Talk:Buruli ulcer/Archive 1

{talkarchive}} {==Rewritten version==

See this mail and my reply for background. Cormaggio @ 10:00, 16 October 2005 (UTC)

Mycobacterium ulcerans infection, the "Buruli ulcer'' or "Bairnsdale ulcer" is an infectious disease which was first described in 1948 from the Bairnsdale district in south-east Australia. The disease was well known in Africa before this time but the mycobacterium had never been identified. [(James Augustus Grant)] in his book "A Walk across Africa" describes how his leg became grossly swollen and stiff with later a copious discharge. This was almost certainly the severe oedematous form of the disease, and his is the first known description of the infection. The infection occurs in well defined areas throughout the world, mostly tropical areas - in several areas in Australia, in Uganda, in several countries in West Africa, in Central and South America, in south-east Asia and New Guinea. The name "Buruli Ulcer" comes from an area in Uganda where the disease was once most prevalent. In East Africa thousands of cases occur annually and in these areas the disease has displaced leprosy to become the second most important mycobacterial disease of man (after tuberculosis). The mycobacterium has been identified in stagnant or slowly moving water sources in endemic areas and in aquatic insects (Naucoridiae). Transmission to man may be by means of insects or by a contaminated aerosol generated from decaying vegetation in the water source. Infection in Australia has occurred in an alpaca, in koalas, possums and other marsupials. The infection in most instances presents as a subcutaneous nodule, which is characteristically painless. In southern Australia the presentation is more often as a papule (or pimple), which is in the skin (dermis) rather than subcutaneous (beneath the skin). The infection is mostly on the limbs, most often on exposed areas but not on the hands or feet. In children all areas may be involved, including the face or abdomen. A more severe form of infection produces diffuse swelling of a limb, which, unlike the papule or nodule, can be painful and accompanied by fever. Infection may frequently follow trauma, often minor trauma such as a small scratch. The disease is primarily an infection of subcutaneous fat, resulting in a focus of necrotic (dead) fat containing myriads of the mycobacteria in characteristic spherules formed within the dead fat cells. Skin ulceration is a secondary event. The mycobacterium produces a toxin, named mycolactone, which causes this fat necrosis and inhibits an immune response. Healing may occur spontaneously but more often the disease is slowly progressive with further ulceration, granulation, scarring, and contractures. Secondary infection may occur with other nodules developing and infection may occur into bone. Although seldom fatal the disease may result in considerable morbidity and hideous deformities. Treatment is primarily by surgical excision of the lesion, which may be only a minor operation and very successful if undertaken early. Advanced disease may require prolonged treatment with extensive skin grafting. Presently available antibiotics are not effective in the primary treatment of the disease but may help to prevent recurrence after surgery. The disease is more likely to occur where there have been environmental changes such as the development of water storages, sand mining and irrigation. It is a major health problem in many countries in West Africa.

Merge
It's clear that two articles refer to the same thing. I'd have gone ahead and just did merge except the Mycobacterium ulcerans article contains a lot of medical terminology that I am not familiar with so I don't feel very qualified to make the merge. -- Whpq 18:20, 8 March 2007 (UTC)
 * I don't agree that the articles should be merged. There seems to be an article for every known actinobacterium, although most are just stubs. Now I'm not an expert, but I guess that not every actinobacterium causes a disease in humans, so it would be wrong to have an article for the bacteria that don't cause a notable disease, but only a redirect for those that do. There's precedent for keeping both: see Mycobacterium leprae and leprosy or Mycobacterium tuberculosis and tuberculosis. Having said that, much of the content of the M. ulcerans article does need moving into this one, as it spreads considerably into the realm of the disease it causes. What do you think? --Smalljim 10:00, 24 March 2007 (UTC)

Symptoms
Some changes should be made in the description of the symptoms.

I believe the ulcerated form is more found than the nodule. Although a nodule might occur more often and frequently before developing into an ulcer, patients in African countries tend to wait to seek health care until the disease has developed into the ulcerated stage, thus (over)representing more ulcers.

Also, the infection can occur on hands or feet, so 'rarely' should be inserted in that sentence.

More importantly, about the physical trauma that seems to occur before infection. There is no proof at all for this! It is suspected that minor trauma or insect bites could introduce the mycobacterium into the skin, but there is no solid proof yet. This should be adjusted in the text.

East Africa
"In East Africa, thousands of cases occur annually and in these areas the disease has displaced leprosy to become the second most important mycobacterial disease of man (after tuberculosis)." OK, first of all, there is no cited reference for this statement. Secondly, the article and its accompanying map both focus on West Africa, and I believe the author intended to say West, but typed East. Similarly, the article only mentions the temperate South of Australia, whereas the North is tropical. I have deleted the quoted sentence above.--71.36.127.39 (talk) 17:17, 29 September 2016 (UTC)

2020 Update
Hi all, I'm going through the article, updating where possible. Just wanted to leave a section here to explain some larger changes for posterity (since it doesn't look like anyone is using this talk page; if someone would like to discuss them, I'm happy to!).
 * In this edit I removed a couple of paragraphs on insect transmission that were expansively descriptive and sourced to papers that are now almost 20-years old. I think the level of detail was a bit much for an overview on this disease, so I replaced them with a couple of sentences sourced to newer reviews. Removed material:

Recent evidence suggests insects may be involved in the transmission of the infection. These insects are aquatic bugs belonging to the genus Naucoris (family Naucoridae) and Diplonychus (family Belostomatidae).

One hypothesis is that humans and other animals, could be contaminated or infected by biting insects such as water bugs. Aquatic bugs are cosmopolite insects found throughout temperate and tropical regions especially rich in freshwater. They represent about 10% of all species of Hemiptera associated with water and belong to two series of the suborder Heteroptera: the Nepomorpha, which include four superfamilies whose members spend most of their time under water, and the Naucoroidea, which include a single family, the Naucoridae, whose members are commonly termed creeping water bugs.

Whether found in temperate countries like France or tropical ones like Ivory Coast, aquatic bugs exhibit the same way of life, preying, according to their size, on mollusks, snails, young fish, and the adults and larvae of other insects that they capture with their raptorial front legs and bite with their rostrum. These insects can inflict painful bites on humans as well. In the Ivory Coast, where Buruli ulcer is endemic, the water bugs are present in swamps and rivers, where human activities such as farming, fishing, and bathing take place. Present findings describing the experimental transmission of M. ulcerans from water bugs to mice are in good agreement with the possibility of this mode of transmission to humans by bites.

Also in strong support of this hypothesis was the localization of M. ulcerans within the salivary glands of Naucoridae. Local physiological conditions of this niche appear to fit the survival and the replication needs of M. ulcerans but not those of other mycobacteria. Surprisingly, infiltration of the salivary glands of Naucoridae by M. ulcerans does not seem to be accompanied by any tissue damage similar to the ulcerative skin lesions developed by bitten individuals and mediated by the cytotoxic activity of the mycolactone and other toxins produced by M. ulcerans. The inactivation of the latter toxins could be the result of salivary enzymatic activities, which remain to be determined.

Happy to discuss with any interested. Otherwise I'll just post here to explain things that would be a bit much to cover in an edit summary. Cheers! Hope all are well! Ajpolino (talk) 22:43, 29 April 2020 (UTC)

Changing reference format
Hi, just a note to say that I changed the format of the references after seeing this discussion at the Featured article candidates page. Basically several regular reviewers there mentioned that they find it cumbersome to verify citations when they point to the entire page range of an article. So as I've been re-writing this article, I've been experimenting with a reference format that seems more common on the non-science pages here, where the full work is cited at the end, and the in-text reference points to a narrower page range where the actual cited fact(s) came from. In the particular case you pointed out, I haven't neglected the Cochrane citation, it's just at the end, in full, in the "Works cited" section. If you'd like to discuss the referencing in this article in general, I'm more than happy to. I hope all is well. Ajpolino (talk) 02:55, 4 June 2020 (UTC)