They are caused by the consumption of contaminated food with infectious agents, which leads to food poisoning. These infections lead to gastroenteritis that typically involves diarrhoea, vomiting, and abdominal cramps. These symptoms usually begin 12—72 hours after contracting the infectious agent and if due to viral agent usually lasts less than one week. Some viral causes may also be associated with fever, fatigue, headaches, and muscle pains. If the stool is bloody the cause is less likely to be viral and more likely to be bacterial.
Some bacterial infections may be associated with severe abdominal pain and may last for weeks without treatment. This is a systemic disease transmitted by the ingestion of food or water contaminated with the faeces of an infected person, the aetiological agents is Salmonella typhi , and man is the reservoir.
Less commonly, a rash of flat, rose-colored spots may appear. Its occurance is worldwide,and multi-drug resistant strains have been reported from asia, middle east and latin America. Sanitation and hygiene are the critical measures that can be taken to prevent typhoid.
Typhoid does not affect animals and therefore transmission is only from human to human. Typhoid can only spread in environments where human feces or urine are able to come into contact with food or drinking water. Careful food preparation and washing of hands are crucial to preventing typhoid. Aetiological agent is numerous serotypes of salmonella. In most countries which maintain salmonella surveillance.
Typhimurium and S.
Enteritidis are two most commonly reported. The reservoir is domestic and wild animals including poultry also humans ie patients, carriers. The mode of transmission is by ingestion of the organism in food derived from infected food animals or contaminated by faeces of infected animal or person. This includes raw and undercooked eggs and egg products, raw milk and raw milk products, meat and meat products,poultry andpoultry products. Its occurrence is worldwide and more extensively reported in north America and Europe.
Aetiological agent is four species of genus shigella. These organisms invade the superficial colonic mucosa causing inflammation. This bacteria has two biotypes, classic and El Tor.
The Epidemiology of Alimentary Diseases by John M. Duggan | | Booktopia
The latter has longer survival ability in nature and can cause sub-clinical cases. Its mode of transmission is by consumption of contaminated water and food, but rarely person to person spread has been reported. Undercooked or raw seafood has frequently been a source of cholera in some countries.
Most infected people with V. However, if left untreated, cholera can be one of the most rapidly fatal infectious illnesses known. In endemic areas the incidence of cholera is highest in children. Campylobacter jejuni food poisoning is characterised by a prodromal malaise, abdominal pain, diarrhoea.
Direct contact with infected animals or contaminated food or water is the transmission mode and animals are reservoirs. The bacteria multiply in the intestines and release endotoxins, with symptoms occurring after 2 to 5 days. It was the most common cause of gastroenteritis in England and Wales in Staphylococcal food poisoning, Clostridium perfringens food poisoning, Bacillus cereus food poisoning and Botulism are also infecting gastrointestinal tract and through their toxins cause gastroenteritis.
Rotavirus is the major cause of gastroenteritis that causes a severe diarrhoea and vomiting in children. This virus is transmitted by faecal oral route, with man being the reservoir. They do not multiply in foods but the lack of hygiene in food handlers and using dirty utensils are causes for their transfer. Usually the patient is less than one year old, rotavirus is only seen in the under fives and in the elderly. Norwalk virus named after the city in Ohio where the first identified outbreak occurred. Virus is shed in vomitus and faeces.
Reservoir is man. It is due to a small, single stranded RNA picornavirus. HAV hepatitis may be referred to as infectious hepatitis.
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The reservoir is man. Parenteral spread may very rarely follow transfusion of blood from a donor who is in the incubation stage of the disease. Buy Hardcover. Buy Softcover. FAQ Policy. About this book In offering this book to what we hope will be interested readers, we have several aspirations.
Show all. Table of contents 42 chapters Table of contents 42 chapters Epidemiology and Clinical Practice Pages Some Epidemiological Concepts Pages Genetics and the Gut Pages Reflux Oesophagitis Pages Carcinoma of the Oesophagus Pages Peptic Ulcer Pages Functional Dyspepsia Pages Carcinoma of the Stomach Pages Lactase Deficiency Pages Irritable Bowel Syndrome Pages Parasitic Diseases of the Gut Pages Acute Appendicitis Pages Benign Colorectal Neoplasms - Adenoma Pages