14. Vector borne disaeses

Vectors can be an insect or an animal. Diseases such as  malaria, filaria, chikungunya, dengue are transmitted through insects, and the diseases are transmitted by through animals are bird flu and swine flu.
 

  

 

  

How it is spreading the disease: Vector such as mosquitoes do not carry the pathogen from its birth. During a blood meal from an infected person, mosquito gets ingested with the pathogen, and when it bites an animal or healthy person, the pathogen will transmit into them. Thus disease-producing microorganisms are transmitted through vectors.

In this topic, we will study about the following vector borne diseases.

It is a disease that had been affecting humans for thousands of years. Hippocrates, Father of Medicine, explained the disease in his medical text (\(4\)'th or \(5\)'th Century BC). There was a rumour that even great warrior Alexander might have died of malarial infection. In \(1718\) the term malaria was first coined by Italian physician Francisco Torti. Malaria is one of the major vector-borne disease in developing countries. Each year approximately \

(300\) million people infected with malaria around the world. It may be fatal disease to human beings, but the cure is available.

 

Protozoan parasite Plasmodium causes Malaria. There are four different species of Plasmodium, namely,
a) P.vivax
b) P.malariae
c) P.falciparum
d) P.ovale 

Note: Malaria caused by Plasmodium falciparum is malignant and fatal.

 

Plasmodium falciparum is a unicellular protozoic parasite of humans and the deadliest Plasmodium species that causes malaria in humans. The parasite causes the disease's most dangerous form, falciparum malaria. Falciparum malaria is associated with more parasites in the blood and has the highest death rate and complications of all malaria types.

 

 

The malarial parasite spreads through the bite of the female Anopheles mosquito, which feeds on human blood. All Plasmodium species can survive in stored blood, even if frozen, and retain their viability for at least \(1\) week, possibly well over \(10 days\). When a mosquito carrying the malarial parasite bites a person, it enters into the person's bloodstream. It is then carried to the liver, where the parasite multiplies. Then it will be transmitted to the next mosquito from the infected person through its blood meal, and the cycle continues.

After the initial symptoms, there will be a rapid rise in body temperature. The fever subsides with profuse sweating.

Treatment: Use of Quinine drugs kills the stages of the malaria parasite.

 

Dengue virus causes dengue fever and dengue haemorrhagic fever. Dengue is a vector-borne disease transmitted from one human to another human through the vector mosquitoes. It is also called as breakbone fever. The name break bone fever is because of the contortions caused due to the intense joint and muscle pain. Dengue haemorrhagic fever is a more severe form of the disease, and it can be life-threatening or fatal.

 

Causative organism: Dengue virus (DENV) It is a single positive-stranded RNA virus.

How it spreads: Dengue is transmitted by infected Aedes aegypti mosquito. If a mosquito had a blood meal from an infected person, it is called an infected mosquito.

Incubation period: Incubation period of the dengue virus is generally\(\ 5\) to \(6\) days.

Treatment: Paracetamol will be prescribed to reduce fever and body ache.  Complete rest is needed and also increased intake of fluid is essential.

Herbal facts on Dengue treatment (Source: AYUSH)
An extraction of tender leaves of papaya and herbal drink Nilavembu Kudineer is given to dengue patients. It is known to increase the blood platelet count.