Adventure Doc

ProMed just released some news of a potential outbreak of Capillaria Philippinensis in the town of Zamboanga del Norte, Phillipines. I guess if there was going to be an outbreak of this intestinal parasite, it would be here.

81 people are already positive for the disease and 40 deaths have been recorded, including 9 children. Death from this parasite is generally through malnutrition and “starvation” or the host’s lungs filling with fluid. The parasites live in the intestines and “steal” all the nutrients from it’s host, causing malnutrition. Severe cases have such large amounts of parasites that the abdomen fills with fluid (ascites) and pleural transudates occur (lungs fill with fluid).

Once a person becomes infected, the parasite sheds its eggs in the feces of the host. The eggs look like trichuris eggs. If the feces contaminate water supply or lakes/rivers, the eggs hatch and begin to infect fish and water animals. Humans get infected when they eat the fish, raw or undercooked.

Capillariasis is an intestinal parasite that people get from eating raw or poorly cooked fish or crabs that are already infected. There are two types of this disease: Capillaria Philippinesis and Capillaria Hepatica. C. Philippinesis was first discovered in the 1960’s, in Luzon, Phillipines.

If you liked this stuff, you have to see more at AdventureDoc.org Helminth Page

The original article can be found here.

Mosquito Bite Prevention

700,000,000 people get a disease from a mosquito, each year. Of those diseases, 1 out of 17 people currently alive will die from the disease.

The species to know about are Aedes, Culex and Anopheles. These are the bad girls that carry diseases such as malaria, yellow fever, dengue fever and filariasis. I say “bad girls” because on the female mosquito bites mammals. The growth on new mosquitoes requires a blood meal. The males are content to only feed from flowers. Certain types of mosquitoes prefer animals, some prefer humans and some feed from both.

Attraction:

What attracts mosquitoes is not fully clear, yet. Mosquitoes do have developed senses of vision, thermal/heat sense and smell. They use all of their senses to find food. It is believed that the olfactory (smell) sense is the most important in finding victims.

During the daytime, dark colored clothing and movement help a female mosquito “lock on” to its target, at long range. As the mosquito nears her prey, the senses of smell and thermal sense take over. Carbon Dioxide and Lactic Acid are two of the most studied mosquito attractants. CO2 is mainly found in exhaled breaths and lactic acid can be found on the skin when muscles are being used, as in exercise. Lastly, skin temperature and skin moisture guide the mosquito to where they want to bite, on the body. It is widely assumed that certain species of mosquito prefer different body parts; hands, face, feet, etc. This could be due to the differences in local skin temperatures. Scented soaps, cologne, lotions and hair products can also attract mosquitoes.

As for personal preference, adults are preferred over children. Men are more commonly bitten than women and larger people get bit more than smaller people, possible due to their increased CO2 output. It also appears my wife is preferred over to me.

Chemical Repellents:

DEET (N,N Diethyl 3 Methylbenzamide) is the gold standard of insect repellent. It has been well studied for over 50 years and provides protection not only against mosquitoes but also flies, chiggers, ticks and fleas. The concentrations of DEET available range from 5% to 100% and the higher the concentration of DEET, the longer the time of protection. Concerns over long term exposure to high doses of DEET have led to the US Military to adopt a 35% slow release formula. The medical literature disagrees over a formula that accurately predicts number of hours of protection and DEET percentage. One study indicates a 4 hour protection with 50% DEET while another indicates 12.5% DEET protected for 6 hours. Products with 20-35% DEET generally provide adequate coverage for most instances. There are reports of skin irritation occurring more frequently with percentages greater than 35%. The Pediatricians advise nothing more than 10% DEET for children less than 12 years old. Use of DEET with sun-block lowers the efficacy of the sun-block. So, more frequent applications of sunscreen will be needed for adequate solar protection. The DEET spray is applied to the skin, first. Sunscreen is applied over the top of the DEET spray. I remember this because the DEET protects your blood and stays the closest. Sunscreen protects against the sun, which is further away. DEET is a well studied and commonly used chemical. High dose DEET has been shown to not be a neuro-toxin. There have been several cases of encephalopathy (brain swelling), mostly in children, with prolonged exposure and inappropriate use of DEET. DEET works by inhibiting signals from the mosquitoes’ antennae and making it hard for them to find you.

Avon Skin-So-Soft is known to be a mosquito repellant. Lab studies showed a 30-minute protection time against Aedes mosquitoes. Ideas as to why it is a repellent center around either fragrance of the cream or the chemicals it contains, benzophenone and diisopropyl adipate.

Permethrin is an insecticide that kills or stuns bugs. Permethrin is effective against mosquitoes, ticks, flies, chiggers and fleas. The chemical does not easily absorb into the skin. This is applied to clothing, bed nets or screens, as a spray.

Citronella is known as the “natural” mosquito repellent. Derived from a plant, Cymbopogon Nardus, the oil has a lemon-like scent. Studies have shown that burning citronella candles and/or incense decrease the number of insect bites, for those near to the candles or incense.

Timing is Everything

Most species of mosquitoes bite at dawn and dusk. Avoiding being outside will lessen your chances of bites. When you are sleeping at night, in open air environments, a bed net is definitely shown to decrease bites. Often, those staying in nicer hotel rooms, with climate control, do not need netting. Open windows mean a need for netting.

Learn more about mosquito carried diseases such as Malaria, Dengue Fever and Yellow Fever over at www.AdventureDoc.org

There is a predition of the worst meningitis outbreak in 10 years, coming to Africa.
Prediction of the worst meningitis outbreak in 10 years is not by loonies who think the sky is falling. Reasons for this potential outbreak are due to the rainy season ending early, in central Africa.

There is a region of Africa known as the “meningitis belt” that can be seen here on Adventure Doc Meningitis. There is also some information about meningitis and the vaccine there, too.

Travelers going to Africa or any other gathering of people who could be carrying meningitis, such as the Hajj, in December, need to be prepared.

The meningitis vaccine covers 4 types of Nisseria Meningitis (A, C, Y, W-135). These are the most common strains you will run into in Africa. Unfortunately there is a “B” type that is not covered by the vaccine. The “B” type happens to be one of the most common strains in North America and Europe.

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!

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

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.

Glaxo experimental malaria vaccine works in babies
Wed 17 Oct 2007, 16:00 GMT
Reuters Africa

By Ben Hirschler

LONDON, Oct 17 (Reuters) – African babies — the group most at risk of dying from malaria — may be protected against the mosquito-borne disease by an experimental vaccine, researchers said on Wednesday.

The finding clears the way for final-stage testing of GlaxoSmithKine Plc’s shot and increases the chance that the world will have a usable vaccine within five years.

Malaria kills one person every 30 seconds, most of them young African children. Doctors believe a vaccine, given as part of routine infant immunisation, is the best hope in fighting the disease.

A clinical trial in Mozambique of 214 infants aged 10 to 18 weeks found the vaccine was safe and reduced new infections by 65 percent over a three-month period after treatment. Clinical illness was cut by 35 percent over six months.

Although such efficacy rates are not as good as for some childhood vaccinations, experts believe the huge burden of malaria means the new shot can still save millions of lives.

“This is a very major breakthrough,” lead investigator Dr Pedro Alonso of the University of Barcelona told reporters in a conference call.

“These tantalising and unprecedented results further strengthen the vision that a vaccine may contribute to the reduction of the intolerable burden of disease and death caused by malaria.”

ONE MILLION DEATHS A YEAR

Malaria, caused by a parasite carried by mosquitoes, kills more than 1 million people every year and makes 300 million seriously ill.

The latest findings, published online in the Lancet, are broadly in line with a 45 percent reduction in new infections reported in 2004 when Glaxo’s vaccine, known as Mosquirix or RTS,S/AS02, was given to children aged 1- to 4-years old.

Mosquirix will now go into a large-scale Phase III trial in the second half of 2008, involving 16,000 infants and young children in seven African countries.

If all goes well, the vaccine — which is the most advanced of a number in development — will be submitted for regulatory approval in 2011, suggesting it could be commercially available in 2012.

Glaxo has promised to sell Mosquirix at low prices in developing countries. The exact price will be negotiated with purchasers, who are likely to be multilateral groups who would cover the cost on behalf of countries where malaria is endemic.

Glaxo has spent $300 million developing Mosquirix and expects to spend another $50 million to $100 million in future.

But the trials programme is also being financed by the nonprofit PATH Malaria Vaccine Initiative, helped by a $107 million grant from the Bill & Melinda Gates Foundation.

Mosquirix — which is given in three doses — targets just one stage in the malaria parasite’s life cycle and its success has surprised some scientists, given the complexity of the disease.

The fact that it works suggests an improved vaccine, targeting multiple elements in the life cycle, might be even more effective.

http://africa.reuters.com/wire/news/usnL17759798.html
Link to Story

http://www.cdc.gov/malaria/risk_map/

CDC Malaria Risk Map

The CDC just released a new Malaria Risk Map that is interactive and pretty cool. The link is to the homepage and the just select to open the map, in a new window. Kinda like google earth with bugs!