Search

OBJECTIVES—As part of a consultancy project on occupational health, the Delphi method was used to identify research priorities in occupational health in Malaysia. METHODS—Participation was sought from government ministries, industry, and professional organisations, and university departments with an interest in occupational and public health. Two rounds of questionnaires resulted in a final list of priorities, with noticeable differences between participants depending on whether they worked in industry or were from government organisations. RESULTS—The participation rate of 71% (55 of 78) was obtained for the first questionnaire and 76% (72 of 95) for the second questionnaire. The participants identified occupational health problems for specific groups and industries as the top research priority area (ranked as top priority by 25% of participants). Ministry of Health participants placed emphasis on healthcare workers (52% ranking it as top priority), whereas those from industry identified construction and plantation workers as groups, which should be accorded the highest priority. Evaluation of research and services was given a low priority. CONCLUSIONS—The priorities for occupational health determined with the Delphi approach showed differences between Malaysia, a developing country, and findings from similar European studies. This may be expected, as differences exist in stages of economic development, types of industries, occupational activities, and cultural attitudes to occupational health and safety. Chemical poisonings and workplace accidents were accorded a high priority. By contrast with findings from western countries, workplace psychosocial problems and musculoskeletal injuries were deemed less important. There also seemed to be greater emphasis on adopting interventions for identified problems based on experience in other countries rather than the need to evaluate local occupational health provisions. Keywords: occupational health; research priorities; Malaysia

Background Anecdotally, many workers complain of stress at work. However, the relationship between work and stress needs clarification to allow risk assessment and risk management of this hazard in the workplace. Objectives To examine relationships between working hours, perceived work stressors, and psychological health in a group of managers. Methods Managers at two factories were invited to participate in an anonymous cross-sectional survey. All were asked to complete a work diary for a period of 1 week and a questionnaire comprising the 30-item General Health Questionnaire, an anxiety and depression scale, and questions identifying perceived workplace stressors. Results Over 60% of managers were above the threshold of caseness on at least one measure of psychological health. No statistically significant relationship was demonstrated between actual hours of work and psychological health. A relationship was demonstrated between some perceived workplace stressors and actual hours worked, and between some perceived workplace stressors and psychological health. Conclusions A large proportion of managers in a typical production environment appeared at risk of developing psychological illness. Hours of work were not directly related to psychological health, but were significantly associated with individual perception of some work stressors which, in turn, were associated with measures of psychological health. Perceived workload appeared more important in determining psychological health than actual workload.

OBJECTIVES: Organophosphates are effective pesticides which are frequently used in several agricultural settings. Although their acute effects are well characterised, it remains unclear whether long term exposure can damage the human nervous system. This study sought to investigate their long term effects by comparing abnormalities on neurological examination between groups of workers exposed to organophosphates and an unexposed group. METHODS: 146 exposed sheep farmers and 143 unexposed quarry workers were recruited into a cross sectional study of symptoms and neuropsychological effects of long term exposure to organophosphates in sheep dip. From a symptom questionnaire given immediately after dipping the 10 most symptomatic and 10 least symptomatic farmers were selected. Several months later each of these, along with 10 of the unexposed quarry workers, underwent a standardised neurological examination similar to that which might be used in clinical practice, at at time as remote as possible from recent exposure to organophosphates so as to exclude any acute effects. RESULTS: All 30 selected subjects agreed to participate. The components of the examination which showed a significant difference were two point discrimination on the dorsum of the hand (symptomatic farmers 22 mm; asymptomatic farmers 13 mm; quarry workers 8 mm) and the dorsum of the foot (symptomatic farmers 34 mm; asymptomatic farmers 10 mm; quarry workers 11 mm), and mean calf circumference (symptomatic farmers 35.0 cm; asymptomatic farmers 36.3 cm; quarry workers 38.6 cm). Overall the prevalence of neurological abnormalities was low. CONCLUSIONS: The differences in neurological examination detected between groups were subtle and their clinical significance was unclear. However, they do suggest evidence of an adverse neurological effect from exposure to organophosphates. Further, larger scale studies will be required before it is possible to confirm or refute the differences detected.

1. The causative agent of infectious laryngotracheitis of chickens was found to be present in bacteriologically sterile tracheal exudate, spleens, and livers of diseased fowls. 2. The causative agent was present regularly in the tracheal exudate, in the spleens of about 60 per cent, and in the livers of about 30 per cent of chickens with active laryngotracheitis infection. 3. Suspensions of the spleen and liver were less effective in inducing the disease than those made from the tracheal exudate. This finding, together with the absence of pathological changes in the spleens and livers would seem to indicate that they are not actively involved but that the causative agent is carried to them by way of the blood. 4. The disease could, in our experience, be produced only in chickens Domesticated ducks and several wild and free-flying species of birds, including sparrows, crows, starlings, doves, and pigeons were found to be refractory, and so too were rabbits, guinea pigs, white rats, and one pig that was tested.

Pentamidine isethionate is currently used for the prophylaxis and treatment of Pneumocystis carinii pneumonia. Its use has been associated with a number of symptoms in staff administering treatment, and there are some additional concerns about possible adverse health effects of long term exposure. The aim of this study was to quantify exposure of health care staff administering nebulized pentamidine to patients. Personal breathing zone and static air samples at the height of the patient's head were collected during the nebulization of pentamidine to nine sequential outpatients attending a haemophilia unit. These were analysed using a standard method allowing the exposure of staff to be estimated. The duration of treatment varied between 15 and 60 min. Personal breathing zone samples showed exposure to be between 2 and 100 micrograms/m3. Static samples showed the concentration of pentamidine in the room varied from 15 to 2,100 micrograms/m3. While these exposures were relatively low, they were higher than some other studies have reported, and may pose some risk of adverse effects to staff. Some simple measures could reduce staff exposure.

Occupational asthma is the most frequently diagnosed occupational lung disease reported to the SWORD (Surveillance of Work-related and Occupational Respiratory Disease) scheme. However, diagnosing occupational asthma is not straightforward, and establishing a link with work may be difficult. This study was undertaken to determine the differences between patients with occupational asthma and those with non-occupational asthma which might help in their diagnosis. Information was collected using a self-completed questionnaire. Questionnaires were distributed to 30 subjects aged 18-65 years at each of two clinics--one for patients with occupational asthma and one for those with cryptogenic and environmental asthma. Replies were received from 26 patients with occupational asthma (87%) and 29 patients with non-occupational asthma (97%). The age of onset was significantly higher for those with occupational asthma (42.6 vs 20.7 years). Significantly more subjects with occupational asthma reported improvement on holiday, whereas no significant difference was found in the numbers reporting worsening of symptoms on work days. Those with occupational asthma were less likely to report seasonal variation in symptoms, exacerbation by allergies, pets and stress, or a family history of asthma. Subjects with occupational asthma were more likely to become unemployed (50% vs 3%). Recognition of some of these features in a patient's history may help in the difficult task of differentiating occupational from non-occupational asthma, potentially avoiding the need for exhaustive investigations in some patients. The high prevalence of holiday improvement among subjects with non-occupational asthma suggested that domestic or environmental allergies arising outside the workplace may have been making an important contribution to ongoing symptoms in these subjects.

In 1997, the Ministry of Health Malaysia introduced a surveillance programme for occupational and work-related diseases including poisonings for cases seen in government health facilities. Between June 1997 and November 1998, there were 36 cases of respiratory disease and 95 cases of poisoning by chemicals and pesticides notified while skin diseases were 108 cases. Respiratory diseases reported were predominantly occupational asthma (25%), pneumoconiosis (17%) and infections (39%). The commonest reported skin disease was contact dermatitis (87%). The commonest causes of occupational poisonings were paraquat (19%), organo-phosphates (16%), agro-chemicals excluding pesticides (15%) and gases (10%). The number of cases reported is still relatively few compared to data from other countries, suggesting that there is still considerable under reporting.

The objective of this study was to compare the validity of the original weightings used by the Life Events Inventory (LEI) with those obtained from a contemporary occupational sample. Fifty male and 62 female manufacturing employees (age range 16-55 years) assigned scores to each item on a slightly modified version of the LEI scale. The current sample consistently assigned higher weights to events/items than did the original sample, but there was high agreement in terms of item ranking. Some distinct age and gender differences in scoring were apparent, and are discussed further. It was concluded that when separate weightings are employed for age and gender groups, the LEI remains a useful tool for quantifying background levels of stress in both workplace stress audits and epidemiological studies where statistical control for non-occupational sources of stress is required.

There is now considerable evidence that T lymphocytes play an important role in generating the IgE-mediated immune response of classical allergic asthma. An immune response can be generated by other routes, including IgG- and cell-mediated mechanisms, as well. Regardless of the mechanism, it is clear that allergic asthma is an inflammatory disease, with activated T lymphocytes, eosinophils, mast cells, and other leucocytes all playing a role. Recently, an irritant asthma called reactive airway dysfunction syndrome also has emerged. It appears to be due to direct irritant or toxic effects, but shares many features of allergic asthma. Thus, several different pathways lead to the inflammatory changes and nonspecific airway responsiveness underlying asthma.

There are established reporting schemes for some occupational and work-related illnesses but these schemes may underestimate the true incidence of such diseases. Not all cases may be referred to a participating physician and access to adequate diagnostic facilities are not always available. Collecting data directly from occupational health departments may overcome some problems related to under-reporting as they have good access to the entire working population within their company. The aim of this paper is to report the results from such a reporting scheme operated by a large multi-national engineering company during the period 1993-96. All UK sites of Lucas Industries (later LucasVarity) participated. A report form was completed by the occupational health department of each participating site each month. The report form gave abbreviated details of each case of occupational and work-related disease occurring at that site during the previous month. Forms were posted to a central office where the data was collated and analyzed. The incidence of respiratory diseases was broadly similar or slightly higher to that reported from other schemes. Musculoskeletal diseases were by far the most common category of disease reported. During a four year period of reporting the incidence of occupational and work-related diseases decreased overall by approximately 75%. As the reported incidence of respiratory disease was comparable with or slightly higher than that from other schemes, it appears that reporting schemes such as this can provide useful and accurate data. Musculoskeletal diseases are the most common type of disease attributed to work and should probably receive greater attention. The decrease in incidence seen in LucasVarity over time may reflect increased emphasis given to health and safety issues within the company during the reporting period.

The water-based paints now frequently used for house painting still contain small amounts of volatile organic compounds (VOCs), with the potential to exacerbate symptoms of asthma. Because of these potential problems and environmental concerns, some manufacturers have produced paints with no VOC content. We wished to compare the effects on asthmatics of conventional water-based paint and the new VOC-free paint. Seventeen asthmatics were recruited on the basis of having previously reported exacerbation of symptoms by paint or other odours. Each undertook a standard painting task with identically coloured conventional acrylic and VOC-free paints in a double-blind, crossover study. Respiratory symptoms, lung function, and airway responsiveness were measured at each visit. A significant increase in reported "wheeze" was detected during use of conventional paint (p0.01), but not with the new paint. There was also a significantly greater increase in reported "breathlessness" whilst using conventional paint than with the new paint (p0.05). In contrast, lung function measurements showed a small but significant increase during the use of both paints (p0.05). There was no significant change in airway responsiveness after use of either paint. The new paint appears to be less likely to cause a worsening of respiratory symptoms than conventional acrylic paint, although this difference is not reflected in measurements of lung function or airway responsiveness. Although the benefit conferred in the majority of asthmatics is probably modest, there may be some patients with an increased sensitivity to paint odour, who would derive a useful symptomatic benefit from using the VOC-free paint.

Organophosphate-based pesticides are widely used throughout the world. The acute effects of over-exposure to such compounds are well known. Concern has also been expressed that long-term exposure may result in damage to the nervous system. In a cross-sectional study, we compared neuropsychological performance in 146 sheep farmers who were exposed to organophosphates in the course of sheep dipping with 143 non-exposed quarry workers (controls). The farmers performed significantly worse than controls in tests to assess sustained attention and speed of information processing. These effects remained after adjustment for covariates. The farmers also showed greater vulnerability to psychiatric disorder than did the controls as measured by the General Health Questionnaire. There were no observed effects on short-term memory and learning. Repeated exposure to organophosphate-based pesticides appears to be associated with subtle changes in the nervous system. Measures should be taken to reduce exposure to organophosphates as far as possible during agricultural operations.

A 46-year-old endoscopy nurse developed symptoms suggestive of occupational asthma after seven years of exposure to glutaraldehyde. An initial inhalation challenge test at the endoscopy suite caused a very dramatic immediate fall in FEV1 from 3.6 to 1.5 litres. To further evaluate the case and establish a threshold for the response, a technique was devised to allow a series of double-blind inhalation challenges with activated glutaraldehyde vapour at exposure levels of 0.01-0.32 ppm. The results suggested marked dual asthmatic reactions following challenges with 0.032 ppm glutaraldehyde; however, similar 'reactions' were observed on control days. These were associated with an increase in airway responsiveness to methacholine, with the PD20FEV1 falling from > 6400 micrograms to 135 micrograms. The interpretation of these results was potentially confounded by an intercurrent respiratory tract infection and by technically poor FEV1 recordings, so the challenge series was repeated three weeks later. The second series of double-blind inhalation challenges with carefully controlled exposures to glutaraldehyde (up to 0.32 ppm for 10 min) gave rise to no obvious asthmatic reactions, in marked contrast to the results of the unblinded workplace challenge. There was a slight increase in airway responsiveness, with the PD20FEV1 falling from > 6400 micrograms to 1850 micrograms. These results illustrate the potential for misdiagnosis of occupational asthma when unblinded challenge tests are used and show that, even with sophisticated investigatory techniques, a clear-cut diagnostic result may be elusive.

Shipyard workers and job applicants (n = 1126) completed an asthma questionnaire, and underwent measurements of ventilatory lung function (FEV1, FEV1/FVC and PEFR) and airway responsiveness. Airway responsiveness (to inhaled methacholine) was expressed as the dose calculated to provoke a 20 per cent fall in FEV1, ie the PD20. Results were categorized into four levels: high (PD20200 micrograms), medium (200-1000 micrograms), low (1001-6400 micrograms) and unquantifiable (6400 micrograms), which correspond with definite, possible, doubtful and no asthmatic activity. These categories agreed closely with diagnoses of asthma by general practitioners and the use of bronchodilator medication. The sensitivity and specificity of the questionnaire and the measurements of ventilatory function for detecting asthmatic activity were then determined. The questionnaire symptoms (wheeze, chest tightness, undue coughing or abnormal breathlessness) had a low (28 per cent) sensitivity for detecting definite or possible asthmatic activity and a specificity of only 73 per cent. The sensitivity of the ventilatory function tests (any one abnormal) was also low at 21 per cent with a specificity of 92 per cent. When the FEV180 per cent predicted criterion was considered separately, its sensitivity was 11 per cent and its specificity was 98 per cent. These results illustrate that caution is needed when interpreting the results of questionnaires and measurements of ventilatory lung function in the diagnosis of asthma among working populations.

IN 1933 a report (1933) was made of the occurrence on certain poultry farms in California of a severe type of respiratory infection which was looked upon as one not previously differentiated and described. The disease has been observed subsequently on numerous other farms and in the course of an investigation of it, it has developed that it probably is not new but, in the past, has been included with the commonly occurring respiratory troubles known as roup, colds, contagious catarrh, oculo-nasal roup, etc. Since the disease has been shown to be infectious and to consist primarily of an inflammation of the nasal passages the name “Infectious Coryza” has been adopted for it. In studies of the etiology of the disease, which are presented elsewhere (1934 (1936), a hemophilic bacillus was found to be the primary etiological factor. The same or a very closely related organism has also been incriminated . . .

does not appear. First page follows. The experiments reported in this paper consist of a series of five trials in which it was attempted to combat artificially-produced coccidial infection in chicks by feeding them with sufficient lactose or dry skim milk to change the hydrogen ion concentration of the ceca from the normal range of 6.0-7.4 to a range of 4.4-5.6. It was thought that, by this means, an environment unfavorable or destructive to the tissue-invading stages of the parasite, viz., the sporozoites and merozoites, might be created. The first three trials were carried out under laboratory conditions, the chicks being confined in cages with grilled bottoms and fed in cups suspended on the cage doors. In the last two trials, the chicks were reared in brooder pens under normal field conditions, except that no outside runs were provided. After the feeding of lactose or dry skim milk was begun, the chicks were inoculated by introducing into their crops with a pipette a large number of sporulated ooeysts of Eimeria aoium. A control group of chicks that was fed neither lactose nor dry skim milk was included in each trial. An estimate of the number of cysts administered to each chick was obtained by making a direct microscopic count of the cysts in 1/100 c.c. of the inoculum. Material for inoculation was provided by cultures of the cecal contents of chicks affected with coccidiosis prepared as follows: A thin layer of cecal contents containing large numbers of oocysts was spread over the surface of salt solution agar plates,1 Salt solution to keep the surface of the plates moist was added as required. The cultures were incubated at room temperature until microscopic examination showed that sporulation of the ooeysts had occurred.

does not appear. First page follows. Introduction All who have used the agglutination test for the detection of fowls that harbor Bacterium pullorum have observed the occurrence of excessive turbidity in many tubes which seriously interfered with accurate reading of the reactions. Hitchner, in 1923, reported that the turbidity resulted from the precipitation of fat that is present in the blood serum of some fowls and that it could be avoided by starving fowls for thirty-six hours before blood samples were drawn. Matthews, in 1926, reported studies which he believed demonstrated that such turbidity was due to the presence of a protein rather than a fatty substance in blood serum of fowls. He stated that this protein substance was soluble in weak alkali solution and that clouding of agglutination tests could be avoided by adding a small amount of sodium hydroxide solution to antigen. Bushnell, Hinshaw and Payne, in 1926, published a very complete discussion of bacillary white diarrhea in fowls which included a resume of the methods used by various agricultural experiment station laboratories in making agglutination tests. This resume shows that in twenty-four of twenty-eight laboratories, phenol is used for preservation of the antigen. The amount of phenol used is 0.5 per cent in nineteen laboratories and 0.4, 0.3, 0.25 and 0.2 per cent phenol in one each of four other laboratories.

Although the several pathological conditions of the head of fowls which have been variously designated as chicken pox, contagious epithelioma, epitheliosis infectiosa avium, avian diphtheria, canker, roup, diphtheritic roup, contagious eye roup, nasal roup, contagious catarrh, colds, etc., have been the subject of much careful study there still appears to exist considerable confusion concerning their relationship. A lack of uniformity of the terms applied by different investigatiors to the different types of lesions has added to the confusion. In this discussion an attempt will be made to point out the relationship and differential features between these diseases as they occur in California. To avoid confusion in nomenclature the classification suggested by the writer in a previous paper will be used. Chicken pox or Contagious Epithelioma:—This is a readily transmissible disease manifested by the formation of wart-like epithelial tumors on the comb, wattles, or skin of the head. Occasionally lesions . . .

THIS paper is a report of a single experiment, the purpose of which was to seek confirmation of Emmel’s conception of the etiology and nature of avian lymphomatosis. This investigator concluded (1935, 1936a, 1936b, 1936c, 1937) that neurolymphomatosis or paralysis of chickens is primarily an infection with Salmonella aertrycke or other members of the Salmonella group of bacteria and is manifested first by the appearance of hemocytoblasts in the peripheral blood, which may be followed by a return of the blood picture to normal or by progressive changes leading to the development of some form of lymphomatosis or to myeloid or erythroleucosis. THE EXPERIMENTAL PROCEDURE Forty-eight White Leghorn chicks, 47 days old, obtained from the division of poultry husbandry and reared in battery brooders, were divided into four equal groups, each of which was placed in a separate isolation unit and treated as follows: Group 1: Each chicken received an . . .

A RESPIRATORY disease of chicks clinically similar to infectious laryngotracheitis was reported upon by Schalk and Hawn (1931) under the title “An apparently new respiratory disease of chicks.” They stated that the disease was confined to chicks from 2 days to 3 weeks of age, the first cases appearing, in most instances, on the fifth to ninth day after removal from the incubator. The symptoms described were gasping, listlessness, and depression. Constant post-mortem findings were said to be acute congestion of all or a portion of one or both lungs and seromucoid liquid exudate in the bronchi and bronchioles. Mucous exudate was found in the nasal passages of a considerable number of the affected chicks. An outbreak ran a rapid course of 3 to 6 days’ duration, from 25 to 75 percent of the chicks became diseased, and from 40 to 90 percent of infected chicks succumbed. The disease was . . .

GENETIC differences in resistance to different infectious diseases of chickens have been extensively studied by a large number of investigators. Since Hutt (1949) has recently reviewed the field it is not necessary to cover the same ground here, except to list the particular diseases for which genetic information is available. They include avian diphtheria (Frateur, 1924), fowl typhoid (Lambert and Knox, 1932), pullorum (Roberts and Card, 1935), and lymphomatosis (Asmundson and Biely, 1932; Taylor, Lerner, DeOme and Beach, 1943; Hutt and Cole, 1948; and many others). Although the various respiratory diseases to which chickens are subject are extremely common in the field, so far apparently no demonstration of genetic variation in resistance to any of them has appeared in the literature. The purpose of the present report is to record the evidence for the existence of such variation in the University of California flock of Single Comb White Leghorns. This . . .

IN THIS paper are reported the results of attempts at transmission and passage in series of fowl lymphomatosis which were initiated in February, 1935, and are still in progress, although in a modified form since data included herein were secured. Material for and method of inoculation: The original material used for the first and a majority of the subsequent passages consisted of nerve tissue and blood taken from fowls affected with neurolymphomatosis or paralysis. In several of the passages, however, there were cases of lymphomatosis-involvement of visceral organs, particularly lymphoid infiltration of the liver, spleen, kidneys and ovary, and such tissues were, therefore, at times used for inoculation. Disease of this character is hereafter termed “visceral lymphomatosis,” without designation of the particular organs involved. A small and negligible number of cases of “gray eyes” that were encountered are included with the visceral lymphomatoses. In all instances, the final identification of . . .

does not appear. First page follows. Introduction The studies by Rettger and Rettger and Harvey, reported in four papers published between 1900 and 1909, definitely established the disease of young chicks commonly known as “white diarrhea” to be a specific infectious disease, the causative organism of which was designated Bacterium pullorum. Further studies by Rettger and his associates were reported in 1909, 1911 1912, and 1914. They determined that apparently healthy adult fowls may be carriers of Bact. pullorum. The infection in hens usually becomes localized in the ovaries and is eliminated in the eggs. When such eggs are used for hatching, the infection is transmitted to chicks. This is considered the usual source of Bact. pullorum infection in chicks. Jones(10), (11) in 1910 and 1911 and Gage in 1911 published the results of investigations which confirmed the findings of Rettger and his associates. The most important problem in the prevention of the disease in chicks, therefore, became the detection and elimination of infected breeding stock. In 1913 Jones demonstrated that the agglutination test was of value for this purpose. His findings were confirmed by others and the testing of breeding flocks by this method has been practiced extensively for several years.

does not appear. First page follows. Introduction The earliest authentic descriptions of fowl typhoid are those of Klein(1) in 1889, in England, and of Moore(2) in 1895-96, in the United States. Klein designated the disease as infectious enteritis and the causative organism, Bacillus gallinarum. Moore called the disease infectious leukemia of fowls and the causative organism Bacterium sanguinarium.§ It has since been determined that these investigators studied the same disease, which is now known as fowl typhoid and has become recognized as an important cause of mortality of adult fowls throughout the world.

THE isolation from the nasal passages of chickens with infectious colds or coryza of a small bacillus with which a coryza of short duration could be produced in healthy chickens has been reported by de Blieck (1932) in Holland, by Nelson (1932) in New Jersey, by Delaplane and Stuart (1934) in Rhode Island, by Eliot and Lewis (1934) in Maryland, and by Schalm and Beach (1934) in California. Nelson stated that the bacillus failed to grow on open blood agar plates but did so when the plates were sealed with clay. De Blieck, Delaplane and Stuart, and Eliot and Lewis experienced no difficulty in growing their organisms aerobically on blood agar but the latter stated that growth was favored by incubation in an atmosphere containing an excess of carbon dioxide. Schalm and Beach, however, obtained no growth of the organism under aerobic conditions but succeeded when they employed an atmosphere . . .

does not appear. First page follows. Introduction A review of the literature of the last decade shows that investigators are far from being in unanimous agreement regarding the value of tests for the detection of fowls that are carriers of Bacterium pullorum. Following the findings of Jones(1) in 1912, that the agglutination test was of value for this purpose, this test came into extensive use in some sections of the country. The rather complicated procedure of performing the agglutination test has undoubtedly been an important factor in retarding its more general employment throughout the United States for the eradication of Bacterium pullorum infection in breeding fowls. In addition, the accuracy of the test has recently been questioned by several investigators, particularly B. A. Beach, Halpin, and Lampman,(2) J. R. Beach,(3) Fitch and Lubbehusen,(4) and Newsom, Cross, and Ufford,(5) who have shown conclusively that a negative reaction to the agglutination test does not always indicate freedom from Bacterium pullorum infection. These factors have stimulated attempts to develop a test of equal or greater accuracy but simpler in application than the agglutination test. In 1917, Ward and Gallagher(6) reported upon an intradermal test for detecting the carriers of Bacterium pullorum.

does not appear. First page follows. Introduction The experiments, herein reported, were undertaken to determine in what manner, if any, the hydrogen ion concentration of the cecal contents of chicks would be influenced by feeding them with milk or certain milk products, and the relation of any changes found to occur to the control of coecidiosis. Why milk feeding should be generally beneficial in intestinal infections of chicks is not made entirely clear by the published work of Rettger and his associates.(4), (5), (6), (7) The experiments of Beach and Corl(1) did not add any information regarding this point, although they proved the practical efficiency of milk in the control of avian coccidiosis. If the reasons for the value of milk feeding in the control of coccidiosis of chicks were known, it might be determined that some of the milk products which can be shipped long distances would be equally effective. In such a case a means of controlling coccidiosis would be available to poultrymen in localities for removed from dairying districts. These studies have been confined to the ceca because coccidial infection of chicks is usually confined to these parts of the intestinal tract.

SINCE the first report of Asmundson and Biely (1932), which indicated that resistance to fowl paralysis is inherited, numerous studies on this subject have been conducted at various experiment stations. The emphasis in these studies has been placed on the importance of breeding selection in the control of this disease, now known in its various common manifestations as neural, visceral, or ocular lymphomatosis. Hutt, Cole, and Bruckner (1941) have recently reviewed the pertinent literature in this field. The purpose of this paper is to present data in extension of earlier reports (Taylor and Lerner, 1938; Taylor and DeOme, 1939) relating to the genetic nature of resistance to lymphomatosis, and also to introduce evidence concerning the fluctuations in the incidence of the disease from year to year under similar managemental conditions for the flock. Lymphomatosis particularly of the neural type, had been current in the Single Comb White Leghorn flock of . . .

In 1917, the senior author 1 reported success in controlling coccidiosis of chicks by dietary regulations, consisting of feeding liberally with buttermilk or sour skim-milk and sparingly with mash, combined with sanitation. Although many outbreaks of the disease in California have been satisfactorily controlled by the sour milk treatment since then, for several reasons further investigation of this and other methods of control was carried out in 1922 and 1923. The most important of the “ reasons ” for further investigation are as follows : First: The conclusions regarding the value of the sour milk treatment were based on success in controlling natural outbreaks of coccidiosis, not on the results of carefully conducted and controlled experiments. Second: Not all poultrymen secured good results from the sour milk treatment. In this connection it may be stated that many of these failures were undoubtedly due to faulty management of the flocks or failure . . .

does not appear. First page follows. Introduction2 The studies reported herein consist of a series of experiments in the immunization of fowls against chicken-pox (Epithelioma contagiosum) by the subcutaneous injection of vaccine containing the lesion tissue removed from fowls affected with the disease. The first report of a successful attempt to immunize fowls against chicken-pox by such means was that of Manteufel(1) in 1910. He reported success in immunizing fowls by injecting into the circulation or under the skin a lymph prepared from scraping of lesions on the comb or mucous membranes of the head of diseased birds mixed with physiologic salt solution and heated in a water bath at 55° C for one hour. According to this investigator, chickens treated in this manner were immune to infection for from one and one-half to two years even though there was no visible reaction following vaccination. Marked curative value for this preparation was also claimed.

The occurrence of fowl cholera in the United States was first reported by Salmon1 in 1880. This is the first recorded study of any infectious disease of poultry in this country. The next mention of the disease was in 1902, when Curtice reported an outbreak of “goose septicaemia”. Two years later Ward reported investigations of outbreaks of fowl cholera in California. The major portion of subsequent investigation of fowl cholera has been made by Hadley2,3,4,5,6,7,8,9, at the Rhode Island Station, although several other investigators including Mack and Records10, Gallagher11, and Van Es and Martin12, have made some study of it. In nearly all writings on this subject the disease is described as an acute infectious disease caused by Bact. avisepticum and resulting in severe losses when it occurs in any flock. The isolation of the causative organism from the body of a dead bird is considered sufficient for a diagnosis.

The finding of Beaudette and Hudson1 that the cloaca and bursa of Fabricius of chickens become infected with infectious laryngotracheitis when the virus is applied to the mucous membrane of these organs, and the application of this phenomenon to the vaccination of farm fowls against the disease raised the question of how long the virus would remain viable in the bursa or cloaca and serve as a source of infection of susceptible chickens with which vaccinated chickens might later become associated. Gibbs2 in testing twelve chickens after their bursas had been swabbed with a paste of laryngotracheitis virus failed to demonstrate the presence of active virus in a bursa later than the ninth day. Later3 he reported negative results from a similar test of 620 birds of a farm flock which was made two months after the birds had been vaccinated.

In a previous experiment reported by the writers 2 in 1926, a commercial oil, extracted from cannery refuse consisting of heads, tails, fins and viscera (including the livers) of salmon, was found to compare favorably with cod liver oil and greens as a source of vitamin A for poultry. That experiment was followed by the one 3 reported in this paper to determine if the salmon oil also contained vitamin D. For this experiment, fifty chicks, three days old, were divided into two groups of twenty-five each, and placed in a brooder-house which was divided, by a wire partition, into two pens. Light was admitted through large glass windows in the front of the house. The feed supplied during the first week was a scratch grain mixture, consisting of equal parts of wheat, granulated yellow corn, and steel cut oats, which was fed three times daily. The feeding of scratch grain was . . .

The relationship between the various pathological conditions of the head of domesticated fowls has been the subject of much controversy. These conditions are variously designated as chicken pox, contagious epithelioma, avian diphtheria, canker, colds, contagious catarrh, swelled-head, roup, etc. Ward and Gallagherl in their recently published work, “Diseases of Domesticated Birds,” express the opinion that all of these conditions are due to the same etiological factor, namely, “the filterable virus of chicken-pox or contagious epithelioma.” The results of extensive study of these diseases at the California Agricultural Experiment Station, however, have led us to the conclusion that, as they occur in California, there is a distinct difference between some of them. Classification of Diseases Involving the Skin or Mucous Membrane of the Head:—In order that there may be no misunderstanding of the nomenclature of lesions or diseases used in this discussion, I will give briefly our conception of them. . . .