MBD Series - Dengue Part 1

We are posting a series about Mosquito-Borne Diseases, along with our other regular articles. This is the first post in that series.

Disclaimer: This post is for information purposes only. This is not written by any medical doctor or government official or anyone related to the worldwide research on mosquito borne diseases. Neither is this a complete information about dengue and should not be relied on for reference. However, we have taken care to refer to reliable sources on the web, the links to which would be provided at the end of the post.

Let's start with,

Dengue

Dengue is a Spanish word, pronounced 'den-gee'. Though its origins are not clear, it's believed to have been from the Swahili phrase ka dinga pepo, that claims the disease to have been caused by evil eye. It has also been called: dandy fever, breakbone fever, break fever etc.

Dengue is the second disease to be identified as caused by virus. The first was the yellow fever.

It is found in the tropical and subtropical regions, especially, 

• the Indian Subcontinent
• some parts of the Caribbean
• some parts of the Central and South Americas
• sub-Saharan Africa
• south east Asia
• the Pacific islands

Dengue has also been identified in other parts of the world where it spread through travellers.

It is spread through mosquitoes of the Aedes genus, Aedes aegypti most known among them. The mosquitoes of this genus are known to bite during the day, dawn and dusk. Dengue is spread via human to human transmission by the females of aedes.

History

The earliest available record of a case that could have been dengue fever was found in the Chinese medical encyclopaedia from the Jin dynasty (265 to 420AD) which referred to a 'water poison' associated with flying insects.

Later, around 15th to 19th centuries AD, Aedes aegypti (the primary vector) spread to other places from Africa due to globalisation and Slave Trade. There have been descriptions about an epidemic in the 17th century.

The most plausible records of dengue epidemics available, however, from 1779 and 1780, when an epidemic swept across Asia, Africa and North America.

In a 1789 report that the US founding father Benjamin Rush, a physician, wrote on the 1780 epidemic of Philadelphia, he used first the term Breakbone fever. Rush however used the more formal Bilious Remitting Fever as the title of his report.

Confirmation of the transmission of dengue by the aedes mosquitoes came in 1906; and in 1907, dengue was the second ever disease know to be caused by a virus. Though much research has been going on for centuries, the basic understanding about dengue was completed in early 20th century.

Since the 17th century epidemic, dengue epidemics have been quite few till the Second World War. The spread of dengue since World War II is attributed to ecological disruptions. The same reason is given for the spread of different serotypes of dengue to new areas, and also for the emergence of dengue haemorrhagic fever- a more severe and probably fatal variation of the dengue fever.

Sources: Dengue Virus Net, WHO, WebMD, Wikipedia, Medindia, US National Library of Medicine, Ministry of Health and Family Welfare (Govt of India)

Dengue - Facts

With death tolls rising in the sub continent because of dengue, I thought of posting some information about this disease. If I had left out anything, do mail us or write on our FB wall.

Dengue (proper pronounciation 'den-gay') is also called the 'breakbone fever' or the 'dandy fever' as deformation of bones is its most known effect. Dengue is originally and mainly a tropical disease. It was unknown in the western hemisphere till the 1960s when the Caribbean saw deaths in the thousands in an epidemic breakout. Predictably, after that many measure were taken around the world to try prevent/control it.

Dengue is spread by mosquitoes belonging to the genus 'Aedes' (of the order Diptera), especially Aedes albopictus (Asian tiger mosquito) and Aedes aegypti (yellow fever mosquito). Aedes mosquitoes, that prefer biting during the daytime mainly at dawn and in the early evening, are also known to spread Chikungunya. (Chikungunya and Dengue share an important symptom - that of affecting the bones)

This disease is contracted by people with a low level of immunity and hence it is very dangerous to children. Those affected by dengue can have a wide range of illnesses from a seemingly normal viral fever to the fatal hemorrhagic fever.

There are four serotypes of dengue and hence, a person affected once by one serotype could contract this multiple times. As a result of such multiple attacks, the hemorrhagic fever is caused which is almost always fatal to children. Sadly, children are the main victims of dengue fever that is increasingly becoming the most dangerous mosquito borne viral disease to affect the human race and is soon sent to dethrone malaria from that spot it currently occupies.

There is also a belief that, after contracting dengue, if one was infected with the virus, they could develop an immunity that lasts a lifetime. With no scientific proof or confirmation, this might as well be a myth.

The common symptoms of dengue include internal bleeding, bleeding of nose and gums, shock, headache, fever, skin rashes, black stool, joint and muscle pains. If tit does not result in the fatal hemorrhage, it is known to deform and soften bones, thus making victims, especially children weaker.

It is dengue season now in the subcontinent and we have already lost lives unnecessarily. So people please be aware and safe. I'd post the precautions and preventive measures against mosquitoes and the diseases they spread soon. Till then, enjoy the m onsoon without the fear of those pesky vampires. (use VIEWnet).

Ciao.