Showing papers by "World Health Organization published in 1977"

Solid-phase enzyme immunoassay or radioimmunoassay for the detection of immune complexes based on their recognition by conglutinin: conglutinin-binding test. A comparative study with 125I-labelled C1q binding and Raji-cell RIA tests

Abstract: Bovine conglutinin was used in a solid-phase assay for the detection of immune complexes. In a first step, the tested serum sample is incubated in polypropylene tubes coated with conglutinin to allow C3-coated immune complexes to bind to solid-phase conglutinin. In a second step, the conglutinin-bound complexes are detected using an enzyme-conjugated or radiolabelled anti-immunoglobulin antibody. The conglutinin-binding (KgB) test does not suffer from the interference of DNA, heparin or endotoxins. Its limit of sensitivity for aggregated IgG is 3 μg/ml undiluted human serum. Immune complexes prepared in vitro using tetanus toxoid, or DNA, and corresponding antibodies in human sera could be detected at various antigen/antibody ratios and at antibody concentrations lower than 8 μg/ml. The KgB test allowed for the detection of immune complexes in sera from patients with systemic lupus erythematosus, rheumatoid arthritis, idiopathic vasculitis, leprosy and leukemia. These sera were also tested using the 125I-labelled Clq-binding activity (BA) test and the KgB test simultaneously, and a significant rank order correlation was observed. In patients with leukemia, a significant correlation was observed using three tests, KgB, 125I-labelled Clq BA and Raji-cell radioimmunoassay (RIA). Therefore, the KgB test appears as a simple and reproducible method, utilizing a very stable reagent, with a sensitivity and specificity comparable to the other tests studied and allowing for clinical application.

Outbreak of Pox Disease among Carnivora (Felidae) and Edentata

Abstract: An outbreak of pox disease in Carnivora of the family Felidae occurred in the Moscow Zoo. Two forms of the disease were found: (1) fatal, fulminant pulmonary without skin lesions and (2) dermal with rash. The severity of the dermal form varied from subclinical to lethal. The pulmonary form was characterized by pneumonia and exudative pleuritis, and large concentrations of virus were observed in the lungs and exudate. In addition to Carnivora of the family Felidae, two giant anteaters had a severe form of the disease (dermal with hemorrhages) and died. The agent of the outbreak appeared to be very closely related to cowpox virus; however, pocks developed at a lower temperature than do those that result from infection with cowpox virus. Strains isolated from sick animals were identical to the virus previously isolated from an outbreak of pox among elephants and okapi. The most probable sources of infection were rats that were fed to some of the animals. During the outbreak, a female attendant at the zoo became infected.

ABO blood groups and cholera.

Abstract: The ABO blood group of 87 bacteriologically proven cases of cholera and 33 bacteriologically negative cholera-like diarrhoea cases was determined. When compared with the normal blood group distribution in the population of the Philippines of the same racial group to which the patients belonged, a relatively larger number of cases were found to occur in individuals of group O and a lesser number in those of group A. A plea is made for further studies on these lines to explain the host susceptibility in cholera and other acute enterotoxigenic diarrhoeas.

Antigenic variation in the salivarian trypanosomes.

Abstract: The term “antigenic variation” has been widely used to describe a phenomenon in which, during infection of the final host by what is taxonomically considered a single species of pathogenic protozoa, there arises a succession of parasite populations, each recognized as antigenically different by the host’s immune response. This results in the formation of antibodies, specific for each population, which are demonstrable by tests recognizing surface antigens of the parasite or parasitized cell such as agglutination and lysis.

Enterotoxigenic Escherichia coli Isolated from Patients at a Hospital in Dacca

Abstract: Enterotoxigenic strains of Escherichia coli, a significant cause of acute, watery, cholera-like diarrhea, were isolated from 23 of 65 patients with diarrhea in whom no other enteric pathogens were found during one week (November 1974) at the Cholera Research Hospital, Dacca, Bangladesh. Diarrhea associated with enterotoxigenic strains of E. coli occurred primarily in adults but affected persons of all age groups and could not be distinguished from cholera or from other cholera-like diarrhea on clinical grounds. Routine bacteriologic methods were inadequate for identification of enterotoxigenic E. coli as the etiologic agent of the diarrhea. The enterotoxigenic E. coli, producing heat-stable and/or heat-labile enterotoxin, were detected by use of assays in the Y1 adrenal cell, the Chinese hamster ovary cell, the rabbit ileal loop, and the infant mouse. The two tissue culture assays yielded comparable results in tests with 640 (193 positive, 447 negative) of 643 isolates of E. coli. The results of this study support the idea that enterotoxigenic E. coli play a significant role as pathogens in the etiology of acute watery diarrhea.

Enterotoxigenic Escherichia coli isolated from food.

Abstract: Approximately 8% of 240 isolates of Escherichia coli obtained from food of animal origin in the United States were found to be enterotoxigenic, as determined in adrenal cells, rabbit ileal loops, and assays in infant mice. These organisms were of diverse serotypes that are not included among the so-called enteropathogenic serotypes and would not have been identified by usual laboratory methods. These enterotoxigenic E. coli are of potential importance to public health.

Schizophrenia succeeded by affective illness; catamnestic study and statistical enquiry.

Abstract: On the basis of data derived from a long-term follow-up of 12 cases and a 2-year follow-up of the International Pilot Study of Schizophrenia it is suggested that some patients with remitting schizophrenic illnesses can subsequently present clear-cut affective disorders. The implications of these findings are discussed.

Circulating immune complexes in patients with malignant lymphomas and solid tumors.

Abstract: Sera from 50 patients with Hodgkin's disease, 78 patients with non-Hodgkin non-leukemic malignant lymphomas, and 75 patients with different types of solid malignant tumors were investigated for the presence of immune complexes using the (125I) C1q-binding test. All patients were untreated. An increased serum C1q-binding activity was found in 22% of the patients with Hodgkin's disease, 35.9% of the non-Hodgkin lymphoma patients and in 37.3% of the patients with solid tumors. The C1q-binding material detected in the patients' sera had properties similar to those of immune complexes. On sucrose density gradient it sedimented as a 10-30 s material. It contained IgG which were dissociated under acid conditions. Passage through anti-IgG immunoabsorbent removed its C1q-binding properties. A prevalent association was found between the presence of serum immune complexes and disseminated disease stages in all the patient groups included. A similar association was found between the presence of serum immune complexes and general symptoms among the malignant lymphoma patients. The nature of the antigens involved in the complexes remains unknown.

The relation between betel chewing and dental caries

Abstract: In the eastern part of Java and on the island of Bali betel chewing is a very common habit confined principally to females. The purpose of the present study was to examine the influence of betel chewing on the prevalence of dental caries. The study, which is based upon 982 villagers, indicates a strong inverse relationship between the prevalence of dental caries and the intensity of betel chewing. The possible mechanisms whereby betel chewing may have a caries-inhibiting effect are discussed.

Antibiotic Susceptibility of Chlamydia trachomatis

Abstract: The antibiotic susceptibility of Chlamydia trachomatis isolates was determined in a tissue culture system. Representatives of all currently recognized serotypes of trachoma-inclusion conjunctivitis agents were tested. Tetracycline and erythromycin yielded similar results, with 1.0 μg/ml preventing chlamydial replication. Rifampin was the most active antibiotic, with 0.25 μg/ml completely suppressing inclusion formation of all strains. Fifty percent end points were usually achieved at one-fourth to one-eighth the 100% suppression level. Penicillin was not as effective, and the assays were often irregular. Antibiotic susceptibility of these chlamydiae was essentially the same, regardless of serotype, anatomic site infected, geographic origin, or antibiotic use in the community.

The incidence of infectious diseases under the influence of seasonal fluctuations - analytical approach

Abstract: Publisher Summary This chapter presents an analytical approach to the incidence of infectious diseases under the influence of seasonal fluctuations. It discusses a model describing in a simplified manner the dynamical behavior of a system of susceptibles, infectives, and immunes ( X , Y, and Z , respectively). The model assumes equal and constant (age independent) birth and death rates (μ), disregarding deaths caused by the infectious agent under consideration so that the population size ( n = X + Y + Z ) remains constant. It is assumed that the number of effective contacts per unit time per individual susceptible with infectives is proportional to the number of infectives, the proportionality constant being β. After an effective contact, a susceptible becomes immediately infective himself and recovers at a rate γ. After recovery, an individual stays lifelong immune. The variations in β are introduced to represent seasonal variations of the contact rate β.

Betel chewing and caries experience in New Guinea

Abstract: The prevalence of dental caries and variables relating to the betel-chewing habit were examined in a sample of 301 rural New Guineans aged 12--24 years. Consistent inverse associations were demonstrated between caries experience and the intensity of betel chewing for individuals and aggregates of subjects. The results indicate that betel chewing confers a degree of protection against caries.

Protein-calorie deficits in developing countries.

Abstract: Twenty years ago, we were invited to present a paper on severe protein-malnutrition in children in a meeting organized by this same Academy. In reviewing that paper for this presentation, it was very frustrating to find that the basic principles we stated there in regard to the nature of the probelm and its epidemiology are as valid today as they were 20 years ago. As most other workers in the field, we were then particularly concerned with the severe forms of protein-calorie malnutrition (PCM): kwashiorkor and marasmus. These individual cases occupied a large proportion of pediatric beds in hospitals of most developing countries, and we were interested in finding better ways to treat them. But also we were studying these cases as a basis for understanding the responsible factors better and for designing possible preventive measures. The interrelations of kwashiorkor and marasmus were recognized then, as well the fact that both protein and calories should be considered together in the epidemiology of the problem. We were also beginning to understand that the severe clinical cases that we were seeing in the hospitals were only the visible part of a much greater problem affecting the communities from which these children came. With the knowledge then available on the epidemiology of PCM, we were also starting to explore some specific measures for its prevention. I would like now to review what progress we have made, if any, in the understanding of the nature and magnitude of the problem, its epidemiology, and in designing preventive measures.

WHO activities in oral epidemiology.

Abstract: Standard methods to facilitate the collection of data on a global basis have been developed by WHO. Data collection in accordance with criteria proposed by WHO began in 1969 from existing sources and was subsequently supplemented by new data collected using the standard methods. Associated with these methods developments, a WHO Global Oral Epidemiology program was begun with the objective of facilitating comparison of data and their use in planning, replanning, and evaluating oral health services according to needs and economic possibilities. That program provides an orderly storage and retrieval system and a visual representation of contrasts in prevalence of those oral diseases which are among the most common known to man. In selecting data for inclusion in the WHO oral epidemiology data bank, a liberal policy has been pursued to make maximum use of available material. The system of classification allows for data retrieval at various levels and for specific ages. Data on caries are available for 95 countries and on periodontal diseases for 50 countries.

Caries Experience and the Mineral Content of Plaque in a Primitive Population in New Guinea

Abstract: Two recent epidemiological studies demonstrated inverse associations between individual caries experience and the total calcium, phosphorus,' and fluoride2 content of dental plaque in industrialized communities. Similar associations are apparent for a range of minerals determined in plaque samples collected from schoolchildren in New South Wales, Australia.3 4 These observations suggest that high mineral content in plaque may confer a degree of protection against caries in Western populations. The present paper reports a study of plaque minerals performed as part of a wider investigation of over 100 intraoral variables in relation to individual caries experience in a rural community in New

Malaria eradication in Portugal.

Abstract: Research on malaria, which was endemic in several parts of Portugal at the beginning of this century, was intensified in the 1940's and led to the development of better control methods, especially in the rice-growing areas of the country. In the 1950's residual DDT spraying was introduced and followed by extensive detection of cases of malaria and their treatment. Plans for eradication of the disease were made, and by 1958 the transmission of the infection was interrupted in nearly all areas of European Portugal. The country was placed in the maintenance phase of malaria eradication and the certification of malaria eradication was confirmed by the WHO in 1973. The political and military events of the past five years greatly increased the number of cases of malaria imported into Portugal from tropical Africa and indicated the need for much vigilance to prevent the resumption of transmission by the local vectors. It appears that the measures put into action have succeeded in this respect. This was due to the high degree of effective surveillance and also to the fact that Anopheles atroparvus does not readily transmit the exotic strains of Plasmodium falciparum and P. vivax. However, further vigilance must be maintained and intensified.

A Global View of Pesticide Safety

Abstract: Publisher Summary This chapter presents a global view of pesticide safety. Pesticide includes a large number of compounds of widely differing chemical structures and use patterns. There is no objective measure to access pesticide safety. Although the number of cases of accidental poisoning seems to be large on a global basis, in many countries it represents only about 5% of the total cases of accidental poisoning by chemical agents and drugs. Most pesticides, except the heavy metals, have the advantage that if an intoxicated person survives, recovery is complete. The importance of pesticide poisoning is that it is 100% preventable if the factors that make up the hazard can be controlled, and the control should be such that the rational use of pesticides for the economic and nutritional advancement of mankind is not limited. If the careful description of the mode of use of a pesticide—which is drafted by the manufacturer and reviewed by regulatory authorities—is the criterion of safe practice, cases of accidental poisoning are generally caused by misuse of the pesticide. This usually arises from either carelessness or ignorance of the precautions that should be taken.

State of the art of the toxicological evaluation carried out by the joint FAO/WHO expert committee on pesticide residues. III. Miscellaneous pesticides used in agriculture and public health.

Abstract: The present review includes miscellaneous compounds considered by the WHO Expert Committee on Pesticide Residues and the FAO Working Party of Experts on Pesticide Residues (also referred to as the Joint Meeting) up to and including 1975 and represents the third in a series of general reviews comprising the major categories of pesticide chemicals evaluated by the Joint Meeting.1

Antigenic variation in Babesia.

Abstract: As babesiosis has been the subject of several recent reviews (Mahoney 1972; Riek 1968; Ristic 1970) and is the subject of another chapter in this volume (Callow, Chapter 8), I will only briefly present the evidence now available to show that antigenic variation also occurs in this disease. Parasites of the genus Babesia, intraerythrocytic parasites in the mammalian host, are transmitted by ixodid ticks. They represent a widespread problem in domestic animal husbandry, causing a disease characterized by erythrocyte destruction with anemia, jaundice, and hemoglobinemia. The patterns of morbidity and mortality depend on the conditions under which the animals are maintained.

Priorities for research likely to contribute to better provision of mental health care

Abstract: Research and delivery of services are complementary and not alternative activities in achieving objectives of mental health programmes. If research is to contribute to the improvement of care for a set of priority conditions it should primarily aim to resolve issues underlying constraints to care provision and be the best way to remove them. Which among the topics that would satisfy this criterion will be selected will depend on secondary criteria such as feasibility, likelihood of utilisation of knowledge gained, timing of the investigations, probability of success, size of contribution to knowledge, likelihood that research will increase self-reliance in matters of research and ethical issues. Priorities for research may thus vary from country to country although the problems and priorities for service delivery may be the same. Themes in which new knowledge is likely to be useful to many settings include research on attitudes and behaviour, information spread, crosscultural issues, the process of service delivery and factors protecting health and enhancing human existence.

A pattern-analysis study of a wild-life rabies epizootic

Abstract: Pattern-analysis and statistical estimation have been used to investigate retrospectively the features of a wild-life epizootic in a 133 km × 133 km study area during 1963–1970. Some terrain-dependency of case-occurrence rates was confirmed and the propagation process was shown to be consistent in sequential periods. Contour maps purporting to display improved estimates of case-occurrence probabilities in successive quarterly epochs were prepared and it is argued that these permit a description in either global or focal terms of propagation of the epizootic.In global terms, the main propagation across the region occurs in a broadly-uniform way in two different phases (each 12–18 months) separated by a 3–6 month transition period. In focal terms propagation is described by a limited set of trajectories of apparently-continuous movement of case-occurrence foci that can sometimes be tracked for long periods. It is shown that these approaches are two extremes of one descriptive view of the process, obtained f...