Mosquitoes and Malaria Prevention

Mosquito borne diseases

Malaria is at large in over 100 countries of the world, and one - two million people die of malaria every year.

Fresh into the mosquito-borne disease spotlight is the USA's Triple E virus, Eastern Equine Encephalitis, which is found in north eastern US locations such as Rhode Island. It is rarely transmitted to humans (averaging 5 cases per year; birds are the main recipient of Triple E), but when it is, it's deadly, killing a third of those infected. There is no cure or vaccine, so keeping mozzies off is the only defence.

West Nile virus is a bigger a problem in the USA where it has killed two or three hundred people in the last two years.

The viral transmitting mosquitoes have now appeared in southern Europe including Portugal, Spain and France. So how can you avoid these sometimes deadly infections?

The best way to avoid Malaria, Dengue Fever and West Nile virus (not to mention rarer but equally unpleasant health threats such as Encephalitis, Triple E, Yellow Fever, Rift Valley fever and more) is to keep the little stingers off you.

Anopheles mosquitoes - the ones that transmit malaria - fly from dusk to dawn, so prepare yourself for this whining and dining time, depending on your region.

The Aedes Albopictus mosquito (Asian Tiger, photo at top), responsible for Yellow Fever, Chikungunya Fever, Dengue Fever and Nile Virus, flies during the day too, tho' they are more aggressive at dusk and dawn. So in Aedes danger areas all day precautions are advisable.

Malaria: 2011 the UK saw a 30% rise in travellers infected with malaria, mostly contracted in West Africa (Nigeria and Ghana 40% of total) and India (11%).
Aedes Albopictus disease found, though not necessarily rampant: SE Asia (even Singapore!), India, West Africa, Central America, Brazil, USA East Coast, Italy, Greece, Croatia, Portugal, Spain, Netherlands, South France.

Indoors, hunt to splat. Look under beds, shake curtains, check dark places. In extremis spray the room with (esp. pyrethrum) insecticide, if it has window nets or air conditioning.

Electric anti-mosquito mats are preferable for all-night protection rather than smouldering coils, as coils tend to run out before dawn, and are smelly, unhealthy devices anyway. But they are very effective.

When travelling in more primitive surroundings sleep under a net, treated with permethrin if possible. If not, mosquito coils are default best system.

Post a comment

Outdoors, wear light colours - mosquitoes know their camouflage - long trousers and long sleeves.

Take especial care of bare ankles underneath restaurant tables, it's the mosquito's favourite dining area, a lovely cluster of veins close to the ground in discreet darkness. Mmm, yummy.

And they'll get you through thin clothes too, so apply repellent to thin fabrics in key places e.g. socks, T-shirt shoulders.

Avoid wearing perfumes and shower off your body odour as soon as you can, as mosquitoes use smell to track their victims.

If you get bitten and the spot is itchy, try 'ironing' it with a hot cup of tea or coffee - it will magically disappear for ever! Hmmm. Alternatively squeeze lemon juice onto it.

There are now traps available that catch significant numbers of Aedes Albopictus, the most elusive mosquito. The trap produces an air current of ammonia, fatty acids and lactic acids that imitates the smell of a human body. With the addition of carbon dioxide, the efficiency of the trap improves further. These traps are expensive (over $500) and still under development.

Post a comment

Repellents

- the latest 'deterrent' is smelly socks. Scientists in Tanzania have discovered that mosquitoes prefer the odour of very smelly socks than humans, by a factor of 4:1. In other words - a) wash your feet after a long hike and put your socks well away from your camp b) or you could try creating a box shrouded in insecticide cloth to kill the little buzzers.

Deet - The most potent mosquito repellents contain lots of Deet (Diethyl-toluamide), so check out the ingredients.
25% Deet is good, 50% is excellent and 100% Deet will force mosquitoes to leave the country; trouble is it will also dissolve your skin, so only use it on clothes or nets.
Be wary of using deet on the skin of small children.

- Mosiguard is relatively natural (citrodiol and eucalyptus) and often very effective, so starting with that and saving the Deet for heavy duty mozzie attacks is worthwhile.

- NeemCare Herbal Insect Repellent. Neem tree oil is used in Ayurvedic medicine and is burned in India to repel insects.
It is now on the market as a general repellent and in tests has successfully repelled the voracious midges that plague the Scottish Highlands as well as mosquitoes.
If mosquitoes do get through the defences, trials indicate that Neem oil also reduces the severity of the body's reaction to the bite.
Personally tested when travelling in Myanmar, it worked perfectly.
Available in health stores and pharmacies, it also works against head lice.

- Refined lemon eucalyptus oil, lavender oil and citronella oil, all of which are disliked by insects; but don't forget to dilute them with some kind of carrier oil, such a sunflower or sesame.
Alternatively bath or shower with lemon gel.

- Vitamin B1/B12. Consistant anecdotal evidence suggests that mozzies hate the smell of B1. Take 100mg a day, starting a few days before your trip. Others swear by B12. They're both worth trying if you plan to spend a while in mosquito disease zones.

- Fish Oil capsules. e.g. Cod Liver Oil.
It must be unrefined so there is a hint of fishy smell about your person. Take a few days before leaving to build up the odour.
Think about it...fish eat mozzies and their larvae, so a mosquito will have an intense aversion to fish. Some people swear by this solution.

- Quercetin. You can also strengthen your body's health system before travelling by taking an anti-inflammatory called quercetin, which is especially effective when taken with Vitamin C.

- Electric 'vape' mats work well in rooms, are relatively inoffensive and last longer than coils, but check local voltage and socket type.

- Electronic buzzers/sonic deterrents do not work as far as we know.

Post a comment

No-see-'ums

These tiny fleas - almost invisible - live around beaches and rivers and bite mainly about dusk, particularly after rainfall. The result of their bite is out of all proprotion to the size of the insect , with massive swellings the size of a hand quite normal. Normal repellants, including deet-based, are useless against these critters though the US army believes they know a product that works - Avon's Skin So Soft.

Gallinippers

The appearance of a giant species of mosquito in Florida is expected this year due to recent tropical storms. Gallinippers (Psorophora ciliata) are 20 times bigger an ordinary mosquito, the size of a US 25-cent piece, and already known in eastern US.
They bite not only at dusk and dawn but during the day too and apparently being bitten feels like 'having a hot nail drived into your back'.
The good news is that Gallinippers are extremly visible and audible, landing on flesh with a heavy thump, so they're irritating but easy to kill. Furthermore they don't appear to carry malaria or other mosquito borne diseases.

Malaria - Treatments and Prophylactics (Preventative Medicines)

Some preventatives can be ineffective, while others can instigate health problems - making you nauseous or turning you into quivering, psychotic jelly. Many experienced travellers only use chemicals in high risk areas, but the choice is yours. One thing that won't turn you into psychotic jelly is travel insurance, protection without the shakes!

Very low risk e.g. Egypt (except Faiyum Oasis area), Bali, use no chemicals.

Low risk e.g. Central America, use chloroquine (trade name Nivaquine, Alocor) once weekly.

High risk e.g. some parts of Asia, Oceania, use chloroquine and proguanil (Paludrine), or mefloquine (Lariam) or malarone.

Very high risk e.g. sub-Saharan Africa, parts of the Caribbean, the north half of Latin America, and Far East (esp. Thai/Cambodia and Thai/Myanmar borders, Papua New Guinea), use:

- Malarone if available, or perhaps Mefloquine (Larium).
In sub-Saharan Africa chloroquine and proguanil is rated as 50%-70% effective, while mefloquine (Lariam) is 90% effective against malaria but can have unpleasant side-effects such as : nausea, panic attacks, fits, manic depression and a tendency to bark at the postman.
A study (reported in The Times 20/9/00) estimated that 1 in 140 Lariam users suffered 'socially disabling neuropsychiatric side-effects.'

- Malarone (atovaquene), as effective as Larium (i.e. nearly 100%) but no psychological side-effects, though 14% of trial users reported some headaches and dizziness (Sept./00).
Also you only need to take it for only 7 days after leaving a malaria zone, as opposed to 28 days for Lariam.
In UK it's available on prescription at BA travel clinics when there is a specific health need.

- Qinghaosu, Chinese wormwood, a naturally produced herb has been used by the Chinese since mid-70s, and is now used in combination with other drugs, especially mefloquine - also known as Artemisinin - where the malaria parasite is particularly drug resistant.
Very effective, but not widely available.

- Doxycycline, an antibiotic (for treatment of chest and other infections), is widely used as a malaria treatment.
It's effective and especially popular in the Far East, e.g. Thailand and Laos. However it makes the skin sensitive to sunshine so it's not good for beach holidays.
It needs to be taken with plenty of water to prevent it sticking in the throat, and you should consume probiotics of some sort to restore healthy bacteria to your system - yoghurt or some other dairy products for example.

After Travel: Take care that health problems such as fever or flu-like illness developing up to 1 year after travel is not put down to flu.
Clearly inform your doctor of the possibility of malaria.

Symptoms: From infection to symptoms generally takes 1- 4 weeks, but can take up to one year.
Initial symptoms in adults for both malaria and West Nile virus: flu-like illness, weakness, dizziness, headache, fever, muscular pains, vomiting, diarrhoea.
Initial symptoms in children: any of the above plus convulsions, coughing and rapid shallow breathing.
Severe symptoms: muscle spasms (including face), jaundice (yellow skin and eyes), kidney failure, rapid shallow breathing, convulsions, coma, death.

n.b. Pregnant women are at increased health risk of contracting severe malaria, which can also damage the foetus.

p.s. If you're living in a malarial area for a while it's worth checking around your property (or even cast an eye over the neighbour's) for stagnant water that has collected in discarded containers and is now a mosquito farm.
Check them VERY closely for writhing little screw shapes (larvae) under water or tiny mosquitoes parked on the edge of the water.
I once lived in an apartment in Venezuela that had netting on all windows, yet we were endlessly savaged by the little blighters. We spent days checking all netting for tiny holes, then found, months later, that the mozzies were breeding in the small bowl of water growing ivy in the middle of the dining table.

Disease by Destination | Malaria site list | WHO malaria fact sheet | Campaign Against Dengue

General Travel Health | Deep Vein Thrombosis | Jet Lag | Travel Safety

Any comments or suggestions?