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Super-flies and parasites

3 Posts tagged with the science tag
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On 25 June the Museum will open its doors to a special event in celebration of the international and global commitment between countries, industry, charities and academia to work together against Neglected Tropical Diseases (NTDs). This commitment was first agreed upon in London in 2012 and has since been termed the London Declaration On NTDs.

 

By joining forces to fight NTDs the world would achieve a huge reduction in health inequality paving the way to sustainable improvements in health and development especially amongst the worlds poor. The 25 June sees the launch of the third progress report, 'Country Leadership and Collaboration on Neglected Tropical Diseases'. A pragmatic overview of what has been done, what has worked, what hasn't and what key areas still need to be achieved.

 

The Museum is thrilled to be participating in this event, having a long-standing history in parasitic and neglected tropical disease research. As both a museum and an institute of research our mission is to answer questions of broad significance to science and society using our unique expertise and collections and to share and communicate our findings to inspire and inform the public. We are excited to be hosting a day of free public events on Neglected Tropical Diseases.

 

What are NTDs?

Neglected Tropical Diseases are termed in this way because they infect hundreds of thousands to millions of people, predominantly the world's poorest and most vulnerable communities, and yet receive comparatively little funding for basic, clinical or drug-development research and even less attention from governments, people and the media of affluent countries. Until now!

 

In total the WHO has identified 17 diseases or groups of diseases that fall within this category.

 

NTD slides from Bonnie Webster.jpg

World Health Organization has identified 17 Neglected Tropical Diseases. 10 of these have been targeted for control and elimination by 2020

 

The 10 selected by the WHO for control and elimination by 2020 are:

 

  1. Onchocerciasis (aka river blindness): A blood worm infection transmitted by the bite of infected blackflies causing severe itching and eye lesions as the adult worm produces larvae and leading to visual impairment and permanent blindness.
  2. Dracunculiasis (aka Guinea-worm disease): A roundworm infection transmitted exclusively by drinking-water contaminated with parasite-infected water fleas. The infection leads to meter-long female worms emerging from painful blisters on feet and legs to deposit her young. This leads to fever, nausea and vomiting as well as debilitating secondary bacterial infections in the blisters.
  3. Lymphatic filariasis: A blood & lymph worm infection transmitted by mosquitoes causing abnormal enlargement of limbs and genitals (elephantiasis) from adult worms inhabiting and reproducing in the lymphatic system.
  4. Blinding trachoma: A chlamydial infection transmitted through direct contact with infectious eye or nasal discharge, or through indirect contact (e.g. via flies) with unsafe living conditions and hygiene practices, which if left untreated causes irreversible corneal opacities and blindness. Trachoma is the leading cause of blindness in the word.
  5. Schistosomiasis (aka bilharzia): A blood fluke infection transmitted when larval forms released by freshwater snails penetrate human skin during contact with infested water. The infection leads to anaemia, chronic fatigue and painful urination/defaecation during childhood, later developing into severe organ problems such as liver and spleen damages, bladder cancer, genital lesions and infertility.
  6. Visceral leishmaniasis (aka Kala azar): A protozoan blood parasite transmitted through the bites of infected female sandflies which attacks internal organs which can be fatal within 2 years. 
  7. Soil-transmitted helminths: A group on intestinal worm infections transmitted through soil contaminated by human faeces causing anaemia, vitamin A deficiency, stunted growth, malnutrition, intestinal obstruction and impaired development.
  8. Leprosy: A complex disease caused by infection mainly of the skin, peripheral nerves, mucosa of the upper respiratory tract and eyes.
  9. Chagas disease: A life-threatening illness caused by a blood protozoan parasite, transmitted to humans through contact with vector insects (triatomine bugs), ingestion of contaminated food, infected blood transfusions, congenital transmission, organ transplantation or laboratory accidents.
  10. Human African trypanosomiasis (aka sleeping sickness): A protozoan blood parasitic infection spread by the bites of tsetse flies that is almost 100% fatal without prompt diagnosis and treatment to prevent the parasites invading the central nervous system.

 

They were selected because the tools to achieve control are already available to us and, for some, elimination should be achievable.

 

Take the Guinea Worm:

 

Guinea worm Peter Mayer.jpgGW (SKnopp).jpg

Guinea worm infection - from over 3.5 million people infected in the 80s to less than 130 cases in 2014. Set to be second human disease to be eradicated after smallpox (photo credits David Hamm&Peter Mayer)

 

In the 1980s over 3.5 million people were infected with Dracunculiasis (i.e. Guinea worm disease), with 21 countries being endemic for the disease. Now, thanks to the global health community efforts and extraordinary support from the Carter Center, only 126 cases were reported in 2014 and only 4 endemic countries remain: Chad, Ethiopia, Mali and South Sudan! If the WHO goal of global eradication of Guinea Worm by 2020 is met then Dracunculiasis is set to become the second human disease in history to be eradicated (the first, and only one, being smallpox). Not bad for an NTD! But there are still challenges!

 

At the Museum we have a long history of working on health related topics. Indeed our founding father Sir Hans Sloane was a physician who collected and identified plants from all over the world for the purpose of finding health benefits - in fact he developed chocolate milk as a health product.

 

Today we have a vast and biologically diverse collection of parasites and the insects/crustaceans/snails/arachnids that carry and transmit them. These are used by researchers both in the museum (such as myself and colleagues) but also internationally through collaborative work.

 

ZEST Zanzibar.jpg

Collaboration is key - Zanzibar Elimination of Schistosomiasis Transmission (ZEST) programme key players: the Zanzibar Ministry of Health, Public Health Laboratories Pemba, the World Health Organization, SCI, SCORE, Swiss TPH, NHM and others

 

We are immensely proud of our collections and the work we do in this field especially of the biological information we can contribute to health programmes in endemic countries. One of our most exciting contributions is to the Zanzibar Elimination of Schistosomiasis Transmission (ZEST) programme where we are working in collaboration with the Zanzibar Ministry of Health, various NGOs, the World Health Organization and the local communities to identify and implement the best tools and methods to achieve schistosomiasis elimination in Zanzibar. This would be the first time a sub-Saharan African country would achieve schistosomiasis elimination. Fingers-crossed we are up to the challenge! You can read more about this project in an earlier post on our Super-flies and parasites blog

 

On Thursday we are bringing out our Parasites and Vectors specimens to showcase them to the public galleries and answer any questions relating to these fascinating yet dangerous organisms. Our wonderful scientists and curators will be on hand to talk to people about our collections and research as will collaborating scientists from the London Centre of Neglected Tropical Disease Research who will talk to you about the diseases and the challenges faced to achieve the WHO 2020 goals. Please do pop by and say hello, come and look at our specimens and help us raise awareness of these devastating diseases and the fight to control and eliminate them.

 

Fieldwork_TZ_FionaAllan_SCAN.jpg

We are working together with schools, communities, government and research institutes to fight Neglected Tropical Diseases. Schistosomiasis fieldwork photo with the team from the National Institute for Medical Research in Tanzania

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Hello Super-flies & Parasites fans!

 

This time we are departing from the familiar world of blood flukes and having a look at something new and exciting: Welcome to the ‘Forever Flies’series of blog posts. I’ve really enjoyed writing this bit as it’s totally new to me and I’m learning so much from our wonderful scientists in the Forensic Entomology group of the Parasites & Vectors division here at the Museum.

 

About forensic entomology


I think I mentioned forensic entomology way back in the first ever Super-flies and Parasites post. But to refresh our memories and delve a bit deeper here’s an explanation taken from the group’s website:

'Forensic entomology is the study of insects and other arthropods (ie spiders, mites) in a situation where a crime may have been committed. The insects recovered from a crime scene can provide vital information for the investigating team. The most common role for Museum forensic entomologists is establishing a minimum time since death in suspicious cases, by analysing the carrion insects on the body.'

 

Flies use the bodies of dead animals to grow and develop, fulfilling a vital nutrient recycling role in an ecosystem. They can turn one vertebrate body into thousands or millions of flies, which are then fed on by other animals - insects, frogs and birds for example. The rate at which they do this, going from eggs to larvae to pupa to adult fly, is pretty consistent.

 

Knowing enough about the species of flies we can exploit this information when they develop on corpses. By determining how long the insects have been feeding on the tissues of the corpse, we can determine the length of time elapsed since flies found the body; thereby providing crime scene investigators with a minimum post-mortem interval.

 

Some flies however don’t hang about and wait for death, they prefer feeding on live animal tissues, and can cause a horrible disease called myiasis, a major economic and animal welfare problem.


2014-10-16 Gross maggots with adult.jpg

Female Bluebottle blow fly, Calliphora vicina, and maggots feeding on a dead pig.

 

Dr Martin Hall and colleagues within the Museum and around the world work together on the taxonomy and biology of flies that develop as larvae on living or dead vertebrate animals. Their expertise and research greatly contributes to the control of a painful and damaging disease, myiasis, but also to the field of forensic entomology, helping CSIs determine crucial information from a crime scene.

 

So there you have it, some real life crime scene investigation stuff! These are the guys CSIs turn to for help! (Cue CSI theme song!)

 

The beauty of maggots lies in their mouthparts

 

I asked Martin for a little blurb to get the Forever Flies series rolling and he sent me some surprisingly beautiful photos of maggots! Here’s what he has to say about them:

To most people maggots are repulsive creatures; they all look much the same and have zero redeeming features.

 

2014-10-16 Gross maggots 1-1.jpg2014-10-16 Gross maggots 2.jpg

Maggots, thought of as repulsive creatures with zero redeeming features. Read on to see how they are transformed by confocal microscopy into beautiful works of art.


However, viewed under a microscope they become much more interesting, with a range of characters that can be used in discrimination, especially when you look at the business end of the maggot, its mouthparts!

 

It’s not so easy to ask a tiny 2mm long newly hatched maggot to 'open wide' to view the teeth, and traditionally we have been limited to viewing slide-mounted specimens by light microscopy. Scanning electron microscopy has its merits, but only for the external features. In normal light microscopy, imaging of these mouthpart structures is limited by problems of resolution, illumination and depth of field.


Lucilia sericata L1 - Light microscope high power.jpg

Greenbottle blowfly, Lucilia sericata light microscope high power image. With normal light microscopy the relationship of the sclerites of the cephaloskeleton (mouthparts) to each other is unclear.

 

At the Museum we have been using a laser confocal microscope for the first time to look inside these maggots to view the mouthparts, the so-called cephaloskeleton, in three dimensions. The mouthparts are crucial to the maggots in establishing themselves on their food source, be it a live animal or a decomposing corpse. The images produced by the confocal microscope rely on the autofluorescence of structures of the cephaloskeleton.


Lucilia sericata LI - Confocal microscope low power.jpg

Greenbottle blowfly, Lucilia sericata confocal microscope low power image - relationships are still unclear but, with the autofluorescence under laser light, the structures look so much more beautiful!

 

We were especially interested in the relationships of the small sclerites to each other and the so called 'hump', present in newly hatched larvae of Lucilia greenbottle blowflies but absent in Calliphora bluebottles.


Lucilia sericata L1 - Confocal microscope high powerWITH ARROW.jpg

Greenbottle blowfly, Lucilia sericata confocal microscope high power image: The structure relationships are becoming clearer (the 'hump' is arrowed) and this is finalised in the next image.

 

The 177 optical sections scanned by the confocal microscope enabled us to rotate and view this structure in three dimensions (see green false-coloured sclerite in image below) and see clearly for the first time how it relates to other structures.

 

In addition to their academic and practical value in identification, the images are also things of beauty in their own right and would not look out of place in an art gallery!


Lucilia sericata - Confocal high power - false colour sclerites named.jpg

Greenbottle blowfly, Lucilia sericata confocal microscope high power image and false colour sclerites. We have rotated the original to give three dimensionality. The red wavelength was selected, as this is the wavelength that gave most autofluorescence of the cephaloskeleton, to enable us to discard other structures and here false-colour has been added to show the different structures, including the 'hump' (in green) or epistomal sclerite.

 

The work was done at the Museum and involved Drs Andrzej Grzywacz (a visitor under the EC-funded SYNTHESIS project) and Krzysztof Szpila from the Nicolaus Copernicus University in Torun, Poland, collaborating with Tomasz Góral and Martin Hall. We used the Museum’s Nikon A1-Si Confocal Microscope.

 

For more information see the article published online in Parasitology Research on 19 September 2014.


By Dr Martin Hall

 

I hope you enjoyed the first 'Forever Flies' post. For more on flies head over to Erica McAlister's Diptera blog.

 

There will be more coming soon but just to let you know there may be a couple of weeks break whilst some important maintenance work is done to the site and my life

 

See you soon

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Come talk to me at Science Uncovered, a free evening of science-based fun and frolics this Friday 26 September! 

 

SU2014_SK_einvite.jpgScience Uncovered is a free evening event at the Museum. Come talk to me and other scientists about research, play games, ask some questions, have a few drinks and lots of fun!

 

At last year's Science Uncovered we had just under ten thousand people visiting the Museum in South Kensington and Tring and we hope to have just as good a turn out this year.

 

On the night there will be three main zones at the Museum:

  1. Origins and Evolution
  2. Biodiversity
  3. Sustainabilty

 

Each zone will have a range of science stations and activites related to the zone's theme. I will be at the Parasites and Pests station in the sustainability zone (which I am delighted to inform you is ideally placed near the cocktail bar!). Do come talk to me. We will have some great stuff for you to look at, including:

  • Live (uninfected) aquatic snails.
  • Portable microscope with samples of the schistosome blood fluke and eggs to look at.
  • Pickled schistosome worms preserved in ethanol (not for consumption just to look at).
  • Fieldwork equipment including the kit used to look for schistosome eggs, to filter eggs and collect the larval stage for DNA work and snail collecting material.
  • Games: Schistosome life cycle jigsaw puzzles.
  • Food: glittery parasite-shaped chocolates for consumption at your own risk (no parasites within, they are just shaped like parasites. Please note I make these myself so they may include nuts and other allergens).

 

schistosome egg.jpg

Come see schistosome eggs under the microscope.

 

snails.jpg

Take a look at our friendly live aquatic worms.

 

glitter parasite chocolates.jpg

Do you dare to sample my homemade parasite-shaped chocolates? They're getting their edible glitter suits on for this special occasion.

 

But this is just at our blood fluke station, I have heard exciting things about what others have planned for their stations, including bringing out shark samples and live animals, creating your own earthquake and of course the recently discovered Dr Livingstone's Beetle collection (covered by the press in this article) and much, much more. For more information on what's going on have a look at the Science Uncovered webpage.

 

What is Science Uncovered?

 

At Science Uncovered researchers showcase their research in engaging, interestings ways and chat with people about what they do, why they do it and why it's fun/important/interesting.

 

Science Uncovered is part of the European Researchers Night, funded by the European Commision. Events are taking place on Friday 26 September in about 200 cities across 43 countries.

 

The main outcomes we are aiming for are:

  • to raise awareness of the key role of research in soceity
  • to raise awareness of the wide diversity of people working in research
  • to give an understanding of the diverse range of research careers
  • to inspire the public to take part in other science activities
  • to encourage young people/students and their parents to consider careers in science

 

So when you come to the event and you're walking around the Museum looking at all the exciting activities, discoveries and discussions, do ask scientists a bit about their background, how they got into science, why they enjoy it, and anything else that takes your fancy. We are all wearing badges saying "I'm a scientist, talk to me". Please do not feel shy.

 

I hope to see you there!