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KLM: An airline that acts responsibly

February 13, 2010 - 21:27 -- Bart G.J. Knols

On 18 January I flew from Amsterdam to Copenhagen for a 3-day workshop on malaria and architecture. The KLM Fokker 100 took off in time at 07.05 am, and nothing eventful happened until the time I opened the in-flight magazine Holland Herald…



This issue was titled ‘The wild issue’, and it was funny to notice that they classified mosquitoes as the most dangerous animals on earth, because ‘This tiny killer is responsible for some two million deaths per year by transmitting diseases such as malaria’. Good point.

But when I browsed the duty-free section of the magazine I saw that the airline had a mosquito buzzer for sale, a product called MozStop, of the Akita electronics company. ‘This device emits a low frequency sound that is unbearable to mosquitoes’ the text accompanying the picture of the black buzzer, that looked like a large lip-stick, said…

This got me thinking. Knowing that such sound-emitting gadgets have never been proven to work against any mosquito species, I wondered how many travellers to countries endemic for mosquito-borne diseases would buy it and think ‘Great, now I am protected without having to use a repellent’. And simply trust KLM to be an airline that would have checked this product before adding it to their assortment of duty-free items on board. I felt the need to do something about this, and kept the magazine for action later on.

On 23 January, a day after I returned to Holland, I sent an email to Mike Cooper, the Editor-in-Chief of the Holland Herald, and expressed my concern regarding this product, besides hinting at the fact that it would not look good upon KLM if it would become publicly known that it sells a bogus product on board. It stayed quiet for a week afterwards, and then I sent a reminder.

On 1 February Mr. Cooper informed me that he had forwarded my email to KLM Tax free representatives, but it stayed quiet for another week afterwards. On the 10th, I informed Mr. Cooper that I intended to write a blog about buzzers on MalariaWorld, which resulted in action straight away. That same afternoon I received an email from Mr. Kruijswijk, Director of in-flight sales, KLM.

Apparently a lot had been happening behind the scenes, and a series of emails and evidence of telephone contact between Mr. Kruijswijk and the company in Sri Lanka that sells the product to KLM was copied in the email to me. It became clear that KLM sells on average 1000 of these gadgets every month (at € 17 per piece!), and that the company in Sri Lanka had sold 40,000 globally in the last six months.

I also received documentation to ‘back up’ the claims. None of these made sense, claimed that mosquitoes make a sound of 50,000 Hz, and in another document that this buzzer produces a sound of 7,000 Hz. Male malaria mosquitoes cannot produce such sounds, which are way lower, in the order of 700-800 Hz.

I replied the same evening with a long email, providing all the details, and refuted the content of the documents I was sent by KLM. The next morning my phone rang. It was Mr. Kruijswijk. He thanked me for the detailed information on buzzers and my comments on the documents he got from Sri Lanka. The conversation was a friendly one, and ended with the confirmation by Mr. Kruijswijk that the product will be removed from the duty-free product assortment on all KLM flights with immediate effect. He confirmed this in a email soon after our call ended, stating: 'The product will no longer be for sale on KLM aircraft from March onwards'.

The decisive action taken by KLM is an excellent signal that this airline operates in a responsible and ethical manner. It was not aware of the fact that mosquito buzzers don’t work, yet did not hesitate to take drastic steps once they were informed. Thank you, KLM!

That same day I approached British Airways. In their HighLife magazine they offer… yes, a mosquito buzzer. That was last Thursday and I have not heard from them yet. Guess they also need to make some phonecalls…

If you come across any advertisement for mosquito buzzers, take action and let MalariaWorld know. It is high time that such products are permanently removed from the market!

PS. If you want to watch a video in which I demonstrate that buzzers don't work, click here [it starts at 4 min, 8 sec; in Dutch].

Thanks to Prof. Paul Garner for providing the Cochrane review article that reviews 10 studies that all clearly demonstrate that electronic mosquito repellers do not work. 

PDF icon CD005434.pdf0 bytes
PDF icon Science - MozStop Mar10.pdf0 bytes


Bart G.J. Knols's picture
Submitted by Bart G.J. Knols on

This airline sells exactly the same product as KLM did...

Submitted by Paul Garner on

Well done Bart, getting evidence into practice and stopping this commercial bogus product that keeps coming back again and again!

If anyone tries to claim these buzzers work, we reviewed the evidence a few years ago: 10 field trials showed absolutely no evidence of an effect on mosquito biting.

See: Enayati A, Hemingway J, Garner P. Electronic mosquito repellents for preventing mosquito bites and malaria infection. Cochrane Database of Systematic Reviews 2007, Issue 2. Art. No.: CD005434. DOI: 10.1002/14651858.CD005434.pub2

Paul Garner, Liverpool School of Tropical Medicine

Bart G.J. Knols's picture
Submitted by Bart G.J. Knols on

Regretfully I do not have access to this article...

Submitted by Paul Garner on

Dear Bart and colleagues

Thanks for your interest in this Cochrane review. The studies were carefully conducted, and clearly demonstrated absolutely no effect of these devices. The Cochrane review is available on the DFID Research for Development Website:

and also through the Cochrane Library, free in low income countries, or places with a national or institutional licence:

With best wishes


Paul Garner, Liverpool School of Tropical Medicine

Bart G.J. Knols's picture
Submitted by Bart G.J. Knols on

I have now had telephone contact with British Airways and they promised to inform me today about their view regarding the electronic mosquito repeller they sell. Singapore Airlines received an email from me this morning.

Bart G.J. Knols's picture
Submitted by Bart G.J. Knols on

As of today, 25 feb, press releases have gone out from the Liverpool School of Tropical Medicine to UK press agencies, and from MalariaWorld to all the major Dutch press channels. Below the UK press release:

Campaign to end sale of electronic mosquito repellents

25 February 2010

A campaign to stop the sale of electronic mosquito repellents by major airlines is beginning to bear fruit with the immediate withdrawal of the products from KLM flights. The issue being that these electronic repellents, sold to airline passengers, many on their way to malaria endemic countries, just don’t work.

Dr. Bart Knols, editor of the advocacy website MalariaWorld discovered that electronic repellents were being sold by KLM on a recent flight he made. The publicity claimed that the ‘device emits a low frequency sound that is unbearable to mosquitoes’ and Knols, knowing that there is evidence that these sound emitting devices don’t work and could give travellers the false impression that they were protected against mosquitoes and in turn malaria, took action.

Armed with the Cochrane Systematic Review, produced by the Cochrane Infectious Diseases Group and first published in 2007, which clearly demonstrates that electronic repellents do not work, Knols approached KLM with the subsequent positive result that the airline will withdraw these electronic repellents from sale from March 2010 onwards. Knols has since approached British Airways and Singapore Airlines who also sell the electronic repellents and is waiting for a response.

The Cochrane review rigorously examines all relevant, reliable research, and these reviews are recognised as being authoritative, state-of-the-art summaries. “These electronic repellents should not be manufactured, advertised or used to prevent mosquito bites and malaria,” said co-author of the review Professor Paul Garner. Along with Dr. Ali Enayati from the Mazandaran University of Medical Sciences and Professor Hemingway Director of Liverpool School of Tropical Medicine, they carefully analysed 10 studies and found there was absolutely no data to support their use. Professor Garner went on to say “These devices appeal to customers but they simply don’t work. They don’t repel mosquitoes and they don’t prevent people getting bitten.”

To read Bart Knols’ blog on MalariaWorld and follow this story

To read the Cochrane review ‘Electronic mosquito repellents for preventing mosquito bites and malaria infection’

Bart G.J. Knols's picture
Submitted by Bart G.J. Knols on

Today I have been informed by phone and in writing that British Airways will cease the sales of their electronic mosquito repeller from their online webshop with immediate effect and stop all sales on board of their aircraft from 1 May onwards.

So I need to change the title of my blog to: KLM and British Airways: Airlines that act responsibly.

Bart G.J. Knols's picture
Submitted by Bart G.J. Knols on

An update on the coverage of the electronic mosquito repeller story. See the following websites:

The Medical News (25 feb):

ScienceDaily (25 feb):

AlphaGalileo (25 feb)

In pursuit of silence (26 feb)

Financial Times (26 feb)

Liverpool School of Tropical Medicine (25 feb)

DFID (1 mar)

Radio Nederland Wereldomroep (3 mar - in Dutch)

Science published the article in its last issue (vol 327, page 1183, 5 March 2010)

Mark Birchmore's picture
Submitted by Mark Birchmore on


Great job of starting to get these ineffective gadgets off the shelves. The next time you take a US carrier take a look in one of their shopping mags and you'll find a plethora of new targets for this activity - unfortunately.

Out of curiosity, have the airlines provided an effective replacement in their in flight magazines, e.g. a proven repellant? Its all very well lobbying to have ineffective products taken away but the mosquito control community should also provide them with effective alternatives.



Mark Birchmore | Head of Vector Control, Syngenta

Bart G.J. Knols's picture
Submitted by Bart G.J. Knols on


I have asked KLM if they wanted an alternative, and also suggested to write a page or so for their in-flight magazine. Haven't heard from them since...

I guess that anything chemical (like a repellent) is too high risk for them and they will rather not offer anything against mosquitoes.

Making people aware of alternatives is also not good at this stage, as you will tell them that what you sold before (the buzzers) is rubbish. Better to stay in the background for a while...


Bart G.J. Knols's picture
Submitted by Bart G.J. Knols on

I was informed today [2 August] that Finnair has also decided to stop with the sales of electronic mosquito repellers on board their aircraft. With thanks to Jani Ruotsalainen who lobbied and achieved this result. That makes three airlines now (Finnair, KLM, British Airways).

Submitted by Guest (not verified) on

I bought 2 in April 2011 at Finnair flight (Finland to China), 18UER per one

Submitted by Guest (not verified) on

The Buzzer was on sale on Cathay Pacific flights this month $15!

Submitted by Guest (not verified) on

Sorry to differ with you but maybe you could live in Townsville Queensland where there are a to on mozzies & I use this product & thankfully the nozzies dont bother me.
I have had it in use for 2 years now

Submitted by Guest (not verified) on

I flew on Portuguese TAP today (March 21st 2011) from Zürich / Switzerland to Lisbon. Their actual inflight sales magazine proposes.... MozStop!

Bart G.J. Knols's picture
Submitted by Bart G.J. Knols on

Good news. After an article appeared in last week's Financial Times ( in which the buzzer story featured again and Cathay Pacific was mentioned explicitly, it decided to stops sales on board its aircraft.

Another article was published to that effect:

So, now KLM, BA, Finnair, and Cathay Pacific have stopped sales. Who will call TAP?

The power of the MalariaWorld community....we can stop sales of buzzers, we can push towards replacement of quinine with artesunate...and more....

Submitted by Lois (not verified) on is selling a 2 pack for $12 from their catalogue and on-line. I doubted the effectiveness and am really glad I checked. Thanks for taking action.