Disease Causative Agents

An airborne disease is any disease that is caused by pathogens and transmitted through the air. all respiratory droplets. The airborne transmission that occurs utilizes small particles or droplet nuclei that contains these infectious agents or pathogens. These particles and droplets are capable of remaining suspended in air for extended periods of time. Inhalation of these particles results in respiratory tract infection. Whooping cough (Bordetella pertussis), meningitis (Neisseria species), diphtheria (Corynebacterium diphtheriae), pneumonia (Mycoplasma pneumoniae, Streptococcus species) and tuberculosis (Mycobacterium tuberculosis) are some of the bacterial diseases that spread through air. 

Cholera is caused by a bacterium called Vibrio cholerae. A person gets cholera by drinking water or eating food infected with the bacterium. Once swallowed, it settles in the lining of the small bowel and releases a toxin (poison) that can cause the body to flush liquid into the small bowel, resulting in watery diarrhoea. Typhoid fever is an acute illness associated with fever caused by the Salmonella typhi bacteria. The bacteria spread through contaminated food or water and occasionally through direct contact with someone who is infected. 

City dwellers are facing the acute problems of water and vector borne diseases due to water logging and improper solid waste management and sanitation. The water logging and reprehensible drainage, contamination of water of upper layer from which major portion of the people get the polluted water through shallow bored hand pumps for drinking and other domestic purposes, are main cause of water borne diseases in the city. It is evident from studies that about 70.5 % population is suffering from the abdomen diseases cause by using polluted and contaminated water. Japanese encephalitis, jaundice, cholera, colitis, diarrhoea, dysentery, typhoid and skin diseases are common.

The diseases which are transmitted through contaminated air are known as airborne diseases. When the person lives in an overcrowded area which is poorly ventilated house, the person may suffer from breathing and airborne related diseases. The person may suffer from respiratory infections and disorders.

The disease can be transmitted directly or indirectly depending on the surrounding factors like example air , water and soil. Therefore, (b) is the correct answer.

Direct transmission is communicable and contagious disease. It is spread from one infected person to the host. It can be transferred due to direct sexual contact, through air in the form of sneezing or coughing, through contaminated food and water due fecal matter etc. Therefore, (d) is the correct answer.

Infections can also be transmitted through contaminated air, soil, water, surroundings etc. Food not prepared in hygienic conditions can also cause infection. Therefore, (c) is the correct answer.

Indirect Transmission is the spread of disease from host to host by means of a vector. Therefore, (b) is the correct answer.

Particles containing organisms which can remain in air for long time Solution:- Dust particles containing microorganisms which can remain in air for longer duration of time results in airborne transmission. They must be resistant to drying and can survive for long outside the body. Therefore, (b) is the correct answer.

Contamination of drinking water sources by sewage can occur from raw sewage overflow, septic tanks, leaking sewer lines, land application of sludge and partially treated waste water. Sewage is a complex mixture and can contain many types of contaminants. The greatest threats posed to water resources arise from contamination by bacteria, nitrates, metals, trace quantities of toxic materials, and salts. Seepage overflow into drinking water sources can cause disease from the ingestion of microorganisms such as E coli, Giardia, Cryptosporidium, Hepatitis A, and helminths. Septic tanks are enclosures that store and process wastes by bacterial decomposition. Badly constructed percolation systems may allow water to escape without proper treatment.This water may seep to the land surface, runoff into surface water or flow directly into the water table causing waterborne diseases like cholera, typhoid, diarrhoea etc.

Airborne diseases are caused by pathogenic microbes small enough to be discharged from an infected person via coughing, sneezing, laughing and close personal contact or aerosolization of the microbe. The discharged microbes remain suspended in the air on dust particles, respiratory and water droplets. Illness is caused when the microbe is inhaled or contacts mucus membranes or when secretions remaining on a surface are touched. Many common infections can spread by airborne transmission at least in some cases, including: anthrax (inhalational), chicken pox, influenza, measles, smallpox, and tuberculosis.

An airborne disease is any disease that is caused by pathogens and transmitted through the air. Potato virus is transmitted by aphids by sticking to aphid mouth parts (stylet). The virus can be acquired from the infected plant within seconds, and transmitted to a healthy plant very fast. It can also be transmitted mechanically by machinery, tools, and damaging plants while walking through the field. Aphids are by far the most efficient means of transmission.

Salmonella bacteria can be found in food products such as raw poultry, eggs, and beef, and sometimes on unwashed fruit. Food prepared on surfaces that previously were in contact with raw meat or meat products can, in turn, become contaminated with the bacteria. This is called cross-contamination.