Community Medicine
Epidemiology of Communicable and Non-Communicable Diseases
Community medicine notes on communicable and non-communicable diseases for MBBS: chain of infection, TB, leprosy and malaria programmes, NCD risk factors and screening, mapped to NMC codes CM8.1 to CM8.7.
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Epidemiology of Communicable and Non-Communicable Diseases
Community medicine notes on communicable and non-communicable diseases for MBBS: chain of infection, TB, leprosy and malaria programmes, NCD risk factors and screening, mapped to NMC codes CM8.1 to CM8.7.
This chapter applies epidemiological principles to specific diseases, covering the chain of infection and the national programmes for tuberculosis, leprosy and malaria. It then turns to non-communicable diseases, their shared risk factors and the population and high-risk prevention strategies that underpin national screening programmes.
High-yield: Epidemiology of Communicable and Non-Communicable Diseases
- The chain of infection runs from reservoir to portal of exit, mode of transmission, portal of entry and susceptible host.
- The National Tuberculosis Elimination Programme uses daily fixed-dose regimens and aims to end tuberculosis in India ahead of the global target.
- Tuberculosis is diagnosed by sputum microscopy and rapid molecular tests such as cartridge-based nucleic acid amplification.
- The National Leprosy Eradication Programme uses multidrug therapy, and a single skin patch with loss of sensation is a classic sign.
- Malaria control relies on early diagnosis with rapid tests, prompt treatment and vector control under the national programme.
- The Revised National Tuberculosis and other disease programmes are increasingly integrated under the Integrated Disease Surveillance Programme.
- The four common non-communicable diseases are cardiovascular disease, diabetes, chronic respiratory disease and cancer, sharing four risk factors.
- The four shared modifiable risk factors are tobacco use, harmful alcohol use, unhealthy diet and physical inactivity.
- The National Programme for Prevention and Control of Non-Communicable Diseases screens adults over thirty for hypertension, diabetes and common cancers.
- Population and high-risk strategies are complementary approaches to preventing non-communicable disease.
- Herd immunity is the resistance of a population to an infection when a high proportion is immune, protecting the susceptible minority.
- Surveillance is the continuous scrutiny of disease occurrence to enable timely public health action.
- Immunising agents include live attenuated, killed, toxoid and subunit vaccines, each with its own cold chain needs.
- Case fatality rate measures the severity of a disease as deaths among diagnosed cases, distinct from the mortality rate in the population.
Non-communicable disease essentials
- **The four diseases:** Cardiovascular disease, diabetes, chronic respiratory disease and cancer account for most NCD burden.
- **Shared risk factors:** Tobacco, harmful alcohol, unhealthy diet and physical inactivity are the four common modifiable factors.
- **National programme:** NP-NCD screens adults over thirty for hypertension, diabetes, and oral, breast and cervical cancer.
- **Prevention strategy:** Population approach shifts whole-population risk; high-risk approach targets the most susceptible individuals.
NMC competencies in this chapter
- **CM8.1:** Epidemiology and control of communicable diseases at primary level
- **CM8.2:** Epidemiology and control of non-communicable diseases at primary level
- **CM8.3:** Disease-specific national health programmes and their treatment protocols
- **CM8.4:** Principles and measures to control a disease epidemic
- **CM8.5:** Planning, implementing and evaluating disease control at community level
- **CM8.6:** Training health workers in surveillance, control and health education
- **CM8.7:** Principles of management of information systems
Frequently Asked Questions
What are the four common non-communicable diseases and their shared risk factors?
The four are cardiovascular disease, diabetes, chronic respiratory disease and cancer, and they share four modifiable risk factors: tobacco use, harmful use of alcohol, unhealthy diet and physical inactivity.
How does the National Tuberculosis Elimination Programme diagnose and treat tuberculosis?
It uses sputum smear microscopy and rapid molecular tests such as cartridge-based nucleic acid amplification for diagnosis, and treats patients with daily fixed-dose combination regimens while aiming to eliminate tuberculosis in India.
What is herd immunity?
Herd immunity is the resistance of a whole community to the spread of an infectious agent when a sufficiently high proportion of the population is immune, which indirectly protects the susceptible individuals who are not immune.
What is the difference between case fatality rate and mortality rate?
Case fatality rate is the proportion of diagnosed cases that die and measures disease severity, whereas the mortality rate is the number of deaths in the whole population, reflecting the overall impact of the disease.
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