Infectious disease cannot develop if any one of the following three basic conditions is lacking: (1) the proper environment, the most important environmental factors being the amount and frequency of rains or heavy dews, the relative humidity, and the air and soil temperatures, (2) the presence of a virulent pathogen, ...

What are the 4 factors considered in a disease pyramid?

The international team presents the concept of a disease pyramid with the four cornerstones of environment, pathogen, host and host microbiome.

What conditions must be present for a disease to develop?

These three elements, pathogen, host, and environmental conditions, make up the disease triangle.

What are the factors of the plant disease?

Plant diseases– their occurrence and severity– result from the impact of three factors: the host plant, the pathogen, and the environmental conditions. This is represented with the disease triangle.

What are the factors affecting the development of epidemics?

Water, sanitation, food and air quality are vital elements in the transmission of communicable diseases and in the spread of diseases prone to cause epidemics. A number of environmental factors influence the spread of communicable diseases that are prone to cause epidemics. The most important of these are: water supply.

Epiphytotics

What is an Epiphytotic disease?

In plant disease: Epiphytotics. When the number of individuals a disease affects increases dramatically, it is said to have become epidemic (meaning “on or among people”). A more precise term when speaking of plants, however, is epiphytotic (“on plants”); for animals, the corresponding term is epizootic.

What are the environmental factors affecting disease development?

Infectious disease cannot develop if any one of the following three basic conditions is lacking: (1) the proper environment, the most important environmental factors being the amount and frequency of rains or heavy dews, the relative humidity, and the air and soil temperatures, (2) the presence of a virulent pathogen, ...

What are the 3 factors that cause disease?

• Bacteria. These one-cell organisms are responsible for illnesses such as strep throat, urinary tract infections and tuberculosis.
• Viruses. Even smaller than bacteria, viruses cause a multitude of diseases ranging from the common cold to AIDS.
• Fungi. ...
• Parasites.

What are plant diseases?

Plant disease is defined as the state of local or systemic abnormal physiological functioning of a plant, resulting from the continuous, prolonged 'irritation' caused by phytopathogenic organisms (infectious or biotic disease agents).

What are plant and environmental conditions could we describe where a plant is susceptible to diseases?

In some cases, poor environmental conditions (e.g., too little water) damage a plant directly. In other cases, environmental stress weakens a plant and makes it more susceptible to disease or insect attack. Environmental factors that affect plant growth include light, temperature, water, humidity, and nutrition.

Can you develop a disease?

As individuals age, depending on their genetic inheritance along with what they do and what they are exposed to, they may develop a chronic disease which progresses over time. It is becoming more widely understood that chronic disease is often the result of multiple factors rather than one single factor.

What are the three stages of disease development?

• Stages of Disease.
• STAGE 1: INCUBATION PERIOD.
• STAGE 2: PRODROMAL PERIOD.
• STAGE 3: ACUTE PERIOD.
• STAGE 4: CONVALESCENCE PERIOD.

What are the three 3 factors that affect the likelihood of infection from a pathogen?

Common pathogen factors are immune evasion, high viral load and low infectious dose.

What are the 3 elements of the disease causation triangle?

Among the simplest of these is the epidemiologic triad or triangle, the traditional model for infectious disease. The triad consists of an external agent, a susceptible host, and an environment that brings the host and agent together.

What is disease triangle and disease pyramid?

A disease pyramid or tetrahedron, which allows for the addition of a fourth causal factor of disease. Humans factor into the disease triangle because the influence of human activity on disease is pervasive in agriculture and, perhaps to a lesser degree, in lower input systems such as forestry and range management.

What is non parasitic?

Plant diseases are separated into nonparasitic (noninfectious, nontransmissible) and parasitic (infectious) diseases. Nonparasitic diseases are caused by improper environmental conditions such as deficiencies and excesses of nutrients, biological toxicants, adverse soil and weather conditions and pollutants.

What are 5 diseases caused by bacteria in plants?

• aster yellows.
• bacterial wilt.
• blight. fire blight. rice bacterial blight.
• canker.
• crown gall.
• rot. basal rot.
• scab.

What is plant infection?

Infection: This occurs when the pathogen invades the plant tissue and establishes a parasitic relationship between itself and the plant. Viruses, bacteria, and phytoplasmas are not able to actively penetrate or enter plant host tissues. Therefore they must rely on other methods to infect plant tissues and cells.

Which is the example of bacterial disease?

Other serious bacterial diseases include cholera, diphtheria, bacterial meningitis, tetanus, Lyme disease, gonorrhea, and syphilis.

What are the 4 types of diseases?

There are four main types of disease: infectious diseases, deficiency diseases, hereditary diseases (including both genetic diseases and non-genetic hereditary diseases), and physiological diseases. Diseases can also be classified in other ways, such as communicable versus non-communicable diseases.

What are 5 infectious diseases?

• Chickenpox.
• Common cold.
• Diphtheria.
• E. coli.
• Giardiasis.
• HIV/AIDS.
• Infectious mononucleosis.
• Influenza (flu)

Which of the following disease is not caused by bacteria?

So, the correct answer is option (d) 'Malaria'.

What are the environmental conditions that often encourage the growth development and distribution of bacterial and fungal blights?

Favorable Environmental Conditions

Development of bacterial blight is promoted by cool, wet weather (70 – 80°F). Infection can occur early but is most common at mid season and continues until hot and dry weather limits development. Disease outbreaks often follow windy, rainstorms.

What are the factors affecting the development of disease in animals?

Predisposition to diseases is a latent susceptibility to diseases which may be activated under certain conditions (Studdert et al., 2012). The predisposition to diseases could be classified to four basic factors which include: animal factor, environmental factor, client factor and sometimes veterinarian‟s factor.

What role does the environment play in disease development?

The environment plays a powerful role in the transmission of infectious diseases, including vector-borne diseases such as malaria, dengue, and human African trypanosomiasis. It is therefore of huge significance to public health strategies around the world.