Filariasis basics for travelers


Condition: Infection by a parasitic worm that often causes lymph-edema in the lower extremities

Infectious Agent: Lymphatic filariasis is caused by Wuchereria bancrofti; Brugia malayi and B. timori. All of these are filarial nematodes.

Signs and Symptoms: Most infections are asymptomatic. As the worms mature they may progressively block lymph channels in the lower extremities, scrotum, arms or breasts. This causes the resultant back-up of lymph and presentation of elephantiasis. Secondary skin infections in these effected areas are also common.

Diagnosis: The standard diagnosis is through a blood smear that demonstrates microfilariae under microscopy. The highest concentrations of microfilariae are seen in peripheral blood at nighttime hours and specimens should be drawn between 10PM and 2AM.

Transmission: The bite of infected mosquitoes such as Aedes, Culex, Anopheles and Mansonia species

Treatment: Diethylcarbamazine (DEC) is the drug of choice for travelers with these infections. Although ivermectin does kill microfilariae it has no effect on adult worms. Once elephantiasis has developed there is no corrective methods to reveres the course. Surgical excision of the filarial worms only result in scarring of the lymph channels and worsening the blockage. Local wound care of the effected region is important including hygiene and infection control.

Prevention: Protective measures include mosquito bite prevention such as long sleeves, pants, bed nets, permethrin treated clothing and DEET 30-35% insect repellent.

Epidemiology: This effects approximately 120 million people worldwide. Lymphatic filariasis is seen in Sub-Saharan Africa, Egypt, Southern Asia, Pacific Islands, Brazil, Haiti and the Dominican Republic. Short term travelers to these regions are at low risk for infection. Travelers in these regions for extended periods of time (>3 months) and are intensively exposed to mosquitoes are considered to be at a higher risk for infection.

Blog changes

The Adventure Doc Blog is undergoing a few changes to match the new websites. These will take place over the next few days and your patience is appreciated! In the meantime, please visit our new homepage at:

Travel medicine video updates from Greece and North Africa

Everything is going quite well from Greece and we are prepping/packing for the upcoming trip to North Africa in 2 days.  We have already been shooting a lot of video on our Adventure Doc Talks video series and hopefully have some usable footage…we will see when we start the editing process.

After a few days in the southern Greek mainland, in the area of Sunio and the port town of Lavrio we started shooting video.  Marine life envenomations were the first topic we started with and we were lucky enough to find some sea urchins and jelly fish very quickly.

After the beaches on the Greek mainland we made our way to the island of  Crete.  On the ferry boat (8 hours) we managed to video sea sickness problems.  The old port of Xania was epic and very amazing…our hotel (Balmondo) was in the perfect location.  We hiked the Samaria gorge and shot our video on lower extremity injuries.  This was the perfect location to hurt your knees and ankles, fortunately none of us did!  We saw some great jellyfish and got some good information on dehydration treatment and prevention.

We are now back in Athens and plowing through a lot of video and completing our transfers onto hard-drive.  Lots of laundry to finish and we are packing for the next leg of the trip…Egypt and North Africa!  We are leaving in a few days and will be working down there for 12 days.  Pyramids, hummus, dehydration, the Nile river and heat stroke are all on the agenda!

Uploading pictures and video, to the web, from this location is difficult so we have to wait until we are back home to share the good stuff!

Week round-up

Christian FisherI have been far too busy lately and most of my time has been reading other websites that have tons of interesting information, all related to travel and expedition medicine.  Here’s some of what I have been reading lately:

Matador Travel:

Juli Huang wrote a great article about “Three essential Medical books for Travelers“…very good selections, I must say!

I submitted an article about Planning for Medical Emergencies while traveling

National Geographic Adventure Blog:

The climbing death of Rob Gauntlett, Nat Geo’s Adventurer of the Year

World Nomads Safety Blog:

I am very proud that World Nomads has two articles, from me!  One about DVT and Travel and another discussing a recent polio outbreak in Western Africa.  They also have a great article about travel to “dangerous locations“…check it out!

Medicine for the Outdoors:

Dr. Auerbach has produced several very good posts on winter accidents and avalanche safety.

Exped Med Conference:

April 1-4 of 2009 is the San Diego Exped Med Conference at the Hotel Del!  I am so sad that I cannot attend this one but I did make their Washington DC event and can say that it was one of the coolest learning experiences of my life!  Anybody looking to brush up their expedition medical skills or a way to break into these jobs should attend.

Hitting Malaria Below the Belt

Rectal Suppository

Rectal Suppository

Treatment of malaria, especially in remote areas, can be challenging.  Severe malaria infections can render a person incapacitated.  Vomiting, fever, lethargy and an inability to tolerate oral medications are some basic examples of barriers to getting the appropriate medicine in the person’s body.  Intravenous medications require a specially trained person to administer, providing the IV medicine is even available. 

The Lancet has an interesting article that looks at the efficacy of giving a pharmaceutical suppository, while the patient is being transported to a higher level of medical care.  The suppository used in their investigation contained Artesunate as their active ingredient.  The study looked specifically at reductions in mortality of patients who took extended time to reach a medical aid clinic, where advanced treatment was possible.  The artesunte suppositories had little effect on decreasing death in those who were able to reach the clinics within six hours.  However, those patients arriving to the clinics after 15 hours or more showed a reduction in mortality from 3.8% to 1.9% in those treated with rectal artesunate.

This information can help save lives of those who are living or traveling in remote areas, infected with malaria.  Typical treatment for travelers and adventurers in remote areas include “stand-by” treatment.  This is simply carrying an oral medication, such as mefloquine or atovaquone/proguanil, to be taken when the person begins to feel symptoms of malaria.  “Stand by” treatment should be used while the person begins to leave the remote area and seek medical attention.  It is not intended to be used and not followed up with a proper exam and diagnosis by a medical professional.  Several problems can occur with using a standard “stand-by” treatment:

  • Nausea and vomiting are common, possibly resulting in persons vomiting their dose of medicine back up
  • If the illness advances rapidly, the person may be unable to swallow oral medications
  • Some of the medicines used for stand-by treatment can be expensive

Rectal artesunate suppositories should be considered by all healthcare providers looking after people in remote malaria prone areas.  The purpose of this medicine should be similiar to a stand-by treatment and used while advanced medical care is being sought.  However, road conditions, methods of transport and distance to advanced medical care may require lengthy transport times.  This simple to administer and inexpensive treatment can save lives.

Pre-referral rectal artesunate to prevent death and disability in severe malaria: a placebo controlled trail

Website and Blog Reveiw 12/15/08 have been finding a lot of cool new websites and wanted to take a few minutes to share them with anybody who reads this:

*First, in the world of travel, a very informative site I saw was and contained lots of great info as well as very photos!

*My friend Greg, travel writer extraordinaire, had a scary experience in Portland.  Apparently he was first on scene of a car versus pedestrian accident and started thinking about advice for travelers put in these scary instances.  Read about it over at 

*World Nomads, the Australian company best known for travel insurance, has a very interesting blog going over at their website.  The blog, World Nomad’s Travel Safety Hub, discusses everything from illness and injury to scams and other things that can ruin a trip.  Very cool blog and worth a look!

*Lastly, I have been pouring over the new study about the Malaria Vaccine trials.  I am still in the process of writing up my review but it is very interesting stuff!

*I am also still working far to much on an upcoming article looking at rock climbing related injuries to fingers.  Specifically, does using tape on the fingers prevent injury?  Coming soon, I hope!

Future Considerations

I find myself entering a unique position. I have just entered my last year of residency training and will be spending it as a Chief Resident. I am now trying to decide what to do, upon completion of my three years of post-graduate medical training. My interests are:

Expedition Medicine

Travel and Tropical Medicine

Global Health

Rural and Remote Medicine

Now, the question is how best to prepare for these types of medical practice? Should I complete a fellowship (additional years of training), perhaps in sport medicine or emergency medicine? Advanced training in sports medicine would help me deal with muscular/skeletal injuries and outdoor sports-related problems. Emergency medicine, with its reductions of dislocated shoulders, laceration repairs and acute problems would be a helpful addition to my skills. There are several rural medicine fellowships, such as the program in Tacoma, Washington.

What about just completing a second residency (3 more years of training)? Instead of doing a rural medicine fellowship (for family medicine doctors), I could just do an additional residency in Emergency medicine. In America, there are several very interesting fellowships open to graduates of Emergency Medicine residencies. The program at Stanford looks especially cool. New Mexico also has a very nice looking Wilderness Medicine program. There is a Family Medicine program, in Montana, that has a wilderness medicine track, but I am already completing my study at a different program.

So how does one gather more knowledge about these specific areas of medicine? Existing specialities I have already begun seeking additional training in include:

Travel and Tropical Medicine
Diploma in Travel and Tropical Medicine and the ASTMH Certificate of Knowledge, Fellow of the Royal Society of Tropical Medicine and the International Society of Travel Medicine

Wilderness Medicine (including Search and Rescue)
The Fellow of the Academy of Wilderness Medicine (FAWM), I am still gathering units for my fellowship through attending conferences like the National Expedition Medicine Conference and the WMS Events.

Global Health
Master’s Degree in Public Health specializing in International Health and Complex Emergencies/Disasters

Rural and Remote Medicine
Co-authored a paper on Portable Field hospitals for Rural and Remote Health

I then began thinking of skills I might be in need of, with this type of career track:

Basic surgical skills such as removing an acute appendicitis, wound incision and drainage, etc

Obstetrical Skills including vaginal and ceserean deliveries

Pediatrics training involving infectious diseases, immunizations and nutrition, plus basic disease treatment

Emergency Medicine’s unique skill set such as fracture and dislocation reductions, toxicology and familiarity with acute issues

Infectious Disease as it especially pertains to tropical medicine such as disease prevention and treatment of illnesses such as malaria

This list is, by no means, a complete skill set and hopefully conveys the wide scope of knowledge practitioners in these fields require. I guess that my point is that there is considerable overlap of medical specialities needed to form a decent skill set for this “new speciality”. I think of it similiar to the growth of Emergency Medicine from Family/General Practice. The job of working in an emergency room was being performed, traditionally, by family medicine doctors with experience giving care to adults, children, obstetrics and general medical training. From this, the concept of a unique skill set that I see Emergency medicine as, evolved.

Is wilderness and travel and expedition and remote medicine all one, unique and new speciality?