By Derek Yach, Victoria Gibbon and Victor Fredlund
Despite 45 years of research, Mseleni Joint Disease (MJD), an unusual geographically isolated degenerative disease, remains an unsolved public health mystery.
Found in the Maputuland region of KwaZulu-Natal, South Africa, it is named after the Mseleni Mission Station. MJD has only been found in patients from a Bantu-speaking background who are mainly of the Zulu culture. Notably, the people of Mseleni are neither culturally nor genetically different from other Bantu-speaking people in South Africa.
Epidemiological studies in the 1970s and 1980s (1, 2) described the disease prevalence by age and sex along with the degree of impairment. The last large field study (1981) obtained information on about 3,368 people and showed a prevalence of 7.4% in women and 3% in menwith rates over 25% in women over 50 years of age. The prevalence dropped off sharply beyond 25km from the Mseleni Hospital. Based on the sampling frame, researchers estimated that up to 3,000 were severely affected in the area (2). These earliest studies both highlighted that the prevalence among adults was more prominent in women, and a concentration of cases on the western side of Lake Sibaya near the Mseleni Hospital.
Since the 1980s, no large study of MJD prevalence within the region has been conducted, although there has been a reduction in new cases presented to the local hospital.
MJD only affects synovial joints; it is most often and severely localized to the hip. Clinical features include narrowing of the joint space, osteoarthritis, subarticular sclerosis, and other physical issues (3). Over time the disease progressively limits movement to various degrees of disability, from requiring the aid of a stick to reducing mobility to the use of the arms. The disease has had a documented impact on the local economy and schooling, and can compel affected individuals to rely on other community members for support.
While surgical hip replacement therapy has helped patients with their MJD symptoms, researchers have not been able to pinpoint the etiology of the condition. Gibbon et al. (2010) conducted a review of all the research conducted on the condition (see reference 3 for further details). Detailed environmental studies, water, food and geographic surveys failed to identify any causative agents. Studies on autoimmunity, infectious agents and genetics have not found any convincing cause. The pattern of the disease suggests a multi-factorial genetic and environmental cause. MJD is more prevalent among adult femalesand traditionally, men in the area were mainly migratory labourers, while women remained in the community throughout life, suggesting that by leaving the area men escaped exposure to the causative agent. These facts suggest an environmental component to the disease. Thus, Dr. V. Gibbon, Dr. D. Narayan and Dr. V. Fredlund are currently conducting a genetic study that assesses both the whole genome (DNA) and whole expression of that genome (RNA), aiming to look for altered genetic expression due to environmental interactions. This approach has the potential to shed light on the affected areas of the genome, which can be subsequently traced towards a single or multiple etiologies for the condition. Until we have an understanding of the etiology for MJD we cannot begin to effectively treat and prevent it.
The quest for the cause of MJD remains important. Conditions like this provide a rare opportunity to observe how our bodies are interacting with our environments with both positive and negative outcomes. Todays improved methodology provides better avenues to determine the cause/s for the disease. Understanding the cause may shed light on many other related arthritic conditions, not to mention lead to more effective treatments and, better yet, disease prevention.
The Mseleni area requires greater attention to support the affected communitys broader development needs.
We hope that this spotlight on MJD will stimulate a fresh look at the mysterious etiology and prevalence of the condition.
Derek Yach, MBChB MPH, is the Executive Director of the Vitality Institute. Victoria Gibbon, PhD, is an assistant professor and director of graduate studies at University of New Brunswick, and the department of Human Biology, Faculty of Health Sciences, University of Cape Town. Victor Fredlund, MBBS, is the medical manager of Mseleni Hospital in South Africa.
1. Fellingham SA, Elphinstone CD, Wittman W. Meseleni Joint Disease: Background and Prevelance. South African Medical Journal 1973; 2173-2180.
2. Yach D, Botha JL. Mseleni Joint Disease in 1981: Decreased prevalence rates, wider geographical location than before, and socioeconomic impact of an endemic osteoarthrosis in an underdeveloped community in South Africa. Int J Epi 1985; 14 (2): 276-284.
3. Gibbon VE, Harington JS, Penny CB, Fredlund V. Mseleni joint disease: A potential model of epigenetic chondrodysplasia. Joint Bone Spine 2010; 77: 399-404.
4. Rose J, Weiser TG, Hider P et al. Estimated need for surgery worldwide based on prevalence of diseases: a modelling strategy for the WHO Global Health Estimate. Lancet Glob Health 2015; 3 (52): 513-30)
Image: A pelvic radiograph from a patient with Mseleni Joint Disease. Photo provided by Dr. V. Fredlund.
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