, may explain their resistance to the red cells' effects which were observed with the K-9 strain.

Upon concentration, hemolyzed red cells and stroma-free supernatant were found to be inhibitory to the K-9 strain of Entamoeba histolytica. Dialysis of the concentrated supernatant revealed that the toxicity probably resided in a non-diffusible, high molecular weight substance. Hemoglobin was found to be highly inhibitory to the K-9, 103, and 200 strains at levels of 8 mg/ml; and it is likely that this substance accounts for the toxicity of RBC. Hemin in solution was found to be highly toxic to these three strains at levels of 75 µg/ml of culture. It is suggested that the heme moiety is responsible for the toxicity of both hemoglobin and whole RBC to the ameba. Low concentrations of hemoglobin and hemin showed a stimulatory effect on the multiplication of E. histolytica. Hematoporphyrin HCl showed only stimulatory effects. All evidence indicates that the effects of hemoglobin, hemin and hematoporphyrin on strains K-9, 103 and 200 are identical. This would seem to suggest that the resistance of strains 103 and 200 to the effects of whole RBC as noted in another publication was the result of the ability of these strains to cause lysis of the erythrocytes. Such lysis results in considerable dilution of the soluble materials of the RBC.

Comparison of the incidence and degree of intestinal parasitism in Durban African males indicates that the incidence of protozoal infection in a control group is similar to that reported elsewhere but there is a significantly lower incidence in patients with bacillary dysentery and an even lower incidence in those with amebic dysentery. There is a high incidence of helminth infection in all three groups but those with amebic dysentery have the highest incidence of Trichuris and Ascaris infections. Heavy loads of Trichuris, Ascaris and hookworm are rare although the two former are slightly commoner in amebic dysentery.

It is concluded that, although no positive evidence exists, there is a possibility that the high incidence of Trichuris may predispose to invasion by Entamoeba histolytica although the association between the amebae and Trichuris and Ascaris may merely be due to common epidemiological factors of poor hygiene and lack of sanitation.

One hundred fifty baboons from Kenya, British East Africa, had a high prevalence of infection with Schistosoma mansoni, indicating that the baboon may be an important reservoir host for this parasite.

The distribution of S. mansoni eggs in the tissues of the baboons is similar to that found in mild human infections and the pathogenesis of lesions in the colon and liver is also similar. Hepatic cirrhosis, however, was not observed in the baboon.

These studies, which point out many similarities between human and baboon infections, confirm Newsome's suggestion that the baboon is an excellent experimental animal for research in schistosomiasis. The baboon is superior in many ways to the common laboratory animals and also to other primates.

Measures to control human schistosomiasis should take into account the possibility that the baboon is an important reservoir host. Other primates should be examined in areas where human schistosomiasis exists to determine their role in host-parasite relationships.

Blood NH3-N, urea, glutamine and keto acids were measured in 29 patients with hepatic fibrosis associated with advanced schistosomiasis and malnutrition. Routine hepatic function tests (BSP clearance, thymol turbidity and bilirubin index) were elevated in all cases. Despite evidence of liver failure and pathologic involvement, none of the biochemical parameters measured were significantly elevated relative to the controls.

Chest x-ray detected a lesion in the lung of a Detroit resident with cardiac symptoms. In the resected cyst-like lesion a filarial worm was found dead in a necrotic pulmonary artery. It was identified as Dirofilaria, apparently a female, and was thought to have been acquired in South Carolina.

Investigations were made on the concentrations of aqueous solutions of iodine required to kill the infective stages of Necator americanus, Ancylostoma caninum, Strongyloides stercoralis, Ascaris lumbricoides, Toxocara canis and Trichuris muris. Solutions containing 70 ppm free iodine, prepared by dissolving tablets of Globaline® or Heliogen® in distilled water, killed the infective free larvae of hookworms and Strongyloides within 5 minutes or less at temperatures ranging from 15°C to 30°C. To kill infective larvae in the eggs of Ascaris, Toxocara and Trichuris under similar conditions concentrations of 100, 120, and 250 ppm, respectively, were required. Killing action was more rapid at the low than at the high temperatures. Solutions at concentrations up to 500 ppm did not adversely affect the flavor or appearance of any of the common types of leafy or rooty vegetables. Solutions of sufficient strength to kill the eggs and larvae of these worms, and at the same time to destroy the common enteric microorganisms, are easily prepared and therefore appear to be suitable for the disinfection of vegetables to be consumed in the fresh state.

Techniques were developed and tested for sampling unbaited domestic flies both outdoors and indoors to determine the natural occurrence of Shigella organisms. A total of 65,273 flies collected outdoors yielded 69 isolations of Shigella and 5,664 flies collected indoors yielded 12 isolations of Shigella.

Comparison of rate of isolations from flies with rate of recovery by the rectal swab technique indicated that the indices from flies generally paralleled the indices from humans, but that they were too low to provide a sufficiently sensitive and effective means of measuring Shigella prevalence. Sampling of flies might be used to advantage in certain situations where high fly populations or high Shigella prevalence occurs.

Eleven different types of Shigella were isolated from flies and the same 11 types were isolated from human sources. Associations in time, location, and Shigella type were noted.

Musca domestica was the most abundant species of fly collected and most common in Shigella-positive fly pools; Ophyra spp. were second in abundance. Major fly attractants were found to be human excrement, scattered garbage, and waste wash water.

Minced chick-embryo tissue, bathed in a lactalbumin growth medium and planted on a modified Zinsser's agar medium, supported excellent growth of Coxiella burnetii. Titration of the viable rickettsial content of samples taken during the growth curve indicated proliferation of rickettsiae. Spectrophotometric measurements of purified suspensions of rickettsiae isolated from cultures incubated for varying periods also showed that growth had occurred. Other ancillary observations indicated that the final yield in mouse- or chick-embryo cultures was comparable to that produced in yolk-sac cultures.

Five viruses of the arthropod-borne group C, designated by Causey as Apeu, Caraparu, Marituba, Murutucu and Oriboca, were propagated in stable human cell lines. Each virus caused a sharp and reproducible CPE when cells were grown in a growth-promoting medium containing tryptose phosphate broth and maintained during the period of viral synthesis in Eagle's medium supplemented with calf serum at a pH of 7.2 ± 0.2.

Results of parallel HI and neutralization tests on immune mouse and rabbit sera, using a HeLa cell-virus system and a constant virus-varying serum technique for the determination of neutralizing antibodies, showed no discrepancies between the two in vitro methods when homologous systems were tested.

The experimental evidence indicates that the tissue culture neutralization test may be substituted for the mouse neutralization test or the HI test in immunological studies of the arthropod-borne group C viruses.

ECHO-13 virus was first obtained from rectal and throat swabs collected in the Philippine Islands in 1953. Isolations were made from 10 apparently healthy children. Serologic evidence of infection was obtained in 11 other individuals.

ECHO-13 virus, although not neutralized at a 1:25 dilution by a single pool of American gamma globulin, has been isolated recently in two cities of the United States. Since it is neutralized by Japanese gamma globulin, it is probably also present in Japan. Apparently both complement-fixing and neutralizing antibodies do not remain elevated for long periods of time after infection.1,3 This limits the usefulness of serologic surveys in quantitative studies of the geographic distribution of ECHO-13 virus and the significance of absence of detectable antibody in gamma globulin as a qualitative test for absence of the virus in a population.

Two patients hospitalized with CNS disease, one of whom was paralyzed, showed a significant serologic response only to type 13 ECHO virus during the course of their illnesses. CNS pathology was observed in two inoculated monkeys. These data, which may be interpreted as presumptive evidence that ECHO-13 may produce CNS disease in man, are too limited and incomplete to permit any definite conclusions to be drawn at this time; but the increasing evidence that a number of the ECHO viruses and the enteroviruses as a group do possess the potential of producing CNS disease3, 4, 8-18 lends more weight to the probability that an occasional human CNS illness is attributable to ECHO-13 virus. Isolations and serological rises from a few children during outbreaks of diarrhea in Pittsburgh also do not lend themselves to interpretation since several other viral agents were isolated from the feces of other patients. This report therefore can serve only to point suspicion to ECHO-13 virus as a pathogenic agent. It shows what may be expected in terms of virus isolation and serological responses during infection, spread within a family, some of the limitations of serologic survey and summarizes what is known regarding geographic and seasonal distribution.

The clinical picture and laboratory findings in the case of a purely systemic infection with EEE virus are described. Another case is described in which the relationship between the EEE infection and the clinical picture is problematical.

Virus was isolated from the blood of the first case, and serologic studies were carried out with paired sera from that case and a single specimen from the second case. Specific serologic diagnosis was possible by means of either neutralization or HI tests, but the CF test was found to be too insensitive to detect significant antibody levels in these sera.

Previous infection with a related virus was recognized to have occurred in one case and to have influenced the pattern of HI response. The possible protective effect of this previous infection against serious consequences of the current EEE infection is mentioned.

An outbreak of influenza occurring on the Isthmus of Panama in 1959 is described. Type B influenza viruses, antigenically similar to B/GL/54, were isolated and serological evidence of infection was demonstrated in a high proportion of persons tested. The outbreak began shortly after the opening of schools and the onset of the wet season and it is possible that these factors contributed to the spread of the virus. Tissue culture techniques were found to be practical for the study of influenza in this outbreak.

The protection afforded by the new polyvalent antivenin preparation (Wyeth), tetanus antitoxin (Wyeth), and polyvalent gas gangrene antitoxin (Lederle) against death in the mouse and local necrosis in the rabbit produced by the venom of the Eastern Diamondback rattlesnake (Crotalus adamanteus) was investigated. The microbiological populations of the mouth and venom of several poisonous and non-poisonous North and South American reptiles were sampled and specifically cultured for spore-forming anaerobes.

While the new polyvalent antivenin gave marked protection against death and local necrosis produced by rattlesnake venom, the polyvalent gas gangrene antitoxin and tetanus antitoxin offered no protection against either. Aerobic growth appeared to a greater extent in the oropharynx than in the venom. Anaerobic growth was not obtained in either case.

These results, especially in regard to the relatively sterile nature of the snake venom, suggest that addition to the foreign protein burden in the treatment of snake bite by the administration of large quantities, i.e., therapeutic dose, of tetanus or gas gangrene antitoxin is unnecessary and indeed contraindicated unless laboratory evidence of clostridial contamination exists. This does not imply the prompt prophylactic use of antitetanus serum or tetanus toxoid should be abandoned.

Kuru is apparently determined by a dominant gene with incomplete expressivity producing fatal disease in childhood in homozygotes of both sexes and in adult life in heterozygous female carriers, but not usually penetrant in male carriers. This simplest genetic hypothesis which will account for the unprecedented situation which kuru presents in New Guinea has not yet been refuted by studies of genealogies in the kuru region or by other human ecological investigations. No outsiders have yet developed kuru on residence in the region. Carriers of the kuru gene must possess a distinct genetic advantage in the region, for unless such carriers were genetically more fit than non-carriers loss of the gene in nonreproducing homozygotes would have prevented its attaining its present high frequency in the society.

The restricted marriage pattern with island-like isolation of small marriage pools would have led to extremely slow diffusion of a new mutant kuru gene throughout the population unless the mutation was present originally in the progenitors of an Urstamm from which at least the central subgroups of the current kuru afflicted population were derived before the near-total marriage isolation of the various groups of hamlets developed.

Environmental variables and the possibilities of infectious, toxic or deficiency factors operating alone or with genetic dependence have not yet been fully excluded. However, the principal investigative approach is the biochemical investigation of intermediary metabolism of kuru patients and normal natives of the kuru region, some destined to die of kuru. Such studies should advance our understanding of kuru etiology and pathogenesis whether or not it is a solely genetically mediated disease.

The problems and methods of epidemiological work in the region are discussed and the ethnic setting of kuru further elaborated. A summary of the age and sex distribution of 804 studied kuru cases is given.

Electrophoresis, on paper, in starch-gels and by the moving boundary method, was carried out on the sera of 85 patients suffering from kuru, 363 other Melanesian natives and 50 other members of tropical populations. The results on sera from kuru patients were compared with those obtained for control groups of natives from kuru-affected and kuru-free areas in the Eastern Highlands and from other parts of New Guinea. Extreme variation in serum protein patterns of different ethnocultural groups indicated the necessity for further work on elucidating the environmental and genetic (racial) variables which underlie these differences.

Sera of kuru patients averaged significantly higher β globulin and total protein and lower albumin than did sera of normal Fore natives. The γ globulin levels were generally lower in both kuru victims and normal Fores than in others in Melanesia. In the terminal stages of the disease there was a tendency towards lowering of the β globulin levels which had become elevated early in the disease. Some terminal patients showed high γ globulin levels.

The electrophoretic pattern of normal Fore natives was distinguished by the appearance of a fairly well separated, elevated γ1 globulin. This was rarely found in other Melanesian groups, even those closely neighboring the Fore.

Starch-gel electrophoresis in kuru patients fell into 6 patterns which are illustrated and discussed. Normal Melanesians, however, showed starch-gel patterns virtually indistinguishable from those of normal Europeans and not the additional five “abnormal” patterns seen in kuru.

Haptoglobin typing was carried out on 80 starch-gel electrophoresis patterns of serum specimens from kuru patients. The Hp2 gene frequency of 0.44 was only slightly higher than that among 62 normal Fore natives (0.36). Transferrin and ceruloplasmin and further haptoglobin studies are in progress.

Electrophoresis of hemoglobin was carried out on 51 kuru and 62 normal subjects. In no case could any abnormal components be detected.

Chromatographic analyses of serum protein of normal Fore and of kuru sera are reported.

Control of Communicable Diseases in Man, by the American Public Health Association. 9th edition, 234 pages. New York, American Public Health Association, 1960. $1.00.

Gesundheitstaschenbuch für die Warmen Länder, by Prof. Dr. J. Grober, Dr. H. Horn and Dr. F. Oberdoerster. 1st edition, 332 pages, illustrated. Berlin, Veb Verlag Volk und Gesundheit, 1960. DM 18.80.

Human Toxoplasmosis. Proceedings of the Conference on Clinical Aspects and Diagnostic Problems of Toxoplasmosis in Paediatrics at The VIII International Congress of Paediatrics, Copenhagen, 1956, Revised and Edited 1959, J. Chr. Siim, M.D., Director, The Toxoplasmosis Department, State Serum Institute, Copenhagen, Denmark, Editor. 220 pages, illustrated. Baltimore, The Williams & Wilkins Co., 1960. $12.50.

Handbook of Microbiology, by Morris B. Jacobs, Ph.D., Associate Professor of Occupational Medicine, School of Public Health and Administrative Medicine, Columbia University, and Maurice J. Gerstein, B.S., M.S., Department of Biology, William H. Maxwell Vocational High School, Brooklyn, New York. 322 + x pages. Princeton, New Jersey, D. Van Nostrand Company, Inc., 1960. $8.50.

In this period of radical change in the medical curriculum, the emphasis on human anatomy and the time allowed for its study in the preclinical years have been reduced to such a degree that the large standard systematic treatises on anatomy no longer can be used effectively as required texts. Several shorter texts of anatomy have appeared in recent years with the avowed purpose of filling the needs of the current, briefer courses in the subject. The present volume is the latest of these works to be published, but by no means the briefest.

As stated in the authors' preface, “… the MAJOR AIMS of the present work are (1) to provide a textbook that is sufficiently brief for the undergraduate medical and dental student during the present shortened course in human anatomy, (2) to provide information on living anatomy and to stress the importance of the relationship between structure and function, and (3), particularly by the citation of relevant reference to meet the needs of the more advanced student and postgraduate worker.”