Anthrax: memorandum from a WHO meeting.

The risk of anthrax can be reduced through international collaboration in health education and training, promotion of research, and provision of scientific and technical advice. These issues were discussed by a WHO Working Group on Anthrax in September 1995, and this Memorandum presents their priority concerns and recommendations in several areas: surveillance, epidemiology, diagnosis in humans and in animals, prevention and control, and international cooperation.     

Cervical cancer control in developing countries: memorandum from a WHO meeting.

This memorandum summarizes the report of a WHO Consultation on the Control of Cervical Cancer in Developing Countries, held on 6-7 November 1994, in New Delhi, India. Evaluated was the current situation with regard to cervical cancer and the relevance of current practices in screening. New pragmatic approaches to cervical cancer were proposed that are relevant for developing countries; this includes empowerment of women to come forward, and visual inspection-"downstaging".     

Public health control of hepatitis A: memorandum from a WHO meeting.

Hepatitis A virus infection is a significant cause of morbidity in many parts of the world, and hepatitis A vaccines will be important tools for its prevention and control. This Memorandum reviews the basic features of the disease and its epidemiology, and considers the measures which are available for control and prevention, including hepatitis A vaccine. The use of this vaccine should be adapted to specific epidemiological circumstances existing within a geographical region, with special attention to the cost-effectiveness of immunization programmes.     

Emerging infectious diseases: memorandum from a WHO meeting.

A meeting of international experts exchanged information on recent activities dealing with new, emerging and re-emerging diseases, discussed ways of responding to this problem and to other communicable disease threats, and reviewed WHO''s activities and role in this area. This Memorandum summarizes the various presentations and concludes with the recommendations and specific tasks for action at every level.     

Epidemiology, prevention and control of legionellosis: memorandum from a WHO meeting.

This Memorandum describes the following aspects of legionellosis: clinical presentations of legionella infection, general epidemiology (including nosocomial outbreaks and travel-associated legionnaires'' disease), surveillance and reporting of cases, the organism and its environment, and measures for prevention and control. These topics were discussed by experts at a meeting in Geneva on 27-29 November 1989. This article also includes their conclusions and recommendations for research in critical areas including surveillance and preventive activities that have been found to be effective.     

Laboratory support for poliomyelitis eradication: memorandum from a WHO meeting.

This Memorandum summarizes the conclusions and recommendations of the participants at the Consultation on Strategy for Isolation and Characterization of Poliovirus Strains and Surveillance of Wild Polioviruses held in Geneva, 28-30 November 1988.     

Prevention and control of neurofibromatosis: memorandum from a joint WHO/NNFF meeting.

Neurofibromatosis (NF) is a serious, common, genetically determined neurological disorder; with a prevalence of about 1:4000 births it affects both sexes and all races and ethnic groups. The two major forms are referred to as NF1 and NF2, as suggested in 1987 by a National Institutes of Health Consensus Development Conference on Neurofibromatosis. In NF1, the disease phenotype is more variable and complex than in NF2. Complications can occur in any of the body systems in tissues of ectodermal, mesodermal and neural tube origin; there is marked variation of disease phenotype even within families. The NF2 gene, in contrast, only seems to be expressed in tissues of ectodermal origin and its expression is more uniform both within and between families. The recent discovery and isolation of the gene responsible for the NF1 mutation has practical applications in the field of molecular genetics which could modify the approaches for diagnosis, treatment and prevention of NF. This Memorandum summarizes the discussions and recommendations of the participants at a joint WHO/National Neurofibromatosis Foundation (NNFF) meeting, held in Jacksonville, Florida, USA, on 27-28 January 1991.     

Alpha 1-antitrypsin deficiency: memorandum from a WHO meeting.

alpha 1-Antitrypsin (AAT) deficiency, also known as alpha 1-antiprotease inhibitor deficiency, is a disease caused by genetically determined AAT deficiency. It occurs as a result of inheritance of two protease inhibitor (PI) deficiency alleles from the AAT gene locus (designated PI) on chromosomal segment 14q32.1. The most common deficiency allele is PI*Z and a large majority of individuals with severe AAT deficiency are PI type ZZ. The disease occurs predominantly in white persons of European origin and its frequency in Europe and North America is comparable to that of cystic fibrosis (1 in 2000 to 1 in 7000.) Persons with AAT deficiency may have no clinical manifestations. Chronic obstructive pulmonary disease (COPD) with a high frequency of panacinar emphysema is the most prevalent clinical disorder associated with AAT deficiency and the most frequent cause of disability and death. Tobacco smoking is the major risk factor for developing COPD, which generally begins by the third decade of life, much earlier than "usual" COPD that occurs in AAT-replete individuals. Liver disease, the second most frequent clinical manifestation of AAT deficiency, typically presents as cholestasis in infancy but is usually not severe and generally remits by adolescence. Chronic liver disease develops infrequently, although AAT deficiency is the commonest cause of chronic liver disease in childhood. Cirrhosis and carcinoma of the liver affect at least 25% of AAT-deficient adults over the age of 50 years. AAT deficiency appears to be widely underdiagnosed and based on predicted gene frequencies even in the most intensely studied populations, only a small proportion of those predicted to have AAT deficiency have been diagnosed. Human AAT is available in limited quantity for augmentation therapy. This Memorandum summarizes the discussions and recommendations made by participants at a WHO meeting held in Geneva on 18-20 March 1996 to review existing knowledge about this highly prevalent genetic disorder, develop a strategy for enhancing awareness of it among health-care-givers and the general public, and explore new case-finding and disease-prevention strategies.     

Destruction of variola virus: memorandum from a WHO meeting.

This Memorandum discusses the fate of variola virus stocks which have been kept in two WHO Collaborating Centres, as well as cloned DNA fragments of variola virus genome, smallpox vaccine, and seed vaccinia virus for the production of this vaccine. General and specific recommendations are given concerning destruction of variola virus; storage, distribution and handling of cloned DNA fragments of variola virus genome; and about stocks of smallpox vaccine.     

Research priorities for diarrhoeal disease vaccines: memorandum from a WHO meeting.

Diarrhoeas caused by rotaviruses, Shigella, Vibrio cholerae, and enterotoxigenic Escherichia coli (ETEC) represent a major health burden in developing countries, and have stimulated much effort towards vaccine development in order to protect against these four disease agents. This Memorandum describes the state of the art and points the way to future research and test trials in this area.     

Facts about once-a-month injectable contraceptives: memorandum from a WHO meeting.

This Memorandum reviews the results of research undertaken in animals and human subjects on once-a-month injectable contraceptives containing a progestogen and an estrogen, in particular the products Cyclofem and Mesigyna. Results from clinical trials, including effectiveness and side-effects, are evaluated and issues arising from health service research are discussed. The Memorandum concludes with a statement regarding the use of Cyclofem and Mesigyna as options for potential contraceptive users.     

Developments in pertussis vaccines: memorandum from a WHO meeting

The WHO memorandum outlines the present situation regarding pertussis vaccines, discusses ways to evaluate candidate vaccines, and identifies future research needs. Most existing whooping cough vaccines are whole-cell vaccines, combined with diphtheria and tetanus toxoid adsorbed on an aluminum or calcium carrier. As whole bacterial cells, they contain a complex array of at least 7 toxins and antigens, and display a narrow margin between potency and toxicity. The Japanese introduced an acellular vaccine, admittedly sometimes less potent, called the Precipitated Purified Pertussis Vaccine, in 1981. This material contains far less bacterial mass, notably less endotoxin, and consequently produces less fever, erythema and induration. WHO has not yet established minimum requirements for standardization; even the mouse potency assay may not be suitable. There are techniques, however, which will measure amounts of component antigens and toxicity. Conflicting results on assays of potency and immunogenicity will have to be resolved. Besides the obvious need for large clinical trials of defined vaccines, a whole range of research needs were suggested, from genetic studies of the organism to specific details of the host response. It is generally agreed that a less reactogenic and more effective pertussis vaccine is needed and feasible.     

A standard international acupuncture nomenclature: memorandum from a WHO meeting.

The WHO Scientific Group to Adopt a Standard International Acupuncture Nomenclature met in Geneva from 30 October to 3 November 1989. The main features of the recommended nomenclature are the use of the English translation of the name of each meridian and an alphanumeric code derived from the English names, and the use of the Chinese phonetic alphabet (Pinyin) names and the Han character names of the meridians and acupuncture points. This standard nomenclature will facilitate the teaching, research and clinical practice of acupuncture, as well as exchange of information globally.     

Anthrax control and research, with special reference to national programme development in Africa: memorandum from a WHO meeting.

The prevalence of anthrax in both animal and human populations has been increasing in Africa. It was therefore appropriate for this WHO meeting to be convened in an endemic area of the Western Province of Zambia in 1992. The participants reviewed anthrax epidemiology and control in some African countries, elaborated national anthrax control and research programmes in Africa, discussed international cooperation and work plans, and elaborated recommendations for anthrax control in Africa. The discussions centred on anthrax surveillance and reporting systems, diagnosis, vaccine production and immunization, disinfection and decontamination, carcass disposal, treatment of human cases, health systems, as well as intersectorial cooperation between public health services, veterinary services and other services such as wildlife conservation, so that national control programmes could take full account of the conditions prevailing in epidemic situations in Africa. The recommendations are applicable in other regions where anthrax poses similar problems in public, animal and environmental health.     

Potential use of new poliomyelitis vaccines: memorandum from a WHO meeting.

Largely due to the intensive use of Sabin attenuated oral vaccines, the incidence of poliomyelitis is continuing to decline, particularly in the western hemisphere. In developing and tropical countries, use of trivalent attenuated vaccine may, however, sometimes produce suboptimal antibody responses, especially to type 1 and 3 polioviruses. Epidemics of poliomyelitis continue to occur in some countries with high vaccination coverage, though these are rare, and cases of vaccine-associated paralysis could become increasingly visible in countries that achieve control of the wild-type virus. Recent progress in understanding the biology of polioviruses has suggested several possible approaches to solving some of these problems. This Memorandum discusses the broad scientific and ethical criteria that would justify submitting new attenuated oral poliomyelitis vaccine candidates to different levels of testing in the laboratory and in humans.