Some facts about Dengue and Chikungunya

1. The onset of monsoons not just relieves people from the scorching heat but also gives rapid rise to diseases. Significant rise to cases of both Dengue and Chikungunya have sent concerning alarming bells over the past many years particularly in the national capital (largely a disease of the southern states but has also bit Delhi hard). It usually happens around October and the stops only by mid-November.

2. Both Dengue and Chikungunya are mosquito-borne viral diseases whose vectors are the species of the Aedes mosquito. Both are characterised by similar signs such as high fever, headache, pain in the joints and eyes, rashes and lethargy. Dengue is spread by numerous species of the Aedes mosquito while chikungunya virus is transferred by two species of the same Aedes type mosquitoes. In India, Chikungunya was never a bigger cause of concern than Dengue, especially in the northern India. However, in the year 2016, there has been an increase in the cases of chikungunya.

3. The incubation period (the period between exposure to an infection and the appearance of the first symptoms) of Chikungunya is of 1-12 days and the duration varies from one to two weeks. However, signs such as joint pain are for a long time. The incubation period for dengue is of 3-7 days. Swelling and pain is high in Chikungunya as compared to that in Dengue.  Chikungunya can create the possibilities of tremendous joint pain. Whereas Dengue can cause bleeding in some cases, breathing problems, etc.

 4. The entire life cycle of Aedes aegypti lasts 8-10 days at room temperature, depending on the level of feeding. There is an aquatic phase (larvae, pupae) and a terrestrial phase (eggs, adults) in their life-cycle. Female mosquitoes lay their eggs on the inner, wet walls of containers with water. Larvae hatch when water inundates the eggs as a result of rains or the addition of water by people. In the following days, the larvae will feed on microorganisms and particulate organic matter, shedding their skins three times to be able to grow from first to fourth instars. When the larva has acquired enough energy and size and is in the fourth instar, metamorphosis is triggered, changing the larva into a pupa. Pupae do not feed; they just change in form until the body of the adult, flying mosquito is formed. Then, the newly formed adult emerges from the water after breaking the pupal skin. Only the female mosquito feeds on blood, which is needed for egg production.

5. The Aedes aegypti mosquito species, is primarily an urban dweller, can breed in pools of water as small as a bottle cap! Aedes aegypti females, feed almost exclusively on humans, not only prefer to live in and around human habitation, but also thrive and proliferate in these conditions. Their larvae are typically found in small, wet places, including discarded bottle caps, soda cans, cups and tires, as well as potted plants and vases. And their eggs can survive for six months or more without being in water. The adult mosquitoes rest in cool, shaded places in the home, such as wardrobes, laundry areas, cabinets and under furniture.

6. Roughly three days after feeding, the mosquito lays her eggs in several locations over multiple days. A single female can lay around 100 eggs per blood feed and can produce up to five batches in her one to two-week lifetime.

7.  Adaptation (the process of change by which an organism or species becomes better suited to its environment) of dengue vectors makes controlling their populations a difficult task. Their eggs can withstand desiccation for several months, which means that even if all larvae, pupae, and adults were eliminated at some point in time, repopulation will occur as soon as the eggs in the containers are flooded with water. Unfortunately, there is no effective way to control the eggs in containers.

8.  When female Aedes aegypti mosquitoes consume blood from an individual with circulating virus, the mosquitoes in turn become infected. Through biting many humans during their life time, female dengue mosquitoes spread diseases (it only takes one bite for a virus to be transmitted).  Male mosquitoes do not bite and therefore do not spread disease.

9. Larvicides are chemicals designed to be applied directly to water to control mosquito larvae. Adulticides are used in fogging and spraying to control adult mosquitoes. When a rapid reduction in vector density is essential, such as in emergencies, space treatment should ideally be carried out every 2–3 days for 10 days. Further applications should then be made once or twice a week to sustain suppression of the adult vector population. Continuous entomological and epidemiological surveillance should be conducted to determine the appropriate application schedule and the effectiveness of the control strategy.

10. One of the insecticides used for fumigation, malathion, can be hazardous for humans, especially for vulnerable groups. The World Health Organisation’s (WHO’s) classification of hazardous insecticides puts malathion as a “Class III” chemical, which is “slightly hazardous”. But inhaling malathion can make the chemical more harmful. “Intake can happen through inhalation and also directly through the skin, and when in the liver, it forms a chemical called malaoxon, which is far more poisonous than malathion itself. Experts say that it is a very dangerous poison, especially harmful for children, pregnant women, and asthmatics. Fogging is harmful both in the long and short term. In the long term, it can have chronic effects, while in the short term; it can cause breathing problems and headaches in a normal person. It is especially harmful to persons with compromised breathing ability.

11. What makes chikungunya and dengue all the more concerning is that long-standing approaches to mosquito control are becoming increasingly ineffective (Aedes aegypti has already developed resistance to many common insecticides, and this resistance is passed on to future Aedes aegypti generations).

12. Anyone affected by chikungunya, the virus is unlikely to infect them ever again. This has been confirmed to TOI by virologists from AIIMS who said that unlike dengue, which can be caused by four serotypes of the virus, the chikungunya virus has only one serotype and hence the risk of repeated infection is minimal. It is possible to get dengue more than once. Being affected by one strain offers no protection against the others. A person can suffer from dengue more than once in her/his lifetime. AIIMS tested 3,500 patients suffering from fever in the last two months. Of them, nearly 2,000 (57%) were confirmed to be suffering from chikungunya. The prevalence of dengue was found to be just 5%. According to a study published in `Virology Journal' in 2014 that analysed immunity in the population affected by chikungunya in 1991 in Thailand, infection with one chikungunya strain confers lasting natural immunity , even against other strains.

(Source: http://timesofindia.indiatimes.com/life-style/health-fitness/health-news/Chikungunya-virus-not-likely-to-infect-twice/articleshow/54493766.cms)

13. Dengue infection is caused by a virus. It occurs commonly as dengue fever. Occasionally the patient suffering from dengue may develop bleeding from common sites like nose, gums or skin. Sometimes, the patient may have coffee ground vomiting or black coal tar like stools. It indicates bleeding from gastro- intestinal tract. The dengue fever with bleeding is called dengue haemorrhagic fever (DHF). It can be fatal if it remains unrecognized and not properly treated. Rarely the patient suffering from dengue haemorrhagic fever (DHF) may develop shock, then it is called dengue shock syndrome (DSS). Dengue should be suspected when a person has sudden onset of fever. The fever is usually high 103-105 degrees F. It is accompanied with severe headache (mostly in the forehead), pain behind the eyes, body aches and pains, rash on the skin and nausea or vomiting. The fever lasts for 5-7 days. In some patients, fever comes down on 3rd or 4th day but comes back. The severe joint pain caused by DF is the reason why DF is also called break-bone fever. All the above symptoms and signs may not be present in the patient. The patient feels much discomfort after the illness.

14. Generally the dengue haemorrhagic fever or dengue shock syndrome occur after 3-5 days of fever. By this time, fever has often come down. This may mislead many of us to believe that the patient is heading towards recovery. In fact, this is the most dangerous period that requires high vigilance from care-givers. The signs and symptoms that should be looked for are severe pain abdomen, persistent vomiting, bleeding from any site like, bleeding in the skin appearing as small red or purplish spots, nose bleed, bleeding from gums, passage of black stools like coal tar. Take the patient to the hospital whenever the first two signs, namely, severe pain in the abdomen and persistent vomiting are detected. Usually it is too late if we wait until bleeding has occurred. The most dangerous type of dengue is the dengue shock syndrome. It is recognized by signs like excessive thirst, pale and cold skin (due to very low blood pressure), restlessness and a feeling of weakness.

15. Most people who suffer from dengue fever recover in 1-2 weeks time. Some may feel tired for several weeks. However, if symptoms persist after this period, one should consult a doctor.  There are many people who are infected with the virus and do not suffer from any signs or symptoms of the dengue. For every patient with symptoms and signs there may be 4-5 persons with no symptoms or with very mild symptoms.

(Source for para13-15:http://delhi.gov.in/wps/wcm/connect /63a3f080440 bb07 cbfe 2bf24a04cfff1/FAQ-dengue.pdf?MOD=AJPERES&CACHEID=63a3f080440bb07cbfe2bf24a04cfff1)

 

16. Treatment of Dengue and Chikungunya

There is no specific treatment for either dengue fever or chikungunya. Treatment for uncomplicated chikungunya cases is symptomatic, with a focus on rehydration and pain relief. Treatment is directed towards relieving joint pains using analgesics and fluids. The symptoms are often difficult to differentiate from Dengue, hence it is important to not take any Non Steroidal Anti-Inflammatory Drugs like aspirin, diclofenac and ibuprofen till Dengue is ruled out as these medicines can cause platelets to fall in Dengue infection. Rehydration is important in all cases of fever.  Patients with severe dengue should be treated with parenteral rehydration and platelet transfusion (Platelets are tiny cells in blood which form clots to help stop bleeding). Currently there are no vaccines available for Dengue or Chikungunya.

If you have fever, joint pains or any signs of Chikungunya or Dengue, please do not self-medicate and consult your doctor.

17.  Chikungunya and Dengu usually happen around October and stops only by mid-November. Most patients recover from the disease and serious complications are uncommon. If immune system of a person is weak then dengu can be  dangerous and occasionally develops into a life-threatening form (known as severe dengue), which causes abdominal pain and vomitting, breathing difficulty and a decrease in of blood platelets that can lead to internal bleeding. In some cases of Chikungunya joint pains can last for weeks to months causing severe disability. Cases with chronic joint pain lasting for years after Chikungunya infection has also been seen.

Prevention and control of Chikunguniya and dengue 

18.1 The main strategy in the prevention and control of dengue is "source reduction", or prevention of breeding places. Community participation is the key to dengue prevention. RWA should play important role in educating residents to tell their domestic helps regarding do's and don'ts regarding vector borne diseases.

18.2 Prevention of dengue relies heavily on preventing the mosquito breeding inside and in the vicinity of our homes. Every household should undertake simple measures to prevent water collections from becoming places for mosquito breeding. Draining out the water by regular changing of water from favoured places for mosquitoes breeding: desert coolers/window air coolers, water storage vessels (tanks, barrels, drums, buckets, mugs), flower vases etc. Remove all objects containing water (e.g. plant saucers etc.) from the house. Collect and destroy discarded containers in which water collects e.g. bottles, plastic bags, tins, used tyres etc. Household members should ensure that there is no exposed water collection.

18.3 Dengue mosquitoes bite during the day time (Highest biting intensity is about two hours after sunrise and before sunset).

·       Wear full sleeves clothes and long dresses to cover as much of your body as possible.

·       Eat plenty of garlic! Mosquitos have been known to be repelled by garlic.

·       Use repellents that contain DEET like dabur odomos cream to prevent mosquito bites. Lemongrass oil and eucalyptus oil work well due to their active component cineole, which has both antiseptic and insect-repellent properties when applied to the skin

·       Use mosquito coils and electric vapour mats during the daytime also to prevent dengue. Use Kala HIT, a tried and tested remedy to keep the mosquitoes at bay

·       Use mosquito nets to protect children, old people and others who may rest during the day. The effectiveness of these nets can be improved by treating them with permethrin (pyrethroid insecticide).

·       Spray garlic and neem water on plants (boil 100 gram neem leaves and 100 gram garlic cloves in one litre water. After it gets cool, strain it).

·       For every patient with symptoms and signs of dengue there may be 4-5 persons with no symptoms or with very mild symptoms. It is therefore suggested efforts should be made strengthen immune system- one should do regular physical exercise- 30 to 40 minute morning walk/ yoga, eat seasonal fruits before breakfast, eat sprouted-kaala chana, green moong, moth,etc and muesli ( a dish based on raw rolled oats and other ingredients like grains, fresh or dried fruits, seeds and nuts, that may be mixed with  milk), drink plenty of water. In the case of fever during monsoon season, patient may be given plenty of fluids- water,  ORS ka Ghol  (Namak and cheeni ka ghol), coconut water, Mousambi juice with salt, clear vegetable soup, etc. Patient should be given light food like patli moong ki khichdi ( prepared from moong kid al and rice), sabudana ki khichdi, dalia (prepared from broke wheat and fresh vegetables), upma, phoa ( prepared from phoa, potato, peanuts, etc).  One or two anjeer/ two or three munakka with black salt can also be given after roasting  on tava for improving the taste( zaika).

·       Maintaining a high number of blood platelets is extremely important after a serious illness, especially with diseases like dengue that cause blood platelets to drop to dangerously low levels. The Asian Pacific Journal of Tropical Biomedicine found that papaya leaf juice significantly increases blood platelet production.  Patients can take a tablespoon of the fresh papaya leaf juice twice a day, morning and evening (source: http://juicing-for-health.com/fruit-juicing).