Mosquito Diseases - A Detailed Feature

Introduction

Mosquito borne diseases are prevalent in more than 100 countries, infecting 300-500 million people and causing about 1 million deaths every year. In India, more than 40 million people suffer from mosquito diseases annually. There are a number of diseases borne by mosquitoes. They are malaria, filaria, dengue, brain fever and yellow fever. Yellow fever is caused by mosquitoes in jungle areas in parts of Africa and South America.

In India, malaria, filaria and dengue are the most prevalent diseases spread by mosquitoes. Over two million cases of malaria alone are reported. Even more astonishing is the fact that India spends 100 million dollars on malaria. In spite of spending so much, the diseases continue to explode from time to time. The reason is that these mosquitoes develop resistance to medicines and chemicals. Hence fighting mosquitoes and the diseases spread by them is a continuous process. Eradication of mosquitoes is the only way to protect mankind. Is it possible?

To a great extent, mosquito diseases can be prevented. This booklet is created to make people aware of the various diseases and how to protech themselves. In fact every household, village and township must participate in this process.

The mosquito borne diseases are no more downmarket diseases, since you find them in boardroom, in the lifts, in the cars, in the theatres, in the golf clubs, etc. However it is also not to be forgotten that mosquitoes and mosquito borne diseases are the result of low hygiene and sanitation in the downmarket areas and poor insect control in the upmarket areas.

Malaria

Malaria is a common disease caused by a microscopic parasite that is passed along from one infected person to another by mosquitoes. It is prevalent in Latin America, the Carribbean, Africa, Arabian peninsula, Central Asia, Afghanistan, Pakistan, Iran, India, Southeast Asia and southern China.

Relative risk of getting malaria:
1. Papua
New Guinea        1:140
2. Nigeria           1:210
3. Kenya            1:926
4. India              1:1450
5. Pakistan         1:5300

How do people get afflicted with Malaria?

Four species of parasites cause malaria in man. The most dangerous of these is the plasmodium falciparum that can cause cerebral malaria. This species afflicts about one-tenth of total malaria victims and might even prove fatal. The parasite enters the body by the bite of the female anopheles mosquito, which is the only mosquito type that transmits human malaria. You cannot catch malaria directly from another human being - the infecting parasite has to pass through a mosquito first. Even if a mosquito that has bitten a malarial patient bites you, the transmitted as malaria parasite has an incubation period in mosquitoes, just as it has in human beings.
 
Four species cause human malaria.
 
P. Falciparum
P. Vivax
P. Malariae
P. Ovale

Life cycle of the malarial parasite
 

1. Sporozoites in salivary gland
2. Oocysts in stomach wall
3. Male and female Gametocytes
4. Liver phase
5. Release of merozoites from liver

These enter red cells where both sexual and asexual cycle continue.

What are its symptoms?

Look for bouts of shivering, accompanied by severe chill that cause chattering of teeth and "goose pimples" on the skin. This will be followed by rise in body temperature. It might go to 40.5 degree C. And accompanied by severe headaches, bodyaches, etc. This usually lasts for 4 to 6 hours after which the temperature declines, profuse sweating occurs, and the symptoms disappear, leaving a feeling of great weakness. But symptoms aren't always clear-cut. They might mimic other illnesses. Sometimes it is wrongly diagnosed as the flu. Or, as when it is accompanied by abdominal pain, vomiting, diarrhoea, it might be mistaken for a stomach upset. Plasmodium falciparum in particular exhibits symptoms of jaundice, convulsion, etc., and can be confused with gastroenteritis, hepatitis, meningitis or viral encephalitis.
 
Fever and high body temperature, chills, sweating, back pain, vomiting, diarrhoea, coma, flu, kidney failure, severe headaches, convulsion.

What are the dangers of malaria?

While most malarial parasites need not be fatal, the resulting bouts of fever, shivering etc., can cause a lot of weakness. The plasmodium falciparum parasite, however, can cause serious complications including low blood sugar levels, abnormal accumulation of fluids in the lungs, spontaneous bleeding, curculatory collapse, and shock. It might be even fatal as when it causes the much-feared cerebral malaria - often described as un-rousable coma. Malaria is highly dangerous for the pregnant women the the unborn child, who are likely to develop the more severe cases of malaria.

Why are treatments not so effective?

Unfortunately, the more the anti-malarial drugs and used, the greater the resistance the parasite develops to them, maing it difficult to control the ailment. Quite often malaria is not easy to diagnose, and by the time it is correctly identified, the severit of attack has intensified. Also, most people tend to make medication only until the fever and more severe symptoms abate; after which they become negligent. But for the treatment to be really effective, it is essential that the patient go through the entire course of medication prescribed.

How can I reduce the risk?

You shouldn't allow water to stagnate, as this forms a breeding ground for malaria's deadly carriers, the Anopheles mosquito. At community level water shouldn't be allowed to stagnate and whenever feasible, water should be drained. Fro efficient control, spraying can be undertaken using pesticides by certified authority. At home, you should change water in flower pots, buckets, coolers etc. at least twice a week. Ventilation of socket outlet pipes should be properly covered with nets. Mosquito nets and door screens also help. But these methods are not convenient. Mosquito repellants like mats, coils, refills, etc., should be sued regularly to keep mosquitoes away.
 
Warding off & minimisation of exposure to mosquitoes
 
1. Avoidance of night-time outside activities.
2. Avoid dark coloured clothing as it attracts mosquitoes. Some perfumes, cologne and aftershave are also reported to attract.
3. Clothing to cover arms and legs in the evenings as mosquitoes prefer the leg ankle region.
4. Spend time in air-conditioned offices and hotels that are generally free from mosquitoes.
5. Use mosquito bed nets if sleeping in unscreened rooms or open spaces.
6. If mosquitoes are present in an otherwise screened room, spray with insecticide.
7. Use reliable mosquito repellents:
Use a dependant insecticide aerosol in the room to kill mosquitoes before retiring. Use knock down sprays.
Use mosquito coils or vaporising mats.
Use electronic repellements.
 
You cannot depend on medication alone to prevent malaria. Avoidance of bites is the best protective plan. Consistent use of these measures both during day and night will not only prevent just malaria and filaria, but also dengue, a day-time biting mosquito disease. It is advisable to carry some form of mosquito repellent while traveling-: either sprays, creams, lotions, mats or coils.
 
Malarial control history in India
 
1946: India started using DDT
1953: NMCP is started
1958: NMCP becomes the NMEP
1959: The first time vector resistance is detected in India (In Gujarat)
1965: Malaria begins to re-emerge
1976: Peak of malaria cases in re-emergence period
1977: India starts MPO and PfPC
1985: 2 million annual cases of malaria in India 
1991: Peal of P.falciparum cases
1994: Large scale epidemics, primarily in eastern India and western Rajasthan.

Control of mosquito borne diseases

∑ Population shift from rural to urban areas
∑ Improved housing and nutrition
∑ Better socio-economic conditions
∑ Better living standards
∑ Improved surveillance has allowed treatment of parasitemic persons
∑ Screening of houses
∑ Insecticide spraying by certified authority.
∑ House spraying (residual insecticide- spray programme)

Treatment of Malaria

A malaria vaccine is under development but is not available. However, the following prescription drugs can prevent malarial infection and always should be taken with travellers visiting areas with high rates of malaria. The type of medication recommended depends on the rate of resistance to the drug chloroquine in the countries you are living or visiting.
 
Chloroquine is a treatment of choice for malaria. But it is recommended only in countries where the malaria parasites are not yet resistant to it.
 
Mefloquine is now being used widely because many malaria causing parasites have become resistant to Chloroquine.
 
Doxycycline is an antibiotic also effective in suppressing malarial parasites. This drug has one disadvantage. It makes some people hypersensitive to the sun. A hat and sunscreen should be used when taking this drug.
 
Please consult a doctor for the exact prescription combination, dosage, usage and duration.

Dengue

Dengue or dengue-like epidemics were reported throughout the nineteenth and early twentieth centuries in the Americas, southern Europe, North Africa, the eastern Mediterranean, Asia and Australia an don various islands in the Indian Ocean, the south and central Pacific and the Carribbean. It has steadily increased in both incidence and distribution over the past 40 years. Annually, it is estimated that there are 20 million cases of dengue infection, resulting in around 24,000 deaths.

What is Dengue?

Dengue is an acute flu like fever caused by virus. It occurs in two forms:
Dengue fever (DF)
Dengue Hemorrhagic Fever (DHF)
Dengue fever is marked by an onset of sudden high fever, severe headache, pain behind the eyes and in the muscles and joints.
Dengue hemorrhagic fever is an acute infectious viral disease usually affecting infants and young children. It is characterised by fever during the initial phase and other symptoms like headache, pain in the eye, joint pain and muscle pain, followed by signs of bleeding such as petechiae (red tiny spots on the skin), nosebleed and gum-bleed. If there is blood in the stoold and/or blood in the vomit and accompanied by shock, this is called Dengue Shock Syndrome and is often fatal. Aedes Aegypti, the transmitter of the disease is a day-bitting mosquito that lays eggs in clear water containers, such as flower vases, cans, rain barrels, old rubber tyres, etc. The adult mosquitoes rest in dark places of the house.

Recognition of Dengue Fever

The Dengue fever has a number of distinct symptoms and can be recognised with:
1) Sudden onset of high fever, which may last two to nine days.
2) Severe headache mostly in the forehead
3) Joint and muscle pain, and body aches
4) Pain behind the eyes which worsens with eye movement
5) Nausea or vomiting of coffee coloured matter
 
Recognition of Dengue Hemorrhagic Fever and shock
Symptoms similar to Dengue fever, plus any one or a combination of the following:

1) Severe and continuous pain in the abdomen
2) Bleeding from the nose, mouth, skin bruising
3) Frequent vomiting with or without blood
4) Black stools like coal tar
5) Excessive thirst (dry mouth)
6) Pale, cold skin
7) Weakness
8) Skin rashes maculopapular rash or red tiny spots on the skin, called Petechiae.

How does Dengue spread?

Dengue is spread through the bite of an infected Aedes Aegypti mosquito. The mosquito gets the virus by biting an infected person. The first symptoms of the disease occur about 5-7 days after the infected bite.

There is no way to tell if a mosquito is carrying the dengue virus. Therefore people must protect themselves from all mosquito bite.

Where does this mosquito live?

This mosquito rests indoors, in closets and other dark places. Outside, it rests where it is cool and shaded. The female mosquito lays her eggs in water containers, in and around homes, schools and other areas in towns or villages. These eggs become adults in about 10 days.

Where does the mosquito breed?

Dengue mosquitoes breed in stored, exposed water collection systems. The favoured breeding places are:
Barrels, drums, jars, pots, buckets, flower vases, plant-pots, tanks, discarded bottles, tins, tyres, water coolers and a lot more places where rain water is collected or is stored.

The styles (needle-like structures) and proboscis (elongated mouth) of an Aedes aegypti feeding. Dengue viruses are transmitted during the feeding process.

Prevention of Dengue mosquito bites ?

Dengue mosquitoes bite during daytime. Protect yourself from the bite. 
Wear full-sleeve clothes or long dresses to cover the hands and legs.
Use repellents.
Use mosquito coils and electric vapour mats during the day to prevent dengue.
Use mosquito nets to protect babies and old people and others who may rest during the day.
Make sure that water storage containers are covered to prevent breeding of mosquitoes. 
You can also clean the house gutters to prevent stagnation of rainwater.
Patients suffering from dengue H-fever must be isolated for at least 5 days.
Please report to the nearest health centre if any suspected case of dengue H-fever is in the neighborhood.

Break the cycle of mosquito - human - mosquito infection.
Mosquitoes become infected when they bite people who are sick with dengue. Mosquito nets and mosquito repellents effectively prevent more mosquitoes from biting sick people and help stop the spread of dengue.

What is Filaria?

Filaria is a long, thread-like roundworm called Wuchereria Bancrofti that lives as a parasite in the bodies of human beings and animals. The male worm is shorter than the female and it has a curved tail. This is mainly found in Central Africa, Asia and the Southwest Pacific.
 
The young worms can be seen in the blood near the body surface of the host or the animal in which the larvae live. When a mosquito bites an infected person at night, it takes up the larvae with the blood. These larvae develop in the mosquito, near the mouth. Then when the insect bites a man or another animal the larvae enter the wound and infect a new host.
 
The adult worms live in the lymph - a body fluid. When the worms block the flow of lymph, a disease called Elephantiasis results. This disease is characterised by severe swelling of the limbs, usually the legs. Sometimes it even can affect the breast or the scrotum.

This gross swelling in the legs and other parts of the body and the thickening of the skin due to blockage fo the vessels of the lymphatic system is called Elephantiasis.
 
While medicines are available to treat filaria, the gross swelling of the leg makes a person look noticeable and ugly. Hence, it is better to protect oneself from the bites of filaria mosquitoes. Use aerosols, mosquito repellenets, creams, mats coils, nets and prevent breeding of mosquitoes with better practice of hygiene and sanitation.
 
Please do no get offended. These rare pictures have been collected to show, as part of education, how filaria can play havoc in a normal human life.

Allethrin is safe

Allethrin is a chemical used in the leading mosquito repellent products.

1) World Health Organisation:

"Allethrin" has been reviewed and has been approved by the High Power Committee of W H O for use in households...Year 1989 based on exhaustive toxicology data submitted by Sumitomo (Japan & Aventis (Germany).

2) Allethrin is approved by Central Insecticide Board, Ministry of Agriculture - Government of India, based on data submitted on chemistry, bio-efficacy, toxicology and packaging.

Protect you lives and lead a happy, healthy and hygienic life

Declare war on mosquitoes. They are easier to kill.
Malaria & Dengue are not.
They kill!
So repel them.

All it takes is a few precautionary measures.
Let's maintain a clean environment.
Have healthy, hygienic habits.

Always use personal protection like mosquito repellents, aerosols, creams, coils, vapourising mats and nets.

Yellow Fever

Yellow fever is a tropical disease, caused by the yellow fever virus, that is spread to humans by infected mosquitoes. The infections are mild, but the disease can cause severe, life-threatening illness.
 
The are two types of yellow fever: jungle yellow fever and urban yellow fever. The latter is a disease of humans. It is spread by mosquitoes that have been infected by other people. Aedes aegypti is the type of mosquito that usually carries yellow fever from human to human. These mosquitoes have adapted to living among humans in cities, towns, and villages. They breed in discarded tyres, flower pots, oil drums, and water storage containers close to human dwellings. Urban yellow fever is the cause of most yellow fever outbreaks and epidemics.
People get yellow fever from the bite of an infected female mosquito. The mosquito injects the yellow fever virus into the bite.

Symptoms for Yellow Fever ?

Many yellow fever infections are mild, but the disease can cause severe, life-threatening illness. Symptoms of severe infection are high fever, chills, headache, muscle aches, vomiting, and backache. After a brief recovery period, the infection can lead to shock, bleeding, and kidney and liver failure. Liver failure causes jaundice (yellowing of the skin and the whites of the eyes), which gives yellow fever its name.

Symptoms start 3 to 6 days after being bitten by an infected mosquito. Yellow fever is diagnosed by a blood test.

Treatment for Yellow Fever ?

There is no specific treatment for yellow fever. Persons with yellow fever should rest and drink plenty of fluids. They should be kept away from mosquitoes for the protection of others. Most people get better after a long recovery period.

Prevention for Yellow Fever ?

Yellow fever can be prevented by vaccination. Travellers should also take precautions against mosquito bites when in areas with yellow fever transmission.
If necessary, get vaccinated for yellow fever before travel. 
Avoid mosquito bites when travelling in tropical areas.
Mosquitoes that spread yellow fever usually bite during the day. Travellers should take steps to reduce contact with mosquitoes when outdoors and inside.

When Outside:
 

Wear long-sleeved clothing and long pants. For extra protection, treat clothing with insecticide.
Use insect repellent on exposed skin. The most effective repellents contain 20% to 35% DEET (N, N-diethylmethyltoluamide). Follow application instructions carefully when using these products.

When Inside:
 

Stary in well-screened areas as much as possible.
Spray living and sleeping areas with insecticide.
Use a net when sleeping in a room that is not screened or air-conditioned. For extra protection, treat the net with insecticide.

Useful tips for better usage of repellent products to keep away mosquitoes ?

Don't let mosquitoes bug you!
MATS
Heaters used in mosquito repellent work only for two years with good temperature (above 150 centigrade). To get better control, change the heater periodically
Perfume added in repellent mats is used to indicate that the heater is switched on.
Blue colour is added to differentiate between used and unused mates.
If colour does not change, it indicates you heater is not giving the right temperature.
Mats are effective ideally when room size is of 30 cum.
COILS
A 8-10 hour coil means the coil will burn effectively up to 8-10 hours when there is no airflow on the coil.
Coil will burn for less duration if there is a breeze.
Avoid keeping coils near any material that can catch fire.
Always keep unused coils inside the pack.
Avoid burning coils on a damp floor or places that are wet as it can absorb moisture and stop burning.

More Valuable Information about Mosquito Disease ?

LIQUID VAPOURISERS
 
For better efficacy, change the heaters periodically.
Switch off the machine when not in use.
Place the vapouriser near the bed for better control.
 
REPELLENT, LOTIONS, CREAMS
 
For effective control, apply throughly on exposed skin.
Avoid contact of the material with eyes and lips.
For effective control up to six hours, do not wash with water after application.

AEROSOLS
 
Use separate specialised spray cans for mosquitoes.
Fro effective control, few "puffs" are sufficient to cover the whole area.
Avoid keeping aerosols in damp areas like bathrooms and open places.
Avoid keeping the cans near open flame.