Showing papers in "Public Health Reports in 1963"

Familial Aggregation of Lung Cancer among Hospital Patients.

Abstract: NUMEROUS clinical, statistical, or epidemiologic studies of lung cancer in man reported in recent decades have dealt almost exclusively with the exogenous, or environmental, factors associated with this disease. A number of investigators, however, have speculated that endogenous, or genetic, factors may be of etiological importance (1-8). These speculations can be summarized by four statements of somewhat different perspective and specificity: (a) lung cancer is more likely to develop in those who are genetically prone or susceptible to the disease; (b) development of lung cancer may be influenced by the sex-linked genetic mechanism or constitutional sex differences, particularly with respect to hormonal balance; (c) incidence of lung cancer may be related to the differential constitutional makeup of a population, as caused by the temporal, general improvement in longevity, with respect to disease resistance and susceptibility; and (d) both lung cancer and smoking habits may be determined by a common genotype. It is generally assumed that individuals of susceptible genotype are widely distributed in the population, and those susceptibles who are actually exposed to the carcinogenic agent are more likely to develop the disease than those who are not so exposed. Despite such theoretical interests, few empirical studies of human populations have been reported which indicate the possible importance of the genetic factor in lung cancer. Data indicating the presence of familial aggregation of lung cancer would provide the first-step clue for the existence of such a factor. We have attempted to demonstrate the presence of familial aggregation of lung cancer in two different, but related, studies; one conducted in Buffalo, N.Y., and the other in Baltimore, Md. (9). The major findings of the two studies were similar; however, some differences were noted in certain specific details. Since the method of selection and the characteristics of control subjects were different, and the smoking factor was considered only in the Baltimore study, the results of the two studies, should be analyzed separately and compared. The findings of the Buffalo study are presented here.

Influenza, pregnancy, and fetal outcome.

Abstract: T HE EFFECT of virus infections on the outcome of pregnancy has been of interest to investigators since Gregg (1) demonstrated a relationship between congenital cataract and German measles in the mothers. Following Gregg's observation in 1941, several investigators have attempted to associate virus infections with congenital abnormalities, prematurity, fetal deaths, or maternal deaths. Swann (2) in 1943 implicated maternal mumps as a cause of fetal anomalies. Others (3-15) have since reported on the influence of virus infections on both the fetus and the mother, with contradictory findings as to the effect of influenza infection. As a result of some of these investigations, pregnant women are generally considered to be a high-risk group with respect to influenza. Eickhoff and co-workers recommended that "immunologic protection through the routine use of influenza vaccine in such high-risk groups may be of great value in reducing the extent of influenza-associated excess mortality" (15). The importance of this recommendation emphasizes the need for critical evaluation and further studies. From August 1957, when the A2 strain of influenza virus first appeared in New York City, througlh June 1961, we were able to identify six periods of increased activity of the A2 influenza virus in New York City. We thus were offered an unusual opportunity to study the relationship between influenza and complications of pregnancy including fetal outcome in a large population during several outbreaks. This paper reports findings pertaining to maternal deaths, prematurity, fetal deaths, and congenital anomalies.

Bedbugs in relation to transmission of human diseases. Review of the literature.

Abstract: rTIHE possible role of bedbugs in transmission of human diseases has been the subject of many studies during the past 55 years (1). Most of these studies were made on either the cosmopolitan bedbug, Cimex lectularius Linnaeus, or on Cimex heimiptevus Fabricius (C. rotundatus Signeret), which is known as the tropical, subtropical, or Indian bedbug. A few studies on transmission of Chagas disease were concerned with other species, such as Cimex (Leptocimex) boueti Joyeux, a tropical bedbug of Africa and South America which normally infests bats; Oeeiacu,s (Cimex) hirundinis (Jenyns), the European barn swallow bug; and Haernatosiphon inodora (Duges), which infests poultry, the California condor, and the great horned owl. Bedbugs have been suspected in the transmission of 41 human diseases, the agents or causes of which coincide with 10 categories, as shown below.

Suicide risk among persons attempting suicide.

Abstract: T HE DISSIMILARITY between persons who attempt suicide and those who compl6te the act has been demonstrated with respect to many important personal and social characteristics (1,3). For example, men, older persons, and whites are overrepresented in completed suicide, while women, younger persons, and nonwhites are overrepresented in attempted suicide. Nevertheless, the most reasonable assumption about the two groups is that the poputlation of completed suicides is drawn from that of attempted suicides but, as suggested by Crocetti (4), not on a random basis. Two complementary hypotheses are involved: (a) persons who have previously attempted suicide are more likely to commit suicide, that is, are at greater risk, than persons who have not, and (b) among attempted suicides, the more closely individuals approximate those who commit suicide in personal and social charaleteristics, the greater the likelihood of their succeed'ing in killing themselves, that is, the greater their risk. The first hypothesis receives some suipport from data on histories of suicidal behavior (attempts, threats, or communication of intent) in studies of completed suicide (5-7); the second hypothesis cannot be tested by these studies because the pertinent data are not provided, but the studies do provide clues regarding the charalcteristics of individuals within a group of attempted suicides most likely to kill themselves in a suibsequent attempt. The studies have important limitations as far as their use in testing the two hypotheses is concerned: (a) it is unclear whether persons not classified as having made previous attempts in fact did not do so or merely represented those for Whom no inlformation was available, and (b) it is not always possilble to determine what percentage of the sample made previous attempts since attempts and threats are sometimes combined into one category. T'he present study avoids these limitations by following a sample of attempted suicides with respect to the number of deaths from suicide within a 1-year period. This makes it possible to compare the suicide risk of attempted suicides and of su!bgroups within the sample with analogous groups in the general population. For the purposes of this study, the general population has been considered a group that has not attempted suicide. Several studies of attempted suicide have presented data on subsequent mortali'ty from suijcides (8-10), but none used general population data as a baseline. Moreover, these studies overlook the concept of risk and tend to minimize the problem by stating that the number of suicide deaths represents a very small proportion of those making an attempt. Such interpretations confuse the issue of risk by equating a small percentage of deaths with little risk or significance.

Quantitative detection of staphylococcal enterotoxin b in food by gel-diffusion methods.

Abstract: RECOVERY of coagulase-positive StaphyloCOCCUs aureus from food implicated in a foodpoisoning outbreak is only circumstant.,ial evidence that the correct etiological agent has been found. Even the determination by animal studies that the strain isolated is capable of producing enterotoxin doeis not prove that it did so in the food. Positive proof depends on demonstration of the enterotoxin in the food itself. Such proof can be obtained by feeding the food to monkeys or human volunteers, but the results are subject to the variations in susceptibility known to occur among both test subjects. The purification (1) of Enterotoxin. B, S6 type ["E" type of Casman (2) ] and t,he determination that it was an antigenically act-ive protein (.3-5) opened t.he way to use of serologic methods for direct detection of enterotoxin in foods. Although Enterotoxin B occurs in food infrequently (2,6) compared with the frequency of Enterotoxin A, 196E type ["F" type of Casman (2)], it is a useful substitute for preliminary studies because it can be produced in a highly purified form. This report deals with the results obtained and the difficulties encountered in the use of the various gel-diffusion techniques for the, direct serologic detection and quantification of 'Enterotoxin B in foods.

Dental caries and periodontal diseases among Ethiopian civilians.

Abstract: THE Interdepartmental Committee on Nutrition for National Defense (1) conducted a nutiition surv-ey in Ethiopia during the fall of 1958. A team of American and Ethiopianl nutritionists, food technologists, biochemists, plhysicians, and a dentist visited widely withiin the country. Inl each area visited an attempt was made to assess certain physical characteristics in a selected sample of men, womeni, and clhildren. Blood and urine samples were taken for biochemical analysis. Data concerning food productioni and availability and dietary patter ns were also obtained. I)ental examinations, included as a part of the physical appraisals, were completed on 1,085 civilian males and females aged from 5 tlhrough 84 years. This sample included residents of 8 of ii geographic regions visited by the team (fig. 1), and it had representation from the major ethnic groups. The survey presented an opportunity to study oral diseases in a population for which little information has been available. All dental observations were made by the one dentist, usin.g a portable chair and standard dental mirrors and explorers, under natural light. Findings for dental caries, fluorosis, molar attrition, periodontal diseases, dental calcu1lus, and debris are discussed below.

Cardiovascular disease field study in evans county, ga.

Abstract: A CARDIOVASCULAR disease field study J began in Claxton, Evans County, during 1958-60. The study developed from observation by one of the authors (C. G. H.), a medical practitioner living in Claxton, that coronary heart disease seemed to occur less coirmmonly among Negro than white patients. Evans County (fig. 1) is located on the coastal plain about 60 miles inland from the port city of Savannah, Ga. The county is 19 miles in greatest diameter, and consists of flat or s:lightly rolling terrain of red clay and sand soils. Much of the county is covered by pine forests, which are harvested for pulpwood, turpentine, and lumber. About half of the population live on farms; the other half live in a few small villages including the town of Claxton (population 2,000). About 40 percent of the population are Negro. The study was designed basically around three questions: 1. Is the observation valid, that is, does coronary heart disease occur more commonly among whites than Negroes living in Evans County; if so, what is the extent of the difference? 2. Presupposing an affirmative answer, what is the reason for the difference? 3. What further data should be gathered to enable study of other cardiovascular diseases and conditions among the population? A morbidity survey was done to measure the prevalence of clinical cases of coronary heart disease. A nutrition survey of a 10 percent random sample of the population was also carried out. A detailed review of mortality in Evans County, undertaken prior to the morbidity survey, revealed higher age-standardized coronary death rates among white than amongt Negro males. Age-specific prevalence rates reported fronm other studies were used to estimate the expected number of cases of coronary heart disease among white males and females in the Evans County population (1-4). Prevalence rates for Negroes have not been reported in the literature, although an extensive review summarizes the clinical studies (05). The white population of Evans County seemed large enough to provide an adequate number of "prevalence" cases, but the Negro population was considered too small. Therefore, a portion of adjoining Bulloch County was included in the census to provide a larger numiber of Negroes for the study population. Dr. McDonough, epidemiologist and examining physician, Miss Stulb, nutritionist, and Dr. Garrison, examining physician, were assigned to Evans County by the Public Health Service Heart Iisease Control Program. Dr. Hames is a medical practitioner in Claxton and chairman of the Evans County Board of Health. Support for the study is from Public Health Service grant H-3341 and a contract of the Georgia State Health Department Cardiovascular Disease Control Service and the Heart Disease Control Program of the Public Health Service. Dr. McDonough and Miss Stulb are currently assigned to the department of epidemiology, University of North Carolina School of Public HLealth, for further analyses of the data.

Variability of blood sugar levels with an automated method.

Abstract: RESULTS of blood glucose determinations vary considerably from one laboratory to another (1). Variations are caused not only by the many different methods used but also by factors influencing the work of individual technicians. Pipetting differences, imperfect calibration of pipettes, inconsistent mixing of solutions, or inadequate control of temperature during reaction can cause generally reliable technicians within a given laboratory to obtain different mean results even when given aliquots of the same sample. Physical and emotional distractions also can affect the performance of otherwise efficient personnel. Automation would seem to assure both greater uniformity and increased speed for such biochemical procedures. Several commercial methods 'are now available, but because results may also vary among the types of automated procedures, each process must be individually appraised. We confined our study to one of the more widely used machines, the AutoAnalyzer (2), and to its manufacturer's recommended methods for blood sugar estimation. Our aim was to achieve a realistic appraisal of its precision and some factors which might affect interpretation of its results when used for clinical or research purposes. Since the AutoAnalyzer is capable of processing large numbers of specimens on a continuous basis, its evident value in public health epidemiologic and screening programs makes determination of its precision a desirable prerequisite.

Nationwide histoplasmin sensitivity and histoplasmal infection.

Abstract: RESULTS of skin testing with histoplasmin and the diagnosis of clinical cases of histoplasmosis have made it clear that where people live is of prime significance in the risk of beicoming infected with the fungus Histopla8ma capsulatum. The purpose of this paper is twofold: to depict State-to-State variations in indigenous sources of sensitivity to histoplasmin, as measured by the prevalence of reactions among young men who have lived all their lives in one State, and to distinguish, in some regions, between the reactions caused by infection with Histoplasima and cross-reactions attributable to infection with other agents. In dealing with geographic units as large as States, the presence of small and perhaps isolated areas of both high and low prevalence will be obscured. State figures, on the other hand, can provide a broad picture of geographic variations across the 3,000 miles from the Atlantic to the Pacific coasts. Several earlier reports from this office have described nationwide variations in the prevalence of histoplasmin sensitivity and variations in the sizes of reactions observed in different geographic areas (1-4). These reports were based on material collected in several studies of young adults during 1945-52. More recently, it has been possible to obtain material in a single study, in which the same histoplasmin, techniques, and procedures were used for giving skin tests, at the same time and place, to large numbers of young men (Navy recruits) from all parts of the country. Results of this newer study confirm and extend the conclusions drawn from the previous material, which was collected, on the average, about 10 years earlier.

Effect of prepaid group practice on hospital use.

Abstract: A GENERATION ago students of medical care were certain that the American people were not getting enough hospital care. Today the concern is, that hospital use in this country may be excessive. Whether this marks merely a change in attitudes (la, 2a) or a change in the real conditions of hospital use (3a) is not known. Yet it is surely characteristic of the present that we search for means to limit the use of hospitals, which have become so costly. The question is, have ways been found to reduce hospital use without impairing the public's health? One suggestion frequently encountered is that the low rate of hospital use reported by prepaid group practice plans be extended to more people. Specifically, this paper examines the literature on the subject of prepaid group practice in relation to hospital use, reviews the findings of several studies, and appraises alternative explanations for the apparent differences in hospital use among populations. It will help our understanding to view the matter chronologically.

Botulism from canned tuna fish.

Abstract: organism. The Wayne ;County (Mich.) Health Department alerted the Detroit District Food and Drug Offic,e, on March 15, to a death believed to be due to botulism and to the hospitalization of a woman with symptoms of botulism. Epidemiologic investigation by two Food and Drug Administration inspectors revealed that on March 14, about 11 a.m., the decea,sed, Mrs. B; her hospitalized neighbor, Mrs. M, who subsequently died; and her mother, Mrs. K, who became ill, had luncheon at Mrs. B's home. The meal consisted of tuna fish salad sandwiches, vegetable soup, and coffee. Mrs. B had eaten a sandwich, soup, and coffee. Mrs. M ha,d only a sandwich and coffee. Mrs. K joined them a little later and ate the small portion of tuna salad that remained, as well as soup and coffee. Mrs. K stated later that the salad contained only two ingredients: canned tuna fish and salad dressing. Allegedly, while preparing the salad, Mrs. B had questioned the odor of the tuna, but Mrs. M was unable to detect an abnormal odor. Both had tasted the tuna and decided that it was "all right." While eating dinner at home, about 6 p.m., Mrs. B complained of blurred vision, and she repeatedly took off and put on her eyeglasses. At 7:30 she went to bed complaining of difficulty in breathing and a tightness in her throat, as well as the vision difficulty. The next morning, at 6:30, Mrs. B was suffering convulsive respiration and could speak only in a whisper. She was sent to the hospital in an ambulance, but she was dead on arrival at 7:30 a.m. Mrs. M became ill about 7:30 p.m. following the luncbeon. She complained of dizziness, blurred vision, and difficulty in breathing. Later her movements became somewhat uncoordinated and she vomited frequently during the night. Mrs. M was hospitalized at 8 a.m. and given polyvalent types A and B botulinus antitoxin. Her symptoms continued to progress. On the fourth day after the luncheon she was given type E botulinus antitoxin, but she did not improve. She died at 5 p.m. on March 19. Mrs. K suffered nausea and vomiting about 24 hours after eating the small portion of tuna salad, and she was hospitalized. She complained of a sore throat and she had some vision difficulties. Mrs. K was given 10,000 units of polyvalent types A and B botulinus antitoxin. She made a relatively rapid recovery, and she was released from the hospital 3 days later. The illness of the three women was diagnosed as botulism. They had eaten three items in common: coffee, bread, and tuna fish salad. About 5 percent of the dressing used in the salad was left in the 1-quart jar. Since a relatively small amount of salad dressing is needed for 61/2 ounces of tuna fish, the dressing presumably had been used previously without ill effects. Samples from the garbage can at Mrs. B's home were delivered to the laboratory on March 16. From the case investigation, it was known that the can had been emptied on the morning of the luncheon. The samples consisted of three newspaper-wrapped packages of miscellaneous garbage, two empty soup cans, and a tuna can The authors are bacteriologists with the Food and Drug Administration, Detroit, Mich.

Intermittent air pollution episode in new york city, 1962.

Abstract: THE CHRONIC effects of exposure to varying levels of air pollution on human beings nmust of necessity be documented over long periods of time. Occasionally, however, there ar-ise opportunities to investigate the short-term impact of unusually high levels of air pollution. Such a period of intense air pollution occurred in New York City in November 1953 and was related to an increase in mortality (1) an(d to a rise in the number of visits to emergency clinics for upper respiratory and car(liac conditions (2). More frequent, however, are periods when air pollution concentrations are intermittently high. Little is known of the impact on health of such raised levels of atmospheric contamination which may be encoulntered for but a few hours or a few days. During the months of November and December 1962, an opportunity presented itself to study the effect of such higher-than-normal levels of intermittent air pollution in New York City. On November 27, 1962, an alert for high air pollution potential was issued for thle area bounded by Buffalo, N.Y,, Charleston, W. 'Va., Boston, Mass., and Caribou, Maine, by the Meteorology Section, Division of Air Pollution, Robert A. Taft Sanitary Engineering Center. This alert was extended to include New York City on November 29 (fig. 1). The weather map for the period indicates two major features: an anticyclone extending from New England's coastal waters southwestward into the Gulf of Mexico and an intensifying lowpressure storm center off the southeast Atlantic coast (fig. 1). The resulting pattern produced a strong pressure gradient with fresh north to northeast winds along the mid-Atlantic coast (table 1). An analysis of the meteorology for New York

Salmonellosis in poultry.

Abstract: The sources most often incriminated in foodborne outbreaks of Salmonella infections in the United States are poultry and poultry products. During 1961, 20 outbreaks of salmonellosis were reported from 8 States. In 11 of these poultry or eggs were believed to be the source of infection. In five outbreaks the source was not determined (1). The question arises as to why poultry products are so frequently incriminated in Salmonella outbreaks. There is no simple answer. Several factors possibly influence this, such as: (a) the unusual susceptibility of poultry to infection, (b) the use of eggs in a raw or semi-raw state, and (c) improper handling of poultry meats in kitchens where it is cut, washed, stuffed, or otherwise manipulated, increasing the chances of contaminating other food products. In 1962 the Communicable Disease Center, Public Health Service, received information on at least three outbreaks of salmonellosis involving bakery products in which eggs were the probable source of contamination. Recent Canadian reports also have indicated the occurrence of salmonellae in egg products in that country. Thatcher and Montford (2) reported having isolated Salmonella organisms from commercial frozen egg products and cake mixes containing eggs. Of 114 samples of frozen eggs 27, or 21 percent, were positive for salmonellae, and of 119 samples of cake mixes containing eggs 65, or 54 percent, were positive.

Five salmonellosis outbreaks related to poultry products.

Abstract: (1) Communicable Disease Center: Morbidi-by and Mortality Weeklly Report 11: 112, Apr. 13, 1962. (2) Thatcher, P. S., and Montford, J.: Egg p:roducts as a source of sialmonellae in processed foods. Clanad J Public Health 53: 61-69 (1962). (3) Quist, K. D.: Salmonella in poultry as related to human health. U.S. Dept. of Agriculture, Report of National Plans Conference, November 1962, pp. 24-30. (4) Biester, H. E., and Schwarte, L. H.: Diseases of poultry. Ed. 4. Iowa State University Press, Ames, 1959, pp. 202-248. (5) Morehouse, L. G., and Wedman, E. E.: Salmonella and other disease-producing organisms in animal by-products. A survey. J Ameir Vet Med Assoc 139: 989-995 (1961). (6) Young, G. A.: Sipecific pathogen-free pigs. J Amer Vet Med Assoc 137: 561-562 (1960). (7) Chute, H. L.: Establishment ;of poultry diseasefree areas. U.S. Department o'f Agricultu:re, Report of National Plians Conference, November 1962, pp. 39-40.

A method of predicting crisis outcome for mothers of premature babies.

Abstract: MEDICINE traditionally tries to prevent a disease even before it knows how to cure it completely. In psychiatry, a growing interest in prevention stimulates the search for the means of identifying those persons most likely to develop mental ill health so that preventive efforts can be applied most efficiently. Psychiatric attention is gradually being focused on certain hazardous situations (1) which seem to increase the risk of emotional disturbances. At the Harvard School of Public Health the factors of behavior linked with successful response to crises are being investigated. Caplan (2) has defined a "crisis" as a temporary disequilibrium in an individual facing a difficult and important problem, transitional phase, or accident for which he has no ready solution. This disequilibrium is severe enough to last several days and is followed by a resolution representing a level of mental health which is higher, the same, or lower than the initial level. During the disequilibrium, when the subject is searching for a way to resolve the crisis, he is considered more prone to accept help, and a smaller amount of professional assistance at that time has a greater beneficial effect than when he is not in crisis.

Studies on medical and veterinary students skin tested for toxoplasmosis.

Abstract: MORE THAN 25 years have passed since Toxoplas8m gondii was first established as causing clinical disease in man (1). Nearly every discipline that deals with the health of man and animals has conducted research on toxoplasmosis. The number of articles published in the world literature increases each year, and thus keeping abreast of new developments has become increasingly difficult. However, several publications review recent advances in toxoplasma research (2,5). The success of this ubiquitous parasite is exemplified by (a) its dubious role as a protozoan parasite-the fact that it is not host-specific; (b) its wide distribution in nature, both zoologically and geographically; (c) its ability to parasitize nearly every body cell type with the possible exception of nonnucleated red blood cells, thus causing protean clinical manifestations in man and animals; (d) the inability to define completely its true life cycle; and, (e) the lack of success in establishing definitive proof of the modes of transmission in man, with the exception of the congenital route. Toxoplasma is an obligate intracellular parasite. In addition to reproduction by longitudinal binary fission (6, 7), recent studies have described two additional methods. Goldman and co-workers (8) have described the process of internal budding which they call "endodyogeny" (meaning birth of two from within). Gavin and co-workers (9) have described a third method whereby at least four progenies are delineated within a rosette-shaped multinucleated toxoplasma cell, following which they eventually separate to become individual parasites. Morphologically and immunologically, the toxoplasma organisms found in various hosts are considered to be of the same species, the main difference being in the virulence of the strain of organism -for different animal species (10). In general, the young of animal species are more severely affected than the old. Infection appears to be the rule; disease the exception. Toxoplasma occurs in two forms, the crescentshaped free proliferative form (fig. 1) and the cyst form (fig. 2). Presently, the modes of transmission must be considered in light of knowledge of these two forms. The proliferative form is considered to be sensitive to changes in osmotic pressure, to drying, and to exposure to artificial gastric juices. This form apparently dies rapidly once it leaves the animal host. The cyst form appears to be more resistant and is considered by maniy to play a All the authors are with the Institute of Agricultural Medicine, State University of Iowa College of Medicine, Iowa City. Dr. McCulloch is assistant professor and public health veterinarian; Mr. Braun is medical field epidemiologist; Mr. Heggen is statistician; and Dr. Top is professor and head of the department of hygiene and preventive medicine and director of the institute. The paper was presented at the Midwest Interprofessional Seminar held at Iowa State University, Ames, on September 16-17, 1962. The study was supported in part by Public Health Service Grant E-3023, National Institute of Allergy and Infectious Diseases.

Bentonite, latex, and cholesterol flocculation tests for the diagnosis of trichinosis.

Abstract: AT THE Communicable Disease Center of the Public Health Service the bentonite flocculation test (BFT) is used routinely for the diagnosis of trichinosis. This test has been under continual evaluation for sensitivity and specificity since 1952. As part of this evaluation and to keep abreast of new developments, we have attempted, whenever possible, to compare the BFT with new tests and reagents as they have become commercially available. The trichinalatex antigen sold by Hyland Laboratories has been tested intensively. The antigen for the Suessenguth and Kline flocculation test marketed by the LaMotte Company and the reagents for a bentonite flocculation test and a latex test prepared by the Difco Laboratories have received limited evaluations. The accumulated results of our studies may be of help to local laboratories in interpreting their tests. They do not constitute an endorsement or rejection of the proiducts examined. Several particle agglutination tests have been used for the diagnosis of trichinosis. Suessenguth and Kline (1) adapted the Kline test for syphilis to a test for trichinosis and used cholesterol particles Icoated with various trichina antigens. They reported high sensitivity for both human and animal trichinosis (2-4). Campbell (5) and Coudert and Coly (6) used coated collodion particles, and Leikina and Poliakova (7), carmin particles in their tests. Vogel and co-workers (8) employed cholesterollecithin particles. Bozicevich and associates (9) introduced the use of bentonite particles. A series of papers from the CDC. laboratory has reported evaluations of the bentonite test for detection of infection in pigs (10) and in humans (11). The efficacy of Melcher's antigen (13) and of metabolic antigen (12) has been reported as well as that of lyophilized reagents (14). Innella and Redner (15) were the first to describe the use of latex particles coated with trichina antigen. Their test was essentially a modification of the latex test for rheumatoid arthritis developed by Singer and Plotz (16). Muraschi and co-workers have been using the latex test since 1957 and recently published their evaluation of a slide latex-particle agglutination test for trichinosis (17).