Disease Causative Agents

Explanation: It is an actual infectious disease of cattle, buffalo, sheep and goat. It distances transportation. In India, the disease is enzootic in nature. Etiology environmental conditions, malnutrition and long distance transportation. In India, the disease is enzootic in nature.

Biological agents which cause disease are known as pathogens that are the micro-organisms which when successfully infect the human body, multiply and produce toxins in incubation period which interfere with the normal functioning of the body and cause disease. A virus is a small, infectious, biological agent that replicates only inside the living cells of other organisms.

Pneumonia is an inflammatory condition of the lung affecting primarily the small air sacs known as alveoli. Symptoms include some combination of a productive or a dry cough, chest pain, fever, and trouble breathing. Pneumonia may spread via airborne droplets from a cough or sneeze. Pneumonia is usually caused by infection with viruses or bacteria and less commonly by other microorganisms, certain medications and conditions such as autoimmune diseases.

• Measles is a highly contagious infectious disease caused by the measles virus. Symptoms include fever, often greater than 40 °C, cough, runny nose, and inflamed eyes. Measles is an airborne disease which spreads easily through the coughs and sneezes of infected people.
  
• Diphtheria is an infection caused by the bacterium Corynebacterium diphtheriae. Symptoms include a sore throat and fever. In severe cases, a grey or white patch develops in the throat. Diphtheria is usually spread between people by direct contact or through the air (droplet).
  
• Pertussis, commonly known as a Whooping cough is a highly contagious bacterial disease. Symptoms include a runny nose, fever, and cough. Pertussis is caused by the bacterium Bordetella pertussis. It is an airborne disease which spreads easily through the coughs and sneezes of an infected person.
• Gonorrhoea is a sexually transmitted infection caused by the bacterium Neisseria gonorrhoeae. Symptoms include burning with urination, discharge from the penis, or testicular pain. Women may have burning with urination, vaginal discharge, vaginal bleeding between periods, or pelvic pain. Hence, it is not transmitted by droplets.

• Droplet infection is an infection transmitted from one individual to another by droplets of moisture expelled from the upper respiratory tract through sneezing or coughing.
• Pneumonia is an inflammation of the parenchyma of the lungs. It is caused by the bacterium Streptococcus pneumoniae.
• Symptoms include a cough with phlegm or pus, fever, chills and difficulty breathing.
• The bacteria that are commonly found in the nose or throat, can infect the lungs if they are inhaled. They may also spread via airborne droplets from a cough or sneeze.
• So, the correct answer is '.Pneumonia ,Streptococcus pnemoniae,Droplet infection'.

Vectors are the organisms, which carries the infectious agents from sick person to another healthy person. For example, mosquito carries malarial parasite from infected person to healthy person. Therefore, option A is correct.

• Meningitis is the Inflammation of the brain and spinal cord membranes, typically caused by an infection.
• If the meningitis is caused by bacterium Neisseria meningitidis, it is called as Meningococcal meningitis.
• Symptoms include pain in sudden high fever, severe persistent headache, neck stiffness, nausea or vomiting, joint pains, drowsiness, confusion, etc.
• People spread meningococcal bacteria to other people by sharing respiratory and throat secretions (saliva or spit) when they cough or sneezes.
  
• Hence Meningococcal meningitis infection is transmitted chiefly from person to person.
• So, the correct answer is 'Meningococcal meningitis.

There are several ways disease-causing agents get from one person to another:

• Airborne or droplet infection (e.g. colds, flu).
• Animal borne or insect borne infection (e.g. rabies, malaria, Lyme Disease).
• Blood borne infection (e.g. HIV, hepatitis).
• Food borne or water borne infection (e.g. salmonella, giardia).
• Sexually transmitted (e.g. chlamydia, gonorrhea, syphilis).
• Other direct contact (e.g. some kinds of warts, scabies).
• Indirect contact (e.g. colds and flu carried from person to person on dirty tissues, money, door knobs, phones, computer keyboards).

Black rot of crucifers is caused by Xanthomonas campestris pv. campestris a bacterial disease common to all cruciferous plants like Broccoli, cabbage, Kale etc. Infecting the stem, leaf, inflorescence and roots.

Tobacco mosaic virus (TMV) is a rod shaped virus, infecting tobacco leaves. It symptoms are mottled appearance that is patches of yellow and green, dwarfing etc. It spreads by mechanical abrasion of the infected tissue with a healthy one.

Rabies is a serious viral disease that can be transmitted to humans through the bite or scratch of an infected animal, most commonly a dog.

The best known example of heavy metal pollution in the oceans took place when Japanese factory discharged a significant amount of mercury metal into Minamata Bay, contaminating the fish stocks there. By that time, many local people had eaten the fish and around 2000 were poisoned. Hundreds of people were left dead or disabled.

Hay fever is a form of allergy due to the pollen of grasses, trees, and other plants, characterized by inflammation of the membrane lining the nose and sometimes of the conjunctiva.

Communicable diseases spread from one person to another or from an animal to a person. The spread often happens via airborne viruses or bacteria, but also through blood or other bodily fluid. The terms infectious and contagious are also used to describe communicable disease. For example- HIV/AIDS.