Prevention Is Better Than Cure | 2018-07-13 |

Mosquito-Borne Diseases

Prevention Is Better Than Cure

Sariful Islam     13 July, 2018 12:00 AM printer

Prevention Is Better Than Cure

Lately, the people in the capital are witnessing outbreak of some seasonal fevers. But is that an outbreak of dengue fever or chikungunya? Usually, the time between May and September is the most vulnerable time when a large number of cases of dengue fever are reported in Bangladesh and it keeps occurring until November. Not only in Bangladesh but the World Health Organization (WHO) says that the incidence of this painful and debilitating disease has grown noticeably around the world in recent decades. It has currently estimated that about 50 million dengue infections occur worldwide each year. But, a more upsetting thing is that some 2.5 billion people – two fifths of the world’s population – are now at risk of falling victims to dengue fever. This is why it is necessary for everyone to be aware of this fever, know its reasons, how to stay immune from it and how to get rid of it if affected.

Dengue fever is caused by any one of four types of dengue viruses spread by mosquitoes called Aedes. These mosquitoes carry the virus of dengue as well as chikungunya. Dengue fever is transmitted by the bite of an Aedes mosquito infected with a dengue virus. However, it cannot spread directly from one person to another. If a mosquito bites a person infected with a dengue virus, the virus enters into the mosquito’s body. And when the infected mosquito bites another person, then the virus enters that person's blood stream, and that is likely to make him ill.



Epidemiologists’ research says that Aedes prefers to breed in clean, stagnant water in containers following rain near households, roadsides ditches and other places near human lodgings. Hence, as soon as the monsoon arrives, it becomes a matter of fear for the city dwellers that Aedes mosquitoes, the transmitters of the dengue virus, will breed copiously. Perhaps, this year has not been different as it has been raining frequently even since January. Perhaps, the mosquitoes that carry the virus of dengue have been able to procreate everywhere freely. But is the monsoon’s rainfall the only thing that facilitates the mosquitoes to breed?

Prof. Meerjady Sabrina Flora, Director of IEDCR (Institute of Epidemiology, Disease Control & Research) stated in this regard that the early rain could be a reason of the increased number of breeding of Aedes mosquitoes but many other reasons must also be taken into consideration. She observed that there was no remarkable rain during the last winter. Yet, there was the outbreak of chikungunya virus in the city. Meanwhile, the IEDCR and DGHS investigations conducted in some areas in the capital have brought into light the fact that the sources of Aedes mosquitoes were so many drums filled with water in slums and similar settlements in Kalabagan and Kathalbagan areas in the capital. Director of DGHS Sanya Tahmina said that this is what mainly caused the chikungunya outbreak last winter.



Here, it is to inform the reader that both dengue and chikungunya are two mosquito-borne diseases, and the mosquitoes of the same kind carry the viruses of the two diseases. The two diseases have some common as well as distinctive features. The common symptoms may include sudden and high fever, severe headaches, pain behind the eyes, severe joint and muscle pain, fatigue, nausea, vomiting, skin rash, which appears two to five days after the beginning of fever, and mild bleeding such as nose bleeding, gum bleeding or easy bruising. When symptoms do occur, they usually begin four to seven days after one is bitten by a poisonous mosquito. However, dengue, which causes flu-like illness, can cause hemorrhagic fever and be fatal at times. People with weak immune systems as well as those with a second or subsequent dengue infection are believed to be at greater risk of developing dengue hemorrhagic fever. On the other hand, chikungunya is not fatal. But it usually causes fever and severe joint pain, muscle pain, headache, nausea, rash and fatigue. A chikungunya patient may suffer the joint pain for weeks even if he or she gets rid of the fever.

In fact, there is no specific medicine applicable to cure dengue or chikununya viruses. If you think you are suffering from dengue fever, you should take medicine to reduce fever, use pain relievers with acetaminophen and avoid medicines with aspirin, which could worsen bleeding, and it would be better if you do all these things according to the suggestion of your doctor. You should also take bed rest and drink plenty of fluids. However, after you've recovered from dengue fever, you have immunity to the type of virus that infected you, but not to the other three types of dengue fever virus. The risk of developing severe dengue fever, also known as dengue hemorrhagic fever, actually increases if you're infected a second, third or fourth time.



Epidemiologists believe that the best way to prevent the disease is to avoid being bitten by mosquitoes that carry the disease. Therefore, we have to take some preventive measures in order to impede the breeding of mosquitoes. This involves protecting yourself and making efforts to keep the mosquito population down. You can help lower mosquito populations by eliminating habitats where they lay their eggs. The following tips may help reduce your risk of mosquito bites. The mosquitoes that carry the dengue virus typically live in and around houses, breeding in standing water. So, we should destroy the tin-made cans, earthen pots, bottles, the shells of coconuts, automobile tires and things like these that hold the stagnant water in them. In addition, we also have to remain careful so that the containers like buckets and drums in our bathrooms, cement-made or plastic tanks or holes in the garden do not contain the same water in them for more than four or five days as there is a greater chance of breeding the germs of dengue in such clean and stagnant sources of water. At the same time, we should clean up the surroundings of our house, throw away water standing stagnantly in the flower vases, balcony and in the box kept under the refrigerator regularly so that the mosquitoes cannot procreate there.

Apart from that, you can also do some other things to stay immune from the bites of mosquitoes. You can use mosquito-killer spray to destroy mosquitoes at home. As it is common for Aedes mosquitoes to bite at day times, you should not forget to use bed-net while sleeping during the day. It is helpful to insert mosquito-protecting net on your doors, ventilation holes and windows. Besides, you can wear protective clothing. When you go into mosquito-infested areas, wear a long-sleeved shirt, long pants, socks and shoes so that you can avoid the bites of mosquitoes. You should also let your children wear full-sleeved pants and shirts instead of half. It is, however, mentionable here that if anyone if affected by the virus, then he has to be kept in a separate bed under a bed-net.



Meanwhile, a most effective tool of controlling dengue and lowering the case of dengue fever in local communities is the use of guppy fish. These fish eat the larvae of mosquitoes and, thus, impede their breeding. So, people can collect these fish from village offices or nearby healthcare centers and keep these tiny fish in different water containers at home. Or guppy fish can be released in nearby drains and other water sources with a view to reducing the populations of mosquitoes. If there are no larvae, there will be no mosquitoes and no dengue fever in the city. If every household in the city would keep these fish in their water containers, then it could effectively check the outbreak of the mosquito-borne diseases. However, it seems that the city dwellers are yet to realize the efficacy of using guppy fish.

Although there is a vaccine namely dengvaxia used to keep people immune from dengue, the vaccine is approved only for older children because younger vaccinated children appear to be at increased risk of severe dengue fever and hospitalization two years after receiving the vaccine. This is why the World Health Organization stresses that the vaccine is not an effective tool to reduce dengue fever in areas where the illness is common. Instead, controlling the mosquito population is still the most feasible solution to dengue virus’s outbreak.