Maulana Rumi, in 13th-century Persian Sunni Muslim poet, jurist, Islamic scholar, and Sufi

Introduction to Communicable Diseases Learning Objectives At the end of this lecture the students will be able to; Describe infectious diseases epidemiology Describe the approaches used for infection prevention and control practices

Infectious diseases are caused by pathogenic microorganisms, such as bacteria, viruses, parasites or fungi etc. Common , Some of them cause death and disability. Some of them cause epidemics.

Classification of infectious Diseases Vector borne diseases (malaria, dengue) Diseases caused by Fecal (cholera, enteric fevers, poliomyelitis, viral hepatitis) Helminthic diseases (Ascariasis, hookworm) Airborne diseases (anthrax, brucellosis) Zoonotic diseases (rabies) Contact diseases (fungal infections, flu) Sexually transmitted diseases (HIV/AIDs) 1.. 2. HIV/AIDS 3. 4. bacillary dysentery, amoebiasis,. 5.. 6. acute respiratory infections, meningitis, TB 7., rabies

Zoonotic diseases defined by WHO Diseases and infections that are naturally transmitted between vertebrate animals and humans. A zoonotic agent may be a bacterium, virus, fungus or other disease causing agents.

Risk factors Anyone can catch infection, most vulnerable are, Patients with chronic diseases e.g. cancer, immunocompromised, HIV /AIDS, tuberculosis Patients with implanted medical devices Malnutrition Extremes of ages Pregnant ladies

Complications Most infectious diseases have only minor complications, but some infections like pneumonia, AIDS, meningitis can become life-threatening. Few infections have been linked to increased risk of cancer. E.g. human papilloma virus linked to cervical cancer, helicobacter pylori is linked to stomach cancer, Epstein-Barr virus is linked to lymphoma.

Tests and diagnosis Blood tests. Urine tests. Throat swabs. Stool samples.  Spinal tap (lumbar puncture).  Imaging scans Biopsies

Treatments and drugs Many infectious diseases, such as common cold, will resolve on their own. Drink plenty of fluids and get lots of rest. Drugs used to treat infectious diseases are; Antibiotics Antiviral Antifungal Anti-parasitics

Different terminologies used in infectious diseases Infection Contamination Pollution Infestation Fomite Prions Infectious and Contagious disease Host Susceptible person Immune Person Contact person Sporadic disease Out break Endemic Epidemic Pandemic Holo – endemic Emerging Re – emerging Iatrogenic disease Opportunistic infections

Infection Prevention and Control

Learning outcomes: By the end of the lecture the students shall be able to: Describe the concepts of infection prevention and control Describe the approaches used for infection prevention and control practices

Infection prevention refers to the process that ensures that a sterile environment remains free of micro-organisms Infection control refers to policies and procedures used to minimize the risk of spreading infections and to reduce infectious diseases (WHO)

Standard Precaution of Infection Prevention And Control Awareness Hand hygiene Safe handling of sharps and needles Use personal protective equipment (PPE) Disinfection Sterilization Early diagnosis Notification Isolation Quarantine Immunization

1. Awareness: Public awareness of infectious diseases plays an important role in disease control; a lack of reasonable knowledge of infectious diseases leads to low detection rates, the interruption of treatment, discrimination and stigma. 

2. Hand Hygiene Hand hygiene refers to both washing with plain or anti-bacterial soap and water and to the use of alcohol gel to decontaminate hands.

3. Safe handling of sharps and needles Safe handling of needles and other sharp devices are components of standard precautions that are implemented to prevent health care worker exposure to blood borne pathogens.

4. Personal protective equipment (PPE) Used to protect from the risks of cross-infection. PPE includes items such as gloves, aprons, masks, goggles visors, hats and footwear.

5. Disinfection The process of disinfection is to destroy all micro- organisms except some bacterial spores. Disinfection may be thermal or chemical Thermal disinfection:   Moist heat at a specific temperature for a set amount of time. Reliable, leaves no residues, more easily controlled and is non-toxic.

 Chemical disinfection Application of a liquid chemical agent to eliminate the majority of pathogenic microorganisms, with the exception of bacterial spores. Used for heat- labile equipment. E.g. endoscopes (laparoscopes) and bronchoscopes.

Thermal and Chemical disinfection

6. Sterilization: A process that removes/kills all forms of biological agents like, fungi, bacteria, viruses, spores, plasmodium etc. Sterilization can be achieved by heat, chemicals irradiation, high pressure, and filtration. Autoclave

7. Early Diagnosis: The first step in control of an infection is its early diagnosis for, Early treatment Epidemiological investigations for source For prevention and control measures.

8. Notification: Notification of infectious disease is required by law to be reported to the local health authorities. This information allows the authorities to, Monitor the disease Provides early warning of possible outbreaks The diseases to be notified vary from country to country.

9. Isolation: Oldest method, defined as separation for the period of communicability, of infected persons from others in such places or conditions to limit the transmission of infection. Hospital isolation is better than home isolation.

10. Quarantine: The limitation of movement of such well persons or domestic animals exposed to communicable disease for a period of time not longer than the longest incubation period of disease in such manner as to prevent effective contact with those not so exposed. These measures are also applied by health authorities to ships, aero planes, trains or containers to prevent spread of infection.

11. Immunization: Immunization reduces preventable infectious diseases.

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