Showing posts with label Africa. Show all posts
Showing posts with label Africa. Show all posts

Sunday, September 11, 2011

The African Snakebite Problem

© IRD / JF Trape
The following press eelease and some interesting photos can be found here.

A million and a half: the number of victims of poisoning after a snake bite each year in sub-Saharan Africa. An IRD researcher has analyzed hundreds of studies and medical reports published over the last forty years. So far, no large-scale review of the situation had been made and the health authorities underestimated the extent of the problem. Thus, today, only 10% of victims are treated because of lack of antivenoms and a non-medical staff awareness. However, clinical complications can be very serious or fatal. A bite of cobra or mamba can lead to death by asphyxiation - due to respiratory paralysis - in 6 hours following the accident. That of échide ocellated, a viper widespread in African savannahs, may in turn cause bleeding resulting in death within days. This new study provides the authorities with figures more accurate and reliable, allowing them to adjust their systems of care as close as needed

The best defense of snakes is a good offense. Some prove to be ruthless when they feel threatened. Each of his method. The Gabon viper, for example, injecting its venom deep into the muscles with its hooks than 5 cm long. The spitting cobra for his blind its victims of his venom. If only one bite of venomous snakes out of two, these reptiles are nonetheless a real danger to humans. The number of accidents is significant, particularly in sub-Saharan Africa where they constitute an important public health issue, neglected by health authorities.

Indeed, as recently shown in an IRD researcher, more than 300,000 people south of the Sahara are being treated each year as a result of a bite. But given the lack of access to health centers and the frequent use of traditional medicine, many cases go unreported. This figure does not reflect all of envenomation. Experts believe that it reflects that between one third and one fifth of reality. According to this new study, so there would be up to one and a half million victims a year. The death from a bite - probably also underestimated - reach for their number of 7000 and amputations in 6000 to over 14,000 per year.

While various specific studies have advanced estimates, no major review has been made so far. To fill this gap, the specialist conducted a meta-analysis, that is to say a critical review of existing scientific studies, taking into account the representation and heterogeneity of their results. To do this, he sifted through hundreds of scientific articles, conference proceedings, and clinical reports published from 1970 to 2010. This detailed study allows to announce much more reliable figures on the number of patients who had a snake.

This work has also helped point the finger at the conditions most conducive to accidents: 95% of bites occur in rural areas, especially in plantations. The people who run the greatest risk are farm workers. Yet in Africa, agriculture is the main economic activity.

Cities are not spared, even though the incidence of bites is about ten to twenty times lower than in rural areas. Thus, in some areas during the rainy season, the envenomation more than 10% of hospitalizations.

Among the most dangerous African species, two types of venom may be opposed, that of cobras and mambas, which is neurotoxic, and the snakes - which échide Frog Eye, the most common in savanna - which is bleeding and necrosis. In other words, the first cause respiratory paralysis, which can lead to death by asphyxiation between 1 and 6am. The second leads to edema and necrosis of the members and a hemorrhage can be fatal within days. The only effective treatment remains the injection of antivenin * intravenously as soon as possible after the bite to neutralize the toxic substance.

But the availability of these products is now small: only 10% of envenomations are treated. Given the lack of data so far, the problem remained underestimated by health authorities. Moreover, the high cost of these remedies and their short life span - 3-5 years - has discouraged supplies. Under these conditions, difficult to set budgets and allocate funds for the management of envenomation, the installation of equipment necessary for sensitization of medical personnel. In the absence of formation of the latter to the use of antivenoms, these treatments can produce disappointing results, discouraging reuse later. These chain reactions reduce claims. Manufacturers are reluctant to produce anti-venom so they are not safe to sell. Hence a reduction in terms of accessibility: the number of doses sold was divided by ten in Africa since the 1980s, from about 200,000 per year to less than 20,000 in the early 2000s.

This study suggests realistic figures needs antivenoms. Given the results, the specialist believes that 500 000 doses would be needed each year. The health authorities of these countries can now use these data to improve the quality of care for victims and deploy a system for identifying and monitoring.

Wednesday, March 23, 2011

Antivenom: Neglect, Confusion, & Hope

The world wide availability of antivenom is quite variable, but no where does it seem to be adequate. There are very few antivenom products that work on more than just a few species of snakes, and therefore it is necessary for each country or geographical area to have antivenom available for local species. This means local production is important in areas where people are bitten by venomous snakes. In the USA this week (March 21-26) is Poison Prevention Week. A a check of the news suggests that while antivenom is, to a degree, available in many places - this is not the case in other countries.The All African.com website is carrying a story from the Nairobi Star, that emphasizes the problems of a lack of antivenom in some African hospitals.
A woman spent three hours writhing in pain in a Teso hospital at the weekend before passing on after she was bitten by a seven-foot snake in her Amagoro semi-permanent house in Teso North District. The death of Mama Flora Odikor, 77, has earned the hospital the wrath of the Anglican Church and the deceased family who accused Kocholia District Hospital administration of negligence that saw the deceased spend three hours without getting anti-venom injection. Medics in Western Province have also raised concerns over the increase in the number of people who die from snake bites due to failure by the government to supply anti-venom drugs to most hospitals and health centres, adding that the region is prone to snakes. Flora's daughters, Margaret Odikor and Jacqueline Amoit, watched helplessly as their mother took her last breath from the bite of the poisonous cobra to confirm the agony patients who seek medical attention at the referral institution were facing at the hands of the hospital staff. Margaret recounted how the staff at the pharmacy, consultation and injection rooms denied having any stock of anti-venom with the available ones allegedly having expired, but only to produce them three hours later after a nurse insisted the government had supplied the drug the previous day.
Antivenom continues to be short supply in many countries, both developed and undeveloped. The Tasmanian Examiner reported in January that a lack of snake antivenom at regional medical centres could leave tourists and hikers in a perilous situation, according to Tasmania's main reptile rescue organisation. 
Reptile Rescue ranger Bruce Press said the lack of access to antivenom in regional areas was particularly dangerous as visitors to the state and possibly many locals do not realise they can only get full bite treatment in Launceston or Hobart. "If a bushwalker is out in the bush then they'll probably have to travel many kilometres just to get back into a town, only to then be told to go on to Hobart or Launceston," said Mr Press, who recovers snakes from an area spanning Buckland to Bicheno. "All the snakes here in Tasmania are dangerous and their venom can kill a human."
The Associated Press Pakistan has a story available on Dawn.com that describes an initiative in Pakistan to increase antivenom supplies. This article is interesting for several reasons, but it seems to somehow blame the US and Australia  for the shortage so those countries could make money by exporting antivenom. 
LAHORE, March 20 (APP): The University of Veterinary and Animal Sciences (UVAS) has launched an anti-venom production project to treat snake-bite victims in the country. Head of the project Dr Ziaullah Mughul told APP that every year around 50,000 people died in Pakistan from snake-bite. “Only five to six percent of anti-venom vaccine is made by the National Institute of Health (NIH) against a requirement of 150,000 dozes per annum and that too is not easily available in the market,” he added. “Most of the patients die due to the unavailability of anti-venom vaccine in the country, putting the number of deaths to 50,000 annually. Around 90 per cent of snake-bite deaths can be prevented if anti-venom is produced at local level. “During the recent flood, snake-bite contributed to five to six per cent of total deaths and vaccine had to be imported from India,” he said.Dr Ziaullah said locally produced vaccine, which would be effective against four snakes, could be available at Rs400 while vaccine imported from India cost Rs1,900 and it was effective for only one kind of snake. “A snake-bite victim needs four doses for complete treatment,” he added. For commercialization of the project, Rs400 million is needed while after its completion, anti-venom will also be available for export to earn foreign exchange, he said. The US and Australia were earning a big amount of money by exporting anti-venom drugs, he added.
Of course, US and Australian antivenoms are all but useless for venomous snakes in Pakistan.


Poison Prevention Week (PPW), in the USA, is the third week of March each year, and provides an opportunity for BTG, the International Healtcare Company that markets and distributes CroFab® (antivenom for crotalid snakes include rattlesnakes, copperheads and cottonmouths/water moccasins).  Their press release (follow link for complete press release) for 2011's PPW states that,
"Beginning in April when the weather gets warmer, one potential poisoning source – venomous snakebite – is more likely to occur.  Approximately 8,000 cases of venomous snakebite and five to six related deaths occur in the United States each year.  Venomous snakebites may have other serious consequences, including loss of a finger or toe, if not treated promptly.  Victims of snakebite should react calmly but swiftly in seeking medical attention.  CroFab® Crotalidae Polyvalent Immune Fab (ovine), an antidote for venomous snakebites from North American pit vipers, or crotalids (rattlesnakes, copperheads and cottonmouths/water moccasins), usually is available at emergency facilities in hospitals....Early use of CroFab® (within 6 hours of snakebite) is advised to prevent a patient's clinical deterioration and the occurrence of systemic blood-clotting (coagulation) abnormalities....For CroFab® full prescribing information, visit:  http://www.crofab.com."
Antivenom is a medical technology that has been available since the 1890's. It is relatively inexpensive to produce, works exceptionally well, and should be available to those who need it. However, the lack of profit, and the fact that each geographic region needs its own supply seems to be barriers to its availability. There is a company, looking for partners in the production of antivenoms, if you are interestes, visit Good Biotech Corporation's website.

Friday, December 10, 2010

Recently Discovered Diversity in Breviciptid Frogs


Callulina kreffti , Nieden, 1911.  
Photo Credit: Michele Menegon
Frogs of the family Brevicipitidae are endemic to Sub-Saharan Africa from Ethiopia southward to Angola and South Africa and is composed of five genera (Balebreviceps, Breviceps, Callulina, Probreviceps, Spelaeophryne) and more than 26 species. They were long considered part of the family Microhylidae. They are bizarre little frogs, most have rounded bodies with tiny legs, and members of the genus Breviceps (the most specious genus) use sticky skin secretions produced in their numerous skin glands, to hold amplexing pairs together because their legs are too short for the male to clasp the female. Breviceps  eggs are laid in burrows and undergo direct development. Recent investigations of the more arboreal genus Callulina has revealed the sky island clade to have more species than previously thought, and the newly described species have small ranges, and show a high degree of endemism in the Eastern Arc Mountains, a global biodiversity hotspot. The number of species before 2004 was one, C. kreffti was described by Fritz Nieden in 1911. C. kreffti was thought to have a continuous distribution throughout the montane forests of the Eastern Arc Mountains with its type locality at Amani in the East Usambara. However, specimens from other localities have proven not to be conspecific with C. kreffti. The northern Eastern Arc range has turned out to have numerous distinct species restricted to small, limited ranges. Five separate species have been described to date: C. kisiwamsitu de Sá et al., 2004, C. dawida Loader et al., 2009a, C. laphami Loader et al.,2010a, C. shengena Loader et al. 2010a, and C. stanleyi Loader et al., 2010a. Michelle Menegon and colleagues (2008) listed four undescribed species of Callilina from the Nguru Mountains based upon preliminary morphological and molecular data. Now, two of those species have been described by Loader et al. (2010b).  Callulina hanseni is from the Maskati side of the Nguru South Forest Reserve, Tanzania; and Callulina kanga is from the Kanga Forest Reserve, Mwomero District, Morogoro Region, Tanzania. Both species were found in shrubs and trees and C. hanseni was collected as high as 10 m above the ground. Both species inhabit primary montane rainforest. Thus there are now 8 species recognized in the genus Callinia, whereas there was only on prior to 2004; and there are more species in this genus yet to be described.

Literature
de Sá, R., S. P. Loader, and A. Channing. 2004. A new species of Callulina (Anura: Microhylidae) from the West Usambara Mountains, Tanzania. Journal of Herpetology, 38, 219–222.

Loader, S. P., G. J. Measey, R. D. de Sá, and P. K. Malonza. 2009a. A new brevicipitid species (Anura: Brevicipitidae: Callulina) from the fragmented forests of the Taita Hills, Kenya. Zootaxa, 2123, 55–68.

Loader, S. P., D. J. Gower, W. Ngalason,  and M. Menegon. 2010a. Three new species of Callulina (Amphibia: Anura: Brevicipitidae) highlight local endemism and conservation plight of Africa's Eastern Arc forests. Zoological Journal of the Linnean Society, 160, 496–514.

Loader, S. P., D. J. Gower, H. Muller, and M. Menegon. 2010b.  Two new species of Callulina (Amphibia: Anura: Brevicipitidae) from the Nguru Mountains, Tanzania. Zootaxa 2694: 26–42

Menegon, M., N. Doggart, and N. Owen. 2008. The Nguru Mountains of Tanzania, an outstanding hotspot of herpetofaunal diversity. Acta Herpetologica, 3, 107–127.