Orris
attachment
attachment

Give me a information about only mark topic in heading of introduction, problem statement, epidemiology, clinical features, diagnosis, treatment, prevention source k park

Asking for Preferences
Reading File
Finding Sources
Finding Sources
Finding Sources
Finding Sources
Finding Sources
Finding Sources
Reading File
Reading File
Reading File
Reading File
Reading File
Reading File
Reading File
Reading File
Reading File
Reading File
Reading File
Reading File
Reading File
Reading File
Reading File
Finding Sources
Finding Sources
Finding Sources
Reading File
Reading File
Here is the comprehensive information for all marked topics from K. Park's Textbook of Preventive and Social Medicine (Chapter 6 - Non-Communicable Diseases):

NON-COMMUNICABLE DISEASES (K. Park)

1. RHEUMATIC HEART DISEASE (RHD)

Introduction

Rheumatic fever (RF) and rheumatic heart disease (RHD) cannot be separated from an epidemiological point of view. Rheumatic fever is a febrile disease affecting connective tissues particularly in the heart and joints, initiated by infection of the throat by group A beta haemolytic streptococci. Although RF is not itself communicable, it results from a communicable disease (streptococcal pharyngitis). RF often leads to RHD - a crippling disease. Consequences of RHD include: continuing damage to the heart, increasing disabilities, repeated hospitalization, and premature death usually by age 35 or earlier. RHD is one of the most readily preventable chronic diseases.

Problem Statement

World: Worldwide there are over 15 million cases of RHD with 282,000 new cases annually. In 2008, 220,000 deaths occurred (about 0.4% of total deaths). RHD is a major cause of mitral insufficiency and stenosis. Insufficiency resolves in 60-80% of patients who adhere to antibiotic prophylaxis. Decline has been seen in affluent countries (North America, Western Europe, Japan) but persists in pockets of poverty.
India: RHD is prevalent at 5-7 per thousand in the 5-15 year age group; approximately 1 million RHD cases in India. RHD constitutes 20-30% of hospital admissions due to CVD in India. Streptococcal infections are very common in children living in under-privileged conditions; RF occurs in 1-3% of those infections.

Epidemiology

Agent Factors:
  • Agent: Group A streptococcus (particularly M type 5, with "rheumatogenic potential"). All group A streptococci are sensitive to penicillin but have great immunological diversity.
  • Carriers: Convalescent, transient, and chronic carriers are frequent; eradication is not feasible.
Host & Environmental Factors:
  • Age: Typically affects children and adolescents (5-15 years). "Juvenile mitral stenosis" is seen in India with faster progression to valvular lesions.
  • Sex: Affects both sexes equally; prognosis is worse in females.
  • Immunity: Toxic-immunological hypothesis - streptococcal products cross-react with host tissue antigens causing immunological damage.
  • Socio-economic status: RF is a social disease linked to poverty, overcrowding, poor housing, inadequate health services.
  • High-risk groups: School-age children 5-15 years; slum dwellers; those in closed communities (barracks).

Clinical Features

  • (a) Fever: Present at onset, may be accompanied by profuse sweating, lasts ~12 weeks with tendency to recur.
  • (b) Polyarthritis: Occurs in 90% of cases - migratory, affecting large joints (knees, ankles, elbows, wrists). Subsides in 6-8 weeks.
  • (c) Carditis: Most serious manifestation. Pericarditis, myocarditis, endocarditis may occur. Characterized by tachycardia, cardiac enlargement, murmurs, pericardial rub.
  • (d) Sydenham's chorea: Involuntary purposeless movements; mainly in girls; may be the only manifestation.
  • (e) Erythema marginatum: Erythematous rash with red margins and pale center; seen in ~10% of cases.
  • (f) Subcutaneous nodules: Found over bony prominences; associated with severe carditis.

Diagnosis

The 2002-2003 WHO criteria (based on revised Jones criteria) are used:
Major Manifestations: Carditis, Polyarthritis, Chorea, Erythema marginatum, Subcutaneous nodules.
Minor Manifestations: Fever, raised ESR/CRP, prolonged PR interval.
Evidence of preceding streptococcal infection: Elevated ASO titre or other streptococcal antibodies, positive throat culture, recent scarlet fever.
For a primary episode of RF: 2 major manifestations, OR 1 major + 2 minor + evidence of streptococcal infection.
For recurrence in established RHD: Minor manifestations + evidence of streptococcal infection.

Treatment

  • Bed rest during acute phase.
  • Penicillin to eradicate streptococci: Single IM injection of benzathine benzyl penicillin (1.2 million units adults; 600,000 units children) or oral penicillin for 10 days.
  • Aspirin for arthritis and fever.
  • Corticosteroids for severe carditis.
  • For penicillin allergy: Erythromycin.

Prevention

a. Primary Prevention: Identify and treat all cases of streptococcal throat infection with penicillin to prevent first attack of RF. Focus on high-risk school-age children under surveillance for streptococcal pharyngitis. Ideally throat swabs are cultured; if not possible, treat sore throat empirically with penicillin.
b. Secondary Prevention: Prevention of recurrences by long-term prophylaxis with benzathine penicillin G monthly injections (more practical approach in developing countries). Duration:
  • No carditis: 5 years or until age 18 (whichever is longer)
  • Carditis without residual heart disease: 10 years or until age 25
  • Carditis with persistent valvular disease: lifelong prophylaxis

2. HYPERTENSION

Introduction

Hypertension is a chronic condition of concern due to its role in causing coronary heart disease, stroke, and other vascular complications. It is the commonest cardiovascular disorder and a major public health challenge. Hypertension accounts for 20-50% of all cardiovascular deaths. Blood pressure is distributed continuously in populations (bell-shaped curve) with no real separation between normotension and hypertension (Pickering's concept).

Problem Statement

World: Global prevalence was estimated at 1.13 billion in 2015. Overall prevalence ~30-40% in adults; age-standardized prevalence of 24% in men and 20% in women. Number with hypertension will increase by 15-20% by 2025. Elevated BP accounts for ~10 million deaths/year and >200 million DALYs. Leading deaths: IHD (4.9 million), haemorrhagic stroke (2 million), ischaemic stroke (1.5 million).
India: Hypertension is the most common NCD in India. Prevalence in North-Eastern states is higher than the national average. There is a consistent increase in prevalence with increasing BMI. 38% of obese men and 29% of obese women were hypertensive.

Epidemiology (Risk Factors)

Non-modifiable:
  • Age: BP rises with age
  • Sex: Higher in young men; post-menopause women catch up
  • Genetic factors: Polygenic inheritance; children of two hypertensive parents have 45% chance
Modifiable:
  • Obesity: Strong positive correlation
  • Salt intake: Positive association
  • Physical inactivity
  • Alcohol excess
  • Stress and psychological factors
  • Oral contraceptives
  • Secondary causes: Renal disease (chronic glomerulonephritis/pyelonephritis), adrenal tumours, coarctation of aorta, toxemias of pregnancy (account for ~10% of cases)
Classification of BP (WHO):
CategorySystolic (mmHg)Diastolic (mmHg)
Optimal<120<80
Normal120-12980-84
High Normal130-13985-89
Grade 1 HTN140-15990-99
Grade 2 HTN160-179100-109
Grade 3 HTN≥180>110
Isolated Systolic HTN≥140<90

Clinical Features

  • Most patients are asymptomatic for years ("silent killer").
  • Symptoms when present: headache (especially occipital, morning), dizziness, visual disturbances, palpitations, epistaxis.
  • Organ damage (target organ):
    • Heart: LV hypertrophy, coronary artery disease, heart failure
    • Brain: stroke, TIA, hypertensive encephalopathy
    • Kidney: proteinuria, renal failure
    • Retina: hypertensive retinopathy (Keith-Wagener grading)
    • Blood vessels: peripheral arterial disease

Diagnosis

  • Based on the average of two or more BP readings on two or more occasions after initial screening.
  • BP measurement must be standardized: sitting position, same arm, 3 readings at 3-minute intervals, lowest reading recorded.
  • Phase I Korotkoff = systolic; Phase V (disappearance) = diastolic.
  • Essential (primary) HTN = 90% of cases (causes unknown).
  • Secondary HTN = 10% of cases (renal, endocrine, etc.)

Treatment

  • Lifestyle modifications: Weight reduction, salt restriction (<5g/day), increased physical activity, reduce alcohol, stop smoking, stress reduction, diet rich in fruits and vegetables (DASH diet).
  • Drug therapy when lifestyle changes insufficient:
    • Grade 1 HTN: Start drug therapy if BP persists after 3 months of lifestyle changes
    • Grade 2 & 3: Start drugs immediately
    • Drug classes: Diuretics (thiazides), beta-blockers, ACE inhibitors, calcium channel blockers, angiotensin receptor blockers
  • Treatment goal: BP <140/90 mmHg; <130/80 in diabetes or CKD

Prevention

Primary: Health education, salt reduction, weight control, physical activity promotion, healthy diet, reduced alcohol intake - targeting the whole population.
Secondary: Early detection through screening, regular monitoring, treatment adherence.
Tertiary: Prevent complications through adequate blood pressure control and management of target organ damage.

3. DIABETES MELLITUS

Introduction

Diabetes describes a group of metabolic disorders characterized by hyperglycaemia in the absence of treatment. The aetiopathology includes defects in insulin secretion, insulin action, or both, with disturbances of carbohydrate, fat, and protein metabolism. Long-term specific effects include retinopathy, nephropathy, and neuropathy. People with diabetes are also at increased risk of cardiovascular disease, stroke, peripheral arterial disease, cataracts, erectile dysfunction, and some infectious diseases including tuberculosis.

Problem Statement

World: Diabetes is one of the fastest growing global health emergencies. An estimated 422 million adults were living with diabetes in 2014 (WHO). Type 2 diabetes accounts for the majority (~90%). The number is projected to rise sharply with urbanization and lifestyle changes.
India: India has the second largest number of diabetics in the world. Prevalence is higher in urban than rural areas (urbanization effect). Rapid increase due to sedentary lifestyle, dietary changes, and obesity.

Epidemiology

Classification (WHO 2019):
  • Type 1: Beta-cell destruction (mostly immune-mediated), absolute insulin deficiency, childhood/early adulthood onset.
  • Type 2: Most common; varying degrees of beta-cell dysfunction + insulin resistance; associated with overweight/obesity.
  • Hybrid forms: LADA (slowly evolving immune-mediated in adults), ketosis-prone type 2.
  • Monogenic diabetes (MODY), diseases of exocrine pancreas, endocrine disorders.
  • Gestational diabetes.
Risk Factors for Type 2 Diabetes:
  • Obesity and overweight (strongest association)
  • Physical inactivity
  • Unhealthy diet: high saturated fats, low dietary fibre
  • Alcohol excess
  • Viral infections (rubella, mumps, coxsackie B4 for Type 1)
  • Chemical agents toxic to beta cells
  • Stress and trauma
  • Malnutrition in early infancy (partial beta-cell failure)
  • Social factors: urbanization, sedentary occupation

Clinical Features

  • Type 1: Sudden onset, polyuria, polydipsia, polyphagia, weight loss, fatigue, prone to diabetic ketoacidosis (DKA).
  • Type 2: Often asymptomatic for years; discovered on routine screening. When symptomatic: polyuria, polydipsia, blurring of vision, recurrent infections, poor wound healing.
  • Complications: Acute (DKA, hyperosmolar coma, hypoglycaemia); Chronic - microvascular (retinopathy, nephropathy, neuropathy) and macrovascular (IHD, stroke, peripheral arterial disease).

Diagnosis

WHO criteria for diagnosis of diabetes:
  • Fasting plasma glucose: ≥7.0 mmol/L (126 mg/dL)
  • 2-hour plasma glucose after 75g oral glucose: ≥11.1 mmol/L (200 mg/dL)
  • Random plasma glucose: ≥11.1 mmol/L with symptoms
  • HbA1c: ≥48 mmol/mol (6.5%)
Impaired Fasting Glucose (IFG): Fasting glucose 6.1-6.9 mmol/L (pre-diabetes).
Glycosylated Haemoglobin (HbA1c): Provides a long-term index of glucose control over the previous 2-3 months. Should be estimated at half-yearly intervals.

Treatment

Secondary Prevention (management when diabetes is detected):
  • Goals: Maintain blood glucose as close to normal as practicable; maintain ideal body weight.
  • Diet alone: Small balanced meals frequently; low glycaemic index foods; high dietary fibre (minimum 20g/day).
  • Diet + Oral antidiabetic drugs: Metformin, sulfonylureas, DPP-4 inhibitors, etc.
  • Diet + Insulin: For Type 1 and severe Type 2.
  • Routine monitoring: Blood sugar, urine proteins/ketones, BP, visual acuity, weight, foot examination.
  • Self-care: Diet adherence, drug regimen, urine/blood glucose monitoring, abstinence from alcohol, optimum weight maintenance.
  • Patient education is essential - patient should carry an identification card.

Prevention

Primary Prevention: Lifestyle modification to prevent type 2 diabetes:
  • Weight reduction in overweight/obese
  • Regular physical activity
  • Low saturated fat, high fibre diet
  • Avoidance of excess alcohol
  • Breast-feeding promotion (protective in infancy)
Secondary Prevention: Early detection by screening high-risk groups; adequate treatment to prevent complications; HbA1c monitoring; foot care; eye examination.
Tertiary Prevention: Rehabilitation of those with complications; management of retinopathy, nephropathy, neuropathy, and cardiovascular complications.

4. ACCIDENTS AND INJURIES

Introduction

An accident is defined as "an unexpected, unplanned occurrence which may involve injury" or "an unpremeditated event resulting in recognizable damage" (WHO, 1956). Accidents represent a major epidemic of non-communicable disease in the present century. They are no longer considered accidental - they are part of the price paid for technological progress.
Accidents have their own natural history following the same epidemiological pattern as any other disease (agent + host + environment). Susceptibility is increased by alcohol, drugs, and physiological states like fatigue. A majority of accidents are preventable.

Problem Statement

World: Injuries constitute a variable epidemic. They are classified by "intentionality":
  • Unintentional: Road traffic injuries, poisoning, falls, burns, drowning.
  • Intentional: Interpersonal violence (homicide, assault), suicide, collective violence (war).
Children and adolescents are especially vulnerable to drowning, burns, poisoning, and road traffic injuries. Road traffic accidents are the leading cause of death in the 15-29 age group globally. Global burden is projected to rise.
India: Road traffic accidents cause considerable economic loss. In South-East Asia, semi-urban and rural areas contribute 60-80% of road accident injuries.

Epidemiology (Types of Accidents)

  1. Road traffic accidents (RTA): Most important type; linked to driver behaviour, alcohol, speeding, defective roads, poor lighting.
  2. Domestic accidents: Particularly in children and elderly; falls, burns, poisoning at home.
  3. Industrial accidents: Occupational hazards; machinery, chemicals, falls at workplace.
  4. Railway accidents: Derailments, level crossing accidents.
Multiple causation: Up to 90% of factors responsible for accidents are attributed to human failure. Causal factors:
  • Human: Alcohol/drug use, fatigue, inexperience, recklessness
  • Environmental: Defective roads, poor lighting, faulty infrastructure
Measurement:
  • Proportional mortality rate (deaths per 100/1000 total deaths)
  • Deaths per million population
  • Death rate per 1000 registered vehicles
  • Abbreviated Injury Scale for morbidity

Clinical Features

Injuries range from minor to fatal. Key consequences:
  • Mortality: Death at scene or within 30 days (WHO definition of "killed" in RTA).
  • Morbidity: Serious injuries and slight injuries (assessed by Abbreviated Injury Scale).
  • Disability: Temporary or permanent; partial or total. Measured using WHO's International Classification of Functioning, Disability and Health (ICF).

Diagnosis

  • Epidemiological investigation: Identify agent, host, environment.
  • Accident reporting and data collection for pattern recognition.
  • Breath analyser for alcohol level in drivers.
  • Assessment of injury severity using Abbreviated Injury Scale.

Treatment

  • Immediate first aid at scene.
  • Emergency medical services/transport.
  • Hospital-based trauma care.
  • Rehabilitation of the disabled.

Prevention

1. Data collection: Basic reporting system for all accidents; supplemented by special surveys and in-depth studies.
2. Safety education: "If accident is a disease, education is its vaccine." Safety education from school level; driver training; risk factor awareness; first aid training.
3. Promotion of safety measures:
  • Use of seat belts, helmets, protective gear.
  • Speed limits and enforcement.
  • Drunk-driving laws.
  • Compulsory vehicle inspection.
4. Environmental measures:
  • Improve road design and street lighting.
  • Road safety engineering.
  • Safe workplace design.
5. Legislation: Road traffic laws, industrial safety regulations, consumer safety standards.
6. Emergency medical services: Trained first responders; accessible trauma care.
Haddon's Matrix is used to analyse accident prevention in terms of host, agent (vehicle/energy), and environment - pre-event, event, and post-event phases.

5. VISUAL IMPAIRMENT AND BLINDNESS

Introduction

WHO defines blindness as "visual acuity of less than 3/60 (Snellen) or its equivalent" (adopted at 25th World Health Assembly, 1972). The ICD-11 (2018) classifies vision impairment into:
Distance Vision Impairment:
  • Mild: Worse than 6/12
  • Moderate: Worse than 6/18
  • Severe: Worse than 6/60
  • Blindness: Worse than 3/60
Near Vision Impairment: Worse than N6 or M0.8 at 40 cm.
India changed its definition of blindness from inability to count fingers at 6 metres (1976) to 3 metres - aligning with WHO criteria.

Problem Statement

World: Globally 1 billion people have a vision impairment that could have been prevented or has yet to be addressed. This includes:
  • Unaddressed refractive error: 123.7 million
  • Cataract: 65.2 million
  • Glaucoma: 6.9 million
  • Corneal opacities: 4.2 million
  • Diabetic retinopathy: 3 million
  • Trachoma: 2 million
  • Unaddressed presbyopia: 826 million
About 80% of blindness is avoidable (treatable or preventable). Overall visual impairment worldwide has decreased since early 1990s due to public health action against infectious diseases and improved eye care services. However, it could triple due to population growth and ageing.
India: Prevalence of blindness by National Blindness Survey 2006-07 was 1.0%. Current survey (2015-2018) projected prevalence is 0.36% (population ~80 lakh blind).
Principal causes of blindness in India (National Survey 2015-19):
  1. Cataract - 66.2% (leading cause)
  2. Refractive errors - uncorrected
  3. Glaucoma
  4. Corneal opacities
  5. Diabetic retinopathy
  6. Trachoma (declining)
Childhood blindness causes: Xerophthalmia, congenital cataract, congenital glaucoma, optic atrophy (from meningitis), retinopathy of prematurity, uncorrected refractive errors.

Epidemiology

Emerging causes: Glaucoma, age-related macular degeneration, diabetic retinopathy, corneal ulcer, ocular trauma (replacing declining infectious causes).
Declining causes: Trachoma and xerophthalmia (largely under control with Vitamin A supplementation in immunization programmes).

Clinical Features

  • Cataract: Painless, progressive clouding of lens; bilateral; treatable surgically.
  • Glaucoma: Raised intraocular pressure; optic nerve damage; peripheral vision loss.
  • Trachoma: Repeated Chlamydia trachomatis infections leading to conjunctival scarring, trichiasis, corneal opacity.
  • Xerophthalmia (Vitamin A deficiency): Night blindness, Bitot's spots, corneal ulceration, keratomalacia.
  • Diabetic retinopathy: Microaneurysms, haemorrhages, exudates, neovascularization.
  • Refractive errors: Myopia, hypermetropia, astigmatism - correctable with glasses/lenses.

Diagnosis

  • Visual acuity testing: Snellen chart (standard).
  • Slit-lamp examination for anterior segment.
  • Fundoscopy for retinal diseases.
  • Tonometry for glaucoma screening.
  • Vitamin A status assessment for xerophthalmia.

Treatment

  • Cataract: Surgical removal + intraocular lens implantation (most cost-effective intervention).
  • Glaucoma: Eye drops (beta-blockers, prostaglandins), laser therapy, surgery.
  • Trachoma: Azithromycin (SAFE strategy: Surgery, Antibiotics, Facial cleanliness, Environmental improvement).
  • Vitamin A deficiency: Massive dose Vitamin A supplementation.
  • Refractive errors: Spectacles, contact lenses, refractive surgery.
  • Diabetic retinopathy: Laser photocoagulation, anti-VEGF injections, vitrectomy.

Prevention

National Programme for Control of Blindness and Visual Impairment (NPCB&VI):
1. Primary Prevention:
  • Control of Vitamin A deficiency: Vitamin A supplementation in under-5 children under the Universal Immunization Programme.
  • Control of trachoma: SAFE strategy; hygiene promotion; safe water supply.
  • Prevention of diabetes (prevents diabetic retinopathy).
  • Eye protection to prevent trauma.
2. Secondary Prevention:
  • School eye screening programmes.
  • Early cataract surgery.
  • Glaucoma screening - tonometry.
  • Regular fundal examination in all diabetics.
3. Tertiary Prevention:
  • Low vision aids and rehabilitation.
  • Braille education, white cane use.
  • Occupational rehabilitation.
Vision 2020 - The Right to Sight: WHO global initiative to eliminate avoidable blindness by year 2020, focusing on cataract, refractive errors, trachoma, onchocerciasis, childhood blindness.
Source: Park's Textbook of Preventive and Social Medicine, Chapter 6 - Non-Communicable Diseases (pages 425-513).
This is a shared conversation. Sign in to Orris to start your own chat.