Communicable diseases. Gastrointestinal track infection. Sarkhell Araz MSc. Public health/epidemiology

Transcription

1 Communicable diseases Gastrointestinal track infection Sarkhell Araz MSc. Public health/epidemiology

2 Communicable diseases : Refer to diseases that can be transmitted and make people ill. They are caused by infective agents (pathogens), e.g. bacteria and viruses, which invade the body and multiply or release toxins to cause damages to normal body cells and their functions. In severe cases, they may lead to death. These infective agents can spread from a source of infection (e.g. patients, sick animals) to a person through various routes of transmission.

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5 Disease Microorganisms (Agent): These are the pathogens that cause communicable diseases. Most commonly these are bacteria, virus, fungi or parasites. Reservoir: The reservoir (source) is a host which allows the pathogen to live, and possibly grow, and multiply. Humans, animals and the environment can all be reservoirs for microorganisms. Sometimes a person may have a disease but is not symptomatic or ill. This type of person is a carrier and she/he may be referred to as colonized. Examples of reservoirs are standing water, a person with a common cold or syphilis, or a dog with rabies. Mode of Escape: This refers to the route by which the infectious microorganisms escape or leave the reservoir. For example, pathogens that cause respiratory diseases usually escape through the respiratory tract (coughing and sneezing).

6 Mode of Transmission: Since microorganisms cannot travel on their own, they require a vehicle to carry them to other persons and places. Mode of Entry: The path for the microorganism to get into a new host (the reverse of the portal of exit). The mode of entry refers to the method by which the pathogens enters the person. Pathogens enter the body by: inhalation (e.g. respiratory tract) ingestion (e.g.gi tract) absorption (e.g. mucous membranes of eyes) break in skin (e.g. needle stick, cut) introduction by medical procedures (e.g. catheters) Susceptible Host: The future host is the person who is next exposed to the pathogen. The microorganism may spread to another person but does not develop into an infection if the person s immune system can fight it off. They may however become a carrier without symptoms, able to then be the next mode of transmission to another susceptible host. Once the host is infected, he/she may become a reservoir for future transmission of the disease.

7 Infectious disease :caused by a microorganism and therefore potentially transferable to new individual Contagious disease: capable of spreading from one person to another. Communicable disease: can be transmitted from one source to another

8 Definition of communicable diseases: A communicable disease is an illness due to as pecific infectious (biological) agent or its toxic products capable of being directly or indirectly transmitted from man to man, from animal to man, from animal to animal, or from the environment (through air, water, food, etc..) to man.

9 Communicable diseases by their occurrences in time and space sporadic: scattered, dispersed cases of a communicable disease, without any connections in time and space (e.g.: Lyme-borreliosis) endemic: permanently or long-lastingly increased presence of a disease in a given area (e.g.: viral haemorrhagic fevers) epidemic: occurrence in excess of expected occurrence (e.g.: Ebola in West-Africa, ) pandemic: diffused spread of a communicable disease on the continents or Earth (e.g.: cholera, influenza) seasonality: enormous, numerous occurrence of a disease in a given season: (in summer)

10 Gastrointestinal track infection Bacterial gastroenteritis happens when bacteria causes an infection in your gut. This causes inflammation in your stomach and intestines. You may also experience symptoms like vomiting, severe abdominal cramps, and diarrhea. While viruses cause many gastrointestinal infections, bacterial infections are also common. Some people call this infection food poisoning. Bacterial gastroenteritis can result from poor hygiene. Infection can also occur after close contact with animals or consuming food or water contaminated with bacteria (or the toxic substances bacteria produce).

11 Symptoms of bacterial gastroenteritis Bacterial gastroenteritis symptoms vary depending on the bacteria causing your infection. The symptoms may include: loss of appetite nausea and vomiting diarrhea abdominal pains and cramps blood in your stools Fever

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13 Causes of bacterial gastroenteritis Numerous bacteria can cause gastroenteritis, including: yersinia, found in pork staphylococcus, found in dairy products, meat, and eggs shigella, found in water (often swimming pools) salmonella, found in meat, dairy products, and eggs campylobacter, found in meat and poultry E. coli, found in ground beef and salads

14 Control of communicable diseases General preventive measures control of patients, contacts and its immediate environment: 1. prompt recognition and identification of a disease (epid. anamnesis, clinical examination, epidemic laboratory investigation) 2. treatment of patients 3. isolation of infectious source 4. early laboratory diagnosis 5. report (cases-epidemics) notification, registration 6. disinfection 7. immunization. 8. epidemic observation 9. epidemic control 10. quarantine 11. epidemic surveillance