Control of Communicable Diseases Ahmed Mandil Prof of Epidemiology KSU College of Medicine

Control of Communicable Control of Communicable DiseasesDiseases

Ahmed MandilAhmed Mandil

Prof of EpidemiologyProf of Epidemiology

KSU College of MedicineKSU College of Medicine

Headlines Headlines

• Aims of Communicable Disease Aims of Communicable Disease ControlControl

• Measures towards: reservoir, Measures towards: reservoir, contacts, carriers, environment contacts, carriers, environment

• Outbreak controlOutbreak control

• ExamplesExamples

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Aims of CD controlAims of CD control

• EradicationEradication of the disease, if possible. This of the disease, if possible. This may indicate complete extinction of its may indicate complete extinction of its agents, reservoir or vectors. It also means agents, reservoir or vectors. It also means complete prevention of transmission. complete prevention of transmission.

• If eradication is not possible, then If eradication is not possible, then transmission could be reduced, in order to transmission could be reduced, in order to control morbidity (control morbidity (eliminationelimination))

• If the latter cannot be achieved, we try to If the latter cannot be achieved, we try to reduce severity and gravity of the disease reduce severity and gravity of the disease ((controlcontrol))


Measures towards reservoir Measures towards reservoir (1)(1)1. 1. Eradication:Eradication:

Extinction of animal reservoirs has been Extinction of animal reservoirs has been successful with diseases as bovine T.B. successful with diseases as bovine T.B. and rabies in several countries. Such and rabies in several countries. Such procedure is only possible for domestic procedure is only possible for domestic animals, while it is difficult or almost animals, while it is difficult or almost impossible for wild animals (e.g. in jungle impossible for wild animals (e.g. in jungle yellow fever, some sylvatic/wild reservoirs yellow fever, some sylvatic/wild reservoirs of leishmaniasis)of leishmaniasis)


Measures towards reservoir Measures towards reservoir (2)(2)2. 2. Reduction of communicability:Reduction of communicability:

(A) (A) Segregation of casesSegregation of cases::

This means that the patient is isolated from the This means that the patient is isolated from the community in a fashion that prevents direct community in a fashion that prevents direct and indirect spread of the infectious agent. This and indirect spread of the infectious agent. This is usually done for a period which equals the is usually done for a period which equals the "period of communicability", at hospital or at "period of communicability", at hospital or at home. Ideally, repeated negative samples from home. Ideally, repeated negative samples from the patient are needed before his (her) release.the patient are needed before his (her) release.


Measures towards reservoir Measures towards reservoir (3)(3)(B) (B) Treatment of casesTreatment of cases: :

Early diagnosis and prompt treatment of infections Early diagnosis and prompt treatment of infections with the appropriate regimens (e.g. antibiotics or with the appropriate regimens (e.g. antibiotics or chemotherapeutic agents) helps reducing chemotherapeutic agents) helps reducing communicability very much communicability very much

3. 3. DisinfectionDisinfection::

Disinfection of the soiled articles by the patient Disinfection of the soiled articles by the patient discharges concurrently (during his presence) discharges concurrently (during his presence) and/or terminally (e.g.after discharge from the and/or terminally (e.g.after discharge from the hospital) helps in reduction of communicability. hospital) helps in reduction of communicability.


Measures towards carriersMeasures towards carriers

Detection and control of carriers would be Detection and control of carriers would be worthwhile in the following conditions:worthwhile in the following conditions:

(A) If they represent important reservoirs of (A) If they represent important reservoirs of infection.infection.

(B) If their proportion in the community is (B) If their proportion in the community is small.small.

(C) If they were suspected in a closed (C) If they were suspected in a closed community, such as a boarding school or army community, such as a boarding school or army barracksbarracks


Measures towards contacts Measures towards contacts (1)(1)After enlistment the following procedures After enlistment the following procedures could be applied:could be applied:

a. a. Surveillance:Surveillance:

This means close medical supervision of the This means close medical supervision of the contacts, without restricting their movement, contacts, without restricting their movement, for the purpose of early detection of the for the purpose of early detection of the disease in question. This should be for the disease in question. This should be for the longest incubation period. longest incubation period.


Measures towards contacts Measures towards contacts (2)(2)b. b. Quarantine: Quarantine: This is only done for a limited This is only done for a limited number of diseases nowadays such as number of diseases nowadays such as pneumonic plague and pneumonic anthrax. pneumonic plague and pneumonic anthrax. It implies restriction of the movement of all It implies restriction of the movement of all those exposed to a case of such a disease, those exposed to a case of such a disease, in order to prevent their contact with those in order to prevent their contact with those not exposed. It also allows early detection not exposed. It also allows early detection of the disease among these individuals. It is of the disease among these individuals. It is done also for a period equaling the longest done also for a period equaling the longest incubation period. incubation period.


Measures towards contacts Measures towards contacts (3)(3)

c. c. Increasing the resistance of Increasing the resistance of susceptiblessusceptibles::

This is done either through active &/or This is done either through active &/or passive immunization, or passive immunization, or chemoprophylaxis. The choice of the chemoprophylaxis. The choice of the measure is disease dependent. The value measure is disease dependent. The value of immunization of contacts in preventing of immunization of contacts in preventing disease depends on the relation between disease depends on the relation between the incubation period and the time needed the incubation period and the time needed to develop immunity.to develop immunity.


Measures towards contacts Measures towards contacts (4)(4)

d. d. DisinfestationDisinfestation: : which is useful in which is useful in diseases transmitted by insects to diseases transmitted by insects to contacts, as in louse-borne typhus. contacts, as in louse-borne typhus.


Measures towards environment (1)Measures towards environment (1)

• Reduction of overcrowding Reduction of overcrowding (better (better housing conditions)housing conditions)

• Environmental sanitation Environmental sanitation (e.g. sanitary (e.g. sanitary sewage disposal, sanitary refuse sewage disposal, sanitary refuse disposal, sanitary water supply, disposal, sanitary water supply,

• Vector control Vector control (insecticiding: directly or (insecticiding: directly or through aerial spraying techniques, through aerial spraying techniques, mosquito-nets, insect repellents, etc.) mosquito-nets, insect repellents, etc.)


Measures towards environment (2)Measures towards environment (2)

• Personal hygiene Personal hygiene (cleanliness, hand-(cleanliness, hand-washing, regular bathing)washing, regular bathing)

• National/international measuresNational/international measures: which : which include different public health measures include different public health measures undertaken within and between undertaken within and between countries, in order to protect the countries, in order to protect the individual and the community at large, individual and the community at large, from different communicable from different communicable diseases.diseases.


Outbreak Control

• An outbreak is occurrence of a number An outbreak is occurrence of a number of cases of a disease that is unusually of cases of a disease that is unusually large or unexpected for a given place large or unexpected for a given place and time.and time.

Outbreaks in emergency situations can Outbreaks in emergency situations can spread rapidly giving rise to high spread rapidly giving rise to high morbidity and mortality rates.morbidity and mortality rates.

Aim should be to detect and control the Aim should be to detect and control the outbreak as early as possible.outbreak as early as possible.

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Steps in the management of a Steps in the management of a communicable disease outbreakcommunicable disease outbreak

1.1. PreparationPreparation

2.2. DetectionDetection

3.3. ResponseResponse

4.4. EvaluationEvaluation


PreparationPreparation

• Health coordination meetingsHealth coordination meetings

• Strong surveillance systemStrong surveillance system

• Outbreak response plan for each Outbreak response plan for each diseasedisease

• Stocks of IV fluids, antibiotics and Stocks of IV fluids, antibiotics and vaccinesvaccines

• Plans for isolation wardsPlans for isolation wards

• Laboratory supportLaboratory support


Detection of outbreakDetection of outbreak

• Surveillance system with early warning Surveillance system with early warning system for epidemic prone diseases.system for epidemic prone diseases.

• Inform ministry of health and WHO in Inform ministry of health and WHO in case of outbreaks of specific diseases.case of outbreaks of specific diseases.

• Take appropriate specimens (stool, CSF Take appropriate specimens (stool, CSF or serum) for laboratory confirmation.or serum) for laboratory confirmation.

• Include case in the weekly report.Include case in the weekly report.


Response to the outbreakResponse to the outbreak

• Confirm the outbreakConfirm the outbreak

• Activate the outbreak control teamActivate the outbreak control team

• Investigate the outbreakInvestigate the outbreak

• Control the outbreakControl the outbreak


Evaluation Evaluation

•Assess appropriateness and Assess appropriateness and effectiveness of containment effectiveness of containment measuresmeasures

•Assess timeliness of outbreak Assess timeliness of outbreak detection and responsedetection and response

•Change public health policy if Change public health policy if indicatedindicated

•Write and disseminate outbreak Write and disseminate outbreak reportreport..


Prevention and Control of specific Prevention and Control of specific communicable diseasescommunicable diseases

• Acute Respiratory Acute Respiratory InfectionsInfections

• CholeraCholera• ConjunctivitisConjunctivitis• DengueDengue• DiphtheriaDiphtheria• HepatitisHepatitis• HIV/AIDSHIV/AIDS• Japanese EncephalitisJapanese Encephalitis• LeishmaniasisLeishmaniasis• MalariaMalaria• MeaslesMeasles

• Meningococcal MeningitisMeningococcal Meningitis

• Relapsing Fever(louse Relapsing Fever(louse borne)borne)

• ScabiesScabies

• Sexually Transmitted Sexually Transmitted InfectionsInfections

• TrypanosomiasisTrypanosomiasis

• TuberculosisTuberculosis

• TyphoidTyphoid

• Typhus (Epidemic louse Typhus (Epidemic louse borne)borne)

• Viral Hemorrhagic feverViral Hemorrhagic fever


Prevention and Control of Prevention and Control of Acute Respiratory InfectionsAcute Respiratory Infections• Early recognition and treatmentEarly recognition and treatment• All children with cough carefully assessedAll children with cough carefully assessed• Assess signs of malnutritionAssess signs of malnutrition• Refer severely malnourished to hospitalRefer severely malnourished to hospital• Manage pneumonia with antibioticsManage pneumonia with antibiotics• Follow national treatment protocolsFollow national treatment protocols• Supportive measuresSupportive measures• Vaccination against measles,diphtheria Vaccination against measles,diphtheria

and whooping cough reduces the impact and whooping cough reduces the impact of ARI.of ARI.


Prevention and Control of Prevention and Control of CholeraCholera

• Prompt diagnosis and managementPrompt diagnosis and management• Establish treatment centers with barrier nursing.Establish treatment centers with barrier nursing.• Fecal material and vomit properly disinfected Fecal material and vomit properly disinfected

and disposed.and disposed.• Health Education on hygiene,safe water, safe Health Education on hygiene,safe water, safe

food and hand washing.food and hand washing.• Funerals to be held quickly and near the place of Funerals to be held quickly and near the place of

death. Meticulous hand washing for those who death. Meticulous hand washing for those who handle the body.handle the body.

• Promote washing hands with soap and water Promote washing hands with soap and water when food is being handled. when food is being handled.


Prevention and Control of Prevention and Control of DengueDengue• Eliminate habitats of Aedes mosquitoes.Eliminate habitats of Aedes mosquitoes.• Personal protection against mosquito bites Personal protection against mosquito bites

during day time.during day time.• Surveys to determine vector density and Surveys to determine vector density and

larval habitats.larval habitats.• In an outbreak use larvicide on all potential In an outbreak use larvicide on all potential

habitats of Aedes aegypti.habitats of Aedes aegypti.• Insecticides to reduce vector population.Insecticides to reduce vector population.• Social mobilization to eliminate breeding Social mobilization to eliminate breeding

sites.sites.


Prevention and Control of Prevention and Control of Viral HepatitisViral Hepatitis

• Enforcement of water and food sanitation.Enforcement of water and food sanitation.• For Hepatitis B and C, all blood products For Hepatitis B and C, all blood products

should be screened for the two (and for should be screened for the two (and for HIV).HIV).

• Vaccination of target population groups for Vaccination of target population groups for Hepatitis A recommended.Hepatitis A recommended.

• Health workers not immune to hepatitis A Health workers not immune to hepatitis A and B should be vaccinatedand B should be vaccinated..


Prevention and Control of Prevention and Control of LeishmaniasisLeishmaniasis

• Reinforced surveillance, early Reinforced surveillance, early detection and treatment.detection and treatment.

• Reduction of animal reservoir.Reduction of animal reservoir.• Vector control.Vector control.• Personal protection with insecticide Personal protection with insecticide

treated nets.treated nets.• Health promotion and social Health promotion and social

mobilizationmobilization..


Prevention and Control of Prevention and Control of MalariaMalaria• Rapid diagnosis and effective case Rapid diagnosis and effective case

management.management.• Use of insecticide treated nets.Use of insecticide treated nets.• Permethrin sprayed blankets or treated Permethrin sprayed blankets or treated

clothing.clothing.• Indoor Residual Spraying.Indoor Residual Spraying.• Chemo prophylaxis to non-immune Chemo prophylaxis to non-immune

expatriates and Intermittent Presumptive expatriates and Intermittent Presumptive Therapy for pregnant women. Therapy for pregnant women.


Prevention and Control of Prevention and Control of Meningococcal MeningitisMeningococcal Meningitis

• Early detection and control of the Early detection and control of the outbreak.outbreak.

• Diagnosis and management of cases.Diagnosis and management of cases.

• Mass vaccinationMass vaccination

• Highest risk group for meningococcal Highest risk group for meningococcal meningitis is children aged 2-10 meningitis is children aged 2-10 years and this should be the priority years and this should be the priority group during vaccination campaigns.group during vaccination campaigns.


Prevention and Control of Prevention and Control of TuberculosisTuberculosis• Need for integration with the national TB Need for integration with the national TB

control Program and involve local TB control Program and involve local TB coordinators.coordinators.

• Use the national TB treatment protocols.Use the national TB treatment protocols.• Cover the local population also.Cover the local population also.• Refer seriously ill patients to local Refer seriously ill patients to local

hospitals.hospitals.• Laboratory services for sputum smears.Laboratory services for sputum smears.• Procedures in place for follow up of cases.Procedures in place for follow up of cases.

• Program evaluation. Program evaluation. April 20, 2023April 20, 2023 2828CD ControlCD Control

Prevention and Control of Prevention and Control of Typhoid feverTyphoid fever• Health education, clean water, food Health education, clean water, food

inspection, proper food handling and inspection, proper food handling and proper sewage disposal.proper sewage disposal.

• Early detection and control are important Early detection and control are important in prevention of spread.in prevention of spread.

• WHO guidelines should be consulted.WHO guidelines should be consulted.• Laboratory services are essential to know Laboratory services are essential to know

the outbreak strain and the anti microbial the outbreak strain and the anti microbial sensitivity pattern.sensitivity pattern.

• Mass vaccination may be an adjunct for Mass vaccination may be an adjunct for the control during the control during a sustained high a sustained high incidence epidemic.incidence epidemic.


Prevention and Control of Prevention and Control of Yellow FeverYellow Fever

• Personal protection against mosquito Personal protection against mosquito bites.bites.

• Sleeping and living quarters should be Sleeping and living quarters should be screened.screened.

• Mass vaccination is key to control of Mass vaccination is key to control of outbreak.outbreak.

• In urban areas mosquito breeding In urban areas mosquito breeding sites should be destroyed.sites should be destroyed.


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Control of Communicable Diseases Ahmed Mandil Prof of Epidemiology KSU College of Medicine