L4.pdf Epidemiology Past Paper PDF

Lesson 4 – Epidemiology – Recapped – Health Informa on Systems (HIS) HIS – Systems that allows es ma ng the size and trend of health problems in the community HIS helps to: - Iden fy the facts - Collect data - Verify - Analyse - Disseminate-distribute results and nece...

Lesson 4 – Epidemiology – Recapped – Health Informa on Systems (HIS) HIS – Systems that allows es ma ng the size and trend of health problems in the community HIS helps to: - Iden fy the facts - Collect data - Verify - Analyse - Disseminate-distribute results and necessary recommenda ons It is a dynamic system of con nuous surveillance of the onset and distribu on of diseases and phenomena that increase the risk of disease. A set of informa on sub-systems designed for the implementa on of specific disease control programs. Allows you to assess priori es and decide how to meet them and to subsequently measure the results of your ac on. Uses of HIS - Es mate the magnitude and trend of a health problem - Impact assessment of interven ons - Transmit informa on to: ci zens, government and decision makers - Classified into: o Popula on-based: Informa on coming from all individuals o Health informa on systems based on health services: Informa on coming from users of health services HIS in public health: - Surveys (info collected me to me) o Interview surveys o Medical examina on surveys o General surveys o (applied to a large group of people from a whole country or from a sample) o Ques onnaire – Qs. Can be open or closed o Objec ve: Incidence, Prevalence, Frequency - Records (info collected con nuously) o Mortality record o Birth record o Record of fetal deaths o Disease record - No fica on systems (info collected passively, need someone to tell us info) o Vic ms of traffic accidents o Vic ms of accidents at work o Occupa onal diseases No fica on systems - Mandatory no fying diseases (MND) (EDO)  - Drug abuse repor ng system - Pregnancy interrup on (abor ons) Stages in the design of a ques onnaire - Define the informa on we need to find out - Choose the type of ques onnaire to be used. - Define ques ons for each variable - Ask the most essen al research ques ons - Avoid ambiguous ques ons - Short Dynamic, simple and logical order. - Must contain filter ques ons for follow-up ques ons (to test if person is telling the truth - Establish order of the ques ons - Start with general ques ons and topics of greater interest. - Define Grading and coding norms (each answer will be transformed into a number Reliability: ability to reproduce the same results, when we repeat the ques onnaire. Validity: ability to measure what we intend measure Pilot test – test we do on a small group of people before we do it on a large group of people. (trial) Likert Scale: used to assess subjec ve aspects and transform them into a number. (objec ve) Health informa on systems based on health services - Records: minimum set of hospital data. Example: HIV/AIDS registry. - Surveys: hospital morbidity (how many people are ill) surveys - No fica on systems: o Mandatory no fica on diseases (MND) (EDO) o Drug dependence repor ng system o Pregnancy interrup on Surveillance systems are used to control communicable disease. - MND (Mandatory no fica on diseases) o Urgent, Nominal and Numerical – (15 diseases, cholera, yellow fever …) o Non-urgent, nominal and numerical – (e.g. hepa s B) o Weekly declara on – (influenza, syphilis, chicken pox) MND - Mandatory repor ng refers to new cases of these diseases seen during the week. - Week is the me unit. - Repor ng modali es (method used for repor ng): Manual and computerised survey - Repor ng is by primary and specialised care upwards to the ministry of health. Objec ve of Epidemiological surveillance - Iden fy health problems - Guidance and enhance of public health interven ons - Sugges ng hypothesis for epidemiological research Ac vi es of Epidemiological surveillance system - Systema c collec on of relevant data and iden fica on of data sources. - Analysis, evalua on and interpreta on of data - Distribu on of informa on and recommenda ons to professionals involved in different stages of epidemiological surveillance. Usefulness of epidemiological surveillance system. - Contributes to preven on and control of disease. - Used to determine whether a disease previously considered unimportant. A ributes of ES: - Qualita ve: Simplicity, Flexibility, Acceptability - Quan ta ve – Sensi ve, Representa veness, Fast, Cost Diseases analysed in the ES: - Infec ous diseases (Influenza) - Food-Borne and water-borne diseases (Salmonellosis) - Airborne diseases (tuberculosis) - Vector-borne diseases - Sexually and parenterally transmi ed diseases - Zoonosis (from animal to human) - Vaccine-preventable diseases (influenza) - Human transmissible spongiform encephalopathies (mad cow diseases) Outbreak or epidemic situa on MND - Relevant increase in the number of cases in rela on to expected values - Appearance of a disease, health problem or risk in an area un l then free of it. - Presence of any relevant event of collec ve acute intoxica on due to accident, handling or consump on. - Occurrence of a catastrophe that can affect community health. (Earthquakes, hurricanes, heavy rain) Working procedures in a outbreak: 1. Confirm existence of outbreak 2. Define and iden fy cases 3. Literature review 4. Organise a working team 5. Epidemiological survey 6. Epidemiological descrip on of the outbreak. Epidemic curve 7. Formula on of hypothesis 8. Test the hypothesis by: a. Clinical-epidemiological studies b. Laboratory and/or environment studies 9. Evaluate the hypothesis. Interpret data. 10. Implement preven on and control measures 11. Communicate findings. Different parts of disease iden fica on, monitoring and control in public health: 1. Clinical defini on of a case a. Meaning: this is a set of clinical symptoms and criteria used to iden fy whether a person has the disease. b. Sensi vity: The defini on should iden fy as many cases as possible c. Specific: Defini on should exclude individuals that do not have the disease. 2. Laboratory Diagnos c criteria a. Meaning: scien fic tests or procedures used to confirm a diagnosis by detec ng the germ in a sample from the body b. Example: Iden fica on of a virus or bacteria in a lab test confirms the presence of the disease. 3. Classifica on of cases a. Suspicious: person has symptoms that fit the clinical defini on of the disease but no further evidence b. Probable: person meets the clinical defini on and has epidemiological link. c. Confirmed: case meets the clinical defini on and has been verified by laboratory tests 4. Methods of surveillance a. Meaning: systems and processes used to track and monitor the spread of disease. b. Mode of no fica ons: how cases are reported c. Epidemiological survey: addi on data collected through charts or reports to track the outbreak and understand pa erns of disease spread. 5. Control methods a. Meaning: strategies for preven ng the spread of the disease and managing infected individuals. b. Preven ve measures: ac ons to stop new cases c. Control of pa ents: managing confirmed cases Microbiological surveillance network (Red MIVA) - AKA Red de Vigilancia Microbiologica - Informa on system of the Conselleria de sanitate, designed for surveillance and research. - Responsible of collec ng microbiological results from hospitals in the CV, storing and analysing them in a centralised system and subsequently dissemina ng the informa on generated to the target popula on. Red MIVA objec ves - Detect on real me circula on of e ological agents - Detect epidemic outbreaks - Iden fy emergent diseases - Define resistance models to an microbial agents. - Help decision making to hospitals commi ees in charge of treatment and control of infec ous diseases. - An microbial treatment and diagnosis orienta on directed to physicians - Internet issuing of relevant data of public interest. Red MIVA steps: 1. Physician send request to the microbiology laboratories, where the analyses are carried out and the results are stored 2. Daily microbiological laboratories send the analysis results from their systems to central systems 3. Sending is done through automa c processes that encrypts the informa on and secures the communica on channel. 4. Data must be sent in a common language defined in XML. 5. Informa on is standardized. 6. System then tries complete the pa ent’s data by consul ng the hospital admission system and the popula on informa on system 7. Each case is carefully classified, determining its geographical loca on 8. Number of cases and the rate are obtained for each disease, microorganism and geographical area 9. Analysed info can be visualised in weekly loca on map 10. An expert system collects info from hospital and studies it to detect cases