Project NYK
COM MED
CONTENTS
- PRINCIPLES OF ENVIRONMENTAL HEALTH……………………………………………………………………..3
- LEVELS OF PREVENTION…………………………………………………………………………………………………7
- DROPLET INFECTION………………………………………………………………………………………………………8
- INTERNATIONAL HEALTH……………………………………………………………………………………………….9
- IMMUNITY……………………………………………………………………………………………………………………10
- WATER-BORNE DISEASES……………………………………………………………………………………………..13
- OCCUPATIONAL HEALTH………………………………………………………………………………………………14
- SCREENING…………………………………………………………………………………………………………………..16
- REPRODUCTIVE HEALTH……………………………………………………………………………………………….17
- FAMILY PLANNING……………………………………………………………………………………………………….20
- NUTRITION…………………………………………………………………………………………………………………..22
- EPIDEMIOLOGY…………………………………………………………………………………………………………….24
- SAMPLING AND BIOSTATISTICS…………………………………………………………………………………….33
- DEMOGRAPHY……………………………………………………………………………………………………………..36
- COMMUNICABLE DISEASES………………………………………………………………………………………….39
- MISCELLANEOUS………………………………………………………………………………………………………….45
- HOSPITAL WASTE MANAGEMENT………………………………………………………………………………..46
- DISASTER………………………………………………………………………………………………………………………48
- BIAS AND CONFOUNDING…………………………………………………………………………………………….49
- IMPORTANT POINTS MISCELLANEOUS…………………………………………………………………………50
- COMMON SKIN DISEASES…………………………………………………………………………………………….53
- IMPORTANT LINKS……………………………………………………………………………………………………….56
PRINCIPLES OF ENVIRONMENTAL HEALTH
-Environment: all that is external to the individual Host. Can be divided into Biological, Psychological, Social and Cultural factors, any or all of which may influence health status in a population.
-Health: a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity
-Disease: trouble or a condition of the living animal or plant body or one of its parts that impairs the performance of a vital function. (Illnessdisturbed function, Sicknesssocial dysfunction)
-Health Indicators: a variable that is susceptible to direct measurements that reflect the state of health of a person in a community e.g. infant mortality rate, incident rates, disability days.
-Mortality Rate: fraction of deaths in a population
-Years of Potential Life Lost: difference between expected age of death and actual age of death, summed across all deaths
-Toxicokinetics: what the body does to an agent e.g. absorption, distribution, metabolism, excretion
-Toxicodynamics: what agent does to the body
-Agents: chemical, biological and physical
-Vectors: water, air, solid, food
-Routes of entry: inhalation, ingestion, absorption
-Risk assessment: determination of the probability that an adverse effect will result from a defined exposure
-Risk management: process of weighing policy alternatives and selecting most appropriate regulatory actions based on results of risk assessment and social, economic and political concerns
-Environment Health: comprises those aspects of human health, including quality of life, that are determined by physical, biological, social psychological factors in environment. It also refers to the theory and practice of assessing, correcting, controlling and preventing those factors in environment that can potentially adversely affect the health of present and future generation.
Agent / Disease / Source / PathwayLegionella pneumophila / Legionnaire’s disease / soil, cooling towers / air, vent system
Salmonella / acute diarrhea / human or animal feces / water, meat, eggs
Dioxin / Chloracne (skin disease) soft tissue tumor / herbicides, paper mills, incinerators / air, water, food
Pesticides / nervous system toxicity / agriculture / food, water
Asbestos / asbestosis, lung cancer / insulation, autobrakes / air, water
Arsenic in groundwater:
.associated with skin lesions, lung, liver and bladder cancer
.WHO maximum permissible level: 50µg/L
Interdiscilplinary roles:
- Health Problem Investigators: epidemiologist, toxicologist, social worker, biostatistician
- Health problem responders: doctor, nutritionist, pharmacist
- Environmental problem responders: engineer, physicist, chemist, toxicologist
Primary Health Care:
- First level of contact between individual and health system
- Essential, closest to people, common diseases
- BHU, RHC
Secondary Health Care:
- Tehsil and DHQ
- More complex problems dealt, curative service
- 1st referral level
Tertiary Health Care:
-Super-specialist care, regional/central level institute
- Provide training programmes
Primary Health Care: essential health care based on practical, scientifically sound and socially acceptable methods and technology made universally accessible to individuals and families in the community through their full participation and at a cost that community and country can afford.
- Includes health education, food and nutrition, water and sanitation, immunization, endemic diseases, common diseases and injuries, essential drug and lab services, health workforce training, referral services, maternal healthcare and family planning.
- Strategies to ↓ mortality of marginal population, ↓ risk factors, develop sustainable health and policy development
- Requirements (8A and 3C) include appropriateness, availability, adequacy, accessibility, affordability, assessibility, accountability, completeness, comprehensiveness, continuity.
Vertical Program: a single program of health service, for a community e.g. EPI
Horizontal Program: a health service delivery program which covers the two dimensions of health i.e. personal and community health e.g. national program of family planning
(when a vertical program is merged into a community it becomes a horizontal program)
Natural History of Disease: the way in which disease evolves overtime from the earlier stage of its pre-pathogenesis phase to its termination as recovery, disability or death, in the absence of treatment or prevention.
Period of pathogenesis: disease agent has not yet entered man but factor which favour its interaction with human host already exist in environment. Begins with entry of agent in susceptible host
Iceberg phenomenon: known cases are outnumbered by undiscovered ones.
LEVELS OF PREVENTION
-Primordial prevention: prevention of risk factors, beginning with change in social and environmental conditions in which these factors are observed to develop, discouraging from adapting harmful lifestyle e.g. by educating about the harms of smoking one can prevent chronic heart diseases
-Primary Prevention:prevention of the onset of disease to reduce the incidence.
.strategies emphasize general health promotion, decreasing risk factors, protective measures, includes health education and health promotion programs and environmental health programs e.g. vaccinations, decreased smoking, diet
.actions taken prior to onset of disease in a high-risk population.
.applied in pre-pathogenesis phase
.interventions include health promotion (health, water, soil) and specific protection (immunization)
-Secondary prevention: applied in pathogenesis phase
.actions that halt the progress of disease at an early stage and prevent complications
.early diagnosis and prompt treatment (before symptoms appear), screening programs, pap smears
.interventions include early diagnosis and treatment
-Tertiary prevention: therapeutic and rehabilitative measures in late pathogenesis phase to reduce or limit impairments and disabilities and minimize suffering, treat diabetes and reduce complications
.interventions include disability limitation and rehabilitation
-Chain of infections: spread of infections
-Infectious agent: a microorganism with ability to cause a disease
-Reservoir: place where an organism can thrive and reproduce e.g. humans, water, soil
-Portal of exit: a place of exit providing a way for microorganisms to leave the reservoir e.g. nose when sneezing
-Portal of entry: means by which the infectious microorganisms gains entry into new host e.g. ingestion, breathing, skin puncture
-Susceptible host: a person who cannot resist a microorganism invading the body, multiplying and resulting in infection
DROPLET INFECTION
Modes of Transmission
Direct Transmission / Indirect Transmission1. direct contact / 1. vehicle borne
2. droplet infection / 2. vector borne (mechanical and biological)
3. contact with soil / 3. airborne (droplet nuclei and dust)
4. inoculation increase soil / mucosa / 4. fomite borne
5. transplacental (vertical) / 5. unclean hands and fingers
-Transmission by respiratory aerosols:
.droplets⇒ land on mucosa and inhaled
.airborne⇒become smaller by evaporation, travel deep into the lungs
.contact⇒reaction contaminate nearby surface, touch, can infect self
.droplet⇒ meningococcal meningitis, measles, rubella, mumps, diphtheria, pertussis, TB common cold, influenza, eruptive fever
-Preventing droplet infection:
1. Control
Early notification, isolation, disinfection, quarantine, immunization of contacts, investigation of contact
2. Preventive measures
Health education, hygiene, protective measures, vaccinations, antibiotic prophylaxis, clean hands with alcohol-based hand rub, wear surgical mask, wear eye protection
INTERNATIONAL HEALTH
- WHO formed on 7th April 1978, headquarters in Geneva Switzerland, 192 countries joined
- Control of disease⇒decrease incidence and prevalence of disease
- Elimination⇒ reduction of transmissions
- Eradication⇒ no further cases of disease occurrence anywhere
- Last known case of smallpox: 1977 in Somalia, smallpox is nearly eradicated
- UNICEF formed in 1946
- World Health Day: 7th April
- World No Tobacco Day: 31st May
- World Environment Day: 5th June
(Do remember the dates that came during your rotation)
IMMUNITY
-Innate immunity⇒skin, mucosa, phagocytosis, acid, lysosomes
-Acquired immunity⇒ cellular response by making antibodies
-Natural Active: antibodies made by WBC after infection
-Natural Passive: maternal antibodies in milk of colostrum
-Artificial Active: vaccination
-Artificial Passive: administration of antibody containing preparation
-Normal Human Immunoglobulin⇒ hepatitis A, measles, rabies, tetanus, mumps (IgG)
-Specific Human immunoglobulin⇒ hepatitis B, varicella, diphtheria
-Non-human Immunoglobulin(antisera from horse)⇒ diphtheria, tetanus, gas gangrene, botulism, rabies
-Live vaccines: made from live infectious agents without any amendments
e.g. smallpox
-Live attenuated: organisms are treated to become attenuated and avirulent but antigen is present, not administered in low immunity
e.g. BCG
-Inactivated vaccine: organisms are killed or inactivated by chemicals or heat but remain antigenic
e.g. cholera
-Toxoid: detoxifying the exotoxin such that toxicity is destroyed but antigen remains
e.g. diphtheria, tetanus
-Polysaccharide Vaccine: extracted cellular fraction, increased efficacy and safety
e.g. meningococcal and pneumococcal vaccines
-Surface AntigenRecombinant Vaccine: prepared by cloning HBsAg gene in yeast cells where it is expressed and produced to be used in vaccines
e.g. Hep B
Emergency: Adrenaline 0.5 ml I/M stat then 0.5 ml every 20 min, antihistamine 10-20 mg of Chlorpheniraminemaleate
-The Cold Chain: a system of storage and transport of vaccine at low temperature from manufacturer to vaccine site. includes cold box, deep freezer, vaccine carriers, ice packs
.freeze compartment vaccines include polio (-20°C), measles and BCG
.cold compartments vaccines include typhoid, DPT, tetanus, DT (should not freeze)
-Shake Test: Remove vaccine from cold chain, shake it well
.if turbidity/flocculation is formed, vaccine should not be used
-Thawing: after taking out polio vaccine from refrigerator, place it for some time somewhere it becomes liquid, then give to children
Extended Program of Immunization
Time / Vaccines / Dose / Route / Site / TypeAt birth / Polio-0
BCG / 2 drops
0.05ml / Oral
I/D / Orally
Right deltoid / Live
Live
6 weeks / Polio-1
Pentavalent-1*
Pneumococcal-1 / 2 drops
0.5ml
0.5ml / Oral
I/M
I/M / Orally
Right thigh
Left thigh / Live
**
Recombinant
10 weeks / Polio-2
Pentavalent-2*
Pneumococcal-2 / 2 drops
0.5ml
0.5ml / Oral
I/M
I/M / Orally
Right thigh
Left thigh / Live
**
Recombinant
14 weeks / Polio-3
Pentavalent-3*
Pneumococcal-3 / 2 drops
0.5ml
0.5ml / Oral
I/M
I/M / Orally
Right thigh
Left thigh / Live
**
Recombinant
9 months / Measles-1 / 0.5cc / S/C / Left deltoid / Live
15 months / Measles-2 / 0.5cc / S/C / Left deltoid / Live
Before 24 months / DPT + Polio
*/** Pentavalent: Diphtheria (toxoid), Tetanus (toxoid), Pertussis (killed), Hep B (recombinant), Hib (conjugate)
.BCG⇒wheal appears in 5 minutes and disappears in 1hr, papule at 2 to 3 weeks, nodule at 4-5 weeks, scar at 2 to 3 months
.Yellow Fever⇒ active, MMR at 12-15 months
.Hep B⇒ post-exposure prophylaxis: 0,1,2 months. Booster 1 year
.vaccine for travelers: Malaria, Cholera, Yellow fever, Hep A
.vaccines against bioterrorism: Anthrax, Smallpox, Plague
.salk is polio vaccine but not live
WATER-BORNE DISEASES
-Recreational water illnesses (RWI): caused by germs spread by swallowing, breathing in mists or aerosols, or having contact with contaminated water in swimming pools, hot tubs, water parks, water play areas, interactive fountains, lakes, rivers or oceans. They can also be caused by chemicals in water and chemicals that evaporate and cause indoor air quality problems
most common⇒ diarrhea caused by cryptosporidium, giardia, shigella, norovirus and E coli
Water Washed Disease: due to poor hygiene and contaminated water
Water Scarce Disease: due to lack of water availability for washing (trachoma)
Water-based Disease: due to organism that spends part of its life cycle in water (schistosomiasis)
Vector-borne Disease: bites from insects that breed in water (malaria)
Water-borne: infectious agent ingested
-Hep A⇒ outbreak, poor sanitation, childhood
.fecal matter can protect Hep A from chlorine
-Hep E⇒ incubation40 days (15-60 days), increase in pregnancy, no chronic state
-Rotavirus⇒ Leading cause of severe diarrhea disease and dehydration in infants and young children throughout the world
.age between 3 months and 2 years
.virus spreads rapidly by person-to-person contact, Airborne droplets, contact with contaminated objects e.g. toys
.treatment: vaccine, ORT
-Polio⇒ leading cause of Limp worldwide
.causes diarrhea in young children and paralysis in adults
.remove source of pathogen by keeping drinking water supply and sewage separated
.block transmission by using boil water
.eliminate susceptibility by vaccinating everyone
OCCUPATIONAL HEALTH
-Occupation: an activity which we perform to earn expenses of our daily lives (in case you didn’t know already)
-Occupational Health: a branch of Public Health, defined as the study of effect of work and working environment on the health of workers and influences of state of health working on his ability to perform the work for which he is employed
-Ergonomics: fitting the job to the worker
-Sickness Absenteeism: using the facility of reasoned leave e.g sick leave
-Pneumoconiosis: disease resulting from inhalation of respirable fraction of different chemical dusts leading to irreversible fibrosis
Inorganic
Silica⇒silicosis
Coal Dust⇒anthracosis
Asbestos⇒asbestosis
Iron⇒siderosis
Organic
Cane Fiber⇒bagassosis
Cotton Dust⇒byssinosis
Tobacco⇒tobaccosis
Hay or Grain Dust⇒farmer's lung
-Silicosis: inhaled crystalline silicon dioxide in mining, granite, ceramics, silica black, sandblasting
.development of hard nodules and fibrosis, prone to TB leading to silicotuberculosis
.cough, dyspnea and chest pain
.snowstorm appearance on chest x-ray, eggshell calcification in hilar nodes
-Anthracosis: inhaled coal dust in coal mining
.cough, black sputum (melanoptysis), progressive breathlessnes leading to TB
.radiology single / multiple large dense nodules in upper lobe
.leads to TB, respiratory and right heart failure
-Asbestosis: manufactured cement, roof tiles, shipyard workers
.4 diseases: 1. Benign pleural plaques (X-ray), 2. Benign pleural effusion (pleural pain and blood-stained effusion), 3.Progressive pulmonary fibrosis (breathlessness, clubbing, crepitations), 4. Malignant disease of pleura (Blue monothelioma)
.sputum shows asbestos bodies, x-ray shows ground glass appearance in lower 2/3 of the lungs
-Byssinosis: inhaled cotton fiber dust from cotton factory
.chronic cough, progressive dyspnea, chronic bronchitis, emphysema, chest tightness, mild fever, malaise, rigor
-Bagassosis: Inhalation of sugar cane in sugarcane industry
.breathlessness, cough, hemoptysis, fever, bronchitis, impaired pulmonary function, thermoactinomycessacchari
-Farmer's lung: inhalation of hay or grain dust
.moisture content causes growth of bacteria and fungi which leads to rise in temperature
.dyspnea,fever, respiratory insufficiency, pulmonary fibrosis and corpumonale
.thermoactinomycessacchari
-Lead Poisoning (Plumbism): manufacture storage batteries, gasoline can be inhaled, ingested, absorbed
.combines with SH group of enzymes in porphyria synthesis, affects membrane permeability and K+ leakage
.abdominal colic, constipation, decreased appetite, blue line on gums, anemia, wrist/foot drop, insomnia, headache, mental confusion, delirium
SCREENING
-Screening: testing of apparently healthy populations to identify previously undiagnosed disease or people at high risk of developing the disease
Screening Test / Positive / Negative / TotalPositive / True Positive (a) / False Positive (b) / a+b
Negative / False Negative (c) / True Negative (d) / c+d
Total / a+c / b+d / a+b+c+d
-Sensitivity: The ability of a test to identify correctly All of those who have the disease: x100
-Specificity: the ability of the test to identify correctly all those who do not have the disease: x100
-Predictive value: the diagnostic power of a test
-Positive predictive value: is the probability that individuals who test positive for the disease actually have the disease
x100
-Negative predictive value: the probability that individual who test negative for the disease are disease-free
x100
Percentage of false negative=x100
Percentage of false positive= x100
Accuracy of the validity of a test= x100
Prevalence of screening test= x100
-Yield: the amount of previously unrecognized disease that is diagnosed as a result of screening efforts for example by limiting screening of a high-risk population
REPRODUCTIVE HEALTH
-Reproductive Health: a condition in which reproductive process is accomplished in a state of complete physical, mental, and social well-being and not merely the absence of disease of reproductive process
-Maternal morbidity: disease in pregnancy but not accident or incidental cause
-Maternal death: death while pregnant or within 42 days after termination of pregnancy but not accidental or incidental cause
-Late Maternal death: death after 42 days but less than one year after terminating pregnancy
-Pregnancy-related death: death while pregnant or within 42 days irrespective of cause
-Maternal Mortality Rate: number of women dying in pregnancy and childbirth per 1000 women aged 15 to 49
-Mother and Child Healthcare: a branch of Public Health which is planned for health supervision of mother and child not only physically but also mentally and emotionally
.weight gain is 10 - 12 kilograms, 60000 kilocalories during pregnancy
.tetracycline, streptomycin, corticosteroids are contraindicated
.tetanus toxoid immunization
.anemia is less than 11 mg/dL, intramuscular immunoglobulinsif husband Rh+ and mother Rh-
.German Measles cause congenital abnormalities so they have to be terminated
.breastfeeding 4-5 months after birth
.daily secretion 450 - 600 milliliters a day
.energy 70kCal/100ml
.colostrum first 2 to 3 days, protein and immunoglobulin against diarrhea and respiratory disease
.contraindicated in high fever, sepsis, breast carcinoma, untreated TB, leprosy, kidney disease
.GOBI: growth monitoring, oral rehydration, breast feeding, immunization
.FFF: female literacy, family planning, food fortification
Human Milk / Cow MilkProteins / 1.5% / 3.5%
Fats / varies with nutrition / varies with breed
Carbohydrates / 7% / 4.5%
Vitamins / A,B,E / low in C and D
Energy value / 20 kCal per ounce / 20 kCal per ounce, risk of allergy, DM type 1, suckling problems
-Weaning: is a process during which child gets familiar to food other than breast milk for example cereals banana, rice, yogurt