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About the Author

Bart Knols
Medical Entomologist (Dodewaard, Netherlands)

Bart G.J. Knols (1965) is the Managing Director of MalariaWorld, the world's first scientific and social network for malaria professionals. He is a malariologist with a Masters degree in Biology and a PhD in Medical Entomology from Wageningen University, the Netherlands. He also obtained an MBA degree from the Open University (UK) in 2006, for which he won the prestigious international ‘MBA Student of the Year 2007 Award’ as well as the Alumnus of the Year Award from the Open University. With 11 years of working experience in Africa he has managed large-scale research and vector control programmes on malaria for ministries, international or national research institutions. He has worked for the UN (IAEA) as a programme manager for three years, has served as a consultant for the World Health Organization, and is currently a Board Member of the UBS Optimus Foundation, the second largest charity in Switzerland. He has published over 130 peer-reviewed research articles, has written 16 book chapters, and has served as senior editor on a WHO/IAEA sponsored book on implementation research. In 2007 he co-edited a best-selling book titled 'Emerging Pests and Vector-Borne Diseases in Europe'. He received an Ig Nobel Prize (2006), an IAEA Special Service Award (2006), and in 2007 he became a laureate of the Eijkman medal (the highest award in the field of tropical medicine in the Netherlands). He has been a member of the Royal Dutch Academy of Arts and Sciences since 2004. Bart held an Assistant Professorship at Wageningen University until April '09 with projects across Africa. He currently directs K&S Consulting, a firm he founded in the beginning of 2007.

Post

How I Removed Malaria From 12.6 km2 of Sudan

Published 02nd June 2010 - 27 comments - 8277 views -

In February 2004 I was charged with a challenging mission to Sudan.

To travel up north in the Saharan desert, find malaria mosquitoes there, and bring them back alive to Austria. I know this sounds crazy, but that’s what medical entomologists like myself do. We needed those mosquitoes for research purposes.

sudanThe journey from Khartoum to Dongola took us the whole day. Through a landscape void of water. The further north we drove, the less vegetation I saw. When the air-conditioning in our battered project vehicle gave up, it became unbearable within minutes. Outside temperature soared over 45 degrees. Sweat evaporated from my skin before I could see it.

It took us (a team of four Sudanese and myself) two full days of intensive searching to find a small puddle of water that contained larvae of malaria mosquitoes (see picture below).  The water, it turned out, was sourced from an underground broken waterpipe. All sources of water you see out there are man-made, pumped up from the Nile. Broken watertanks, leaking irrigation canals. It rains a mere 8 mm per year up there.

We were thrilled to find mosquitoes at last and frantically started collecting the larvae and pupae in our empty plastic water bottles. ‘Mission accomplished’, I thought to myself. Hundreds of larvae were transported back to the make-shift field station over the next two days.

sudanBut, no matter how hard we kept searching the surroundings of our ‘positive’ site, we didn’t find any more larvae. Nowhere. House after house we searched for adult mosquitoes, but I did not see even one during the two weeks I was there.

Early on the fourth morning, when the sun was not yet high enough to remove the coldness of the desert night, we stood there, watching over our only source of mosquitoes. The little waterpipe puddle. I then got a plan.

I asked all of the six of us to walk away from the puddle in different directions. And search, search, search. For water with larvae. For at least a 2 km radius from where we were. We’d all get back to our puddle after two hours.

When we all returned, nobody had found any traces of water, let alone mosquito larvae.

sudan‘Right’, I said. ‘Let’s do some malaria control here. Where can I get a shovel?’ They all looked at me as if I had had too much sun the day before. But within minutes a shovel turned up. Then, in front of the team, it took me less than a minute to shovel enough sand into our puddle that it was hard to notice any water left in it.

Done.

It is only now that a discussion on the potential of larval control for malaria elimination is underway, that I realise that our puddle may have been the sole source for malaria in a 12,6 square kilometre area (radius of 2 km, squared, times pi).

A shovel was all that was needed. Would the next 12,6 km2 have looked the same? With one, two, or maybe three breeding sites that could easily be dealt with?

I don’t know. My mission was to bring mosquitoes back from Africa. Not to control malaria out there. 

Now I wonder what would have happened if I had just stayed and continued shovelling sand into breeding sites with my Sudanese colleagues…

 


Category: Health | Tags: malaria, mosquito, sudan, elimination,


Comments

  • Iris Cecilia Gonzales on 02nd June 2010:

    Very interesting Bart. I am in awe of your passion for your work. You are privileged to be able to be in these places. We’re talking of concrete results here. Thanks for this important post.


  • Radka Lankašová on 02nd June 2010:

    Bart, thank you for your story. It shows all process of research - right from the very start, which sometimes can be quite dangerous as you can get infected yourself.

    What keeps your passion for your work? All your blogs are full of it.


  • Bart Knols on 02nd June 2010:

    @Iris @Radka. This is interesting. You both mention the word passion on your comment. I guess that I AM passionate about what I do, hence my full joy of participating in TH!NK3. And I AM a believer that we can make this world a better place. This includes freeing major parts of the globe of malaria.

    And, considering that I suffered malaria NINE times myself over the 11 years that I lived in Africa, I guess it is not all that difficult to be passionate about doing something against the little evil devils…


  • Radka Lankašová on 02nd June 2010:

    Nine times?! No wonder you want to make it disapper for ever!


  • Bill Jobin on 02nd June 2010:

    Bart the folks from northern Sudan must love you.
    I have a special place in my heart for Sudan, but lived only in central Sudan along the Blue Nile River 1979-84.  I am also proud of having supressed malaria there among 2 million people for 9 years, but Al Bashir did us in at the end.  By the way, we used the Kitchen Sink Strategy - about 5 control methods applied together in an integrated strategy against malaria, as described in Blue Nile Monograph One, to be published next month.  I am glad you have personally tasted the joy of habitat elimination, which is even better than larval control with biocides, bacillus or killifish.
    However, the only time I was in northern Sudan, around Merowe, was a health impact assessment about 1990 for the new dam which I believe is now finished.  When the new dam and reservoir are fully operating, there will be a tremendous drawdown zone from the dam at Merowe upstream on both sides for at least 100 km, flooding the Fourth Cataract and Abu Hamid.  When the water level is dropping, I am afraid there will be incredible numbers of An funestus, maybe also An arabiensis and An gambiae as well.  So the next time you go up there, you might find a few more mosquitoes.
    The Border Control Commission (Egypt-Sudan) has been working since WW2 to prevent Anophelines from re-entering Egypt.  Their work is also at risk now that the dam is filled.  And I think the dictator Al Bashir is planning another dam up that way.
    Bill


  • Bart Knols on 03rd June 2010:

    @Radka. Nine times indeed. On top of that, I nearly lost my wife to malaria as well… She was hit by a multiple resistant strain of the most deadly form of the parasite (Plasmodium falciparum) in Tanzania and just made it (on a quinine drip)... These were tough times, but fuel your determinism to do something about it…


  • Iwona Frydryszak on 03rd June 2010:

    i’m sorry for the heat, although on the photo the desert looks pretty cool compering rainy and flooding Poland.
    I have a question… While I was in Tanzania one of the volunteer was telling the story about painting all the walls with some poisonous paint to kill the mosquitos… as I remeber it worked while the malaria mosquite has bitten you so it’s so heavy and tired that’s first what it’s do is flying to the closest wall… Does it make sense. Do you know any exemples or links to this kind of experiment?


  • Bart Knols on 03rd June 2010:

    @Bill. Thought you might like this story about Sudan. The simplicity of some measures make the millions that go into the search for a potent vaccine look very different.

    The Gambiae Control Programme (GCP) of Egypt is a good example of how re-invasion can be overcome. By having a stretch of the Nile surveyed and sprayed every year.

    If Soper would be alive today, he would bang his shoes on the table (like Chroestsjov once did to hammer home his point) and argue fiercely with all of us about why we are not out there eliminating malaria. He would marvel at us sitting in front of a computer and see any spot on the planet with Google Earth… he would marvel at the replacement of Paris Green we have now (Bti)...


  • Bart Knols on 03rd June 2010:

    @Iwona. The behaviour of the mosquitoes you describe has been one of the key elements on which so-called Indoor Residual Spraying (IRS) is based. It is not paint but just a small swath of insecticide that is put on the walls of houses. Mosquitoes that have fed on people than sit on it and pick up a lethal dose.

    Several of these insecticides also exert a repellent effect, making fewer mosquitoes go into the house in the first place. Thanks for comment.


  • inge on 03rd June 2010:

    If there are so few breeding sites for malaria mosquitoes in hot and dry Sudan, why has malaria not been eradicated in this country?


  • Atul Salgaonkar on 04th June 2010:

    This is a very exciting and intersting model and I wanted to see if it cn be applied, with adjustments, for other vectors and geographies.


  • Bart Knols on 04th June 2010:

    @Inge. This is a very good question. Let’s start with Egypt, which had malaria mosquitoes eliminated along the Nile in the period following WWII. Fred Soper was involved in the campaign (published by Shousha in 1948). The approach was the same - find breeding sites and treat them with Paris green. However, DDT was also added to the arsenal of tools.

    Since the early 1970, Egypt maintains the GCP (gambiae control project) which does the same thing to keep mosquitoes from invading northwards from Sudan. But one could argue that you could move the other way around, and start moving south.

    There is, in my opinion, no reason why the old approach would not be they way to eliminate malaria from the entire Sudan north of the capital Khartoum…


  • Bart Knols on 04th June 2010:

    @Atul. Whether or not this can be applied depends on the vector species, local ecology of the vectors (types of breeding habitats, etc.) and intensity of malaria transmission. This will differ between geographical settings. Where are you based?


  • Marit on 05th June 2010:

    Another great post Bart, thanks!
    It really made me wonder how many malaria researchers have been in similar situations; trying to find and collect mosquitoes, but not taking up a shovel and filling up that puddle.

    I actually experienced myself in Benin how happy I was when we finally found Anopheles mosquito larvae. (It can be much more difficult than people may think.) There, the water bodies were way too big to close with sand, but to be brutally honest I don’t think that I would have even thought about it in my excitement and my goal being to collect the insects.

    So I think your story is a great lesson to all. We should get our priorities straight. Every effort can help big time! Any puddle less may mean several malaria cases less.


  • Manik on 05th June 2010:

    Hi Bart thanks for the post. I too think this is very underused approach to malaria control. One question though, is there any chance that leaking pipe was a source of water for people?


  • Bart Knols on 06th June 2010:

    @Marit. Thanks. What you raise here is the difference between researchers and those that control malaria. Regretfully, you won’t find both tasks in the same individuals. There are those that see the malaria system as a research topic, and those that need to do something about it. Your Benin experience sounds very familiar because of this…

    I really wonder how this situation would change if researchers would put control (if not elimination) first, rather than their scientific interests, although I appreciate that those involved in basic science may be too distant from the real world of malaria control. All the reason to start focusing more on the latter…

    @Manik. The pipe was indeed a source of water for people. Fixing it would have been the best solution of course, but I did not have the means at the time to do something about it. The only thing I could do out there was getting rid of the source of mosquitoes…


  • Manik on 06th June 2010:

    Actually what I was trying to get at with my question was: was that puddle you filled in itself a drinking water source for people that didn’t have access to piped water, and did your action inadvertently remove that source?

    Great discussion here, and I’m so happy to see you respond so promptly!


  • Bill Jobin on 06th June 2010:

    How to kill a mosquito with a shovel?  A form of LSM - Larval Source Modification.
    What is the most realistic overall strategy?

    Bart you are on a roll! Thanks for your wonderful ideas and thought-provoking points. As you might guess from my lengthy comments below, I have also been working on these questions since about 2005 when I gave up on PMI and WHO in Angola, in disgust.

    Your story about your shovel seems to also be asking these questions:

    Who should do it?
    And How should we do it?

    Those are broad questions that we can all work on.

    1. First, let us stay away from words like elimination, eradication and even control. What we can do is fight malaria. We can fight it with an integrated strategy of sustainable methods. Our goal should be to reduce transmission significantly. For the continent of Africa at least, a significant reduction, which we can maintain with sustainable methods, is enough to strive for. But elimination or eradication concepts merely distort our planning. They are chimeras, not likely for Africa.

    2. For the goal of reduced transmission, our strategy should be integrated and sustainable, thus LSM is another important weapon to be added to the overall strategy. LSM has been neglected partly because the bewildered folk in Geneva cannot imagine anything other than newer and more expensive drugs, or vaccines.

    3. Who will do it? Not WHO anymore. When I first worked for WHO in the 1960’s it was a competent organization with a real budget and with all the best people in international health. Because their budget was emasculated in the 1980’s by strong conservative governments, they are now able just barely able to buy light bulbs for their building in Geneva, and except for PAHO, the regional offices are on paper only. So what is our alternative?

    4. In Africa, I think we should build directly on the strong countries, where they have demonstrated capabilities and stable, progressing governments. This means South Africa first. Also Senegal in the West and Tanzania and Mozambique in the East. We should work with these countries to support them and expand their national programs. The US PMI has some funds and flexibility, so they might possibly be major players. If not, I think we should go right to the NMCPs in each of the 4 countries above. As they progress, on their own budgets, they can also start training centers for their own personnel, and then for folks from nearby countries with the same language.

    5. How should we do it? LSM should be added to the current mix of unsustainable methods, in order to give the overall programs a real future. The LSM portion should include habitat reduction with shovels, and attacks on the larvae with bacillus, fish and biocides. These approaches to LSM require repeated application, except for the shovel work. The biocides worry me too, but the rest can be safely done with a labor-intensive budget. But as Mark Benedict pointed out, larval reduction is subject to the insane effect of density-dependence, where partial reduction in larval density is of no avail, we have to go to the limit. The other challenge to LSM is management of the folks who do the work, and so Soper gives us courage.

    6. Continuing the answer to “How?” - the Swiss Cheese sandwich comes in. We want a sandwich made of multiple layers of Gruyere. Admittedly the cheese has holes in it, so one layer does not give complete coverage. But a sandwich with 6-7 layers, each put on slightly askew, can give us complete coverage. To illustrate: a mass-treatment program with drugs will miss the people away on vacation or on nomadic trips or visiting the big city. But if we do LSM around their town, and help some of their neighbors plaster and screen their houses, and spray the houses of some other neighbors, and give accurate diagnoses and rapid drug treatment in the local markets, we will thus gradually knock a growing hole in the transmission. So we need multiple methods, especially the permanent measures such as habitat elimination and house screens.

    7. The size and shape of a budget for this strategy of transmission reduction is modest, with gradual expansion based on success and on budget realities of the country.

    8. We have to divest ourselves of the fantasies about huge initial dollar inputs from Gates or others. A budget like that is distorted by the dream about eradication, and is a chimera for Africa. If malaria is important for South Africa, they will make national budget commitments. The same is true for Senegal, Tanzania and Mozambique.

    9. The fight against malaria must be based on a sustainable and affordable strategy, one stable country at a time, gradually expanding according to budget realities. It thus becomes a realistic strategy, a program that we can carry out, not a fantasy.

    Bill, still hopeful


  • Bart Knols on 07th June 2010:

    @Manik. No it wasn’t, the pool itself was not a source of drinking water - sorry for misinterpreting your question.


  • Bart Knols on 07th June 2010:

    @Bill. Thanks for your lengthy response and valid contributions to this and other blogs. Let me respond to your 9 points:

    1. I respect your views on this, and gauging from your extensive experience, this may indeed be the case. My opinion differs somewhat, in that I maintain the belief that as long as we have not really tried an integrated approach that includes rigorous larviciding, that we don’t know if this is feasible.

    2. In agreement.

    3. Seeking out the right partners is the next (critica) step. I honestly think that it should first be the government/population of a carefully selected part of Africa that considers this a worthwhile approach to try out. The more locally this can be orchastrated and executed, the more likely the chance of success.

    4. In line with my views mentioned above. Personally I feel that a proof-of-principle may be the most we can opt for at this stage, and the selection of a target area should be done on the basis of a careful evaluation. I have discussed with others the option of bringing together a party of people interested in this approach, people with long-standing experience in Africa, to discuss this.

    5-9. All in agreement.

    Thanks very much for continued insight into this matter. Much appreciated!


  • Rune Bosselmann on 10th June 2010:

    Hi Bill,

    Some story. A man with a shovel against malaria. Sounds almost a bit like Don Quixote. But there is definitely good sense to what you do. Our own project using a combination of larvicide and environmental engineering (fixing roads, drainage canals etc) proved this can be both an efficient and a cost effective way of controlling mosquitoes. Not just Anopheles but also Culex, which was very much appreciated by the populations in the intervention zones.

    I believe the solution is very cost effective compared to what we see now and probably also more sustainable from an entomological/ technical point of view. Unfortunately, despite the low cost, the great reduction in total mosquito populations, added value from better roads and free flowing drainage canals, we were not able to convince anyone in the municipality to continue the effort past the duration of the project. As you very well know there is no funding for this type of intervention in the present malaria control environment even if from a technical point of view any municipality should have the competence and capacity to take it on themselves.

    Do you or anyone on here have any suggestion to solve this part of the problem?


  • Rune Bosselmann on 10th June 2010:

    That should obviously have been “Hi Bart” though I am very happy to say hello to Bill as well.

    br

    Rune
    Intelligent Insect Control


  • Bart Knols on 10th June 2010:

    @Rune. Yes - by simple achieving elimination. Once we demonstrate that larval control combined with larval source management is the key to eliminate malaria, there will be ample funding. The point, simply enough, is to find a place where this can be demonstrated.

    If you have a suggestion for a place, please let me know…


  • Rune Bosselmann on 10th June 2010:

    Hi Bart,

    We are looking for a place and a set of partners for cooperation to go with it.

    I dont believe the problem is entomological demonstration but rather to find a model that is compelling to both municipalities or local private initiatives and funding. It may well be that such initiatives, cost effective as they are, can run under a micro finance regime. Again citing the Burkina studies, people already spend a lot of money on fighting mosquitoes in their homes though at least as much for nuisance as for disease prevention. If you can demonstrate to them that this is done much more effectively and more cheaply via some kind of communal effort then maybe this may sustain an effort jump started via micro finance means. 

    I dont believe funding will come to run the campaigns. Again at the RBM meeting in May it was emphasized by the VCWG and the GMP that only tools that can be applied universally across the continent or at least regions, eg EARN, will be recommended for funding. larvicide and source management requires a lot of local planning and modeling and there are likely areas where it is not feasible and for these reason it will not be supported. That is clear policy and not a question of evidence.


  • Bart Knols on 10th June 2010:

    @Rune. Your first point sounds good to the point of ‘communal effort’ - this is where we have different opinions.

    On the 2nd point - it is fine if RBM has such views and I will not argue against them. It is just that THEY will not put money into it. But does that mean that NOBODY will put money into it? No.

    Evidence is all that is needed to change everybody’s opinion on how things should be done. We all talk, and talk more. But in the end, he/she that comes with success will be listened to best…


  • Rune Bosselmann on 10th June 2010:

    Bart, I hope you re right. I would be very interested in hearing how and from where funding would be provided then - given, say, proof from one large scale study.


  • Bart Knols on 10th June 2010:

    @Rune. If proof from one large-scale study is provided, getting substantial amounts of money will be easy. That will also be the time that RBM and other groups will have to consider this success (and perhaps change their strategy accordingly).

    The key is to find funding for the proof-of-principle study, the first project that aims to remove malaria entirely from an area in the manner proposed above. That’s the challenge. I have ideas about raising the sort of money for this, and see funding from non-regular sources (so not RBM, GF, NIH, Wellcome Trust, Gates Foundation) as the best option.

    Once success is in, it will all be a lot easier… and no doubt, the eyes of the big funding organizations will open.


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