Monday 23 September 2013

Malaria and Dengue are back, every time


Symptoms for the two mosquitoes borne diseases:


Malaria                                                       Dengue

Chills and shivering                                    Muscular weakness    
Vomiting                                                     Body rash or itching             
Fever with flu like symptoms                    Pain around & behind eyes
Blood test & drugs                                     Fever & acute body ache
Blood test to monitor platelet count, no lesser than 20,000

Every time, the incidences of Dengue and Malaria in the country corroborate its resurgence in a virulent form and poses a formidable challenge to public health administration, medical researchers and leads WHO to reshape its strategy.  Unfortunately, today the combat seems too far away since the world’s promising and the most advanced potential malaria vaccine RTS,S has failed to live up to the promise as the scientists from Oxford University recently doubted the final leg tests since the effectiveness wanes over the time. Earlier, it was claimed that the vaccine could be a reality and expected to hit the markets by 2015. There were expectations that the vaccine (RTS,S/AS01E) by attacking the malaria parasite in the  very early stages while entering the bloodstream or liver cells would prevent and abate  infection of red blood cells and the development of serious symptoms.

Breakthrough at Home

The Bengal Engineering and Science University (BESU) scientists have found an easy and economical method to control the menace of mosquitoes with carbon nano-particles by adding around 3 milligrams of water soluble carbon nano-particles with a litre which does wonders by killing the mosquitoes and larvae according to the researchers studies published in the UK Journal Riyal Society of Chemistry, recently. The scientists claim that the method is a cheaper one and safe enough in contrast to the hazardous chemical sprays. 

Earlier, the scientists at International Center for Genetic Engineering and Biotechnology (ICGEB), New Delhi discovered key antigens and claimed that the discovery would lead the way for the development of a novel malaria vaccine chiefly against Plasmodium falciparum, one of the species of the malaria parasite causing disease among humans. Also, CSIR has initiated crowdsourcing drugs for malaria and TB through a venture for building a chemical library with diverse compounds on country level basis that will drive drug discovery programmes especially for neglected diseases like malaria and TB.  In 2008, CSIR launched Open Source Drug Discovery (OSDD) project with the objective of discovering the drugs for Malaria and TB and other diseases through open innovation and sharing of researches which brought about 34 institutions including a few IIT’s besides other organization on the prestigious OSDD project.

 In the beginning of the year, the researchers successfully launched a gene disruption technique to change the colour of mosquito a very critical step towards the genetic strategies aimed at disrupting the transmission of diseases like dengue etc. Scientists from Virginia Polytechnic and State University used a pair of engineered proteins to cut DNA in a site-specific manner to disrupt a targeted gene into mosquito genome.  The Malaysian researchers, in early 2011 released about 6000 genetically modified mosquitoes into a forest in the first of its kind experiment in Asia aimed to curb the dengue fever. The test was meant to pave the way for the use of genetically engineered Aedes aegypti male mosquitoes to mate with females and produce no offspring or  ones with shorter lives, thus curtailing the mosquito population.

The dengue and malaria cases reported to the WHO have doubled multifold in recent years which could be too high with the unreported cases across the countries. Around three decades back, the resistance to conventional insecticides was recorded in 62 countries out of 107 exposed to malaria and resistant strains of the malarial parasite to the chloroquine treatment reported from around 20 countries. Once, the then WHO Director General, Mr. Halfdan Muhler said that the anti-malaria programme in India has received a great setback during the last five years because of parasite resistance to the anti-malarial medicines which resulted in an increase upto 30 to 40 times.

Background

The book, ”Man’s Mastery of Malaria” describes Hippocrates as the first malariologist who correctly identified the relationship of the ecological conditions with the disease. After Lerven, the French Army Surgeon who discovered plasmodium in 1880 Sir Ronald Ross in 1898 showed the cycle of the parasite and the female anopheles mosquito involved in the transmission of the disease. Manson confirmed it in 1900.

The WHO in 1935 had indicated the number of positive cases of malaria over 100 million whereas the League of Nations (1930) and Fletcher (1932) indicated that the disease affected one third of the human population in Central America, Asia and Africa – more than 300 million people all over the world in 1940.Earlier, pyrethrum and kerosene sprays were used to kill mosquitoes. The advent of DDT, a long acting insecticide without toxic effect on mammals brought new hopes for malaria control. But its widespread use during World War II to protect troops against lice and parasites suppressed its effectiveness against mosquitoes.

Time and again, the dengue outbreak is there with about 1300 cases reported in the capital till recently. Malaria cases all over have gone up many fold with most of the cases unreported which demands that the disease needs a radical treatment to the patients, otherwise, one unattended positive case of Malaria has the potency to communicate the disease to 1200 persons during its peak season. But still the control of malaria transmission, which today is termed as the programme of eradication, has almost rid the world of this calamity. The Dengue cases similarly always keeps on increasing with taking the death toll every year. By 1968, this programme covered a population of about 715 million with another 70 million people in different countries. There were aggressive programmes with various launches and further campaigns.

It was estimated at the close of 1952-53 that about 75 million people suffered from Malaria every in every year in India. Since the country’s population was approaching 361 million in (1952-53), roughly one out of every five persons was likely to suffer from the disease every year. The total annual number of reported cases was somewhat between 0.8 million and one million against the total mortality rate of 5.5 million. Apart from direct mortality, the disease was indirectly responsible for the victimization of another 8 to 10 million individuals every year. The post-independence period showed some improvement owing to successful use of the insecticide on a very limited scale and by 1965 the disease had been virtually eradicated. The total number of positive cases all over the country touched the all time low of 40,000 in 1966. Unfortunately, it did not last long and this improvement led to the discontinuance of the National Eradication Programme.

The position to worsen, resulting in a gradual increase till the number of malaria cases reached about 1.5 million in 1972. After a decade of nil mortality (since 1966) about 100 persons died of malaria in 1975 and 1976. Simultaneously, the number of cases, around the world, touched 120 million in 1976 and the problem assumed World-wide significance once again.

Previously, about 12,00 million tablets were procured, 100 million from the country and the rest from abroad. The Central Government doubled the allocation of malaria-control representing 75 per cent of the total health budget. This year, about 16,000 tonnes of DDT have been allocated for the national Malaria Eradication Programme. Nearly 35,000 tonnes of more powerful BHC insecticide have also been allocated. Officials state that about 500 million chloroquine tablets have been released in the market.

Money for the fight  

The World Health Organisation in 1959 allocated about 1,691 million dollars for malaria eradication all over the world. The WHO alone contributed 83 million dollars and the UNICEF and the US Agency for International Development gave 246 million dollars but estimated figures fell a little short of the real figures. The WHO spent more than 95 million dollars over 1956-72, the Pan America Sanitary Bureau spent $33.5 million
dollars, the UNICEF $95 million and the UN Development Programme $10 million to eradicate malaria from all regions of the world. This year, the WHO has a target of $20 million dollars for the proposal etc.


 The mosquito has once again become a powerful enemy to the man. The research in malaria and dengue has, therefore, assumed a degree of urgency. Dengue –transmitting mosquitoes have become immune to many popular and commonly used repellents across the world and it has been found that the mosquitoes are able to ignore the smell of the insect repellent for upto three hours after being exposed to it.

The scientists claimed that their tests changes in responses to the repellent in Aedes aegypti mosquitoes which are more notorious for biting during the day and are capable of transmitting the dengue fever and yellow fever viruses. The research on the development of anti-malarial drugs from indigenous plants was earlier in process but without concrete results. The success in the development of a vaccine will be treated as a great achievement in this direction. The anti-malarial programme has acquired more significance due to the worsening epidemicological situation in several regions of the world. The Governments across the globe and the WHO need to prepare strategies to provide these against the changes in the environment. 

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