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Health and Disease Control - Mosquito-borne Diseases: Malaria and Dengue

Grade 5CBSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

Malaria is caused by a protozoan parasite called Plasmodium. It is transmitted to humans through the bite of an infected female Anopheles mosquito.

Dengue is a viral disease caused by the Dengue virus (DENVDENV). It is spread by the Aedes aegypti mosquito, which typically bites during daylight hours.

Mosquitoes require stagnant water (H2OH_2O) to lay their eggs. Common breeding sites include flower pots, discarded tires, and water coolers.

Malaria is characterized by recurring high fever, chills, and sweating. Dengue is often called 'breakbone fever' because of the severe muscle and joint pain it causes.

Preventative measures include using mosquito nets, wearing long-sleeved clothes, and applying repellents containing DEETDEET or natural oils like citronella.

Biological control involves introducing fish like Gambusia into ponds, which eat mosquito larvae, or spraying oil on H2OH_2O surfaces to block the supply of oxygen (O2O_2) to the larvae.

📐Formulae

Stagnant H2O+Mosquito EggsLarvaePupaeAdult Mosquito\text{Stagnant } H_2O + \text{Mosquito Eggs} \rightarrow \text{Larvae} \rightarrow \text{Pupae} \rightarrow \text{Adult Mosquito}

Oil Layer on H2OBlocks O2 supplyLarvae Death\text{Oil Layer on } H_2O \Rightarrow \text{Blocks } O_2 \text{ supply} \Rightarrow \text{Larvae Death}

Female Anopheles+Plasmodiumhuman biteMalaria Infection\text{Female } Anopheles + Plasmodium \xrightarrow{\text{human bite}} \text{Malaria Infection}

💡Examples

Problem 1:

Why is it recommended to clean water coolers and change the H2OH_2O at least once a week?

Solution:

Cleaning prevents the accumulation of stagnant H2OH_2O.

Explanation:

The life cycle of a mosquito from egg to adult takes about 77 to 1010 days. By changing H2OH_2O every week, we break the life cycle and prevent larvae from maturing into adult mosquitoes that spread diseases like Malaria and Dengue.

Problem 2:

A patient suffers from a very high fever and severe pain in the joints. Which mosquito-borne disease is more likely: Malaria or Dengue?

Solution:

The patient is likely suffering from Dengue.

Explanation:

While both cause high fever, the 'breakbone' sensation or intense joint and muscle pain is a signature symptom of the Dengue virus (DENVDENV), whereas Malaria is more commonly associated with cycles of shivering (chills) followed by high fever.

Mosquito-borne Diseases: Malaria and Dengue Revision - Class 5 Science CBSE