Part 1, Dr. R. Harrison: Strategies to reverse the neglect of tropical snakebite victims

This is a talk given by Dr. Robert Harrison from the Liverpool School of Tropical Medicine, on the occasion of the "One-day meeting: Topics on infection", organized by the Royal Society of Tropical Medicine and Hygiene, in London, on February 4th, this year.

As Dr. Harrison is one of the impulsors of the "Global Snake Bite Initiative", I would like to continue with his talk before moving forward. I'm adding the transcription of the speech. As it is quite long and really deserves to be listen and read with attention, I will split it into several post. The first part is mostly dedicated to present which could be the main reasons for such a high numbers of SB in Africa and Asia. 

I would like to start with the last slide of his presentation, that highlights these key points: 
* Snakebite is an important, neglected disease of the rural poor in Africa and Asia.
- more accurate data is needed on mortality, morbidity and socieconomic impact - raise     awareness.
- need Gov'ts and IHAs to recognize the neglected snakebite disease burden
* Current antivenom therapy can be effective but requires urgent improvement
- better regulatory control needed
- production and delivery of effective and affordable antivenoms
- need to establish regional training on clinical management of snakebite
- need Gov'ts and IHAs to support development and delivery of effective, affordable antivenom
*Need for funding agencies to support science devising more effective, affordable snakebite therapy

"I'm going to be talking about the strategies to reverse the neglect of tropical SB victims and to introduce that topic by describing to you that there are two main groups of snakes: The elapids that include the cobras, the mambas, the krait snakes that primarily cause a neuromuscular paralysis, and then you got the vipers, the pit vipers and the adders and so on that primarily cause cardiovascular effects: bleeding, sometimes coagulopathy, sometimes hypovolemic shock and the antivenom can be a very effective treatment for either of this pathologies as consequences of snakebite. 

Antivenom is a drug that has been around in its essence for over a hundred years and hasn't changed that much. Essentially what you do is you take the venom from a snake, you lyophilized that and then you resuspend it in the required amounts, in sub-toxic amounts and inject that into horses or sheep, and you do that on numerous occasions until you get a state of hyper-immunization. Once the animals are seroconverted to that venom, you then harvest the blood and then the process, the expensive process is purifying the IgG from the blood. That is the drug: IgG from hyperimmunized animals.

Antivenom in many ways provides the tool to control SB but despite that, despite the fact that has been around for over a hundred years, we have over hundred thousand people dying of SB every year. This is the Global SB mortality map, remarkable coincidence with the map of the previous talk here on yaws (yaws is tropical infection of the skin, bones and joints caused by the spirochete bacterium Treponema pallidum pertenue), or any of the Neglected Tropical Diseases (NTD). Is the same map, the same people that suffers SB that suffers the other NTDs.

We do know from diverse studies that this are widely inaccurate, probably greatly underestimated, because they are mostly hospital based data. A lot of SB victims never get the hospital, so the deaths are not recorded on the hospital based data, we do not capture that, so it could be as many as three times that, we do not know. So, one of the recommendations is to improve the SB disease burden accuracy by getting data from community based studies and also to capture the socioeconomic burden of SB. We will go through that with more detail later. 

It is absolutely clear that most of the SB deaths occur in Africa and Asia and the question is why is that? given that antivenom (AV) is so effective or can be so effective, why is it?. In particular, the Africa SB victims suffer the highest case mortality rate, twice the number of people die in Africa that they do in Asia, and nearly four fold that in Latin America. What is the reason for that? And is partly this. This is a study that we did sometime ago. Just looking into the global data and dividing that by countries various indices related to poverty and here you can see that those countries with a higher SB mortality spend the least on health per person. Those countries with a higher SB mortality have the lowest quality of life indices. This is very significant statistical data and so, for that reason we describe SB as a tropical disease of rural poverty and it causes very hight mortality and disability. 

In a context of other tropical diseases, SB annually kills one fifth of the number of people dying from malaria every year, half the number of people that are dying from HIV in India are dying from SB. What's very significant about that is those tropical diseases, have extraordinary support, and thanks goodness they do, from International Health Agencies (IHAs). SB receives no support from any of those IHAs including the W.H.O., ?,?, Bill and Gates Foundation. We have tried several times to get them involved, its not happening, we do not know why. Is it because SB is not eradicable? Don't know, but is also neglected by many of the tropical governments whose people are suffering from that, who are dying from this, and that is something that we are trying to reverse and one of the reasons I'm here giving this talk. 


So, the question then is: it is something to do with the people that makes some difference than suffering from this other NTDs? no, that's really no. An example of one of the communities when we are working in North-East Nigeria, in Gomba State, the landscape is dominated by the savannah, it is either used for subsistence farming or for cattle grazing, and is the poverty-induced system's that creates SB. This communities cannot afford mechanized agricultural equipment: tractors, ?... They cannot afford boots that will protect from most of the SB in this area, "flip-flops" is the normal, probably more comfortable in the heat as well. The way they store the grain... It takes them away from the chickens and the goats and so on but it doesn't stop the rats getting up in there and then snakes follow the rats so then when the farmer comes to the harvest he is at risk of SB. 

Saw scaled viper

Their homes offer very little if any protection to ingress of snakes in fact, that fact that is perfect environment for rodents and rodents attract snakes. And in Africa particularly snakes can be very hard to see, there is a snake in here, very dangerous snake of Africa, you cannot see it because it is very well camouflaged and is so small but kills more people than any other snake in Africa. So, it's not surprise that subsistence farmers are at greatest risk of SB and they get bitten, here all this pictures from Nigeria, primarily on the feets and also the hands, and this is an example why never to use tourniquet as a first aid treatment for SB as in can result in amputation, because it restricts the venom necrosis into one area. 

Permanent disfigurement is a result of SB tissue necrosis, is not at all uncommon. 

Children are the next highest next risk group so this two young lals where putting the hands down rat holes trying to play have some fun, they both got bitten by snakes because the snakes were following the rat. This girls was showing the signs of coagulopathy as a results of saw scaled viper bite. All survived well. This is a four month old girl in Caltunga in north east Nigeria bitten in the kitchen of the house by a huge pufadder. Pufadders deliver vast amounts of venom that are very necrotic and you can see the airways here of this young girl of extreme risks irrespectible of what the toxins are doing. But the physician, Dr. Abubaku was able to pull this... /... by taking a lot of scalp away by debriding it. By the point is, in this particular hospital where we are providing AV, I will talk to you about that, it can be dramatically effective, a really positive drug. This is the little girl two days later treated expertly by Dr. Abubaka and obviously  very well in the way to recovery. 

SB are one of the 10 main causes of hospital admissions in Ghana. In some hospitals 70% of beds are occupied by SB victims. Many of my colleges would say "Rob that's rubbish", I toked pictures of the register. Pages and pages and pages, it is only the red entries the non-SB victims occupying this hospital beds and the reason is because those hospitals that have AV become informal referral centers and people flood in from miles. The two hospitals that we have got, we are working on north-east Nigeria, they are coming in from Chad, they are coming in from Camerun, spending 24, 48 hours to get this medicines. That is way you get this large numbers in the beds. I'm sorry we will get back there. We just completed a study in Burkina Fasso, working with lymphatic filariasis in ?program and ten hospitals provided their respective data on the last year and the most outstanding result was: 10 hospital, over one year, twenty seven thousand bed days were consumed by SB victims so there is a difference between other entities often treated as out patients and SB. SB occupies a lot, consumes a lot of energy and funds from this rural hospitals. 

SB is an unavoidable hazard in places like Nigeria, because people are bitten or at risk at whatever they do and whenever they are doing it, night, all day. And because the saw scaled viper is such a dangerous snake, one of five people bitten by this snake will die if they don't get treatment. So, this communities can't change their circumstances, can't reduce their risks of SB because they do not have political voice, they have very, very inadequate access to health care and they don't have income to change their circumstances and that very poor situation was made a great deal worse by the cessation of any AV supply to that region in 2000. Why? What happened? 
00:11:14. I will stop here. 

On the next posts Dr. Harrison is talking about what the actions they perform to mitigate the lack of AV in Nigeria, how they developed an antivenom in collaboration with several organizations and further which are the steps ahead.

ॐ लोकाः समस्ताः सुखिनो भवन्तु ॥

Om Lokah Samasthah Sukhino Bhavantu

May all beings everywhere be happy and peaceful.