Community medicine 1 (1).txt

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Community medicine 1 (1).txt
2014-12-20 11:34:42
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  1. If alternate to medicine were accepted as a modality of therapy, then 'Yoga' would be best described as a form of [AI 12]
    A) Physiotherapy 
    B) Emergency medicine 
    C) Caloric usurper
    D) Preventive medicine
    D) Preventive medicine

    Yoga is a practice that involves training of the mind, body and breathing to deliver various health benefits.
    Regular practice of Yoga can be best defined as a form of 'Preventive Medicine' that has shown benefecial effect on several ailments including  backache, anxiety, headache, hypertension etc.
    (this multiple choice question has been scrambled)
  2. What is natural history of  disease? [IOM 96]
    Natural history of disease signifies the way in which a disease evolves over time from the earliest stage of its prepathogenesis phase to its termination as recovery, disability or death, in the absence of treatment or prevention.
  3. What are the phases of natural history of disease?
    The natural history of disease consists of two phases:

    a) Prepathogenesis  phase - This refers to the period before the onset of disease in man. The disease has not yet entered man but the factors which favor its interaction with the human host exists in the environment. The epidemiological triad (Agent, Host and Environment factors) are present and are interacting to initiate the disease in man. Intervention at this stage include Primary Prevention in the form of health promotion and specific protection.

    b) Pathogenesis phase - This refers to the period after the onset of disease in man. The disease has already entered the susceptible host. However at this stage the host's reaction to infection with the disease is not predictable. The infection at this stage may be clinical, or subclinical, typical or atypical. Interventions at this stage include Early diagnosis and treatment (screening is useful)  or Tertiary Prevention with Disability Limitation and rehabilitation.
  4. In the Natural History of Disease, all of the following statements about the 'Period of Pathogenesis' are true except [AI 12]
    A) Occurs after agent enters the host 
    B) Tertiary prevention is possible at this stage 
    C) Subclinical Phase may be present 
    D) Screening has no role in this phase
    D) Screening has no role in this phase
    (this multiple choice question has been scrambled)
  5. What is iceberg phenomenon in disease?
    • Disease in community is just like an iceberg.
    • The floating tip of  the iceberg represents clinical cases, while the vast submerged portion represents  the hidden mass of disease.
    • This phenomenon is commonly seen in the following diseases 
    • - Anemia
    • - Mental illness 
    • - Hypertension
    • - Protein energy malnutrition  [UP 94] 
    • - Diabetes
  6. Iceberg phenomenon differentiates [AI 08]
    A) Diagnosed and undiagnosed
    B) Cases and carriers 
    C) Apparent and inapparent 
    D) Symptomatic and asymptomatic 
    C) Apparent and inapparent

    According to this concept, disease in a community may be compared with an iceberg. The floating tip of the iceberg represents what the physician sees in the communily, i.e., clinical cases. The vast submerged portion of the iceberg represents the hidden mass of disease, i.e., latent, inapparent, presymptomatic and undiagnosed cases and carriers in the community. The "waterline" represents the demarcation between apparent and inapparent disease.
    (this multiple choice question has been scrambled)
  7. What is disease control, elimination and eradication?
    Disease control refers to the reduction of disease incidence, prevalence, morbidity and mortality to a locally acceptable level as a result of deliberate efforts. Continued intervention methods are required. Disease transmission is not stopped (but reduced) and agent persists. 

    Disease elimination refers to the reduction of a specified disease incidence to 'zero' in a defined geographical area as a result of deliberate efforts. Continued intervention methods are required. Disease transmission is stopped (zero incidence) but agent persists. [AI 12] 

    Disease eradication has been defined as extinction of the disease pathogen. Continued intervention methods are not required. Disease transmission is stopped and 'agent' is eliminated/extinct.

    [@ eradicate - from radicle (root)]
  8. What are the diseases that are amenable to eradication? [KARNATAKA 01]
    • Measles 
    • Diphtheria 
    • Guinea worm
    • Polio [PGI 01] 
    • [@ MDGP]
  9. What is Epidemic, Pandemic and Endemic?
    • Epidemic - excess of expectation of disease. 
    • Pandemic – worldwide epidemic of disease 
    • Endemic – expected rate of disease that is constantly present. [AI 05] 
    • Exotic - disease which are imported into a country in which they do not otherwise occur. [UP 93]
  10. What is Primary case, Secondary case and Index case?
    Primary case - first case of communicable disease introduced into the population unit being studied. [IOM 96] 

    Secondary cases are those developing from contact with primary case.  [KARNARAKA 01] 

    • INdex case  - is the first case to come to the attention of the INvestigator [IOM 96,97,07].
    • It is not always the primary case.
  11. What is Bradford Hill Criteria?  [AI 08,09]
    • Bradford Hill criteria  point out that the likelihood of a causal relationship is increased by the presence of the following criteria:
    • 1. Temporal association
    • 2. Strength of association
    • 3. Specificity of the association
    • 4. Consistency of the association
    • 5. Biological plausibility
    • 6. Coherence of the association
  12. What are various types of epidemics?
    Three major types of epidemics may be distinguished:

    • A. Common - source epidemics
    • (a) Single exposure or "point source" epidemics. – Bhopal gas tragedy in India [UP 1996, AI 1999], Minamata disease in Japan resulting from consumption of fish containing high concentration of methyl mercury, Chernobyl tragedy in Ukraine (nuclear accident)
    • (b) Continuous or multiple exposure epidemics - Legionnaire’s disease in Philadelphia

    • B. Propagated epidemics - epidemic in hepatitis A and Polio. 
    • (a) Person-to-person
    • (b) Arthrpod vector
    • (c) Animal reservoir

    C. Slow (modern) epidemics
  13. What are the features  of point source epidemics? [SGPGI 02]
    • The exposure to the disease  is brief and essentially simulataneously, the resultant cases all develop within one incubation period of the disease
    • The  curve has usually one peak. 

    • The main features of point source epidemic are:
    • – the epidemic curve rises and  falls rapidly with no secondary waves
    • - the epidemic tends to be explosive, there is clustering of cases within a narrow interval of time
    • - all cases develop within one incubation period of disease
  14. What are the features of propagated epidemic? [AI 2000]
    • Propagated epidemic is most often of infectious origin. 
    • It results from person to person transmission of infectious agent. 

    The epidemic  usually shows a gradual rise and  tails off over a much longer period of time. 

    The speed of spread depends upon herd immunity,  opportunities for contact and seconday attack rate.

    Secondary waves are present.
  15. What are the various types of periodic fluctuation?
    Seasonal trend - related to environmental conditions [AI 2001]
  16. What are the different levels of prevention?
    • A. Primordial prevention:
    • Prevention of risk factors.
    • - It deals with individuals without risk factors. [AI 00]
    • - Intervention method is Health education. 

    • B. Primary prevention:
    • Prevent disease occurrence and  action taken prior to the onset of disease.
    • - It prevents incidence.
    • - Intervention method is health promotion and specific protection. E.g. exercise promotion, reduction of salt, and weight reduction to prevent hypertension. [AI 97]
    • - It deals with individuals with risk factors.  

    • C. Secondary prevention:
    • - Screening early for disease.
    • - Intervention involves early diagnosis and prompt treatment.
    • - It prevents prevalence.

    • D. Tertiary prevention:
    • - Treatment to reduce disability from disease (e.g., chemotherapy).
    • - Intervention involves disability limitation and rehabilitation.
  17. Give examples of  specific protection?
    • To avoid disease altogether is the ideal but this  is possible only in a limited number of cases.
    • The following are some of the currently available interventions aimed at specific protection:  
    • a. immunization
    • b. use of specific nutrients like iron and folic acids [AI 02] and vitamin A [AI 09]  
    • c. chemoprophylaxis  
    • d. protection against occupational hazards  
    • e. protection against accidents
    • f. protection from carcinogens
    • g. avoidance of allergens  
    • h. the control of specific hazards  in  the general environment,  e.g., air pollution, noise control  
    • i. control of consumer product quality and safety of foods, drugs, cosmetics, etc.
  18. What is quarantine?  How does it differ from Isolation?
    • Quarantine is the limitation of freedom of movement of such well persons or  domestic animals exposed to communicable disease for a period of time not longer than the longest period of disease. 
    • It may be absolute quarantine as defined as above or modified quarantine such as exclusion of children from school. 
    • In contrast to isolation, quarantine applies to restriction on the healthy contacts of an infectious disease. [AIIMS 2004]
  19. What are the diseases is which isolation is strictly recommended?
    • Diphtheria 
    • Cholera 
    • Streptococcal respiratory infection 
    • Pneumonic plague [AI 08]
  20. What are health promotion strategies?
    • It is the method of enabling people to increase control over, and to improve health.
    • It is not directed against any specific disease, [KARNATAKA 2001] but is intended to strengthen the host through a variety of approaches.
    • These intervention include:
    • - Health education
    • - Environmental modifications
    • - Nutritional interventions 
    • - Lifestyle and behavioral changes
  21. What is secondary attack rate?
    • The number of exposed persons developing the disease within the range of the incubation period, following exposure to the primary case.
    • It is a important measure of communicability. [IOM 2054]
    • It also measures virulence of disease. [KARNATAKA 2001]
    • It is given by formula:

    SAR = (number of exposed persons developing the disease within the range of the incubation period/ Total number of  exposed/susceptible contacts[AI 2003] ) X 100.  

    Supposing  there  is a family of 6 consisting  of 2 parents  already  immune)  and 4 children who are susceptible  to a  specific  disease, say measles. There  occurs a primary case and within a short  time 2 secondary  cases among  the  remaining  children. The secondary  attack rate  is 2/3 or 66.6 percent. The primary case is excluded   from both numerator and  denominator.

    • - If in among 72 children, 2 have measles, and subsequently 14 acquire measles, the SAR will be: [AI 02]
    • = 14/(72-2) X 100%
    • = 20%
  22. What is latent period?
    • It is defined as the period from disease initiation to disease detection.[KARNATAKA 2001]
    • Latent period is used in non-infectious diseases (cancer, heart disease, mental illness) as the equivalent of incubation period in infectious disease.
  23. What  is median incubation period?  [IOM 2067]
    It is the time required for 50% of the cases to show signs and symptoms following exposure.
  24. What is Serial interval, Generation time and Communicable period?
    Serial interval: The gap in time between the onset of the primary case and secondary case. [AI 02, AIIMS 02] 

    Generation time: the interval of time between receipt of infection by a host and maximal infectivity of that host. [AIIMS 96, KARNATAKA 00] 

    • Communicable period: the time during which an infectious agent may be transferred directly or indirectly from an infected person to another person, from an infected animal to man or from an infected person to an animal, including arthropods.
    • It varies in different disease. [KARNATAKA 01]
    • It bears absolutely no relation to the incubation period [AI 04], and may occur during the incubation period or during the actual illness.
  25. What are healthy carriers?
    • Healthy carriers emerge from subclinical cases.
    • They are victims of subclinical infection who have developed carrier state without suffering from overt disease, but are shedding the disease agent. E.g. Poliomyelitis, Cholera, Meningococcal meningitis, Salmonellosis, Diphtheria

    Healthy carriers are not seen in measles. [AI 02]
  26. What are convalescent carriers?
    • Those who continue to shed the disease agent during the period of convalescence, e.g typhoid fever, desentry, cholera, diphtheria, whooping cough.
    • In these diseases, clinical recovery doesnot coincide with bacteriological recovery.
    • A convalescent carrier can pose a serious threat to the unprotected household members and those in the immediate environment, as in the case of a typhoid fever patient who may excrete the bacilli for 6-8 weeks.
    • This highlights the importance of bacteriological surveillance of carriers, after clinical recovery.
  27. Name zoontic diseases.  [AI 08]
    • Bacteria - Anthrax, Brucellosis, Q fever, Leptospirosis, Tuberculosis, Plaque 
    • Viral - Yellow fever, Japanese encephalitis, Rabies
    • Protozoan - Leishmaniasis, Toxoplasmosis, Trypanosomiasis, Babesiosis
    • Helminthic - Fasciopsis, Taeniasis, Trichenellosis
  28. Which diseases were the target diseases for which CB-IMCI iniatiative was taken?
    • The CB-IMCI initiative was take to prevent morbidity and mortality from five major childhood conditions. They are - [AI 08] 
    • - Diarrhoea 
    • - Acute respiratory tract infections (includes ottitis media
    • - Malaria 
    • - Measles 
    • - Malnutrition 
    • [@ 3MAD
  29. What is herd immunity?
    • Herd immunity is the level of resistance of a community or group of people to a particular disease. It concerns the freedom form infection of individuals within a herd by sole virtue of the influence of the herd structure. 
    • Elements which contribute to herd immunity are: [AI 05] 
    • - Clinical and subclinical infection in herd (Builds up herd immunity) 
    • - Immunization to herd 
    • - Herd structure 
    • Herd immunity is more for infections that have a subclinical phase.
    • Herd structure includes the host population, the animal hosts (and insect vectors), environmental factors and social factors that favor or inhibit spread of infection from host to host.
    • It is never constant. It is subject to constant variations because of new births, deaths and population mobility.
  30. What are the implications of Herd immunity?
    • Herd immunity predicts occurrence of epidemics. If herd immunity is significantly high, the occurrence of epidemics is highly unlikely. 
    • Herd immunity may lead to elimination of disease. 

    • Notes: 
    • - Diphtheria and Poliomyelitis may be eliminated by stepping up herd immunity. 
    • - Small pox was eliminated by elimination of infection and not by herd immunity. 
    • - Herd immunity does not protect individual in case of tetanus. [KERELA 91]
  31. All of the following statements are true for Herd immunity except [AI 07]
    A) Herd immunity is constant 
    B) It is mostly due to subclinical infection
    C) Can be acquired by immunization 
    D) Spread of epidemic is influenced by it
    A) Herd immunity is constant
    (this multiple choice question has been scrambled)
  32. What is most common mode of transmission of Nosocomial infections? [JIPMER 95]
    The most common route of infection is via hands. Thus, hand washing is the best method to prevent cross infection occurring in other patients in the same ward. [AI 03]