Communiable disease control and prevention

1. Communicable Disease Control Nursing
for 2nd year ECCN Students
By Ame M.
HU , College of Healthand MedicalSciences, Dep’t of ECCN

2. Outline
• Learning objectives
• Introduction
• Section1: Communicable Disease
– Specific Feature of Communicable Disease
– Classification of Communicable Disease
– Chain of Disease Transmission
– Host Parasite Interactions/Measuring of
Infectiousness
– Source of Infection
– Course of an Infectious Disease over Time
– Spectrum of Infectious Disease/Gradient of
Infection
– Natural History of Disease
• Section 2: Epidemiology & General Methods of
Prevention & Control of Communicable Diseases
– Epidemiology of Communicable Disease
– Importance of Studying Communicable Diseases
Epidemiology
– General Methods of Prevention and Control of
Communicable Diseases
– Principles of communicable disease control
• Section 3: Surveillance & the Investigation & mgt of
Outbreaks
– Surveillance
– Investigation & mgt of Outbreaks
• Section 4: Notification & Health Regulation
Surveillance
– Diseases under national & international health
regulations
– Integrated disease surveillance & response
• Review Questions
• References
Communicable Disease Control Nursing December, 2023 © Haramaya University, CHMS,
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3. Learning Objectives
• By the end of this chapter the students will be able to;
– Describe the principles of communicable disease control and prevention.
– Describe what communicable diseases are.
– Discuss successive events implicated in the chain of disease transmission
– Explain the epidemiologic principles in the control and prevention of
communicable diseases
– Describe the surveillance concepts as applied in communicable diseases
– Name the notifiable diseases as stipulated in the national and international health
regulation
– Discuss the approaches used in responding to epidemics and outbreaks.
Communicable Disease Control Nursing
By Ame M. (Assistant Prof. of EMCCN * December, 2023 © HaramayaUniversity, CHMS,
Department of Emergencyand CriticalCare Nursing

4. Introduction
• Disease can be
– Communicable (those having causative organism like
• malaria, measles, and Typhoid fever etc) or
– noncommunicable (those have nonspecific causative organisms like
• coronary artery disease, accidents, HPN…).
• These diseases affect people of all ages but more children, due to their exposure to
env’tal conditions that support the spread.
• Communicable or infectious disease
– continues to remain a leading cause of morbidity, disability & mortality worldwide.
Communicable Disease Control Nursing
By Ame M. (Assistant Prof. of EMCCN
December, 2023 © HaramayaUniversity, CHMS,
Department of Emergencyand CriticalCare Nursing
*

5. Introduction.... cont’d
• Communicable or infectious disease
– continues to remain a leading cause of morbidity, disability & mortality worldwide.
• It accounts for
– one tenth of deaths in rich countries &
– six out of ten deaths in poorer countries.
• Annually worldwide
– 2 millions deaths occurs from diarrhea;
– 4 millions die of LRTI,
– 700,000 die from measles and
– 2 millions die from TB,
– 90% of all deaths occur in developing countries.
• more affect the poor & marginalized sections of society
• contribute to ill health and poverty.
Communicable Disease Control Nursing
By Ame M. (Assistant Prof. of EMCCN
December, 2023 © HaramayaUniversity, CHMS,
Department of Emergencyand CriticalCare Nursing
5

6. Introduction.... cont’d
• Definitions
– Communicable Diseases
• is a disease due to specific agent or its toxic products that a rises through
transmission of that agent or its products from infected person, animal or
reservoir to susceptible host either directly or indirectly through an
intermediate plant or animal host, vector or intermediate environment.
• are diseases that can spread from person to person or sometimes animals to
people.
Communicable Disease Control Nursing
By Ame M. (Assistant Prof. of EMCCN
December, 2023 © HaramayaUniversity, CHMS,
Department of Emergencyand CriticalCare Nursing
*

7. Specific Feature of Communicable Disease
A case may be risk factor.
Each infectious disease has its own incubation period.
People may be immune.
An individual may be a source without being recognized as a
case.
There is some times a need for urgency.
Preventive measures (usually) have a good scientific ground.
Intervention in infectious disease can have several effects.
*
CommunicableDiseaseControlNursing
ByAmeM.(AssistantProf.ofEMCCN
December,2023©HaramayaUniversity,CHMS,
DepartmentofEmergencyandCriticalCareNursing

8. Classification of Communicable Disease
classified into several divisions based on
causative organisms,
clinical presentation or
system of body attacked.
 However, the most appropriate classification considered for ease of
understanding depend on;
Clinical manifestation
Time course
Taxonomy of infectious agent
Mode of transmission and Others
*
CommunicableDiseaseControlNursing
By AmeM. (AssistantProf.ofEMCCN
December,2023©HaramayaUniversity,CHMS,
DepartmentofEmergencyandCriticalCareNursing

9. 1. Based on Clinical manifestations or system
involved
1. Diarrhoeal disease – Watery/secretary, dysentery/invasive
2. Febrile illness - Malaria, relapsing fever, typhoid fever
3. Respiratory tract infection
4. Central Nervous system infection – Meningitis
5. Cardio vascular infection – endocarditis
6. UTI
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CommunicableDiseaseControlNursing
ByAmeM.(AssistantProf.ofEMCCN

10. 2. Based on time course
I. Acute
Disease with short duration (less than two weeks)
It needs urgent care,
Rapidly progressive
Have abrupt onset
II. Chronic
indicate duration usually > 2wks
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CommunicableDiseaseControlNursing
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11. 3. Based on taxonomy of infectious agents
Metazoan disease – Helmenthiasis
Protozoal disease – Malaria, Giardiass
Bacterial disease– Leprosy
Fungal disease – Candidiasis
Viral disease – measles, polio
December, 2023 © Haramaya University, CHMS,
Department of Emergencyand CriticalCare Nursing
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CommunicableDisease ControlNursing
By Ame M. (Assistant Prof. of EMCCN

12. 4. Based on mode of transmission
 Those diseases use respiratory tract as portal of entry and/or exit.
E.g. pertussis, meningococcal meningitis, TBC, measles etc
 GIT as entry and/or exit. E.g. B/dysentery, cholera, salmonellas, Typhoid fever,
Ascariasis.
 Mucus membranes and/or skin as portal of entry/exit
e.g. STI, Trachoma, Ring worm, Candidiasis, Hepatitis B&C
 Direct inoculation e.g. Schistosomiasis, Hookworm.
 Vector bone disease – Malaria, leishmaniasis, Trypanosomiasis relapsing ferver,
typhus fever
 Inoculation by bite of animal/ contacts ć animal products.
E.g. rabies, tetanus, plaque, anthrax.etc
December, 2023 © Haramaya University, CHMS,
Department of Emergencyand CriticalCare Nursing
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CommunicableDisease ControlNursing
By Ame M. (Assistant Prof. of EMCCN

13. 1.3 Chain of Disease Transmission
 is a logical order of events/series of events which must occur in order for
disease to be transmitted and causing infection.
 It is the series that is essential to the dev’t of infectious agents &
propagation of disease.
 There are six successive events implicated in the chain of disease
transmission
1. Infectious agent (Ethologic or causative agent)
2. Reservoir
3. Portal of exit
4. Mode of transmission
5. Mode of entry
6. Successive host
December, 2023 © Haramaya University, CHMS,
Department of Emergencyand CriticalCare Nursing
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CommunicableDisease ControlNursing
By Ame M. (Assistant Prof. of EMCCN

14. 1. Infectious Agent
It can be
an organism (Virus bacteria, rickettsia, protozoan helminth,
Fungus or arthropod)
or
physical/chemical/agent (toxin or poison)
December, 2023 © Haramaya University, CHMS,
Department of Emergencyand CriticalCare Nursing
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CommunicableDisease ControlNursing
By Ame M. (Assistant Prof. of EMCCN

15. 1. Infectious Agent
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DepartmentofEmergencyandCriticalCareNursing
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CommunicableDiseaseControlNursing
By AmeM. (AssistantProf.ofEMCCN
Multiplicati
on→ two
methods
• Asexual (almost exact replicas produced →any natural selection occur on
the batches than single individual.
• Sexual- scope of variety are there
Survival
• Agent survive by finding suitable hosts
• Agent prolong the period of survival by different methods
Reservoir
s
• Suitable place to store infectious agent
• Reservoir can be humans, animals, vectors or inanimate environment (soil,
waters)
Infection agents’ needs

16. 1. Infectious Agent
 Infection agents’ needs
December,2023©HaramayaUniversity,CHMS,
DepartmentofEmergencyandCriticalCareNursing
*
CommunicableDiseaseControlNursing
By AmeM. (AssistantProf.ofEMCCN
Persiste
nce
• Development of special stages by agent to with stand distraction in adverse
environment. E.g. forming cyst (protozoa), eggs (nematodes) spore
(bacteria)
Latency
• Developmental stage in the environment not Infective to a new host.
• Parasite time of suitable condition.
Vector
• Parasite use service of arthropods to transmit from one host to other
• It can be part of transmission process (Mosquito)
Intermed
iate host
• some parasite needs intermediate host for development before they invade
the final host.E.g. Schistosoma uses a molluscan

17. 1. Infectious Agent
 Effect of the agent on host
If enough agents survive to infect a new host, they will produce a
reaction or illness.
 The reaction depends on the response of host and agent.
 The effect of host is determined by
 Virulence
Toxicity
Dose response
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18.  The effect of host is determined by
December,2023© HaramayaUniversity,CHMS,
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CommunicableDiseaseControlNursing
By AmeM. (AssistantProf.ofEMCCN
 Virulence
Ability of an infectious disease to
produce very sever disease
How harmful the disease will be
Severity of the infectious agent
Determined by strain (influenza
virus have different effects) & sub
species (plasmodium)
Dose response – For each infectious agent
a minimum number of organisms is required
to overcome the host defence & cause a
disease.
 Large dose e.g. cholera
 Very few e.g. E-histolytica
 For some organism low dose produce no
infections rather produce immunity e.g. polio
Toxicity
Infectious agent produces host
reaction both as by foreign
organism & by virtue of their toxic
proteins.
E.g. Tetanus bacilli produce toxin
at site of infection & Clostridium
botulinum – produce toxin in food
when they grow

19. 2. Reservoir of infection
 A living (human being, plant, animal or arthropod) or non living (soil,
water etc) in which an infectious agent normally lives, transforms and
multiplies on which it primarily for survive and where it produce itself in
such a way that it can be passed to (transmitted to) new susceptible host.
 Types of reservoir
 A. Man as the only reservoir
 Measles, Gonorrhoea, syphilis, smallpox, typhoid meningococcal
meningitis with transmission cycle man to man
 B. Animals-
 ùInfectious disease where animals are primary reservoirs includes:
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20. The 5Fs
Feces
Water
Soil
Flies
Finger
Food
20
The five “Fs” which play an
important role in fecal oral
disease transmissions:
1) Finger 2) Flies
3) Fomites 4) Fluid 5) Feces
Communicable Disease Control Nursing
By Ame M. (Assistant Prof. of EMCCN December, 2023 © Haramaya University, CHMS,
Department of Emergency and Critical Care Nursing