Nav: Home

Sniffer dogs could detect malaria in people

October 29, 2018

Dogs could be trained to sniff out malaria in people according to new research aimed at preventing the spread of the deadly disease.

Researchers found that dogs could scent malaria in samples of socks worn by infected children.

They say their findings could potentially lead to the first rapid and non-invasive test for malaria.

Although the research is in its early stages, the scientists hope trained sniffer dogs could help to stop malaria spreading between countries and lead to infected people being spotted earlier and treated quickly.

The research is being presented today (Monday, 29 October 2018) at the American Society of Tropical Medicine and Hygiene Annual Meeting in New Orleans, USA.

Principal Investigator Professor Steve Lindsay, in the Department of Biosciences, Durham University, UK, said: "While our findings are at an early stage, in principle we have shown that dogs could be trained to detect malaria infected people by their odour with a credible degree of accuracy.

"This could provide a non-invasive way of screening for the disease at ports of entry in a similar way to how sniffer dogs are routinely used to detect fruit and vegetables or drugs at airports.

"This could help prevent the spread of malaria to countries that have been declared malaria free and also ensure that people, many of whom might be unaware that they are infected with the malaria parasite, receive antimalarial drug treatment for the disease."

The research was funded by the Bill & Melinda Gates Foundation. It was carried out by Durham University, the charity Medical Detection Dogs, the London School of Hygiene & Tropical Medicine (LSHTM) and the University of Dundee (all UK), the Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, and the National Malaria Control Programme, The Gambia.

Researchers from the MRCG and the LSHTM used nylon socks to collect foot odour samples from apparently healthy children aged five to 14 in the Upper River Region of The Gambia in West Africa.

Using a simple finger-prick test the children were also screened to determine if they had the malaria parasite Plasmodium falciparum in their blood.

The sock samples were transported to the Medical Detection Dogs charity in Milton Keynes, UK where two dogs, a Labrador-Golden Retriever cross called Lexi and a Labrador called Sally, were trained to distinguish between the scent of children infected with malaria parasites and those who were uninfected.

In total 175 sock samples were tested including those of all 30 malaria-positive children identified by the study and 145 from uninfected children.

The dogs were able to correctly identify 70 per cent of the malaria-infected samples. The dogs were also able to correctly identify 90 per cent of the samples without malaria parasites.

Malaria is a life-threatening disease caused by parasites transmitted to people through the bites of infected female Anopheles mosquitoes, but it can be prevented and cured.

According to the World Health Organization (WHO), since 2000 six countries have been certified malaria free, with another 12 countries reporting that no malaria cases have originated within their borders.

Despite this success, however, progress in global malaria control has stalled. According to the WHO's latest World Malaria Report, there were an estimated 216 million cases of malaria in 2016, an increase of five million cases over the previous year. Deaths stood at approximately 445,000, a similar number to the previous year.

Identifying people infected with the malaria parasite, but not presenting symptoms, is critical as they can be treated with antimalarial drugs and the spread of the disease can be prevented.

Sniffer dogs could provide a non-invasive, portable and rapid test for identifying malaria carriers and would be particularly useful in settings where there are few individuals with malaria parasites. Confirmation of the disease would then be made by taking a finger-prick sample of blood using a rapid diagnostic test following World Health Organization guidelines.

An accompanying study introduced a fake biodetection dog to Gambian villages to gauge their acceptability, with researchers reporting that most people were favourably disposed to their use in principle.

Since the initial study a third dog, a Springer Spaniel called Freya, has also been trained to detect malaria.

Study co-author Dr Claire Guest, Chief Executive Officer of Medical Detection Dogs, said: "MDD have had positive results training dogs to detect diseases including cancer and diabetes sugar changes by odour. This is the first time we have trained dogs to detect a parasite infection and we are delighted by these early results.

"The possible potential to train dogs to detect tropical disease where diagnostics are poor, such as leishmaniasis and trypanosomiasis is huge. I believe that this study indicates that dogs have an excellent ability to detect malaria and if presented within an individual infected with the parasite or a piece of recently worn clothing, their accuracy levels will be extremely high. This is a reliable, non-invasive test and is extremely exciting for the future."

Surveys of schoolchildren were undertaken by the Medical Research Council Unit The Gambia and ARCTEC at LSHTM. Sock samples were processed before being sent to Medical Detection Dogs.

Co-author Professor James Logan, Head of the Department of Disease Control, at the London School of Hygiene & Tropical Medicine, said: "Worryingly, our progress on the control of malaria has stalled in recent years, so we desperately need innovative new tools to help in the fight against malaria.

"Our results show that sniffer dogs could be a serious way of making diagnosis of people who don't show any symptoms, but are still infectious, quicker and easier."

Co-author Professor Umberto D'Alessandro, Unit Director at the MRCG at LSHTM, said: "Detecting malaria-infected but otherwise healthy people is a laborious and time-consuming process that requires collecting a blood sample to be then processed in a well-equipped laboratory.

"New approaches to facilitate the identification of infected individuals to be treated would help enormously in addressing the human reservoir of infection and possibly reduce malaria transmission. The opportunity to use trained dogs for this purpose is promising. Results show that it may be possible to identify infected people by their body odour."

The results of the study are broadly in line with the criteria for procurement of rapid diagnostic tests.

The researchers say that in future artificial odour sensors might be developed to detect malaria parasites, but until then trained dogs could be a useful alternative at ports of entry.

However, they say that further research is needed to see if dogs can directly sniff out malaria in people infected with the disease.

Future studies are also needed to see if dogs can detect malaria in the odour of infected people from other parts of the world before the animals could be used in the field, the researchers added.
-end-


Durham University

Related Malaria Articles:

Breakthrough in malaria research
An international scientific consortium led by the cell biologists Volker Heussler from the University of Bern and Oliver Billker from the Umeå University in Sweden has for the first time systematically investigated the genome of the malaria parasite Plasmodium throughout its life cycle in a large-scale experiment.
Scientists close in on malaria vaccine
Scientists have taken another big step forward towards developing a vaccine that's effective against the most severe forms of malaria.
New tool in fight against malaria
Modifying a class of molecules originally developed to treat the skin disease psoriasis could lead to a new malaria drug that is effective against malaria parasites resistant to currently available drugs.
Malaria expert warns of need for malaria drug to treat severe cases in US
The US each year sees more than 1,500 cases of malaria, and currently there is limited access to an intravenously administered (IV) drug needed for the more serious cases.
Monkey malaria breakthrough offers cure for relapsing malaria
A breakthrough in monkey malaria research by two University of Otago scientists could help scientists diagnose and treat a relapsing form of human malaria.
Getting to zero malaria cases in zanzibar
New research led by the Johns Hopkins Center for Communication Programs, Ifakara Health Institute and the Zanzibar Malaria Elimination Program suggests that a better understanding of human behavior at night -- when malaria mosquitoes are biting -- could be key to preventing lingering cases.
Widely used malaria treatment to prevent malaria in pregnant women
A global team of researchers, led by a research team at the Liverpool School of Tropical Medicine (LSTM), are calling for a review of drug-based strategies used to prevent malaria infections in pregnant women, in areas where there is widespread resistance to existing antimalarial medicines.
Protection against Malaria: A matter of balance
A balanced production of pro and anti-inflammatory cytokines at two years of age protects against clinical malaria in early childhood, according to a study led by ISGlobal, an institution supported by ''la Caixa'' Foundation.
The math of malaria
A new mathematical model for malaria shows how competition between parasite strains within a human host reduces the odds of drug resistance developing in a high-transmission setting.
Free malaria tests coupled with diagnosis-dependent vouchers for over-the-counter malaria treatment
Coupling free diagnostic tests for malaria with discounts on artemisinin combination therapy (ACT) when malaria is diagnosed can improve the rational use of ACTs and boost testing rates, according to a cluster-randomized trial published this week in PLOS Medicine by Wendy Prudhomme O'Meara of Duke University, USA, and colleagues.
More Malaria News and Malaria Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

Risk
Why do we revere risk-takers, even when their actions terrify us? Why are some better at taking risks than others? This hour, TED speakers explore the alluring, dangerous, and calculated sides of risk. Guests include professional rock climber Alex Honnold, economist Mariana Mazzucato, psychology researcher Kashfia Rahman, structural engineer and bridge designer Ian Firth, and risk intelligence expert Dylan Evans.
Now Playing: Science for the People

#541 Wayfinding
These days when we want to know where we are or how to get where we want to go, most of us will pull out a smart phone with a built-in GPS and map app. Some of us old timers might still use an old school paper map from time to time. But we didn't always used to lean so heavily on maps and technology, and in some remote places of the world some people still navigate and wayfind their way without the aid of these tools... and in some cases do better without them. This week, host Rachelle Saunders...
Now Playing: Radiolab

Dolly Parton's America: Neon Moss
Today on Radiolab, we're bringing you the fourth episode of Jad's special series, Dolly Parton's America. In this episode, Jad goes back up the mountain to visit Dolly's actual Tennessee mountain home, where she tells stories about her first trips out of the holler. Back on the mountaintop, standing under the rain by the Little Pigeon River, the trip triggers memories of Jad's first visit to his father's childhood home, and opens the gateway to dizzying stories of music and migration. Support Radiolab today at Radiolab.org/donate.