Tag: useful and harmful microbes

There is no vaccine to protect against dengue. Developing a vaccine against the disease is challenging. With four different serotypes of the dengue virus that can cause the disease, the vaccine must immunize against all four types to be effective. 

Diphtheria is caused by a bacterium, Corynebacterium diphtheriae. The actual disease is caused when the bacteria release a toxin into a person's body. Diphtheria bacteria live in the mouth, throat, and nose of an infected person and can be passed to others by coughing or sneezing. Influenza, commonly known as the flu, is an infectious disease caused by the influenza virus. The most common symptoms include: a high fever, runny nose, sore throat, muscle pains, headache, coughing, and feeling tired. These symptoms typically begin two days after exposure to the virus and most last less than a week. 

DPT refers to a class of combination vaccines against three infectious diseases in humans: diphtheria, pertussis (whooping cough), and tetanus. MMR vaccine is a live attenuated viral vaccine used to induce immunity against measles, mumps and rubella. Dengue has no vaccine yet.

Influenza (also known as the flu) is a contagious respiratory illness caused by influenza virus. Typhoid fever is an acute illness associated with fever caused by the Salmonella typhi bacteria. Cholera is an infectious disease that causes severe watery diarrhoea, caused by bacterium called Vibrio cholerae. Diphtheria is caused by the Corynebacterium diphtheriae bacterium.

Diseases caused by viruses are common cold, influenza, AIDS and dengue. Therefore, (b) is the correct answer. Tuberculosis and cholera are caused by bacteria.

The correct answer is 'influenza'

Explanation: It is caused by Pasteurella multocida. Treatment is effective if given in early stage of disease. The nearest Vety officer or paravet of the department should be contacted for treatment and  prevention.

Aedes is a genus of mosquitoes originally found in tropical and subtropical zones but now found on all continents except Antarctica. Some species of this genus (like Aedes albopictus and Aedes aegypti) transmit serious diseases, including dengue fever, yellow fever, eastern equine encephalitis and chikungunya. So, the correct answer is option D.

• Dengue fever is spread through the bite of the female mosquito (Aedes aegypti). 
• The mosquito becomes infected when it takes the blood of a person infected with the virus. After about one week, the mosquito can then transmit the virus while biting a healthy person.
• Hence Dengue fever is spread by Aedes.
• So, the correct answer is 'Aedes'.

• A disease vector is an agent who carries and transmits an infectious pathogen into another living organism.
• Aedes mosquito is known to transmit dengue virus, yellow fever virus, chikungunya virus, Zika virus and Encephalitis(inflammation of the brain).
• It can be recognized by white markings on its legs and a marking in the form of a lyre on the upper surface of its thorax.
• Hence Aedes is a vector of 'Encephalitis and Dengue'.
• So, the correct answer is 'Encephalitis and Dengue'.