Adventure Doc

The CDC released a statement a few days ago about some deaths associated with the yellow fever vaccine.

The immunization campaign was the country’s response in attempting to stop an epidemic, following their recent earthquake.

The Yellow Fever Vaccine is commonly given and well tolerated. There is an ongoing investigation with the CDC, WHO and PAHO to determine what the problem is. Theories include: a problem with the vaccine itself, a problem with the people who died (their bodies had a personal bad reaction to the vaccine) or a combination of the two.

The specific make of vaccine that is implicated is produced in Brazil and widely used in areas where YF is endemic. The Vaccine for YF, used in America, is from a different manufacturer. The batch of vaccines that is linked to the deaths has already been removed from use.

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

Caution should be used when traveling in Fiji, especially in the capital of Suva. According to the UK Foreign/Common Wealth Office, there are some reports of military checkpoints that are detaining any person deemed to be a threat to the newly formed interim government.

The “State of Emergency” has been lifted, since early October, but caution should be used due to potential political instability.

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.