John F. Kessel

Occurrence of Infectious Myxomatosis in Southern California.

During the summer of 1930 twelve reports from rabbitries in the regions of Santa Barbara, Ventura, and San Diego were made of a disease presenting the following symptoms. The rabbits were acutely ill and exhibited, as a rule, an oedematous condition in the regions of the nose and lips, the external genitalia and a conjunctivitis. A purulent discharge occurred from the eyes and nose. The ears also became greatly thickened and drooped as a rule. Animals that lived longer than a week or 10 days after the appearance of symptoms often developed nodules around the nose, eyes, or on the ears. Upon autopsy, the lymph nodes and spleen were found usually to be enlarged. The nodules and oedematous areas were found to contain a gelatinous material. The disease was transmitted with facility by rubbing the discharge from the eyes and nose, or the extract from tissues, into the skin, or by injecting the same. Comparison of the above findings with reports of Hobbs, 1 Rivers 2 and others who have studied infectious myxomatosis produced by the South American virus shows striking similarities, the chief difference being that the disease encountered in California is not transmitted with as great ease by contact among experimental animals as is the South American disease. First attempts to transmit the disease by filtrates passed through medium Berkefeld filters were negative, but later attempts with coarser filters were positive. Dr. Rivers has exchanged histopathological slides and virus and after studying our slides states: “From your sections there is good reason to suppose that the disease you are working with is the so-called infectious myxomatosis of rabbits.” Certain comparative experiments of the California strain with the South American strain provided by Dr. Rivers are recorded in Table I.

The experimental transfer of certain intestinal protozoa from man to monkeys.

The species identity of intestinal amóbae harbored by monkeys with the intestinal amóbae of man presents a difference of opinion among protozoologists, one group believing them to be identical with the common species found in man, and another group believing them to present distinct species differences. It seems that this question can best be settled by investigation from three main angles, first, by a study of the morphological characteristics, second, by experimental transfer of the protozoa from one species of host to another closely related host, and third, by a comparative study of the various forms under artificial culture conditions. This paper is a preliminary report of the experimental transfer of certain of the intestinal protozoa from man to monkeys. The routine examination of the faeces of seven monkeys from Southern China, belonging to the genus, Pithecus, showed the presence of protozoa indistinguishable morphologically from E. dysenteriae, Endolimax nana, Endamoeba coli, Councilmania lafleuri, Iodamoeba bütschlii, and Chilomastix mesnili. To the knowledge of the writer this is the first report of the presence of Councilmania and of Chilomastix in monkeys. All seven of the monkeys harbored amóbae morphologically indistinguishable from E. dysenteriae, and consequently no feeding experiments with E. dysenteriae from man could be performed. It should be noted, however, that successful transmission of E. dysenteriae from man to monkeys has been reported by Franchini 1 and Ujihara. 2 Certain of the monkeys of the present series were negative for one or more of the other protozoa in question, and feeding experiments were performed as indicated in the table.

Emergency Sterilization of Drinking Water with Heteropolar Cationic Antiseptics

Although there are many practical uses for antiseptics which are effective against cysts of Endamoeba histolytica, one of the most important and difficult is the emergency sterilization of drinking water under military combat conditions. Various halogen preparations have not been entirely satisfactory because they tend to be inactivated by organic nitrogenous material and by alkalinity. Since natural waters encountered in the field may sometimes contain very high concentrations of organic nitrogenous material or may be alkaline, and since military emergency conditions in the field require uniform dosage, it is necessary to use the halogens in high initial concentrations under all conditions so that they may prove effective even under the worst conditions. These high concentrations of the halogens are distasteful and may not be entirely without toxicity. The antiseptic activity of certain heteropolar cationic compounds, or synthetic, cationic detergents, was described in 1935 by Domagk (1) and Katz and Lipsitz (2).

Observations on the Virus Recovered from 1934–35 Poliomyelitis Epidemic in Los Angeles:

Attempts were made to recover virus from 19 autopsy cases during the recent epidemic of poliomyelitis in Los Angeles, Seven of these were successful in 1934, four in 1935, as judged by the following results upon inoculation of the emulsified human cord into Macacus rhesus monkeys: (1) Occurrence of pyrexia, roughness of coat, hyperirritability and tremor with subsequent development of paralysis. (2) Transmission of the virus in successive animal passage of selected strains. (3) The histopathology was characteristic in that oedema and hemorrhage, perivascular and diffuse infiltration, and necrosis of nerve cells were apparent. Since the 1934–35 epidemic of poliomyelitis in Southern California has been described as being especially mild in its clinical manifestations with a corresponding low mortality rate and a low residual paralysis rate, it seemed desirable to compare the viruses recovered from this epidemic with other strains of poliomyelitis virus. To date these Los Angeles strains and the “M.V.” strain from the Rockefeller Institute have been compared with reference to symptomatology and pathology produced and comparative immunologic studies have been made in detail with one Californian strain, the “McK” recovered from an autopsy in 1935. Observations include (a) symptomatology as shown by incubation period, temperature changes, type and degree of paralysis, residual paralysis rate and death rate; (b) histopathology produced in the brain and cord, (c) immunity produced and (d) neutralizing substance developed. Symptomatology. Both pyrexia and paralysis appeared in monkeys on an average of 2 days later with the “McK” strain than with the “M.V.” strain. In comparing the paralysis and recovery rate in monkeys infected with these 2 strains, it was found that monkeys inoculated with the “M.V.” strain showed a partial paralysis rate of 3.7%, a complete paralysis rate of 96.3%, with 4.7% of the total number recovering, while the monkeys inoculated with the “McK” strain showed a partial paralysis rate of 78%, a complete paralysis rate of 22%, with 84% recovering.

Attempts to Transmit Poliomyelitis Virus to Rodents.

Although a variety of animals have in the past been injected with the virus of poliomyelitis with the intent to infect them, only a few species of primates have without question been successfully infected. Most experimental work reported has been done either with Macacus mulatta, (rhesus), M. irus (cynomolgus) or chimpanzees. These animals are expensive and as a consequence much important experimental work has been neglected because of the prohibitive cost. Recently, renewed search for a cheaper, suitable, experimental animal was undertaken by several investigators, among them, Armstrong of the National Institute of Health and ourselves. For the most part rodents have been used in these experiments and our results with 25 strains of virus have been negative with all species tested with the exception of the Antelope ground squirrel which occasionally developed questionable neurologic symptoms but which we cannot state definitely were caused by poliomyelitis virus. Armstrong, 1 on the other hand, reports successful infection of the cotton rat, Sigmodon hispidus hispidus, with a strain of virus from Lansing, Michigan. Table I gives a summary of recent attempts on our part to infect Sigmodons as well as several other species of rodents, both with Los Angeles strains of poliomyelitis virus and with the Armstrong virus. It will be seen from the table that: (1) Rodents of the genera listed have been refractory to inoculation with a number of strains of poliomyelitis virus collected in Los Angeles. (2) These same animals are subsequently susceptible to inoculation with the Armstrong virus. It is known that rodents occasionally harbor natural infectious neurotropic viruses, e.g., lymphocytic choriomeningitis has been isolated from white mice, and Theiler 2 , 3 and Olitsky 4 , 5 report natural infections in mice of an encephalomyelitis virus, which produces typical paralytic symptoms.

The Effect of an Exclusive Milk Diet on Intestinal Amoebae.

Conclusions During the feeding of an exclusive raw milk diet there is almost always a reduction in the number of intestinal amcebae and in certain instances the intestinal tract has been cleared of E. dysenteriue and other forms arid has remained clear for a period of three months following the conclusion of the experiment. This diet, however, cannot be recommended as a therapeutic measure since the results are so uncertain, the diet inadequate and offensive to some and since the possible dangers of infection in feeding raw milk are considerable.

Some similarities between the dystentery amoeba of the monkey and of man.

The dysentery amoeba of the monkey and that of man are so similar in structure that some regard them as probably being the same species, though other investigators have given them different species names. In an attempt to procure experimental evidence on this question two monkeys found to be amoeba-free were fed cysts of E. dysenteriae of man. Examination of the feces during a period of three months and of histological sections following autopsy showed the presence of cysts and trophozoites of E. dysenteriae, morphologically and racially indistinguishable from the amoeba fed, thus indicating that the dysentery amoeba of man may be experimentally established in the monkey. Subsequently, two cats, six months and seven months of age respectively, found negative for protozoa by preliminary examination, were given rectal injections of monkey feces containing cysts of the dysentery-like amoebae of a naturally infected monkey, using the technique of Boeck and Drbohlav. 1 Two months later, autopsy of the cats showed the amoebic infection to be well established in the upper colon and cecum, where there was excessive mucous, pronounced hyperemia, and a distinct thickening of the gut wall. Trophozoites of amoebae, many of which contained red blood corpuscles, were found in great numbers in these regions and histological sections showed necrosis of the mucosa and penetration of the amoeba into the tissue. Amoebae from the infected colon of the cats were planted into the L. E. S. medium of Boeck 1 and at the time of writing seventeen successful subcultures have been made on alternate days and the cultures show no signs of dying out.

Poliomyelitis Antibodies in Inhabitants of the Society Islands, French Oceania

Summary and Conclusions Early in 1951, an epidemic of poliomyelitis occurred in Tahiti during which Type 1 virus was recovered from feces of a paralytic case. Tests on 131 serum samples collected from inhabitants of Tahiti and others of the Society Islands, during and after the outbreak, yielded the following results: 1. A higher percentage of Type 3 than of Types 1 and 2 neutralizing antibodies was found in sera from persons living in the outer Society Islands. On the other hand, higher percentages of neutralizing antibodies against Type 1 and 2 viruses were present in sera of residents of Tahiti during and after paralytic attacks of poliomyelitis than in normal serums from the outer islands. 2. After the epidemic, complement-fixing antibodies for Type 2 virus were present in sera of individuals from the outer islands, and in even higher percentages in sera of post-paralytic patients in Tahiti. Since complement-fixing antibodies to Type 2 virus may indicate serologic response to the heterologous Type 1 virus, widespread dissemination of Type 1 virus probably occurred at this time. 3. These observations suggest that immunity to poliomyelitis in the Society Islands prior to the epidemic of 1951 was greater to Type 3 virus, and that the outbreak resulted from recent introduction of Type 1 virus, a new type for the area. It is possible that Type 2 virus was present coincidentally.

Manson's Tropical Diseases

This is the 14th edition of the first important text on Tropical Diseases which for almost six decades has been a classic in this field. When Sir Patrick Manson discontinued his editorial activities, Sir Philip Manson-Bahr assumed responsibility of subsequent revisions. Innumerable students and workers in the tropics cannot but express a debt of gratitude to “the father of Tropical Medicine” for having originated the text and to Sir Philip for having supervised the last eight editions. A wealth of pertinent information and detailed knowledge is contained in this volume and the reader is stimulated by the fact that the author often finds opportunity to express his own opinions following a review of the literature; e.g., on certain phases of filariasis in which subject he has been especially active. The volume is in reality two books in one, the text and the appendix.

The application of the eosin-eriterion for the viability of protozoan cysts to cysts of Hartmanella hyalina treated with chlorine-water.

Owing to the fact that no satisfactory method has been developed to induce the excystment and growth of the amebse parasitic in the human intestinal tract, no absolute criterion has been established to distinguish the viable from the non-viable cysts. The penetration of the cysts by analine dyes is regarded as an indication that the cysts are dead and the use of eosin as an indicator has been generally accepted. The ultimate fate of the cysts which fail to take the eosin stain has not been finally determined. It has been shown that cysts which undergo a plasmolysis may not stain red by the eosin, though they are considered to be incapable of development. The present investigation was undertaken in order to determine the percentage of free chlorine in water necessary to retard the development of cysts of Hartmanella hyalina and at the same time to determine the fate of the cysts which presented an apparently normal appearance. It is hoped that by comparing the resistance of the cysts of the human intestinal Protozoa with the resistance of the coprozoic ameba under consideration that information may be procured regarding the relative value of methods employed in disinfecting fruits and vegetables for table use and regarding the general resistance of Protozoan cysts. Cysts of Hartmanella hyalina were placed in water containing different percentages of free chlorine in solution. A ten minute interval was allowed before the cysts were transferred to a suitable culture medium which in this investigation was 10 per cent horse serum in Lockes solution diluted with 50 per cent distilled water. The cysts were counted at the time of their transfer to the culture medium and the reaction of a representative number of the cysts to Donaldsons iodine-eosin was noted.