Control of Communicable Diseases Ahmed Mandil Prof of
Control of Communicable Diseases Ahmed Mandil Prof of Epidemiology KSU College of Medicine
Headlines • Aims of Communicable Disease Control • Measures towards: reservoir, contacts, carriers, environment • Outbreak control • Examples 9/26/2020 CD Control 2
Aims of CD control • Eradication of the disease, if possible. This may • • indicate complete extinction of its agents, reservoir or vectors. It also means complete prevention of transmission. If eradication is not possible, then transmission could be reduced, in order to control morbidity (elimination) If the latter cannot be achieved, we try to reduce severity and gravity of the disease (control) 9/26/2020 CD Control 3
Measures towards reservoir (1) 1. Eradication: Extinction of animal reservoirs has been successful with diseases as bovine T. B. and rabies in several countries. Such procedure is only possible for domestic animals, while it is difficult or almost impossible for wild animals (e. g. in jungle yellow fever, some sylvatic/wild reservoirs of leishmaniasis) 9/26/2020 CD Control 4
Measures towards reservoir (2) 2. Reduction of communicability: (A) Segregation of cases: This means that the patient is isolated from the community in a fashion that prevents direct and indirect spread of the infectious agent. This is usually done for a period which equals the "period of communicability", at hospital or at home. Ideally, repeated negative samples from the patient are needed before his (her) release. 9/26/2020 CD Control 5
Measures towards reservoir (3) (B) Treatment of cases: Early diagnosis and prompt treatment of infections with the appropriate regimens (e. g. antibiotics or chemotherapeutic agents) helps reducing communicability very much 3. Disinfection: Disinfection of the soiled articles by the patient discharges concurrently (during his presence) and/or terminally (e. g. after discharge from the hospital) helps in reduction of communicability. 9/26/2020 CD Control 6
Measures towards carriers Detection and control of carriers would be worthwhile in the following conditions: (A) If they represent important reservoirs of infection. (B) If their proportion in the community is small. (C) If they were suspected in a closed community, such as a boarding school or army barracks 9/26/2020 CD Control 7
Measures towards contacts (1) After enlistment the following procedures could be applied: a. Surveillance: This means close medical supervision of the contacts, without restricting their movement, for the purpose of early detection of the disease in question. This should be for the longest incubation period. 9/26/2020 CD Control 8
Measures towards contacts (2) b. Quarantine: This is only done for a limited number of diseases nowadays such as pneumonic plague and pneumonic anthrax. It implies restriction of the movement of all those exposed to a case of such a disease, in order to prevent their contact with those not exposed. It also allows early detection of the disease among these individuals. It is done also for a period equaling the longest incubation period. 9/26/2020 CD Control 9
Measures towards contacts (3) c. Increasing the resistance of susceptibles: This is done either through active &/or passive immunization, or chemoprophylaxis. The choice of the measure is disease dependent. The value of immunization of contacts in preventing disease depends on the relation between the incubation period and the time needed to develop immunity. 9/26/2020 CD Control 10
Measures towards contacts (4) d. Disinfestation: which is useful in diseases transmitted by insects to contacts, as in louse-borne typhus. 9/26/2020 CD Control 11
Measures towards environment (1) • Reduction of overcrowding (better housing conditions) • Environmental sanitation (e. g. sanitary sewage disposal, sanitary refuse disposal, sanitary water supply, • Vector control (insecticiding: directly or through aerial spraying techniques, mosquito-nets, insect repellents, etc. ) 9/26/2020 CD Control 12
Measures towards environment (2) • Personal hygiene (cleanliness, hand- washing, regular bathing) • National/international measures: which include different public health measures undertaken within and between countries, in order to protect the individual and the community at large, from different communicable diseases. 9/26/2020 CD Control 13
Outbreak Control • An outbreak is occurrence of a number of cases of a disease that is unusually large or unexpected for a given place and time. ØOutbreaks in emergency situations can spread rapidly giving rise to high morbidity and mortality rates. ØAim should be to detect and control the outbreak as early as possible. 9/26/2020 CD Control 14
Steps in the management of a communicable disease outbreak 1. Preparation 2. Detection 3. Response 4. Evaluation 9/26/2020 CD Control 15
Preparation • Health coordination meetings • Strong surveillance system • Outbreak response plan for each disease • Stocks of IV fluids, antibiotics and vaccines • Plans for isolation wards • Laboratory support 9/26/2020 CD Control 16
Detection of outbreak • Surveillance system with early warning system for epidemic prone diseases. • Inform ministry of health and WHO in case of outbreaks of specific diseases. • Take appropriate specimens (stool, CSF or serum) for laboratory confirmation. • Include case in the weekly report. 9/26/2020 CD Control 17
Response to the outbreak • Confirm the outbreak • Activate the outbreak control team • Investigate the outbreak • Control the outbreak 9/26/2020 CD Control 18
Evaluation • Assess appropriateness and effectiveness of containment measures • Assess timeliness of outbreak detection and response • Change public health policy if indicated • Write and disseminate outbreak report. 9/26/2020 CD Control 19
Prevention and Control of specific communicable diseases • Acute Respiratory • • • Infections Cholera Conjunctivitis Dengue Diphtheria Hepatitis HIV/AIDS Japanese Encephalitis Leishmaniasis Malaria Measles 9/26/2020 • Meningococcal Meningitis • Relapsing Fever(louse • • CD Control borne) Scabies Sexually Transmitted Infections Trypanosomiasis Tuberculosis Typhoid Typhus (Epidemic louse borne) Viral Hemorrhagic fever 20
Prevention and Control of Acute Respiratory Infections • Early recognition and treatment • All children with cough carefully assessed • Assess signs of malnutrition • Refer severely malnourished to hospital • Manage pneumonia with antibiotics • Follow national treatment protocols • Supportive measures • Vaccination against measles, diphtheria and whooping cough reduces the impact of ARI. 9/26/2020 CD Control 21
Prevention and Control of Cholera • Prompt diagnosis and management • Establish treatment centers with barrier nursing. • Fecal material and vomit properly disinfected and • • • disposed. Health Education on hygiene, safe water, safe food and hand washing. Funerals to be held quickly and near the place of death. Meticulous hand washing for those who handle the body. Promote washing hands with soap and water when food is being handled. 9/26/2020 CD Control 22
Prevention and Control of Dengue • Eliminate habitats of Aedes mosquitoes. • Personal protection against mosquito bites • • during day time. Surveys to determine vector density and larval habitats. In an outbreak use larvicide on all potential habitats of Aedes aegypti. Insecticides to reduce vector population. Social mobilization to eliminate breeding sites. 9/26/2020 CD Control 23
Prevention and Control of Viral Hepatitis • Enforcement of water and food sanitation. • For Hepatitis B and C, all blood products should • • be screened for the two (and for HIV). Vaccination of target population groups for Hepatitis A recommended. Health workers not immune to hepatitis A and B should be vaccinated. 9/26/2020 CD Control 24
Prevention and Control of Leishmaniasis • Reinforced surveillance, early detection and treatment. • Reduction of animal reservoir. • Vector control. • Personal protection with insecticide treated nets. • Health promotion and social mobilization. 9/26/2020 CD Control 25
Prevention and Control of Malaria • Rapid diagnosis and effective case management. • Use of insecticide treated nets. • Permethrin sprayed blankets or treated clothing. • Indoor Residual Spraying. • Chemo prophylaxis to non-immune expatriates and Intermittent Presumptive Therapy for pregnant women. 9/26/2020 CD Control 26
Prevention and Control of Meningococcal Meningitis • Early detection and control of the outbreak. • Diagnosis and management of cases. • Mass vaccination • Highest risk group for meningococcal meningitis is children aged 2 -10 years and this should be the priority group during vaccination campaigns. 9/26/2020 CD Control 27
Prevention and Control of Tuberculosis • Need for integration with the national TB • • • control Program and involve local TB coordinators. Use the national TB treatment protocols. Cover the local population also. Refer seriously ill patients to local hospitals. Laboratory services for sputum smears. Procedures in place for follow up of cases. • Program evaluation. 9/26/2020 CD Control 28
Prevention and Control of Typhoid fever • Health education, clean water, food inspection, • • proper food handling and proper sewage disposal. Early detection and control are important in prevention of spread. WHO guidelines should be consulted. Laboratory services are essential to know the outbreak strain and the anti microbial sensitivity pattern. Mass vaccination may be an adjunct for the control during a sustained high incidence epidemic. 9/26/2020 CD Control 29
Prevention and Control of Yellow Fever • Personal protection against mosquito bites. • Sleeping and living quarters should be screened. • Mass vaccination is key to control of outbreak. • In urban areas mosquito breeding sites should be destroyed. 9/26/2020 CD Control 30
Thanks for your kind attention 9/26/2020 CD Control 31
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