Showing papers by "World Health Organization published in 1992"

Longitudinal monitoring of bone mass accumulation in healthy adolescents: evidence for a marked reduction after 16 years of age at the levels of lumbar spine and femoral neck in female subjects.

Abstract: The amount of skeletal mass acquired during adolescence is one of the most important determinants for the risk of postmenopausal and involutional osteoporosis. In both sexes, a large variance in bone mineral density (BMD) and content (BMC) is observed among healthy individuals at the beginning of the third decade. To determine the crucial pubertal years during which bone mass accumulation mainly occurs, we longitudinally monitored the gain in BMD/BMC at clinically important sites, such as lumbar spine and femoral neck, with respect to osteoporotic fracture risk. The changes in BMD (grams per cm2) and BMC (grams) were determined at 1-yr intervals at the level of lumbar spine vertebrae (L2-L4), femoral neck, and midfemoral shaft, using dual energy x-ray absorptiometry (Hologic QDR 1000), in 198 healthy adolescents (98 females and 100 males), aged 9-19 yr. Mean daily energy and calcium intakes, height, weight, and body mass index of the studied cohort were within the normal range for age. In females, the increment rate in BMD/BMC was particularly pronounced over a 3-yr period, i.e. from 11-14 yr of age. This increment dramatically fell after 16 yr and/or 2 yr after menarche. The mean gains in lumbar, femoral neck, and midfemoral shaft BMD were not statistically significant between 17-20 yr. In males, the gain in BMD/BMC was particularly high over a 4-yr period, i.e. from 13-17 yr. Then the increment rate markedly declined, but remained significant between 17-20 yr for L2-L4 BMD/BMC and midfemoral shaft BMD. In contrast, no significant increase was observed for femoral neck BMD. An impressive interindividual variation was observed between the yearly height increment and the bone mass accumulation. The bone mass-height gains relationship during puberty evolved according to a loop pattern, with maximal variance at Tanner stages P3-P4. This longitudinal study delineates the crucial pubertal years during which the skeletal mass accumulates at high, but various, rates at skeletal sites where the consequences of the osteoporosis are particularly dramatic. Furthermore, the results indicate that in a cohort of healthy females with apparently adequate intakes of energy and calcium, bone mass accumulation is drastically reduced by 16 yr of age in both lumbar spine and femoral neck.

Tuberculosis: a global overview of the situation today.

Abstract: The overall tuberculosis situation in the world in 1990 and its recent trends are reviewed by an analysis of the case notifications to WHO and tuberculosis mortality reports. Estimates of the prevalence of tuberculosis infection and the incidence of tuberculosis disease and deaths predicted in 1990 were carried out with simple epidemiological models. Approximately one third of the world's population is infected with Mycobacterium tuberculosis. In the past decade, an average of 2.5 to 3.2 million cases were notified every year globally, the small decrease in notification rates in recent years being offset by population growth. In 1990, an estimated 8 million people developed tuberculosis worldwide and 2.6 to 2.9 million died. The majority of these cases and deaths occurred in Asia, with an increasing number among HIV-infected individuals, especially in Africa where an upward trend is clearly detectable. Data on tuberculosis cases notified by WHO Member States demonstrate the magnitude of the problem but must be interpreted with caution. Being less than the expected incidence, they reflect the inadequacies of tuberculosis control programmes. This review confirms the very high global magnitude of the tuberculosis problem and calls for an urgent revitalization of tuberculosis control programmes throughout the world.

The WHO Histological Typing of Odontogenic Tumours. A commentary on the Second Edition.

Abstract: This article introduces the revised World Health Organization (WHO) classification of odontogenic tumors and jaw cysts and certain bone lesions that either are peculiar to the jaws or have distinctive features in that location. The new and revised classification is compared with the previous version, the reasons for the changes are outlined, and reference is made to a number of newly characterized lesions that have been included.

The International Pilot Study of Schizophrenia: five-year follow-up findings.

Abstract: A five-year follow-up of the patients initially included in the International Pilot Study of Schizophrenia was conducted in eight of the nine centres. Adequate information was obtained for 807 patients, representing 76% of the initial cohort. Clinical and social outcomes were significantly better for patients in Agra and Ibadan than for those in the centres in developed countries. In Cali, only social outcome was significantly better.

Intestinal parasitic infections: a soluble public health problem

Abstract: Lorenzo Savioli’, Don Bundy’ and Andrew Toni ‘WHO Collaborating Centre on the Epidemiolop of Intestinal Parasites, Department of Biology, Imperial College of Science, Technology and Medicine, London, UK; Centre for International Child Health, Institute of Child Health, University of London, UK

Epidemiological patterns of ocular trauma

Abstract: Ocular trauma is the cause of blindness in approximately half a million people worldwide, and many more have suffered partial loss of sight. Trauma is often the most important cause of unilateral loss of vision, particularly in developing countries. There is a cumulative risk of ocular trauma and visual loss during life, but the true incidence of accidents involving the eyes is not known. Males tend to have more eye trauma than females, and this is already apparent from childhood; lower socioeconomic classes are also more associated with ocular trauma. The setting for the occurrence of trauma is most commonly the workplace and, increasingly, road accidents. On the other hand, domestic accidents are probably under-reported. Of particular importance in some developing countries is the occurrence of superficial corneal trauma in agricultural work, often leading to rapidly progressing corneal ulceration and visual loss. The impact of ocular trauma, in terms of need for medical care, loss of income and cost of rehabilitation services when indicated, clearly makes the strengthening of preventive measures very worthwhile.

Human leishmaniases: epidemiology and public health aspects.

Abstract: The leishmaniases are parasitic diseases caused by different species of Leishmania, protozoa transmitted by sandflies, haematophagous biting insects. The reservoir hosts are man (anthroponotic cycle) and domestic or wild animals (zoonotic cycle). In man the disease takes four main clinical forms: visceral, cutaneous, mucocutaneous and diffuse cutaneous. Morbidity and mortality due to leishmaniasis are on the increase. Leishmaniasis, which is now found on four continents, is endemic in 82 countries (21 in the New World and 61 in the Old). The large number of endemic countries shows the global scale of the problem, though it is particularly severe in certain countries (90% of cases of visceral leishmaniasis come from 4 countries). Annual incidence is estimated at some 600,000 new clinical cases, officially reported, with a global prevalence of 12 million cases and a population at risk of approximately 350 million. It is very difficult to provide realistic estimates given the frequency of subclinical forms of visceral leishmaniasis, the large number of undiagnosed or unreported cases, the frequent absence of active screening and the fact that the leishmaniases are notifiable diseases only in a few countries (30 out of 82); nevertheless, it seems clear that official reporting of cases considerably underestimates the problem. Over the last two decades, it has become clear that leishmaniasis is a growing public health problem in terms of geographical extent and incidence with the occasional severe epidemic, such as that which occurred in Sudan.(ABSTRACT TRUNCATED AT 250 WORDS)

Vector-borne disease problems in rapid urbanization: new approaches to vector control.

Abstract: Owing to population growth, poor levels of hygiene, and increasing urban poverty, the urban environment in many developing countries is rapidly deteriorating. Densely packed housing in shanty towns or slums and inadequate drinking-water supplies, garbage collection services, and surface-water drainage systems combine to create favourable habitats for the proliferation of vectors and reservoirs of communicable diseases. As a consequence, vector-borne diseases such as malaria, lymphatic filariasis and dengue are becoming major public health problems associated with rapid urbanization in many tropical countries. The problems in controlling these diseases and eliminating vectors and pests can be resolved by decision-makers and urban planners by moving away from the concept of "blanket" applications of pesticides towards integrated approaches. Sound environmental management practices and community education and participation form the mainstay of some of the most outstanding successes in this area. On the basis of these examples, it is argued that the municipal authorities need to apply a flexible methodology, which must be based on the possibilities of mobilizing community resources, with minimal reliance on routine pesticidal spraying. In this way, vector control becomes a by-product of human development in the city environment. This is now a true challenge.

Serologic identification of hepatitis E virus infections in epidemic and endemic settings.

Abstract: Recombinant chimeric protein C2 containing the N-terminal region of trpE (37 kilodaltons [kDa]) and the C-terminal half (468 kDa) of the polypeptide encoded by ORF2 of the hepatitis E virus (HEV) genome was used for the construction of a Western blot diagnostic test for IgG and IgM antibodies to the virus (anti-HEV) (The C2 protein and the trpE protein devoid of C2 activity and used as a control for non-specific reactions were purified by recovery from sodium dodecyl sulfate-polyacrylamide gel electrophoresis [SDS-PAGE] and used for preparation of strips) Specificity of the test was proven with sera obtained from patients with acute hepatitis non-A, non-B, non-C (NANBNC) from outbreaks in different geographic regions of the world IgG antibodies reactive to the recombinant C2 protein were detected in 93% of patients with acute hepatitis NANBNC and remained detectable in 89-100% of these patients 1-24 months after onset of jaundice IgM antibodies were detected in 73% of patients within 26 days after onset of jaundice, in 50% 1-4 months after onset, in 6% 6-7 months after onset, and in no patients by 8 months after onset When this test was used to identify sporadic hepatitis E cases in different regions of the world, such cases were found almost exclusively in areas where outbreaks of the disease had occurred and rarely in any other regions

Mycobacterial heat-shock proteins as carrier molecules. II: The use of the 70-kDa mycobacterial heat-shock protein as carrier for conjugated vaccines can circumvent the need for adjuvants and Bacillus Calmette Guérin priming.

Abstract: In a recent work, we have shown that mycobacterial heat-shock proteins (hsp) of 65-kDa (GroEL-type) and 70-kDa (DnaK-type) acted as carrier molecules in mice, previously primed with Mycobacterium tuberculosis var. bovis (bacillus Calmette-Guerin, BCG), for the induction of high and long-lasting titers of IgG against the repetitive malaria synthetic peptide (NANP)40. Anti-peptide antibodies were induced when the malaria peptide, conjugated to the mycobacterial hsp, was given in the absence of any adjuvants (Lussow et al., Eur. J. Immunol. 1991. 87:2960). In this report, we show that mice immunized with peptides or oligosaccharides conjugated to the 70-kDa hsp produced high titers of IgG antibodies in the absence of any previous priming with BCG. The anti-peptide antibody response persisted for at least 1 year. This adjuvant-free carrier effect of the 70-kDa hsp was T cell dependent, since no anti-peptide nor anti-70-kDa IgG antibodies were induced in athymic nu/nu mice. Previous immunization of mice with the 65-kDa or 70-kDa hsp did not have any negative effect on the induction of anti-peptide IgG antibodies after immunization with hsp-peptide conjugates in the absence of adjuvants. Furthermore, preimmunization with the 65-kDa hsp could substitute for BCG in providing an effective priming for the induction of anti-(NANP) antibodies. Finally, both the 65-kDa and 70-kDa hsp acted as carrier molecules for the induction of IgG antibodies to group C meningococcal oligosaccharides, in the absence of adjuvants. These findings strongly suggest that the use of hsp as carriers in conjugated constructs for the induction of anti-peptide and anti-oligosaccharide antibodies could be of value in the design of new vaccines for eventual use in humans.

Onchocerca volvulus DNA probe classification correlates with epidemiologic patterns of blindness.

Abstract: Onchocerciasis, or river blindness, results from infection with Onchocerca volvulus. The parasite is endemic to West Africa, in both rain forest and savanna bioclimes. Several lines of evidence suggest that different strains of the parasite exist in the rain forest and savanna. Furthermore, epidemiologic evidence indicates that ocular onchocerciasis is most severe in savanna regions. This has led to the hypothesis that there is a strain association with ocular pathology. To test this hypothesis, parasites from villages in which severe and mild onchocerciasis were endemic were classified with two strain-specific DNA probes. A strong correlation (P less than .001) was found between disease severity and probe recognition, supporting the hypothesis that pathogenicity is strain related. The results suggest that pFS-1 and pSS-1BT may be used to predict the pathogenic potential of parasite populations throughout much of West Africa.

Diagnosis, treatment, and prevention of pulmonary embolism : report of the WHO/international society and federation of cardiology task force

Abstract: To assess the state of the art of venous thrombosis and pulmonary embolism for the medical and other health-related professions, the World Health Organization (WHO) and the International Society and Federation of Cardiology (ISFC) convened a task force in Geneva, Switzerland. Members of the task force prepared position papers and presented brief oral presentations. A report was subsequently prepared by the task force members, who contributed sections in their areas of expertise. Revisions of the report occurred both during the task force meeting itself in Geneva and during the ensuing months. The final report was approved by the WHO-ISFC Task Force on Pulmonary Embolism Steering Committee. More quantitative information is needed on the frequency of venous thrombosis and pulmonary embolism in hospitalized medical patients as well as in outpatients at high risk. Population studies should focus on incidence, survival, and long-term complications in different parts of the world with respect to gender and race. Further educational efforts are needed to increase awareness about venous thrombosis and pulmonary embolism prophylaxis. Finally, research into effective techniques for changing physician practice would be useful. (JAMA. 1992;268:1727-1733)

Comparison of Composite International Diagnostic Interview and clinical DSM-III-R criteria checklist diagnoses.

Abstract: This article describes a comparison of Composite International Diagnostic Interview (CIDI) diagnostic results and results based on clinicians' observation of CIDI assessments. Psychiatrists scored a DSM-III-R criteria checklist either while observing or after administering 20 CIDI interviews. Overall diagnostic concordance between the checklist and CIDI diagnoses was found to be good (kappa = 0.78). Good diagnostic agreement was also found for 3 groups of DSM-III-R disorders: depressive disorders (kappa = 0.84), psychoactive substance use disorders (kappa = 0.83) and anxiety phobic disorders (kappa = 0.76). These results are consistent with the results from a similar comparison between the CIDI and checklist results for ICD-10 diagnoses.

Dietary intake, exercise, obesity and noncommunicable disease in rural and urban populations of three pacific island countries

Abstract: Dietary intake surveys of rural and urban communities in three Pacific Island countries were conducted using an adjusted 24-hour dietary recall method. Dietary survey samples were drawn from noncommunicable disease surveys of Melanesians and Indians in Fiji, Micronesians in Kiribati and Melanesians in Vanuatu. Comparisons of total energy and macronutrient intakes and of obesity, hypertension, diabetes mellitus, serum cholesterol and physical activity levels revealed similar rural/urban trends. Urban subjects were more obese than rural ones, had higher prevalence rates of diabetes and hypertension, and generally had higher cholesterol levels. Rural subjects were leaner, suffered less from diabetes and hypertension, and had greater total energy intakes than urban dwellers. Rural people ate a greater proportion of carbohydrates, while urban subjects ate proportionally more protein and fat, apart from the outer Kiribati atolls with high coconut intakes. Rural subjects in all three studies had higher levels of physical activity. These studies provide persuasive evidence that exercise as well as diet has a significant effect on rural/urban differentials in obesity and noncommunicable disease, and that energy intake reflects energy expenditure.

Capsular Types of Streptococcus pneumoniae Isolated from Blood and CSF During 1982–1987

Abstract: Knowledge about the type distribution of Streptococcus pneumoniae is fundamental to ensure an effective formulation of pneumococcal vaccine, especially with the possibility of producing a polysaccharide-protein-conjugated vaccine for the prevention of invasive disease in children. During the 6-year period 1982-1987, we received and typed 10,298 isolates from patients with invasive pneumococcal disease: 7,812 (76%) from blood and 2,486 (24%) from CSF. Of all isolates, 81% were recovered from individuals in Europe and 23% were from children. In order of frequency, S. pneumoniae types 6A + 6B, 14, 18C, 19F, 1, 7F, 23F, 19A, 4, and 5 were most commonly isolated from children, and types 3, 1, 14, 7F, 4, 6A + 6B, 8, 23F, 9V, and 19F, from adults. The pneumococcal types in the currently available 23-valent vaccine represented 87% of all isolates in this study, but the proportion of vaccine types varied somewhat with age and source. In all pneumococcal groups included in the vaccine, the vaccine types represented > 80% of the isolates, except in groups 6, 15, and 18.

Evaluation of a commercially available second-generation immunoglobulin G enzyme immunoassay for detection of Helicobacter pylori infection.

Abstract: We evaluated a commercially available second-generation anti-H. pylori immunoglobulin G enzyme immunoassay (EIA) (Cobas Core Anti-Helicobacter pylori EIA; Roche S. A., Basel, Switzerland) for serodiagnosis of H. pylori infection. The results of the assay were assessed in relation to the results of bacterial culture, urease testing, and histological Giemsa stain of gastric biopsy specimens from 1,134 patients with a variety of symptoms relating to the upper gastrointestinal tract. H. pylori was detected in biopsy specimens from 660 (58.2%) patients: 6 had a normal mucosa, 123 had chronic gastritis only, and 531 were found to have chronic active gastritis by histology; endoscopy showed duodenal and gastric ulcers in 137 and 64 patients of the last two groups, respectively. The test was evaluated with different age and ethnic groups. The prevalence, sensitivity, specificity, and positive and negative predictive values were, respectively, (i) for Belgian patients between 18 and 40 years old, 34, 93, 95, 91, and 96%; (ii) for Belgian patients more than 40 years old, 53, 96, 91, 93, and 95%; and (iii) the Mediterranean patients more than 17 years old, 87, 94, 70, 95, and 64%. All sera showing discordant immunoassay results compared with the results of histology and culture of biopsy specimens, as well as those with borderline immunoassay results, were tested further by immunoblotting. Among the EIA results considered false negative, we demonstrated an absence of seroconversion in 14 of 19 patients tested by immunoblotting. Among the EIA results considered false positive, immunoblotting showed the presence of specific antibodies in 28 of 37 patients tested. Among the borderline results obtained in the first assay with 22 patients' sera, a second assay showed positive results in 10 patients (8 were positive by immunoblotting) and negative reactions in 10 patients (9 were negative by immunoblotting), whereas 2 remained borderline. These data indicate that sera showing borderline immunoassay results must be tested again. In conclusion, this commercially available second-generation EIA, which is easy and quick to perform, was found highly reliable for the serodiagnosis of H. pylori infection.

Epidemiology of Trachoma in Bebedouro State of São Paulo, Brazil: Prevalence and Risk Factors

Abstract: Trachoma was considered to have been 'eradicated' from the state of Sao Paulo, Brazil, until 1982 when a number of new cases of trachoma were reported in preschool children in Bebedouro, a small town in northwestern Sao Paulo. A household survey was undertaken to assess the prevalence and epidemiological characteristics of trachoma. A total of 2939 people of all ages was examined having been selected from a two-stage probalilistic household sampling frame based on census data. Overall, 7.2% of the population had evidence of one or more signs of trachoma and 2.1% had inflammatory trachoma. Inflammatory trachoma was more common in children aged one to ten years, especially in the peripheral urban and rural areas, and was more common in boys. The presence of chlamydia was confirmed by direct fluorescent antibody cytology. No cases of blindness due to trachoma were seen. A number of socioeconomic and hygiene variables were studied in order to determine the independent risk factors for trachoma in a household. Variables significantly associated with the occurrence of trachoma in the household were the number of children in the house aged one to ten years, the 'per capita' water consumption, the frequency of garbage collections, source of water, and the educational level of the head of household. Clustering of trachoma in different parts of this community was entirely explained by the concentration of households with these characteristics.

Progress and Stagnation: Changes in Fertility and Women's Position in an Indian Village

Abstract: This paper compares women's status, fertility, and contraceptive use in 1975 and 1987 among married women aged 15–26 in a Maharashtra village. Changes in women's position over the 12 years were both positive and negative. Although education and age at marriage had increased, the 1987 cohort was more conservative in many respects. Fertility appeared to be declining, and women were increasingly completing their families quickly and then undergoing sterilization. However, the decline in fertility goals was not primarily due to changes in women's status but to the active sterilization campaign in the community. The one constraint on fertility limitation was the need for sons, and in this some indicators of women's status – education, age at marriage and distance from the women's natal home – made a significant difference. The finding that women's autonomy seemed to be related to ‘marriage distance’ deserves further study, particularly in South Asia and other patrilocal societies.

Progress towards the global elimination of neonatal tetanus.

Abstract: Neonatal tetanus (NT) can be effectively prevented through immunization and clean delivery practices. However, NT claimed the lives of over 433,000 infants in 1991. It is endemic in 90 countries throughout the world. Community-based neonatal tetanus mortality surveys helped to determine the true incidence of NT and revealed that, before immunization and clean delivery programmes were well established, approximately 1 million children contracted NT each year, of which 800,000 died. Mortality rates varied markedly by locale, ranging from 0 to 70 NT deaths per 1,000 live births. NT is still one of the most underreported notifiable diseases, and routine reporting systems identified only 4% of the NT cases estimated to have occurred in 1990. Based on WHO estimates, tetanus toxoid (TT) immunization and clean delivery practices prevented over 793,000 infant deaths in 1991. Of the 433,000 infants who died of NT that year, approximately 212,000 died in South-East Asia; 127,000 in Africa; 46,000 in the Western Pacific; 37,000 in the Eastern Mediterranean; and 1,300 in Europe. The Pan American Health Organization, using a separate methodology to estimate mortality, calculated that 10,500 newborns died of NT in the Region of the Americans. NT consistently clusters in geographical areas and population groups where shared practices or the environment enhance the risk of cord contamination. 80% of the newborns who died of NT in 1991 were born in South-East Asia or Africa. Of the 90 countries endemic for NT, 10% produce 80% of the world's NT deaths. NT also clusters at country level.(ABSTRACT TRUNCATED AT 250 WORDS)

Chagas disease: epidemiology and prospects for interruption of transmission in the Americas.

Abstract: American trypanosomiasis, or Chagas disease, is a parasitic disease caused by the haemoflagellate protozoa, Trypanosoma cruzi. The human infection occurs only in the Americas, where it is widely distributed in the periurban and rural areas of tropical and subtropical countries, from Mexico to Argentina and Chile. It is transmitted to man and other mammals mainly through insects, the triatomine bugs. As an enzootic disease, it extends from approximately latitude 42.5 degrees N (northern California and Maryland) to latitude 43.5 degrees S (southern Argentina and Chile). The results of several serological surveys indicate an overall prevalence of 16-18 million infected individuals. Up to 30% of those infected will develop the cardiac and/or hollow viscera irreversible lesions that characterize chronic Chagas disease. The endemic countries can be divided into four groups according to several indicators such as the number of confirmed human cases, the prevalence of seropositive tests in blood donors and population samples, the presence of infected vectors and reservoirs, and the existence or absence of coordinated actions towards the control of this disease. The domestic cycle of transmission, involving man and domestic animals such as dogs, cats, and domestic triatomine bugs, is the one that maintains the infections in the rural and periurban areas. Some triatomine species are well adapted to human dwellings where human and animal reservoirs are in intimate contact. The poor socioeconomic condition of the population and the domestic nature of the vector play crucial roles in maintaining the infection at an endemic level.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of T cell subsets during the recall of immunologic memory to Leishmania major.

Abstract: The contributions of different T cell subpopulations to the maintenance of immunity during secondary Leishmania major infections were analyzed in healed, resistant animals by depletion of T cell subsets in vivo. The strong delayed-type hypersensitivity mounted in immune genetically resistant mice upon challenge with viable promastigotes was mediated by both CD4+ and CD8+ T cells. Each T cell subpopulation alone contributes, although to a different extent, to the resolution of secondary lesions; both subsets, however, are required for an efficient and rapid healing of the secondary lesions and the decrease in the parasite burden in infected tissues. The results indicate that in immune, genetically resistant CBA mice, the activity of both T cell subsets is required for successful resistance to reinfection and an efficient maintenance of immunity.

Pain control: Barriers to the use of available information

Abstract: One of the World Health Organization's (WHO) top priorities is cancer pain relief. Simple guidelines for assessing and relieving pain have been developed, published, and field tested. WHO has concluded that there is enough knowledge currently to permit an approach to cancer pain relief that can be implemented on a worldwide basis. This information, when used correctly, allows pain control in 75% or more of patients with cancer pain. However, numerous barriers prevent the application of this knowledge and the achievement of cancer pain relief

The endemic treponematoses: not yet eradicated.

Abstract: The endemic treponematoses which comprise yaws, endemic syphilis (bejel) and pinta constitute a group of potentially disabling and disfiguring infections which primarily afflict children in tropical and subtropical areas. Foci where these diseases are now endemic have a patchy distribution and are typically confined to underprivileged communities living in remote rural areas, with little or no access to health services and removed from the mainstream of socioeconomic development. A drastic decline in the prevalence of these infections was brought about by the implementation of mass treatment campaigns with penicillin under the technical guidance of WHO and with material support from UNICEF in the 1950s and 1960s. These worldwide campaigns against the endemic treponematoses halted disease transmission in many areas and held the promise of complete eradication if intensive surveillance could be continued for some time with the increasing involvement of the basic health services. National campaigns were so successful that relatively low priority was given to the preparation of the rural health services for this new task. The failure of many countries to integrate active control measures into the functions of the rural health services led to the gradual build-up and extension of treponemal reservoirs and the resurgence of foci of increased disease transmission particularly in communities where standards of hygiene and health care had remained low. In a number of former endemic foci only low-level transmission persisted; in a few areas disease prevalence increased dramatically to reach pre-campaign levels. The lack of technical and financial resources limited the success of renewed national control activities in the most affected areas. Today, with waning interest in these diseases confined to remote, and thus silent, population groups, and a decreasing ability of health staff to identify cases, data collected by countries need to be supplemented by information from other sources in order to arrive at a more valid assessment of the situation concerning the endemic treponematoses. Central and West Africa are most severely affected by the resurgence of the endemic treponematoses. In recent years a number of countries (e.g. Ghana, Cote d'Ivoire and Mali) have launched renewed control efforts, often combining yaws or endemic syphilis control with other public health programmes. In Central Africa itinerant pygmy groups are still highly affected by yaws and are an important source of infection for the sedentary population with which they come into contact. In Chad, Sudan and Ethiopia, there is some evidence of persistent foci of endemic treponematoses; the epidemiological situation in Southern Africa is not well established.(ABSTRACT TRUNCATED AT 400 WORDS)