Yaws truly--a survey of patients indexed under 'yaws' and a review of the clinical and laboratory problems of diagnosis.
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Bone Diseases↗
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Neuro-ophthalmological study of late yaws. I. An introduction to yaws.
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Child↗
Yaw direction neurons in the cat inferior olive.
1. Single units that responded to yaw rotation were recorded extracellularly in the caudal inferior olive (IO) of barbiturate-anesthetized cats. Of 276 neurons, 55 responded reliably to yaw, and extensive quantitative data were recorded from 25. 2. No yaw-sensitive IO neuron responded to somatosensory or auditory stimuli but two responded, though unreliably, to flash. 3. Yaw-sensitive IO cells fired at low (1-4 spikes/s), irregular rates during one direction of rotation. Though cells responded reliably during yaw, firing rates varied considerably from cycle to cycle. Rotation speed and acceleration were not represented in any cell's firing rate. 4. Eighty five percent (47/55) of yaw-sensitive cells fired during contralateral rotation, 9% (5/55) during ipsilateral rotation, and 6% (3/55) fired from late in the ipsilateral phase of a sinusoidal oscillation to the middle of the contralateral phase. 5. Responses were tested to 0.1-Hz sinusoidal yaw oscillations with a range of peak angular velocities (1-200 degrees/s). Thresholds were not sharp because of the cycle to cycle variability in response rates but were estimated using averaged responses. The peak rate of the most sensitive cell was driven to criterion (2 SD above spontaneous rate) by an oscillation with a peak velocity of 1 degrees/s. Other cells reached criterion between 5 and 50 degrees/s. 6. Sinusoidal oscillation at all frequencies tested (0.01-0.5 Hz) elicited approximately the same firing rates. Even at 0.01 Hz cells responded well. Responses lagged acceleration by approximately 25 degrees at 0.01 Hz and shifted to later parts of the cycle as frequency increased so that firing lagged acceleration by approximately 200 degrees at 0.5 Hz. 7. Histological reconstruction showed that yaw-sensitive neurons were recorded in olivary subnucleus beta (N beta), the dorsal cap of Kooy (DC), the posterior medial region of the medial accessory division of the inferior olive (MAO), and in the medial-lateral center of the caudal MAO. 8. Yaw-sensitive neurons in the inferior olive provide a signal to the cerebellum that indicates the direction of passive rotation over a wide range of velocity and acceleration. The signal from individual neurons does not reliably encode either rotation velocity or acceleration. Yaw-sensitive IO neurons are therefore unlike other central vestibular neurons but are similar to somatosensory IO cells which signal the presence, but not the intensity of a stimulus.
Action Potentials↗
After smallpox eradication: yaws?
The WHO-coordinated Smallpox Eradication Program (SEP) has reduced the number of smallpox-endemic countries from 30 to 1, and now expects to complete the eradication of smallpox after a 10-year campaign. Campaigns to eradicate yaws were begun in the early 1950's with WHO and UNICEF support, and have greatly reduced the prevalence of that disease. Yaws has not yet been eradicated from any large geographic area, however, and is already resurgent in some countries. Some of the differences between the two diseases and available control measures are discussed. The thesis of this paper is that yaws programs have been deficient in failing to aggressively seek and contain yaws cases and contacts after mass treatment campaigns reduced yaws prevalence to low levels. It is further suggested that by using a modified SEP-type strategy to focus investigation and control efforts on infections yaws cases and their contacts, and by taking advantage of new methods to obtain more accurate diagnosis of yaws cases in the field, it should be possible to control yaws more effectively and efficiently, and perhaps to eradicate it. Outstanding barriers to yaws eradication are also discussed.
Adolescent↗
Integration of yaws control and primary health care.
Where a primary health care (PHC) system (e.g., a community health worker and a health center as the first referral level) is fully operational, control activities for yaws should be part of PHC. Where the whole population is adequately covered, the PHC system is responsible for early detection of cases of active clinical yaws, treatment and follow-up of these cases, treatment and follow-up of contacts, and health education related to yaws control. In circumstances where PHC is not as yet fully implemented, the structure for a yaws control program must be different. In areas with adequately functioning static health services or with a nascent PHC system, yaws control could be started as a vertical program--initial treatment survey and resurvey by a yaws team working in close collaboration with a health worker selected by the community. Subsequently, active yaws surveillance is taken over by that worker who also assumes the other functions of primary health care. In areas with nonexisting or poorly functioning static health services, a program for yaws control should not be implemented because control and effectiveness are likely to be poor.
Adolescent↗
Yaws in Colombia.
By the beginning of this century, yaws was a well-known endemic disease in Colombia. Colombian authorities estimated that by early 1930 there were 70,000 active cases of yaws, most of which were located in the Pacific coastal regions. With the advent of penicillin therapy, Colombia organized an anti-yaws campaign, which began in 1950. The campaign relied on the use of penicillin and house-to-house case finding. From 1950 to 1953 more than 111,000 persons with active cases of yaws and 125,000 of their contacts were treated with penicillin. The reported incidence of yaws declined dramatically, and by 1973 only 573 cases were reported in the endemic areas. By 1983 this number had fallen to 31. Because of the persistence of small foci of yaws activity, the anti-yaws campaign has been reorganized to provide a firm basis for the final eradication of the disease in Colombia.
Colombia↗
Yaws in the Americas, 1950-1975.
Yaws was introduced into the Americas by African slaves beginning in the 16th century and may have already been present before the arrival of Columbus. In the 1950s, programs for the eradication of yaws were undertaken in almost all American countries in which yaws was endemic. By mass treatment of cases and contacts with penicillin, the programs against yaws have dramatically reduced the incidence of reported cases throughout the Western Hemisphere from greater than 44,000 cases per year during 1950-1954 to 437 cases in 1975. In Brazil, efforts against yaws reduced the number of patients treated by 99% between 1965 and 1974. By 1975, yaws apparently remained a significant public health problem in only a few communities in Brazil, Columbia, Dominica, Ecuador, Haiti, Peru, St. Lucia, and St. Vincent, and possibly in Guiana and Surinam. It may be possible to eliminate infectious yaws entirely from the Western Hemisphere within the next few years.
Humans↗
Occurrence of congenital, cardiovascular, visceral, neurologic, and neuro-ophthalmologic complications in late yaws: a theme for future research.
Late lesions of yaws are thought to be limited to skin, bones and joints, without congenital, visceral, or central nervous system (CNS) involvement. However, the treponemes isolated from patients with yaws, endemic syphilis, and venereal syphilis are genetically identical subspecies of Treponema pallidum. The controversy surrounding distinctions between syphilis and yaws is presented in its historical context, and reports of congenital, visceral, and CNS complications of yaws are reviewed. Isolation of treponemes from aqueous humor, as well as CSF abnormalities in 24.9% of 902 patients with yaws, indicate the existence of CNS involvement. The high prevalence of tropical myeloneuropathies of unknown origin discovered in areas of previous treponemal endemicity, particularly in Jamaica and Colombia, may represent late complications of yaws. Careful analysis of the collected evidence indicates that potential sequelae of yaws include congenital, visceral, and tertiary CNS lesions identical to those of venereal syphilis. The current worldwide resurgence of endemic treponematoses provides an unparalleled opportunity to settle conclusively questions still unanswered regarding the natural history of these infections.
Cardiovascular Diseases↗
Studies on a focus of yaws in Ubangi, Zaire.
Yaws (buba, Frambösie, pian), a non-venereal treponematosis of skin and bones is a tropical disease that affects primarily children. Eradication programs launched between 1950 und 1970 reduced the incidence substantially; resurgences, however, have been reported from several countries. We have studied a geographically isolated focus of yaws in the Ubangi area of northwestern Zaire. In survey I, in 1981, of the 4.407 participants from 11 villages, 348 (7.9%) had active lesions of yaws. All patients and their contacts were treated immediately with benzathine penicillin G. In survey II, in 1982, in 6 of the previously studied villages, of 5,390 participants, 136 (2.5%) had active lesions of yaws. In 1981, the predominance of primary lesions (86%) and high numbers of patients in all age groups, with the highest prevalence (23.4%) in children 10-14 years of age, suggest that yaws recently recurred at this focus. In 1982, only 25.7% of the lesions were primary and the highest prevalence (6.5%) had shifted to the younger age group of 5-10 years-old. In survey I more males (63%) were infected in the age group 0-24 years, and more females (89%) in those over 40 years. In survey II, more males (61.3%) were infected in the age group 0-14 years, and only females (100%) in the age groups 25 years and older. Seventy-one percent (1981) and 86% (1982) of the initial lesions were on the lower limbs. Participation of the population in survey I was 41.7% and was greatest (62%) in the locality where there was a newly established dispensary. In survey II, participation rose to 73.8%. Areas adjacent to the focus of yaws with longstanding dispensaries were free of yaws.(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
Relationship between direction of rolling and yawing of golden hamster and sea urchin spermatozoa.
As a first step towards understanding the function and mechanism of spiral movement of spermatozoa swimming through a medium, the direction of rolling (rotational movement of the spermatozoa around their long axis) and that of yawing (circular motion of spermatozoa upon the surface of a glass microscope slide and coverslip) were examined for golden hamster and sea urchin spermatozoa. Most golden hamster spermatozoa yawed clockwise over the upper surface of a glass slide when viewed from above, whereas in most sea urchin spermatozoa yawing was counterclockwise. Under the lower surface of a coverslip, the direction of yaw of golden hamster or of sea urchin spermatozoa was reversed. Most golden hamster spermatozoa rolled counterclockwise as seen from the anterior end, whereas all examined sea urchin spermatozoa rolled clockwise relative to the observer. On the basis of quantitative analysis of the proportion of spermatozoa rolling (or yawing) clockwise to those rolling (or yawing) counterclockwise, a close relationship between the direction of rolling motion and that of yawing motion was shown for both golden hamster and sea urchin spermatozoa.
Animals↗
Yaws in West Sumatra, Indonesia: clinical manifestations, serological findings and characterisation of new Treponema isolates by DNA probes.
The results of a yaws survey on the island of Sumatra in Indonesia are presented. The prevalence of yaws in the investigated region was found to be very high, a minimum of 300 cases per 100,000 individuals, which indicates that yaws is far from being eradicated and that campaigns for treatment are necessary. Patients suffering from early infectious yaws showed florid skin lesions. Of 101 serum samples from such patients, 100 had a positive reaction in one or more treponemal tests. The Treponema pallidum haemagglutination assay was found to be the most sensitive test (97% positive) in detecting antibodies against Treponema pallidum subsp. pertenue, followed by the fluorescent treponemal antibody absorption test (94%), the Venereal Disease Research Laboratory test and the TmpA enzyme immunoassay (91%), and analysis by Western blot using Treponema pallidum antigens (88%). Of 42 asymptomatic contacts of yaws patients 32 showed positive reactions in one or more tests, indicating that many people in the investigated region have been infected with treponemes. Eight new Treponema pallidum subsp. pertenue strains were isolated from yaws skin lesions. In vitro amplification of treponemal DNA and hybridisation with specific DNA probes showed that all eight strains were identical with Treponema pallidum subsp. pertenue CDC 2575, with regard to the subsp. pertenue specific tyfl gene.
Adolescent↗
Surveillance and control of resurgent yaws in the African region.
Yaws, once one of the most common infections in Africa, was expected to be eliminated in some countries and controlled in others after the mass treatment campaigns sponsored by the World Health Organization and the United Nations Children's Fund during the 1950s and 1960s and the implementation of improvements in education, sanitation, and other health-promoting activities. However, the curtailment of yaws control activity allowed the reservoir of untreated yaws to grow unchecked, and the number of reported cases of active yaws has increased in certain parts of Africa, especially in West Africa. In the Central African Republic, the prevalence of yaws is notably high among the Pygmies. Renewed programs for yaws control are under consideration. Mass campaigns are still necessary in some developing countries for the control of certain diseases but should be complementary to the development of general health services and should not be limited to the administrative borders of a given country.
Africa↗
Feasibility of eradicating yaws.
The elimination of yaws from large geographic areas provides evidence that global elimination of person-to-person yaws transmission is feasible. The failure to reach that goal to date is the result of managerial rather than technical deficiencies. If the eradication of yaws can be accomplished, it should be done to reduce the suffering that is associated with the disease. In addition, a positive benefit-cost ratio is likely to be realized within a period of decades, and in areas endemic for yaws, its elimination could well provide a basis for the development of a strong system of primary health care. The decision to eliminate yaws must be made deliberately by the World Health Assembly with full knowledge of the implication of not making such a decision. A positive decision would result in enriched lives for countless potential victims of yaws and save the world money in the long term.
Humans↗
Papua New Guinea. Yaws problems assessed.
The present status of yaws in Papua New Guinea cannot be determined because of the lack of data. Because yaws was deemed under control as a result of the nationwide total mass treatment campaign in the late 1950s and limited regional effort in the late 1970s, the health department lost interest in yaws and pursued other diseases. Individual reports from certain areas of Papua New Guinea have provided the only information on yaws since 1978. These reports concentrated on outbreaks on Karkar Island in the Madang Province and indicated the possibility of a recurrence of yaws. It was not until early 1984, when further reports became available from other provinces in the country, that the national health department renewed its interest in yaws. Monthly reports are currently being collected from hospitals, health centres, and aid posts throughout the country. This effort was started in 1984, however, and no conclusions are available. The initiation of a nationwide survey seems inevitable at this stage. For this to be made possible, capital and appropriate manpower are needed.
Humans↗
Effect of repeated mass drug administration on the transmission of yaws: a retrospective genomic epidemiology study.
BACKGROUND: Yaws, a neglected tropical disease caused by Treponema pallidum subspecies pertenue (T p pertenue), has evaded eradication, in part due to a high proportion of asymptomatic cases. Repeated mass drug administration (MDA), whereby an entire population is repeatedly treated irrespective of disease, could provide a solution. Here, we aimed to investigate the effect of MDA on the genomic epidemiology of T p pertenue. METHODS: We conducted a retrospective genomic epidemiology study on samples collected during a cluster-randomised trial of mass administration of azithromycin for yaws eradication in the Namatanai District of Papua New Guinea. Participants were in 38 wards (administrative units encompassing several villages) in three local-level government areas (LLGs). The experimental group received an initial round of MDA followed by two further rounds 6 months and 12 months after the first round. The control group received one round of MDA followed by two rounds of treatment targeting clinical cases and contacts only, on the same schedule as the MDA in the experimental group. A follow-up survey on both groups was done 18 months after the first MDA round. Swab samples were collected at each round from ulcerative and nodular skin lesions, and blood was collected by finger-prick for serological testing at 18 months. Metadata on ulcer size (cm) and duration (days) were recorded at each round, and treponemal and non-treponemal antibodies were recorded at 18 months. Samples from swabs positive for T p pertenue underwent library preparation and whole-genome sequencing. We examined the phylogenetic relationships between genomes, linking them with geospatial and patient metadata to understand the impact of MDA on T p pertenue diversity and transmission. FINDINGS: Swabs collected from 297 individuals with active yaws from April 30, 2018, to Nov 2, 2019, yielded 222 good-quality Tp pertenue genomes. We identified 20 sublineages of T p pertenue in the control group and 21 in the experimental group at the beginning of the study. At the end of the study, there were 13 sublineages in the control group and three in the experimental group, of which two persisted in both groups. Three sublineages not detected at baseline were observed in the control group after commencing MDA. The two sublineages that persisted in both groups had non-synonymous mutations in penicillin-binding proteins. One of these sublineages evolved macrolide resistance in three individuals and was associated with lowered treponemal antibody (p=0·0036) and longer ulcer duration (p=0·015). Despite the study taking place within a small island, sublineages were geographically clustered, with pairs of samples from the same ward (odds ratio 7·1, 95% CI 5·7-8·8; p<0·0001) or neighbouring wards (4·3, 3·3-5·4; p<0·0001) more likely to share the same sublineages compared with pairs from different LLGs. Additionally, older individuals were more likely to share sublineages than were younger individuals (1·5, 1·2-1·9; p<0·0001). INTERPRETATION: Repeated MDA was successful in reducing and maintaining the genetic diversity of T p pertenue at a low level but was associated with the development of macrolide resistance. Yaws re-emergence after MDA was attributed to multiple sublineages, of which the majority were detected in the population before MDA. Participants within the same ward were more likely to share sublineages than those that were more widely geographically separated, suggesting that re-emergence was driven by local transmission. These findings could inform future yaws elimination strategies. FUNDING: European Research Council, EU, Provincial Deputation of Barcelona, Barberà Solidària Foundation, Wellcome, and Fundació "la Caixa".
Adolescent↗
Some epidemiologic aspects of yaws in the Ivory Coast.
Because of the prevailing high levels of yaws, a mass treatment campaign was conducted in the Ivory Coast from 1956 to 1970. In 1970, at the end of the mass campaign, less than 30,000 cases of yaws were reported. After 1970, a program of detection and treatment of remaining foci of infection was carried out to control the disease. The number of cases reported annually continued to decline until 1974, when the number of reported cases began to rise. Since 1980, the annual reported incidence of yaws has declined. It is concluded that the mass campaign of 1956-1970 reduced the endemicity of yaws in the Ivory Coast. However, significant foci of the disease remain, and efforts to detect and treat yaws must be continued to prevent a resurgence of this infection in the Ivory Coast.
Cote d'Ivoire↗
Yaws in Suriname.
Frambesia tropica, or yaws, is still prevalent in the urban population of some of the districts in Suriname. In 1911 a campaign against yaws, probably the first such campaign in the world involving treatment with salvarsan, was organized. It resulted in the rapid cure of all hospitalized patients. As a consequence of this success, the disease became less important to the medical authorities in the country. After introduction of penicillin (1945) for the treatment of yaws, the disease almost disappeared in Suriname. After 1970 new cases were diagnosed, and the resurgence of yaws in Suriname became apparent. The symptoms in these cases were attenuated in comparison to those described in standard handbooks. A survey of yaws in the different districts of Suriname was undertaken to determine the prevalence of the disease and its spread through the country in order to plan a new treatment campaign.
Adolescent↗
Pinta, yaws, and venereal syphilis in Colombia.
Three treponemal infections of man have coexisted in Colombia, South America for centuries. In former years, Colombia and Mexico were the world's most highly endemic countries for pinta. Within Colombia, highest rates of infection with pinta occurred among the mestizo and Indian populations in the Andean and Caribbean departments of Huila, Tolima, Antiochia, Magdalena and Cesar. Yaws occurred primarily in rural areas along the Pacific coast among descendants of African slaves. Infectious syphilis is most often reported from the three largest urban areas, and from three other densely populated departments in the Andean region. During the 21-year period from 1954 to 1974, almost four times as many cases of pinta as yaws were reported. The incidence rates of yaws and pinta have declined almost in parallel in Colombia, even though there has been a national campaign against yaws, but not against pinta. The incidence of primary and secondary syphilis increased only slightly during the same period. The total burden of reported treponematoses (excluding tertiary and congenital syphilis) declinded by over 40 per cent, while the ratios of reported yaws, pinta and infectious syphilis rose from 1:3:4 in 1954 to 1:7:975 in 1974.
Colombia↗