SPACIAL AND TEMPORAL DISTRIBUTION OF DISEASES
Spatial distribution: Population-based distribution of diseases
Temporal distribution: Time-based distribution of diseases
Temporal Distribution of Diseases
The temporal distribution of the diseases can be shown at the time of the calendar or at the absolute time.
The distribution of disease frequency over time is analyzed under 3 headings according to the time dimension
considered:
1- Short-term 2- Periodic 3- Long term
SPACIAL AND TEMPORAL DISTRIBUTION OF DISEASES
Short-term distribution: Sudden outbreaks cluster in a short period of time. Epidemics show short temporal distribution
Periodic (cyclic) distribution: The frequency of some diseases regularly increases and decreases over certain time periods, ie fluctuates over time. The cycle in which these fluctuations are observed may be seasonal and annual, depending on the disease
Seasonal distribution
Increase of vector-transmitted diseases in summer IBS disease in cattle is more frequent in summer
More frequent occurrence of cattle and calves during dry seasons in Africa
Fungal infections seen in winter
Abortive infections and neonatal septicemia
More frequent occurrence of hypomagneseminin in cattle during the spring
SPACIAL AND TEMPORAL DISTRIBUTION OF DISEASES
Annual distribution
Distemper's disease in dogs and camylobacter infections in sheep in cities increases over 2-3 years periods
Long-term (secular) distribution: Changes that occur in disease frequency over a long period of time. The secular distribution of diseases is calculated by evaluating
information obtained from past records (retrospective research)
tuberculosis in Turkey in the last 50 years, the reduction in the incidence of diseases such as rabies and glanders has occurred
Between 1945 and 1875, rabies cases in dogs were
reduced in the United States, but increased in wild animals In recent years there has been a gradual increase in
cancer and respiratory system infections
SPACIAL AND TEMPORAL DISTRIBUTION OF DISEASES
The reasons for the changes in the secular distribution of diseases can be explained by reasonable assumptions
Increase in cancer and respiratory system infections can be linked to environmental pollution
The reduction in the frequency of some infectious diseases seems to be related to vaccination and disease eradication programs
Changes in the virulence of infectious agents affect the secular distribution of diseases in the long run
Recent developments in diagnostic methods have led to the discovery of many previously unidentifiable or misdiagnosed diseases (enteric campylobacter infections, Lyme disease) Absolute time disease distribution
SPACIAL AND TEMPORAL DISTRIBUTION OF DISEASES
Spatial Distribution of Diseases
- Factors affecting the spatial distribution of diseases include population structure, transmission routes and ecological factors
- In order for a disease to be visible in a region, the susceptible animal population must be found if it is transported by diseased vectors
- For an epidemic to come into contact, the number of susceptible animals must be at a certain concentration - The minimum animal density required for the formation of the epidemic is called the threshold level, which is
determined by the Kendal threshold theorem
- In order for the parvovirus epidemic to occur in dogs, there must be at least 12 animals in km2
ECOLOGICAL APPROACH
An ecology is called science that studies animals and plants in relation to the environment they live in
When working on diseases in populations, it is necessary to know the host and its relation to the environment
These relationships determine when the illnesses are seen and where they are seen
The climate of a region affects the life of living animals and disease agents in that region or the life of plant-fed vectors because of the life of plants
The ability of animals to obtain minerals and trace elements from food depends on the vegetation and soil structure in that area
