Community Health Nursing Notes: Epidemiology, Health Care Delivery, Environment and Roles

These community health nursing notes bring together the topics that CHO, ANM, staff nurse and AIIMS NORCET papers test again and again: concepts of health, levels of prevention, epidemiology and vital rates, the health care delivery system in India, health education, environmental health, demography, records and the roles of the CHO, ANM and ASHA. Community health is one of the highest-weightage subjects in CHO and ANM exams and a steady scorer in NORCET.

Read it with our national health programmes notes, since many questions combine both areas.

Community health nursing notes: scope and weightage

For CHO and ANM recruitment, community health is usually the core of the paper, so expect detailed questions on population norms, registers, home visits and programme facts. In NORCET and staff nurse exams, the subject appears regularly with emphasis on epidemiology, rates, prevention levels and water and waste management. The standard reference is Park’s Textbook of Preventive and Social Medicine, along with the Indian Public Health Standards (IPHS) 2022 and Ministry of Health guidelines.

Concepts of health and disease

The WHO (1948) defines health as a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity. Dimensions of health include physical, mental, social, spiritual, emotional and vocational dimensions.

• Determinants of health: biological (genetic), behavioural and lifestyle, environment, socio-economic conditions, health services, ageing, gender and others.
• Indicators of health: mortality indicators (IMR, MMR, CDR, life expectancy), morbidity indicators (incidence, prevalence), disability rates (DALY, QALY), nutritional status, health care delivery indicators.
• Physical Quality of Life Index (PQLI): combines infant mortality, life expectancy at age one and literacy.

Natural history of disease

The natural history has a prepathogenesis phase (interaction of agent, host and environment before disease) and a pathogenesis phase (from entry of the agent to recovery, disability or death). Prevention is planned around these phases.

Levels of prevention

Level	Aim	Modes of intervention / examples
Primordial	Prevent the emergence of risk factors	Healthy lifestyle education in children, discouraging smoking and junk food habits
Primary	Prevent onset of disease in the prepathogenesis phase	Health promotion (nutrition, sanitation, health education) and specific protection (immunisation, chemoprophylaxis, iodised salt, helmets)
Secondary	Halt progress at an early stage	Early diagnosis and adequate treatment: screening, Pap smear, case finding in TB
Tertiary	Reduce impairment and disability	Disability limitation and rehabilitation: physiotherapy, prosthesis, vocational training

The five modes of intervention (Leavell and Clark) are health promotion, specific protection, early diagnosis and treatment, disability limitation and rehabilitation. Primordial prevention is now considered the most fundamental level.

Epidemiology basics

Epidemiology studies the distribution and determinants of health-related states in populations and applies this to control health problems. John Snow, who traced the 1854 London cholera outbreak to the Broad Street pump, is called the father of modern epidemiology.

• Epidemiological triad: agent, host and environment.
• Endemic: constant presence in an area. Epidemic: occurrence clearly in excess of normal expectancy. Pandemic: epidemic over a wide area, usually several countries. Sporadic: scattered cases.
• Incidence: new cases in a defined period. Prevalence: all existing (old plus new) cases. Prevalence = Incidence x Mean duration.
• Study designs: descriptive; analytical (case-control: proceeds from effect to cause, gives odds ratio; cohort: proceeds from cause to effect, gives relative risk and attributable risk); experimental (randomised controlled trial is the gold standard).
• Incubation period: time from entry of infection to first signs or symptoms. Quarantine is limiting the movement of healthy contacts for the longest incubation period; isolation separates the infected person.

Important rates and formulas

Indicator	Formula
Crude birth rate (CBR)	Live births in a year / mid-year population x 1,000
Crude death rate (CDR)	Deaths in a year / mid-year population x 1,000
Infant mortality rate (IMR)	Deaths under 1 year of age / live births in the same year x 1,000
Neonatal mortality rate (NMR)	Deaths under 28 days / live births x 1,000
Perinatal mortality rate	(Late foetal deaths of 28 weeks or more + early neonatal deaths in the first 7 days) / (live births + stillbirths) x 1,000
Under-5 mortality rate	Deaths under 5 years / live births x 1,000
Maternal mortality ratio (MMR)	Maternal deaths / live births x 1,00,000
General fertility rate (GFR)	Live births / women aged 15 to 49 years x 1,000
Case fatality rate	Deaths from a disease / total cases of that disease x 100
Attack rate	New cases during an epidemic / population at risk x 100

Current figures: India’s IMR was 25 per 1,000 live births, CBR 18.4, CDR 6.4 and TFR 1.9 as per the SRS Statistical Report 2023 (released September 2025). The MMR was 88 per 1,00,000 live births as per the SRS special bulletin on maternal mortality for 2021 to 2023 (released 2025). Check for newer SRS releases before your exam.

Health care delivery system in India

The Bhore Committee (1946) laid the foundation of primary health care in India, and the Alma-Ata Declaration (1978) set the goal of “Health for All” through primary health care. Rural health care is organised in three tiers below the district hospital.

Population norms (IPHS 2022)

Facility	Plain areas	Hilly / tribal / difficult areas	Key points
Sub Health Centre (AAM-SHC)	5,000	3,000	Most peripheral contact point; led by a CHO with MPWs (female and male) and ASHAs
Primary Health Centre (AAM-PHC)	30,000	20,000	Medical officer-led; referral unit for about 6 sub centres
Community Health Centre (CHC)	1,20,000	80,000	Specialist care, First Referral Unit, usually 30 beds; referral for about 4 PHCs

Under Ayushman Bharat (2018), sub centres and PHCs were upgraded to Health and Wellness Centres (HWCs) to provide comprehensive primary health care with an expanded package of services (12 service packages including NCDs, mental health, eye, ENT, oral, elderly and palliative care, and emergency services). The first HWC was inaugurated at Jangla, Bijapur district, Chhattisgarh, on 14 April 2018. In late 2023 the Union Health Ministry renamed HWCs as Ayushman Arogya Mandir (AAM) with the tagline “Arogyam Parmam Dhanam”. States have since been asked to use the names AAM-PHC and AAM-SHC. Exams may use either the old or new name, so learn both.

Other tiers: Sub-Divisional Hospital and District Hospital (secondary care), and medical colleges and AIIMS-type institutions (tertiary care). In urban areas, Urban PHCs and Urban AAMs serve slum and vulnerable populations under the National Urban Health Mission.

Village level functionaries

• ASHA: generally one per 1,000 population (relaxed in tribal and hilly areas), a resident woman of the village, preferably aged 25 to 45 years and literate.
• Anganwadi Worker (ICDS): one Anganwadi Centre for roughly 400 to 800 population in plain areas.
• Village Health, Sanitation and Nutrition Committee (VHSNC) and monthly Village Health, Sanitation and Nutrition Day (VHSND).

Health education: principles and methods

Health education aims to change knowledge, attitude and practice (KAP). Communication involves a sender, message, channel, receiver and feedback.

Principles of health education (Park)

• Interest, participation, motivation and comprehension (use the people’s language and level).
• Reinforcement and learning by doing.
• Known to unknown, setting an example, good human relations, feedback.
• Credibility and the use of local leaders.

Methods

Approach	Methods
Individual	Personal contact, home visits, counselling, personal letters
Group	Lecture, demonstration (method and result), group discussion (about 6 to 12 members), panel discussion (4 to 8 experts discuss in front of an audience with a chairperson), symposium (series of short speeches by experts on one topic), workshop, role play, seminar
Mass	Television, radio, newspapers, posters, hoardings, social media, health exhibitions

Demonstration is the most effective method for teaching skills such as ORS preparation or breastfeeding positioning, while mass media are best for creating awareness.

Environmental health

Water

Safe and wholesome water is free from pathogens and harmful chemicals, pleasant to taste and usable for domestic purposes. Bacteriologically, no E. coli or thermotolerant coliforms should be detected in any 100 ml sample of drinking water.

• Large-scale purification: storage, filtration and chlorination.
• Slow sand (biological) filter: the “vital layer” or schmutzdecke on the sand surface is the heart of the filter; cleaned by scraping.
• Rapid sand (mechanical) filter: uses alum as a coagulant; cleaned by backwashing; occupies less space.
• Chlorination: water should be clear; break-point chlorination; contact period of 1 hour; free residual chlorine of 0.5 mg/L at the end of the contact period.
• Tests: orthotoluidine (OT) test or OTA test for residual chlorine; Horrock’s apparatus finds the dose of bleaching powder needed.
• Bleaching powder contains about 33% available chlorine; it is used for disinfecting wells (the double pot method can be used for continuous chlorination of wells).
• Household methods: boiling (rolling boil), chlorine tablets, filtration and solar disinfection.
• Fluoride: the desirable level is about 0.5 to 0.8 mg/L; excess (above 1.5 mg/L) causes fluorosis, deficiency increases dental caries.

Waste disposal

• Solid waste (refuse): sanitary landfill (controlled tipping), composting (Bangalore method is anaerobic, Indore method is aerobic) and incineration.
• Excreta disposal: sanitary latrines such as the water-seal latrine (RCA type), twin-pit pour-flush latrine and septic tank. A sanitary latrine should not contaminate soil or water and should be inaccessible to flies.
• Biomedical waste: segregated by colour coding under the BMW Management Rules 2016; see our microbiology notes for the full table.

Demography basics

• Demography studies the size, composition and distribution of populations and the changes in them (fertility, mortality, migration).
• India’s census is held every 10 years; the first synchronous census was in 1881, and the last completed census was in 2011 (population about 121 crore, sex ratio 943 females per 1,000 males, literacy 74.04%).
• Demographic cycle: high stationary, early expanding, late expanding, low stationary and declining stages.
• Total fertility rate (TFR): average number of children a woman would have through her reproductive years. Replacement level TFR is 2.1.
• Net reproduction rate (NRR) of 1 means the population replaces itself.
• Eligible couple: currently married couple where the wife is in the reproductive age group of 15 to 49 years.

Records and registers at the sub centre

Records support continuity of care, planning, evaluation, legal needs and reporting to HMIS and the RCH portal. Common registers and records are:

• Eligible couple register and family planning register
• Antenatal (maternal health) register and delivery register
• Immunisation register and due lists
• Birth and death register (vital events)
• Village / household survey register (population records)
• NCD screening records and Community Based Assessment Checklist (CBAC) forms
• Drug and stock register, equipment register
• Mother and Child Protection (MCP) card and RCH portal entries

Home visit and bag technique

A home visit is a planned, purposeful contact with a family in its own setting. Principles: it must have a purpose, be planned around family needs, be flexible, involve the family in decisions, maintain confidentiality, use available resources and include health education.

1. Pre-visit planning: review records, set objectives, prepare the bag.
2. Initiation: greet, introduce yourself and build rapport.
3. Conduct: assessment, care, health teaching.
4. Termination: summarise and plan the next visit.
5. Recording and follow-up.

Bag technique is a tool for performing nursing procedures at home without spreading infection. Place the bag on a clean, flat surface on a newspaper or paper lining, wash hands before taking out articles, keep clean and used articles separate, and clean articles before putting them back.

Roles of CHO, ANM and ASHA

Worker	Main roles
Community Health Officer (CHO, mid-level health provider at AAM-SHC)	Team leader of the sub centre; delivers the expanded primary care packages; population-based screening for hypertension, diabetes and common cancers in adults aged 30 years and above; teleconsultation; dispensing essential medicines and point-of-care tests; supervision and mentoring of MPWs and ASHAs; reporting on the AAM portal
ANM / MPW (female)	Antenatal, intranatal and postnatal care, immunisation sessions, family planning services and counselling, newborn and child health, maintenance of registers, VHSND, disease surveillance
MPW (male)	Vector-borne and communicable disease control, sanitation, NCD screening support
ASHA	Link between community and health system; mobilises for ANC, institutional delivery and immunisation; home based newborn care visits; depot holder for ORS, condoms, oral pills and pregnancy kits; community-level screening using the CBAC form

Under Home Based Newborn Care, ASHA makes visits on days 3, 7, 14, 21, 28 and 42 after an institutional delivery, plus a day-1 visit after a home delivery. CHO aspirants should also read the CHO exam pattern and syllabus and CHO preparation strategy, and ANM aspirants the ANM preparation strategy.

Quick revision points

• Father of modern epidemiology: John Snow.
• Prevalence = Incidence x Mean duration.
• Cohort study gives relative risk; case-control study gives odds ratio.
• Immunisation is specific protection, a primary level of prevention.
• Screening is secondary prevention; rehabilitation is tertiary prevention.
• Sub centre population norm: 5,000 in plains, 3,000 in hilly and tribal areas.
• PHC: 30,000 in plains, 20,000 in hilly and tribal areas.
• CHC: 1,20,000 in plains, 80,000 in hilly and tribal areas.
• Health and Wellness Centres are now called Ayushman Arogya Mandir.
• Bhore Committee: 1946. Alma-Ata Declaration: 1978.
• One ASHA per 1,000 population.
• Residual chlorine after 1 hour contact: 0.5 mg/L.
• Vital layer of the slow sand filter: schmutzdecke.
• Bleaching powder has about 33% available chlorine.
• MMR is expressed per 1,00,000 live births; IMR per 1,000 live births.
• Replacement level TFR: 2.1.
• Demonstration is the best method to teach a skill.

Practise these facts in the CHO test series or the ANM test series. Maternal and child health topics continue in our obstetrics and gynaecology nursing notes and pediatric nursing notes.

Frequently asked questions

Which book is best for community health nursing?

Park’s Textbook of Preventive and Social Medicine is the standard reference for epidemiology, programmes and environmental health. Add a community health nursing textbook based on the INC syllabus and the latest IPHS and Ministry of Health guidelines for policy facts.

Is community health important for AIIMS NORCET?

Yes. It appears regularly, mainly through epidemiology, levels of prevention, rates, immunisation and environmental health. It is even more important for CHO and ANM exams, where it forms the core of the paper.

What is the new name of Health and Wellness Centres?

Ayushman Bharat Health and Wellness Centres were renamed Ayushman Arogya Mandir in 2023. Sub centres and PHCs functioning as these centres are referred to as AAM-SHC and AAM-PHC.

What are the population norms for SC, PHC and CHC?

As per IPHS 2022, a sub centre covers 5,000 people in plains (3,000 in hilly and tribal areas), a PHC covers 30,000 (20,000) and a CHC covers 1,20,000 (80,000).

How should I revise vital statistics?

Learn the formulas and denominators first, because most MCQs test whether a rate uses live births or the mid-year population. Then note the latest SRS values with their year, as these change with each release.