KONSEP DASAR EPIDEMIOLOGI 2/2014 DISIAPKAN OLEH PROF. DR.DRH.PRATIWI, TS. MS DRH.ROSITAWATI, I. MP 2/22/2014 PTS-RST-PKH- 2- 2014

Epidemiologic Triad Disease is the result of forces within a dynamic system consisting of: agent of infection host environment 2/22/2014 PTS-RST-PKH- 2- 2014

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Infectious disease Terminology untuk menggambarkan penyakit infeksi berkaitan dengan keadaan dan prevalensi penyakit pada populasi meliputi Infectivity Pathogenicity Virulence 2/22/2014 PTS-RST-PKH- 2- 2014

Factors Influencing Disease Transmission Agent Environment Weather Housing Geography Occupational setting Air quality Food Infectivity Pathogenicity Virulence Immunogenicity Antigenic stability Survival Age Sex Genotype Behaviour Nutritional status Health status Host 2/22/2014 PTS-RST-PKH- 2- 2014 (www)

Infectivity the percentage (or proportion) of individuals exposed to a particular agent who become infected No of infected following exposure Total of population at exposure Infectivity = 2/22/2014 PTS-RST-PKH- 2- 2014

Pathogenicity the percentage of infected individuals who develop clinical disease due to the particular agent Pathogenicity = No of clinically affected following exposure Total of infected at exposure 2/22/2014 PTS-RST-PKH- 2- 2014

Virulence the percentage of individuals with clinical disease who become serious ill or die Virulence = No of severe (fatal) cases following exposure Total of clinically infected cases at exposure 2/22/2014 PTS-RST-PKH- 2- 2014

Agents Biological Chemical Physical Viruses Bacteria Parasites or prions Chemical Toxins Man-made (Dioxins and melamine) Inorganic/organic: zearalenone Physical Foreign bodies Trauma Radiation 2/22/2014 PTS-RST-PKH- 2- 2014

Natural host: Atypical host: Agent Factors Host Dose Environmental hardiness Virulence (microbial) Infectivity (microbial) Toxicity (poisons) Natural host: agent has adapted itself and co-exists in balance in the host Atypical host: agent is not normally encountered 2/22/2014 PTS-RST-PKH- 2- 2014

Herd immunity Susceptibility Host Host Innate (genetic capability) Demography Age, Sex, Species, Breed Production type / level, Density Biology Genetics, behavior Management Intensive (housing) / extensive (free roaming) Nutrition Hygiene Husbandry Vaccination / medication Herd immunity Innate (genetic capability) Acquired through vaccination or deliberate exposure Proportion of total population that is resistant to a disease agent Susceptibility Lack of resistance to the disease agent 2/22/2014 PTS-RST-PKH- 2- 2014

Host Factors Behavior (e.g. mutual grooming, dominance, pica) Innate resistance (e.g. gastric barrier, mucocilliary transport mechanism) Previous exposure Passive immune status (neonates) Vaccination status and response Age Gender Behavior (e.g. mutual grooming, dominance, pica) Production status (e.g., lactating vs. non- lactating) Reproductive status (e.g., pregnant vs. non- pregnant, sterile vs. intact) Genetics Host Factors 2/22/2014 PTS-RST-PKH- 2- 2014

Epidemiologic Triad-Related Concepts Infectivity (ability to infect) (number infected / number susceptible) x 100 Pathogenicity (ability to cause disease) (number with clinical disease / number infected) x 100 Virulence (ability to cause death) (number of deaths / number with disease) x 100 All are dependent on host factors 2/22/2014 PTS-RST-PKH- 2- 2014

Predisposition to Infections (Host Factors) Gender Genetics Climate and Weather Nutrition, Stress, Sleep Smoking Stomach Acidity Hygiene 2/22/2014 PTS-RST-PKH- 2- 2014

Ecological Factors in Infections Altered environment {Air conditioning} Changes in food production & handling {intensive husbandry with antibiotic protection; deep-freeze; fast food industry} Climate changes {Global warming} Deforestation Ownership of (exotic) pets Air travel & Exotic journeys / Global movements Increased use of immunosuppressives/ antibiotics 2/22/2014 PTS-RST-PKH- 2- 2014

Dua (2) Jenis studi epidemiologi Deskriptif Analitik Menelaah distribusi suatu penyakit pada suatu populasi & mengamati gambaran mendasar sebarannya menurut waktu – tempat – individu terserang Desain studi: Sigi kesehatan ‘masyarakat’ (≈ studi cross sectional, studi deskriptif Menguji hipotesis tentang hubungan antara kejadian penyakit dengan kemungkinan penyebabnya, melalui pelaksanaan studi epidemiologi yang menghubungkan exposure dengan penyakit yang diduga Desain studi: Cohort, case-control Dua (2) Jenis studi epidemiologi 2/22/2014 PTS-RST-PKH- 2- 2014

2/22/2014 PTS-RST-PKH- 2- 2014 Agen Nutrients Poisons Allergens Radiation Physical trauma Faktor Lingkungan Kepadatan Atmosfir Modus komunikasi (vector, vehicle, reservoir) Faktor Inang Genetic endowment Immunologic state Age Personal behaviour 2/22/2014 PTS-RST-PKH- 2- 2014

KONSEP EPID DALAM POPULASI 2/22/2014 PTS-RST-PKH- 2- 2014

TRIAD dasar epidemiologi deskriptif Tiga karakteristik esensial kejadian suatu penyakit yang berusaha dielusidasi dalam epidemiologi deskriptif Waktu Tempat Individu TRIAD dasar epidemiologi deskriptif 2/22/2014 PTS-RST-PKH- 2- 2014

2/22/2014 PTS-RST-PKH- 2- 2014 Waktu Berubah atau stabil? topografi Variasi musiman Clustered (epidemic) or evenly (endemic) distributed Point source or propagated Tempat Secara geografis terbatas atau tersebar (pandemi) Berhubungan dengan suplai air/pakan? Multiple cluster or one? Individu Spesies Bangsa/Ras Umur Kelamin 2/22/2014 PTS-RST-PKH- 2- 2014

TRIAD dasar epidemiologi analitik Tiga phenomena yang dikaji dalam epidemiologi analitik Inang Lingkungan Agen Catatan: ingat terminologi necessary – sufficient - contributory TRIAD dasar epidemiologi analitik 2/22/2014 PTS-RST-PKH- 2- 2014

2/22/2014 PTS-RST-PKH- 2- 2014 Agen Nutrients Poisons Allergens Radiation Physical trauma Faktor Lingkungan Kepadatan Atmosfir Modus komunikasi (vector, vehicle, reservoir) Faktor Inang Genetic endowment Immunologic state Age Personal behaviour 2/22/2014 PTS-RST-PKH- 2- 2014

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Penularan Penyakit Vertikal horizontal langsung tidak langsung media penularan vektor mekanik daur hidup 2/22/2014 PTS-RST-PKH- 2- 2014

Infectious Disease Definitions Note Infectious diseases Caused by an infectious agent Communicable diseases Transmission – directly or indirectly – from an infected person Transmissible diseases Transmission – through unnatural routes – from an infected person Note Infections are often subclinical – infections vs infectious diseases! Antonyms not well-defined Non-communicable diseases – virus involved in pathogenesis of diabetes? Chronic diseases – HIV? Tetanus Measles vCJD 2/22/2014 PTS-RST-PKH- 2- 2014 (www)

Transmission Cases Index – the first case identified Primary – the case that brings the infection into a population Secondary – infected by a primary case Tertiary – infected by a secondary case P S T Susceptible Immune Sub-clinical Clinical 2/22/2014 PTS-RST-PKH- 2- 2014 (www)

Chain of transmission Mode of Transmission Direct Direct contact Secretions, Blood, Faeces/urine Droplet spread Indirect Food/water Aerosol Animal vectors Fomites Medical devices and treatments 2/22/2014 PTS-RST-PKH- 2- 2014

Chain of transmission Reservoir Human Person with symptomatic illness Carriers: Asymptomatic Incubating Convalescent Chronic Animal: zoonosis Environmental: soil, plant, water 2/22/2014 PTS-RST-PKH- 2- 2014

Chain of transmission Portal of exit Human/animal Respiratory tract Genito-Urinary tract Faeces Saliva Skin (exanthema, cuts, needles, blood-sucking arthropods) Conjunctival secretions Placenta Environmental Cooling towers 2/22/2014 PTS-RST-PKH- 2- 2014

Chain of transmission Portal of entry Mouth (faecal-oral transmission) Respiratory tract Mouth (faecal-oral transmission) Skin Mucous membranes Blood 2/22/2014 PTS-RST-PKH- 2- 2014

Chain of transmission Mode of Transmission Indirect Food/water Aerosol Animal vectors Fomites Medical devices and treatments 2/22/2014 PTS-RST-PKH- 2- 2014

Chain of transmission Mode of Transmission Direct contact Secretions, Blood, Faeces/urine Droplet spread 2/22/2014 PTS-RST-PKH- 2- 2014

Chain of Transmission Reservoir Susceptible Host Agent Person to person transmission Reservoir Susceptible Host Portal of exit Portal of entry Agent 2/22/2014 PTS-RST-PKH- 2- 2014 Mode of transmission

Chain of transmission Portal of exit Human/animal Respiratory tract Genito-Urinary tract Faeces Saliva Skin (exanthema, cuts, needles, blood-sucking arthropods) Conjunctival secretions Placenta Environmental Cooling towers 2/22/2014 PTS-RST-PKH- 2- 2014

Routes of transmission Direct Skin-skin Herpes type 1 Mucous-mucous STI Across placenta toxoplasmosis Through breast milk HIV Sneeze-cough Influenza Indirect Food-borne Salmonella Water-borne Hepatitis A Vector-borne Malaria Air-borne Chickenpox Ting-borne Scarlatina Exposure A relevant contact – depends on the agent Skin, sexual intercourse, water contact, etc 2/22/2014 PTS-RST-PKH- 2- 2014 (www)

Sampai jumpa minggu ke 3 2/22/2014 PTS-RST-PKH- 2- 2014