Adventure Doc

The north-eastern area of Italy has recently been dealing with an outbreak of Chikungunya virus, for the last 2-3 months. The villages of Castiglione di Ravenna and Castiglione di Cervia in the province of Ravenna appear to be the center of the outbreak. There have been approximately 131 suspected cases, since July of 2007. More cases are under investigation, and testing results are still pending.

The center of the outbreak is believed to be traced back to a visitor, to the area, from Kerala, India. The mosquito Aedes albopictus is a new immigrant to Italy and is a know vector for this viral disease and mosquito “season” in the area is expected to run through mid-November. The chance of more transmissions in the area is likely.

Chikungunya Virus is a self-limiting (it goes away on its own) disease that is characterized by fevers, arthritis and a rash, mainly on the chest and back. The arthritis can persist for months, after the infection subsides and fevers generally last 10 days. The illness has been known to progress into hemorrhagic (bleeding) complications, similiar to Dengue Fever. More about hemorrhagic viruses can be found on the Adventure Doc page: Adventure Doc Hemorrhagic Viruses

To avoid this illness, protect yourself from mosquito bites! The diagnosis is made by serology from a blood sample.

You can view the Promed update here

Aircraft Cabin Air Recirculation and Symptoms of the Common Cold
http://jama.ama-assn.org/cgi/content/abstract/288/4/483

This was a pretty interesting article that looked at risks of catching a cold while traveling via airliner, due to recycled air.

The study looked at the main factor of recycled air in the cabins of commercial airliners and its risk factor for catching a cold. The article basically said there was no increased risk of catching a cold while flying, commercially.

I was convinced that I was getting sick from other people, in the cabin, due to recycled air. Hmmm, I guess it turns out I am just a hypochondriac with bad info!

Water disinfection

Knowledge of how to make water safe for human consumption or use is vital. There are basically three methods: heat, chemicals and filtration.

Heat:

Bacteria, viruses and most protozoan cysts (Giardia and E. Hystolytica) can easily be destroyed by heat. Time and temperature are inversely related. That means that the higher the temperature, the less time needed to disinfect the water.

I believe the best way to disinfect water is through boiling. Water is, generally, safe to drink after it reaches boiling point (100 degrees C). Just bringing the water to boiling temperature is killing pathogens. Just to make sure, boil the water for an additional minute. Giardia and E. Hystolytica have thermal death points at 60 degrees C, enteric viruses and bacteria die in seconds at 100 degrees C. The general rule is to boil water for a complete five minutes at sea level. There is a myth that you must boil water longer at higher altitudes. There is no need to significantly increase boiling time above 5 minutes, at altitude, because the thermal death points of most enteric pathogens is still within the 5 minute time window. Some negative sides of boiling water are the need for a heat source and fuel. Not everywhere is a good place for a fire and you may not always have cooking fuel. Heat is a one step process but doesn’t make the water look better if it is cloudy/murky.

Sterilization occurs after boiling for 10 minutes and kills spores, although spores are generally not know to cause GI problems. Pasteurization occurs when food or beverages are heated to 150 degrees Celsius for 30 minutes or 160 Celsius for 1-5 minutes.

Chemicals:

Halogens (chlorine and iodine) are very good disinfectants. The thing to remember about using chemical to treat water is the concentration of the chemical and the time needed disinfect the water. Concentration (the amount of the chemical in the water) is measured in milligrams per liter (mg/L) or PPM (parts per million).

Chlorine is used by most cities to purify drinking water for people’s houses. Chlorine kills Giardia, E. hystolytica, viruses and bacteria. Generally, using chlorine, I advise a 60 minute contact time. The amount of time required for 99.9% kill of pathogens depends on water pH and temperature. Household bleach (5% hypochlorite) is chloride. Adding 4 drops (0.2 mL) of bleach to one liter of water produces adequate concentration of 10 PPM and should be left to site for one hour.

Iodine is another halogen that is widely used to treat water. The goal of concentration of iodine to treat water is 3-4 mg/Liter or 4 PPM, given adequate contact time. Iodine generally requires less time than chlorine. Iodine, at 3-4 mg/L, generally makes water safe after 30 minutes of contact time. Remember that cold water needs a longer contact time. The iodine tablets are very easy to carry and small.

A few negatives about using chemical water treatment is the bad taste of the water. I advise mixing some electrolyte powder after the water has been treated. Also, people with unstable thyroid disease or those with iodine allergy should not use iodine. Its use in pregnancy should be avoided, longer than 1 week.

Filters:

Filtration is a very easy method to disinfect water. Most everybody knows somebody with a water filter. The thing to know about is pore size. This is the size, in diameter, of the particles than can pass through the filter.

Parasitic eggs and larvae are about 20 micro-meters
Giardia and E. Hystolytic are about 3-5 micro-meters
Bacteria are 0.4 micrometers
Filtration is ineffective against viruses because they are too small

Filters tend to clog, easily. This is especially true if you are filtering dirty/muddy water. Try to let the water settle for 30 minutes before filtering. This gives the larger particles time to drop to the bottom of the container via sedimentation. Filters can also be bulky to carry. There are some new filtration straws that work well, too.

Choosing which method to use is dependent on number of people in the group, time to devote to purifying water and equipment. Often times, a two-step process is best. Iodine with filtration is a very popular treatment that removes resistant cysts that iodine may not kill.

As for me, I prefer boiling, if I have the time and equipment. Actually, if possible, I try to filter and then boil. Filtration is my second favorite method, but takes up some extra room. Lastly, I carry iodine tablets for emergency. They are not my first choice, but I always have them nearby.

Food borne illnesses

People who travel are naturally adventurous. They are explorers and enjoy trying new things. This also includes eating new and different foods. To me, eating new and local foods when I travel is one of the most exciting and fun parts! There are a few illnesses that you can get from eating food, other than traveler’s diarrhea.

Scromboid is an allergic reaction people get from eating certain types of fish that are not prepared well. This involves a substance called Histamine. You may know this from allergy medicines that are anti-histamines. Histamines cause puffy, watery and itchy eyes, runny noses and swelling. Sever reactions can cause the throat to tighten so much that air cannot get into the lungs! When fish in the Scromboidea family (tuna, mackerel, skipjack and bonito) are killed and not quickly processed, the flesh can release large amounts of Histamine. When people eat this fish flesh they also eat large amounts of histamine. The symptoms include tingling and paresthesia (pins and needles feeling) around the mouth and arms. Symptoms usually resolve in 12 hours, on their own (self-limiting). For a bad reaction, anti-histamine medicine such as allergy pills work great.

Ciguatera poisoning is gotten from eating reef fish such as barracudas. Any reef fish that eats other fish may carry this risk, though. The symptoms of this illness begin with GI symptoms such as nausea and vomiting, usually within a day of eating the fish. Weakness in the legs is also common. Very severe cases may progress to coma and respiratory failure. Most patients recover in a few days to a week. The cause of this is a tiny organism called Gambierdiscus Toxicus that grow on the reefs. Smaller fish eat this stuff and when the larger, predatory, reef fish eat many of the smaller fish, the toxins accumulate in the larger fish. Humans eat the bigger fish and there is an accumulation of this toxin in the fish flesh. Mannitol (a diuretic medicine) can be lifesaving in severe cases. More about this can be read at this link:
Gambierdiscus Toxicus PDF Article

Paralytic Shellfish poisoning is just like them name sounds. You get it from eating mollusks (shellfish like bivalve mussels) and it causes paralysis. People generally suffer from paresthesia (pins and needles feeling) of the mouth and extremities (arms and legs) that lasts 1-2 days after the eating the shellfish. The symptoms usually begin with hours after ingestion. This is caused by Saxitoxins gathering in the shellfish. These Saxitoxins are associated with massive algae blooms know as “red tides”. When these shellfish are gathered by fisherman, the USA, Canada, Japan and Europe have mandatory screening for this toxin.

Puffer Fish Poisoning is a rare problem in Japan. There, Fugu is a special delicacy eaten in sushi bars. Fugu is a puffer fish that contains a poison called Tetrodotoxin. The poison can cause paralysis and death by respiratory failure, if not prepared by a highly trained chef. If you are going to try this…make sure you go to a reputable restaurant that has a lot of experience with this food. A good link to learn more about this is at:
Tokyo Cube Fugu Page

I guess you could call this post a “review” of the books I think are great to study from. As I run into some new books, I’ll put them up, too! Like anybody reads this, anyway. The two people, including my mom who read this, please tell me any books I might not know about!

TRAVEL:

Travel and Tropical Medicine Manual
By: Jong and McMullen
0-7216-4214-4

Control of Communicable Diseases Manual
By: American Public Health Association, Edited by D. Heymann
0-87553-035-4

WILDERNESS:

Field Guide to Wilderness Medicine
By: Auerbach, Donner, Weiss
0-323-01894-7

This list is in no way complete, but a good place to start. In fact, these are the books I often refer to, the most. Anybody want to mention any others?

A few more cases of malaria have been confirmed in Kingston, Jamaica, bringing the total number of confirmed cases to 370. The outbreak started in fall of 2006 and involves Plasmodium Falciparum, the most severe type.

Malaria is not normally found on Jamaica and the CDC is advising chloroquine, as prophylaxis, for those staying overnight in Kingston. The other areas of Jamaica are not considered at risk.

The Jamaican government is working to control vectors (mosquitoes) by spraying and destroying possible breeding grounds.

This is believed to be a temporary problem, but the advice is still to take prophylaxis for people sleeping in Kingston, for now.

Here is a CDC link for more information:
CDC Malaria in Kingston, Jamaica

Hope this helps!

Unfortunately, I cannot attend these conferences…But I thought I would spread the word because they are going to be great! Anybody with an interest in wilderness medicine should consider going to these events.

You can learn some great survival skills, how to treat AMS (acute mountain sickness) and altitude related problems, diving medicine, treatment of ski and snowbaord injuries, travel with kids in the wilds, lightening strikes, navigation and a chance to get in some ski/board time, when not learning! Both conferences are accredited by the WMS (wilderness medical society) and have some of the best instructors in the field.

Anyway, I am jealous of anybody who gets to go…have fun for me! Also, if you go, you have to tell me about it!

Here is the link:
wilderness-medicine.com

The site is giving me trouble, and not in the technological way. Although it is usually the main problem. Nope, this time, it is layout of a few, new pages.

I know the material and what I want to say. I just cannot organize it into a presentable format. It has become a “soup sandwich”!

Perhaps I should break the material down into smaller sections? The content reads good, in my opinion :), but only on paper. I am having trouble fitting it into a website format. It seemed great on paper, but when you put it on screen, with pictures, boarders, links, etc. It doesn’t read well. Then again, not many of my pages read well and it hasn’t stopped me yet!

Long Term Malaria Prophylaxis

I seem to be hearing this question a lot, lately. I will try to give a brief summary of what I know…

Atovaquone/Proguanil (Malarone)

Basically, there is not a lot of good literature on long term use of atovaquone/proguanil (Malarone). This seems to be an area that needs some more research. Most of the data that is being discussed, currently, centers around a short study of UN Peacekeepers who took the drug combo for approx 6 months with no severe reactions noted. It is a small study with only a few hundred patients, if memory serves. Nothing solid. The two drugs in the compound are both, individually, well studied and safe for long term use. Proguanil is not suitable for solo-protection as drug resistance is common. Oh, I got a good bit of info about malarone and it’s efficacy being increased when taken with a fatty meal versus an empty stomach. This appears to be true, as the fat in the meal helps it absorb. The EU has set a limit of use that ranges from 5 weeks to 3 months, depending on the country. The USA does not have any restriction on its use, with respect to time.

Chloroquine

Well studied and commonly used, often for long term use. The main thing to know is “Will this protect me?” This is only a drug to be used in geographic areas with known sensitivity to chloroquine. There is a link between long term chloroquine use and retinopathy (eye problems). Literature disagrees on how many YEARS that is, but a commonly accepted value is 5 years of 300 miligrams per week or 3 years if taking 100 miligrams per day. Most all people I see and talk with get advised to have a regular eye exam (every 6 months) after 2-3 years of any dose of chloroquine.

Mefloquine (lariam)

There is a lot of study on the long term use of this medication and it seems to be safe for long term use. If you can tolerate the mefloquine for the first 3-4 weeks, you should be fine for several years of use.

Doxycycline

Again, if you can tolerate the side effects of the medication (sun sensitivity, risk of vaginal yeast infections, GI/diarrhea and dietary restrictions), this medication seems safe for long term use, greater than 6 months. Most of the studies do not show any data of use longer than six months.

This information is from a collection of resources including:

Travel and Tropical Medicine Manual
Author: Jong and McMullen

TravMed
TravMed.com

Pretty good journal link about long term malaria protection (technical)
Malaria Prophylaxis for Long-Term Travelers
This is a PDF from Communicable Disease and Public Health

Many, many issues of The Journal of Travel Medicine and too many years of higher education.
If there are any other opinions or sources out there that have some good data, please send them to me…I am always trying to learn more!

Schistosomes

Basics: Also known as Bilharziasis. This Trematode/blood fluke infection may lead to portal hypertension, liver fibrosis or bladder cancers, depending on location and length of infection. Eggs enter a freshwater pool, mature in snails and then become free swimming. They directly penetrate skin when it contacts infected water. Two species have a preference for mesenteric veins (Schistosoma Mansoni and S. Japonicium). Schistosoma Hematobium is generally found in the bladder.

Location: S. Mansoni is seen in Africa, South America and parts of Caribbean. S. Hematobium is found in Africa and Middle East. S. Japonicium is found mainly in China and Phillipines.

Transmission/Incubation: Transmitted by direct contact with infected water, allowing penetration of free-swimming cercariae. Eggs are deposited in water from infected person’s urine or feces.

Prevention: Avoidance of infected water, wearing of waterproof boots if wading, topical application of a 70% alcohol solution immediately after contact with infected water and vigorous drying

Diagnosis: Demonstration of eggs in Kato fecal smear or in urine. Urine filtration often facilitates demonstration. Various attempts are underway to have a rapid antigen analysis card for either blood or urine.

Treatment: Praziquantel single dose of 40mg/kg for S. Mansoni and S. Japonicium. A 60mg/kg dose may be used for S. Hematobium.

These are blood flukes and have two sexes, male and female. These parasites like to live in the bladder or mesenteric veins of the abdomen. There are several types of Schistosomiasis: Schistosoma Mansoni and S. Japonicium like to live in the mesenteric veins of the abdomen. Schistosoma Haematobium likes to live in the bladder.
These parasites clog the veins or bladder that they live in.

The life cycle of this parasite requires a snail to mature within. The eggs are passed from an infected individual, either in feces or urine. These eggs hatch miracidae (baby schistosomes) that mature within a snail, that lives in the water. Once they grow up a bit, they leave the snail and swim freely in the fresh water. These are known as cercariae (teenage schistosomes). These bad guys directly penetrate your skin while you are swimming or wading in the water.

To keep this from happening, wear waterproof boots while wading in the water. If you contact the water, vigorously dry skin and immediately rinse your body off with 70% alcohol solution after drying off, to kill the cercariae before they penetrate. This illness is found in Africa, Saudi Arabian peninsula, South America, the Middle East and some Caribbean islands. S. Mekongi and S. Intercalatum are two addition species worth mentioning. Katayama fever (systemic manifestation) is rare, but may occur 3-5 weeks after primary exposure.

Iodine or Chlorine may be used to disinfect water prior to bathing, laundry or drinking. Ensure 3-4 hours for treatment, prior to use.