Tropical diseases not only cause health and life expectancy loss but can also lead to economic consequences including reduced ability to work. Tropical diseases, especially the mosquito-borne ones are very common in India, which is the world’s second most populous nation and itself accounts for 18% of the world’s population. Among all, malaria is one of the most life-threatening tropical diseases. Approximately, 3.2 billion people – almost half of the world’s population – are at risk of malaria. India accounts for the 4th highest number of malaria cases and deaths in the world. Earlier we have discussed Dengue. In this article, we will look at another mosquito-borne tropical menace – malaria.
Malaria – A Tropical Menace
by Sujoy Sengupta
Deepak aged 28 yrs, pursuing his career in an advertisement agency suddenly felt a headache and body ache on one Sunday morning. In addition to this, he had nausea & vomiting tendency making it harder for him to get up from the bed. Though the weather was hot outside he was shivering and feeling cold. With the aid of a thermometer, he noticed that the mercury reading goes up to 104 degrees Fahrenheit. His family, friends & well-wishers took him to a doctor. After a few diagnostic tests, it was revealed that he has contracted malaria.
All over India, almost 70% of cases occur in the South-east Asian region (For e.g. West Bengal, Jharkhand, Orissa,etc.). Roughly two million malaria cases and 1000 deaths due to malaria are reported from India annually. The disease is highly prevalent in those areas of Orissa, Jharkhand, Madhya Pradesh & Karnataka which has a dense forest, an ideal place for mosquito breeding. Besides India, the malaria disease occurs in Saharan and Sub-Saharan Africa.
What is Malaria?
Malaria is an infectious vector-borne disease. In this case, the vector is a mosquito belonging to Anopheles species. It has certain characteristics such as fever, body ache, chills and sweating.
The ancient holy book Vedas has records of this kind of disease having similar features. The name malaria has been derived from the word ‘mal aria’. It is an Italian word which means ‘bad air‘.
A parasitic protozoan which is a single-celled microorganism is responsible for this disease. If not taken seriously the disease may become fatal. There are five different types of parasites that are capable of causing malaria, namely, Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale & Plasmodium malariae. Amongst these four species, the most dangerous is Plasmodium falciparum. A host is required for the survival of these microorganisms.
It deserves special mention that the life cycle of the elusive parasite Plasmodium falciparum is complicated. It involves two hosts- the human being & the mosquito. The carrier that transmits this disease to the human is a female Anopheles mosquito which is already infected with this parasite. The infected female Anopheles mosquito bites a human and sucks blood from its arteries and veins to feed and fertilize its eggs. During this process the unfortunate human victim. All through the bloodstream, the parasite travels mosquito injects the deadly falciparum parasite into the bloodstream of them to reach the liver and matures as well as reproduces theirs at a very rapid rate.
A considerable number of parasites move out from liver to attack the red blood cell leaving some parasites in the liver for their further multiplication. In the red blood cells, the parasites get another opportunity to multiply vigorously. As a result, the red blood cells rupture and in the next 48 to 72 hours more parasites are released into the bloodstream to assault more red blood cells. In most cases, the patients feel the chills and shivering of malaria after 72 hours from the time of biting of the infected mosquito. This is in concurrence with the release of one-celled microorganism i.e Plasmodium falciparum into the bloodstream from the red blood cell.
The different symptoms of the disease shall be visible generally after 14 days from the time of biting. The common symptoms include fever, chills, vomiting, nausea, body ache, headache, cough, diarrhoea. Fever and chills get repeated in a cycle and the vicious cycle starts after 48 hours from the time of biting corresponding to the release of the parasite from the red blood cells. The cycle of fever & chills continue and subsequently, the victim develops anaemia due to the destruction of red blood cells by the parasite. Beneath the rib cage, an organ is presently named spleen enlarges and touches the stomach.
Malaria can be classified into two categories (depending on symptoms) – Uncomplicated Malaria & Severe Malaria.
This is the first stage of malaria when ordinary symptoms like chills, shivering, fever & sweats followed by a return to normal temperature accompanied by tiredness, body ache. In this stage, there will be no signs to indicate any severe infection or failure of the vital organs. If proper and prompt treatment is not provided to the victim or he or she has poor or no immunity then these symptoms can lead to severe malaria.
The above-mentioned symptoms of uncomplicated malaria can last up to 6 to 7 hours and gets repeated every second day. In areas where malaria does not take place frequently the above symptoms may be undiagnosed, misdiagnosed or taken lightly. In areas where malaria is very common people identify the above symptoms as malaria and treat themselves with the anti-malarial drug without feeling the need of visiting a doctor or undergoing any pathological tests.
The victims having the symptoms of uncomplicated malaria needs immediate medical treatment within 24 hours of the appearance of the symptoms, otherwise, the disease may lead to the following serious complications resulting in death.
- Extreme anaemia which is caused due to the break down of red blood cells.
- Cerebral malaria- the parasite-containing red blood cells choke the blood circulating vessels of the brain resulting in coma, seizures and eventually leading to death.
- Very low blood pressure resulting in disorientation, misbalance causing a fall-related injury and shock.
- Liver(a vital organ) failure
- Kidney (a vital organ)failure
These life-threatening complications can become more troubling in the case of pregnant women, babies and the elderly.
- Monsoon season is the most ideal time for the breeding of mosquito. Different regions in the neighbourhood become waterlogged in this season due to frequent raining in this season. Stagnant water is an ideal place for the breeding of mosquito. Water remains stagnant in the open drain which should always remain covered. Any container which contains water inside the house must remain covered and cleaned. Avoid installing plant pots, bird baths, fountains that holds stagnant water inside the house. Circulation and chlorination of water in the swimming pools and ponds is a necessary task.
- Avoid storing water in the house and if very necessary keep the stored water in a closed container.
- Sleeping inside insecticide-treated mosquito nets is necessary. The inhabitants of a mosquito-infested area should cover their windows with magnetic insect repellant mosquito screen, fibreglass meshes. The evening time i.e. immediately after dusk is the time when most of the mosquito bitings take place. So venturing out during this time is risky. If you are compelled to get outside then dress up your body to a large extent and apply mosquito repellant cream to the exposed parts of your body.
- Spraying insecticide inside your room will keep the mosquitoes at bay.
- Bed nets should be treated with insecticide in areas where mosquito population is large and malaria cases take place very often.
- The travellers should take an antibiotic named Chemoprophylaxis before visiting a country which is malaria-endemic. Consulting the doctor before travel is a good idea.
In most of the cases, a drop of blood is taken from any of the fingertips with the help of a surgical needle for the pathological test for the confirmation of malaria. The presence of the falciparum parasite in the red blood cells (haemoglobin) of the victim will confirm that he has obtained malaria disease.
Nowadays malaria diagnosis & treatment is conducted on the basis of the guidelines proposed by the National Institute of Malaria Research.
- The doctors at first prescribe antibiotics like Chloroquine to the patients. The given dose will be in accordance with the body weight of the patients. But throughout the years because of the extensive use of this drug many Chloroquine-resistant falciparum parasite cases have spooked up. To those patients, a new antibiotic called Artemisinin is administered.
- The anti-malarial drug should not be administered in an empty stomach. Monitoring is essential when the first dose is given.
- To avoid dehydration and to compensate for the loss of mineral salts from the body a sufficient amount of water and ORS must be given to the victim.
- The patient must remain under constant observation to see if there are any warning signs like reduced urine output, bleeding, seizures or coma.
- If the patient does not improve within 48 hours he must be immediately admitted to the hospital for better treatment.
There have been several attempts to produce an effective malaria vaccine and clinical trials are going on to make it a reality. Much of the funding has been done by Bill & Melinda Gates Foundation. To produce a vaccine for this parasite is challenging because of the complex nature and complicated life cycle of the organism. The parasite keeps changing its surface constantly and due to this bizarre ability it very difficult to develop a vaccine. So the immune system cannot have the scope to fight against this parasite.
Moreover, the scientists have not yet totally understand the complex responses of the immune system that protect the humans from any kind of antigen i.e. foreign body that enters the body. In this context, it should be mentioned that the other methods of eliminating malaria have not succeeded so far. So finding a vaccine will serve as a great benefit for the human beings and hence scientists all over the world are putting all their efforts in this research which is considered as one of the most important in public health.
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