CPH chap 3

• There are three principal uses of population data in health administration: the computation of vital and health statistics rates and ratios, setting up coverage of activities, and setting up norms for assignment of health facilities, staffs and funds.
• Estimates of Population Size can be obtained through continuous population registration, surveys, and mathematical estimates.
• Continuous population registration consists of registering births, deaths, emigration and immigration, making necessary additions and subtractions to the existing population.
• Surveys are a simple way of estimating the number of population in a smaller area.
• One way to estimate the population in a smaller area is to count the number of houses and for every ten houses, conduct a census.
• Mathematical estimates may be done by means of arithmetic and geometric increase method.
• The arithmetic increase method assumes that the population increases at a constant amount per year, and the difference between the last two censuses is taken and then divided by the number of years between them to get the average amount of population increase per year.
• The geometric increase method assumes that population increase at a constant rate per year, and the principal mathematical operation is the determination of the annual rate of population change.
• Humoral defense involves cells in our body like plasma cells and lymphocytes that produce antibodies to neutralize harmful effects of the infectious agents and body fluids in our body that possess substances that have antimicrobial properties.
• Host factors of diseases include age, sex, race, habits, customs and religion, exposure to agent, and defense mechanism of the host.
• Nose is the portal of entry for diseases through inhalation.
• Cellular defense involves cells in our body like macrophages and neutrophils that are involved in the process of phagocytosis.
• Mouth is the portal of entry for diseases through ingestion and kissing.
• Skin is the portal of entry for diseases through skin penetration, injection, and bite of arthropods.
• Droplet nuclei are usually small residues which result from evaporation of fluid from droplets emitted by an infected host.
• Portal of entry for dust mites is through the nose.
• Genitals are the portal of entry for diseases through sexual intercourse.
• In many instances, administrators have resorted to the use of growth rates (difference between CBR and CDR).
• The same computation procedure is followed for the estimation of population using growth rates.
• The formula for prevalence is: Number of cases old and new of a particular disease existing at a particular point in time Population at that time.
• The formula for crude death rate is: Total deaths from all causes in a year Midyear population.
• Neonatal mortality rate measures the risk of dying in the first four weeks of life of the infant (newborn).
• Peri-natal mortality rate measures the loss of life in later pregnancy and early infancy.
• The rate is expressed in population unit of 1000 to make the figures meaningful.
• Age group description: 0 – 11 months: infants, babies; 12 – 23 months: children under 2 years; 2 – 4 years: toddlers, pre-school children; 5 – 9 years: juvenile; 10 – 14 years: adolescents; 15 – 19 years: young adult; 20 + years: adults.
• Crude birth rate (CBR) is a rough measure of the fertility of the population.
• Crude death rate (CDR) is a measure of the risk of dying from all causes in a population.
• Fetal death rate measures the risk of dying before birth.
• Prevalence refers to the newly discovered cases of a particular disease over a population.
• Prevalence is usually determined by means of a survey.
• The rate is called crude for the following reasons: only livebirths are counted and the denominator is the total population which includes children, old people and males.
• Prevalence answers the question “what proportion of the group or population is actually ill with a particular disease at a point in time”.
• Infant mortality rate (IMR) measures the risk of dying due to infancy (under 1 year of age).
• Maternal mortality rate (MMR) measures the risk of dying due to the process of pregnancy, childbirth and puerperium.
• Characteristics of agents of disease directly related to man include infectivity, pathogenicity, virulence, antigenicity.
• Direct transmission is the immediate transfer of infectious agent to a receptive portal of entry.
• Epidemiology can be used to study the history of the health population and the rise and fall of diseases and changes in their character.
• Epidemiology can be used to study the work of health services with a view of improving them.
• Neonatal mortality rate g
• Fetal death rate f