Core Skills, News & Features — 28 February 2015 at 10:49 am

The Adventure Medic Guide to Parasites

Sarah Richardson / Clinical Research Fellow in Emergency Medicine, Edinburgh

Last year, Dr Sarah Richardson removed a three inch-long leech from Daniela Liverani’s right nostril. The story went viral. Over 120 articles were published internationally, along with 100,000 shares on social media sites. Sarah spends much of her time working as a General Physician in Uganda, so is no stranger to parasites. However, the reaction of both the ED staff and the general public got her thinking: parasitic infections are out of most of our comfort zones, but actually they are common and quite easily managed if you know how. So, here’s Sarah’s Guide to All Things Creeping and Crawling:

Anyone who has travelled in the developing world will tell you how the environment is always creeping into your life. Sometimes, it is the lines of ants chasing the smallest crumbs on a surface. At other times it is the pleasing sight of several large spiders, left undisturbed in a house to ‘keep the mozzies under control’. Contrast this with the developed world. In the UK, we now have 57 insects on the endangered species list and we do our very best to sterilise the bubbles we live in.

As a physician in Africa, you would think that the most common things I see would be malaria, typhoid, cholera, haemorrhagic fevers and all the other tropical illnesses lurking in the deep depths of the ‘dark continent’. In reality the most frequently seen ailments are often much more minor and related to the various creepy crawlies that have worked their way into our daily lives. Given that little time is spent on these conditions during conventional Western training, I thought I’d share my top tips for treating the more commonly seen diagnoses, from the simple to the slightly more challenging.


Not actually a worm, but extremely common. Whilst we do see this in the Western world it is by far more common in Africa, and plagues both locals and returning travellers. Typically starting with a small erythematous papule, the infection spreads out with an inflamed scaly edge and a pale centre. Highly infectious, multiple children within a family are usually infected with the scalp being a particularly common place.

There are two classical presentations of ringworm in travellers and tourists. The first involves unclean bed linen and dirty hostels, with the infection presenting on areas such as the thighs, after they have pressed against the unclean edges of a bed. The second (and most typical) is from hugging small children (with infected heads) whilst wearing a low necked top, resulting in cleavage infection.

Treatment is simple: a topical anti-fungal such as ketoconazole, clotrimazole or miconazole applied until the symptoms have resolved, then for a minimum of a further two weeks to avoid recurrence. If you are treating scalp ringworm, use an anti-fungal shampoo but for extensive disease, oral treatment may be needed.

Jigger Worms

Itchy to the point of pain, the Jigger worm is actually the parasitic chigoe flea found in Central and South America and sub-Saharan Africa. As the flea can’t jump very well, the larvae bury into the skin of feet, particularly around the toes and under the toenails. Patients usually don’t notice the initial infection, so present several weeks later with one or more intensely itchy (or painful) pea-sized papules. The papules have a black dot, which is the flea’s respiratory organs. They are often secondarily infected at the time of presentation, with some patients presenting after they have noticed tiny eggs and faeces being secreted from the area.

To remove the larvae, clean the area. Then, take some simple tweezers or a needle and make a larger hole around the black dot. Remove the top layer of dead skin on top of the Jigger. Then using forceps, grab the Jigger as close to the head as possible and slowly pull it out. Try to always remove it as intact as possible to prevent infection. The larvae will have been producing eggs so ensure none are left in the wound. Be warned, sometimes multiple jiggers have worked their way into the same hole so make sure you remove them all before cleaning and dressing the remaining wound.

Tape worm

“There’s something hanging out of my bottom doctor…”

Pretty rare in the UK, tapeworms are relatively common throughout the developing world. Caused by parasitic cestodes flatworms, they are consumed as larvae in contaminated food such as pork or beef. Once in the digestive tract, they can grow to up to 17m long. They are usually asymptomatic though sometimes complications can occur.

Patients usually present either with abdominal pain or, more commonly, after finding segments of the tapeworm in their faeces. These are usually shedded proglottids, but in one case I had a patient with almost a metre of tapeworm shedded at once. Simple infections are treated with praziquantel or albendazole (readily available in Africa and other developing countries, though only accessible on a named patient basis in the UK). Faeces should be monitored to ensure the head and neck of the worm is passed, then rechecked after one and three months to ensure there has been no recurrence.

Mango worms – Bot flies and other myiasis

The mango fly or tumba fly is found mostly in central and eastern Africa. These flies generally lay their eggs on soil, damp clothing or linen that is being dried outside. The larvae hatch 2-3 days later, attach themselves to unbroken skin and then burrow under the surface. They classically pupate in the skin of the buttocks, waist and lower back – usually in areas where clothes are relatively tight fitting.

Bot fly larvae present in a similar way, after laying their eggs directly on the skin. Patients commonly dismiss the initial swelling as being caused by a mosquito bite. It is only after the larva grows and a boil-like swelling develops that they seek medical advice. The area initially may appear like a typical furuncle, but on closer examination there will be a hole for the maggot to breathe and for excretion of waste products.

Small larvae may be squeezed out if they are noticed early enough. With larger larvae, it may be too painful to squeeze it out due to local swelling. However, even gentle squeezing of the area will reveal a squirming maggot that retreats quickly, confirming the diagnosis. The best treatment is to put a large amount of Vaseline over the breathing hole. The maggot then usually climbs through this to reach fresh air and can be easily plucked from the area.

If this fails then the area can be incised under local anaesthetic and the maggot removed whole. Given that flies lay 100-300 eggs at a time, check the patient over for any further signs of potential larvae before discharging them.

Loa Loa

Loa loa is not for the faint-hearted. It is a blood dwelling roundworm, generally found in Africa and spread by mango flies (or deer flies). Once developed, the adult worms wonder through the subcutaneous tissues, finding their way to the conjunctiva and growing up to 20cm in length. Patients often are unaware of a worm until they notice them in their conjunctiva. Sometimes, they see the worm crawl across their vision. Swelling and oedema can occur in the subcutaneous tissue at any site where the worms have died.

Treatment is usually quoted as being surgical removal of the worm, after paralysis of the worm in the eye. I’ve found that in the developing world where surgical settings are not ideal and paralyzing drops not available, the locals have come up with a reliable way of getting the worms out with a lot less fuss.

1. Get a large chunk of meat (usually goat, because its cheaper than beef)

2. Warm it in the African sun but make sure it remains nicely moist

3. Open the patient’s eye that contains the worm and place the meat onto the open eye

The worm will usually crawl into the meat if left on the eye for about 15-20 minutes. If it doesn’t, you may need to make a small incision in the conjunctiva for it to crawl through. After removing the adult worms, the microfilariae should be cleared with DEC (diethyl-carbamazine). This can be difficult to get in the developing world, in which case albendazole can also be used.


Let’s face it; leeches in bodily orifices are pretty rare. However, I couldn’t finish this article off without a tip about how to get them out. It’s my claim to fame, after all. Leeches are generally found in freshwater environments, where they attach with their sucker to an external area of skin. They will either drop off once they have had their feed (usually taking between 20 minutes and two hours), or you can flick them off the skin, interrupting the suction under their sucker. If a leech has made its home in an orifice such as the nose, then:

1. Get direct vision of the leech using a nasal speculum (or similar)

2. Using fine suture forceps attempt to grab and remove the leech

If the leech disappears up the patient’s nose, then move into an area with a sink. Run the hot tap of the sink to create steam (some leeches love steamy environments). If you still can’t remove the leech then get some form of foam or absorbent material and soak it in water hot enough to create local steam. Hold the foam under patient’s nose to encourage the leech to come more anteriorly, then remove it with forceps. You may need to tug a little.

If all else fails, then either refer for a scope or use the meat trick, so lovingly described above.

In summary

Worms and parasitic infections are extremely common in the developing world and in those returning from the area. If you come across them at home, then don’t panic or freak out. If you’re in doubt, call your local regional tropical medicine registrar – they probably have a few tips. If you are feeling bold, then gently warm up some meat and get stuck in.

(Cover photo: Gastrophilus equi – Wikimedia Commons)