Umm Al-Qura University Lecture 4 PDF

Umm Al-Qura University Faculty of Public Health & Health Informatics Health Promotion & Education Department Dr\ Mohamed Osama Nour Associate Professor Health Promotion & Education Department Faculty of Public Health & Health Informatics Umm Al-Qura University Food-borne Disease (Food Poisonin...

Umm Al-Qura University Faculty of Public Health & Health Informatics Health Promotion & Education Department Dr\ Mohamed Osama Nour Associate Professor Health Promotion & Education Department Faculty of Public Health & Health Informatics Umm Al-Qura University Food-borne Disease (Food Poisoning) • Acquired through eating or drinking contaminated food or drinks (raw and undercooked food, meat and poultry, improperly canned foods, unpasteurized milk, contaminated water, juices, holding food at incorrect temperature, etc.). • Most common symptoms are vomiting, diarrhea, and abdominal pain but other serious consequences may include dehydration, kidney and liver failure, neural disorders, arthritis, cancer, and death. • Population at risk: Infants, children, pregnant, elderly, and immunocompromized. • Most common causes are: ✓ Bacteria as Salmonella, Shigella, E coli, Campylobacter, and Clostridium. ✓ Viruses as Hepatitis A virus, Norwalk virus, and Norovirus. ✓ Parasites as Giardia, Entameba, and Trichinosis. ✓Toxins as bacterial toxins (Staph aureus, Clostridium botulinum), chemical toxins, and toxins of plants, animals, and fungi. Prevention of food-borne disease (food poisoning) 1) Food processing safety. 2) Cook thoroughly. 3) Eat immediately. 4) Store carefully & keep food at safe temperature. 5) Reheat thoroughly. 6) Avoid contact between raw & cooked foods. 7) Wash hands repeatedly. 8) Keep food preparation surfaces clean. 9) Protect from pests, insects, rodents, etc. 10) Use safe water. Diseases Related to Water Water-borne Diseases Water-based Diseases Water-washed Diseases Water-related Diseases Diseases Related to Water Category Transmission Examples Waterborne Ingestion of pathogens in contaminated water Typhoid, paratyphoid, amoebic dysentery, bacillary dysentery, shigellosis, giardiasis, cholera, leptospirosis, poliomyelitis, Rotavirus Waterwashed Skin or eye contact with contaminated water & poor personal hygiene Intestinal helminths (ancylostomiasis, ascariasis), conjunctivitis, trachoma, typhus, and other diseases transmitted by flea, lice, and tick. Waterbased Parasite found in intermediate host (snails) living in water, skin penetration Schistosomiasis (bilharziasis) Waterrelated Insect vectors (mosquitoes) breeding in water or biting near water Dengue fever, yellow fever, malaria, filariasis, trypanosomiasis Acute Gastroenteritis • Definition: Acute infection of the gastrointestinal tract. • Occurrence: worldwide (more in developing countries, more in summer but Rotavirus more in winter). • Infectious agent: Bacterial (salmonella, shigella, E coli, campylobacter), Viral (Rotavirus, Norwalk virus, enteric adenovirus), Parasitic (Giardia). • Source of infection: human (cases or carriers). • Portal of exit: human excreta. • Mode of transmission: 1) feco-oral, 2) ingestion of contaminated food, water, milk, 3) Flies & cockroaches can transmit infection. • Portal of entry: mouth. • Incubation period: few hours to few days. • Symptoms: fever, vomiting, diarrhea (watery, mucus, or blood), abdominal colic. Acute Gastroenteritis • Complication: dehydration , electrolyte imbalance, malnutrition , etc. • Prognosis: excellent because gastroenteritis usually is self-limited. • Fatality rate: more among premature and malnourished. • Carrier state: may develop. • Immunity: previous attacks are not protective. •Prevention: Socioeconomic development, environmental sanitation: pure water supply, sewage disposal, refuse disposal, health education, flies' control, encourage breast feeding, proper weaning practice, personal hygiene especially to children, washing vegetables and fruits, supervision of food-handlers, etc. •Control: management of dehydration with ORS (oral rehydration solution), superchlorination of water in summer. Typhoid Fever (Enteric Fever) • • • • • • Definition: Acute infectious disease caused by salmonella typhi. Occurrence: worldwide (related to poor hygiene and sanitary conditions). Infectious agent: salmonella typhi (contains 3 antigen; H, 0, and Vi antigens). Source of infection: human (cases or carriers), food-handlers are dangerous carriers. Portal of exit: human excreta (feces and urine). Mode of transmission: 1) feco-oral, 2) ingestion of contaminated food, water, milk, 3) Flies & cockroaches can transmit infection. • Portal of entry: mouth. • Incubation period: average 1 – 3 weeks. • Symptoms: 1st week: high fever, headache, malaise, anorexia, constipation. 2nd week: still high fever, rapid weak pulse, toxic appearance. Typhoid Fever (Enteric Fever) 3rd week: still high fever, toxicity increases, weight loss, diarrhea, abdominal distension, splenomegaly, impaired consciousness. Death may occur at this stage from toxemia, myocarditis, intestinal hemorrhage, or perforation. 4th week: regression (fever, mental state, and abdominal distension slowly improve). Convalescence is prolonged, and most Relapses occur at this stage. • Complication: intestinal hemorrhage or perforation, myocarditis, cholecystitis. • Period of communicability: usually from the first week through out convalescence. • Prognosis: is good with early treatment but becomes poor if complications develop. • Fatality rate: 1 – 2 %. • Carrier state: may develop. • Immunity: previous attacks are not protective. Typhoid Fever (Enteric Fever) • Diagnosis: Blood-culture: diagnostic in 1st week. Stool-culture and Urine-culture: diagnostic in the 2nd and 3rd week. Widal test: diagnostic (+ve test) about 7th – 10th day, used to estimate antibodies against salmonella antigens, rising or high antibody titers indicate acute infection. •General prevention: Socioeconomic development, environmental sanitation: pure water supply, sewage disposal, refuse disposal, health education, personal hygiene especially to children, washing vegetables and fruits, supervision of food-handlers (periodic medical examination, typhoid vaccine , chest x-ray, medical license). •Specific prevention: Typhoid vaccine (food handlers, healthcare workers, close contacts, pilgrims, travelers to endemic areas, during epidemics). • Control: Antibiotics as ciprofloxacin, release after 3 –ve stool cultures, 3 days apart. Food Poisoning Food Poisoning • Definition: Food-borne illnesses that may follow ingestion of infectious organisms or noninfectious substances, characterized by nausea, vomiting, diarrhea (watery, mucus, or bloody), abdominal pain, cramps, may be fever, CNS involvement. • Classification according to incubation period (IP): ➢ Short incubation (within 1 day): Chemical (IP 1-2 hours): metal poisonings as arsenic, lead and mercury, fish-associated toxins. Bacterial (IP 1-6 hours): Staph aureus, Clostridium perfringens. ➢ Intermediate incubation (IP 1-3 days): Clostridium botulinum (Botulism), E coli, Campylobacter, nontyphoidal Salmonella, Shigella, Rotavirus, Adenoviruses. ➢ Long incubation (IP 3-5 days): Yersinia, Enterohemorrhagic E coli. ➢ Very Long incubation (IP 1-4 weeks): Parasitic: Entamoeba histolytica (Amebiasis), Giardia, Cryptosporidium. Bacterial: Listeria, Brucella (Brucellosis). Viral: hepatitis A. Protozoal: toxoplasma (toxoplasmosis). Bacterial Food Poisoning • Characteristics of bacterial food poisoning: ✓ Very short incubation period (within hours). ✓ Outbreak ✓ Cases of many cases within a short time. have shared some common food, +/- similar manifestations. ✓ Manifestations: ✓ Examples: ✓ Staph GIT in salmonella & staph poisoning, and CNS in botulism. Salmonella food poisoning, Staph food poisoning, and Botulism. aureus produces enterotoxin while Clostridium produces neurotoxin. Salmonella Food Poisoning • Infectious agent: salmonella species • Source of infection: human (cases or carriers), animals (rodents, cattle, poultry, swine) where organisms found in the intestine and excreta of infected animals. • Portal of exit: human and animal excreta (feces and urine). • Mode of transmission: 1) Ingestion of food from infected animals or poultry (eggs, meat and meat products as sausages, and poultry meat), 2) Ingestion of food contaminated by excreta of human or animals, flies and cockroaches, handling by food handlers, and dust in animal sheds. 3) Drinking water polluted with excreta of human or animal. 4) Contact with infected man (hand-to-mouth). • Incubation period: average 12 – 36 hours. Salmonella Food Poisoning • Prevention: Socioeconomic development, environmental sanitation: pure water supply, sewage disposal, refuse disposal, control of rodents and insects, food sanitation, adequate preparation, handling, and storage of food, health education, personal hygiene, supervision of food-handlers. Cholera • • • • • • • • • • • Definition: acute diarrheal illness and one of the quarantinable diseases. Occurrence: endemic in low-income countries; Bangladesh, Pakistan, India. Infectious agent: Vibrio cholera. Source of infection: human (cases or carriers). Portal of exit: human feces or vomits. Mode of transmission: 1) feco-oral, 2) ingestion of contaminated food or water. Portal of entry: mouth. Incubation period: few hours to few days. Symptoms: vomiting, watery diarrhea (rice-water stool), abdominal cramps. Period of communicability: as long as stools are positives with Vibrio cholera. Complications: dehydration, electrolyte imbalance, renal failure, shock, and death. Cholera • Prognosis: If left untreated, severe dehydration can lead to shock, coma, and death within hours. With early and proper treatment, the case fatality rate below 1%. • Fatality rate: more among premature and malnourished. • Carrier state: may develop. • Immunity: previous attacks are protective against the same strain only. • Specific prevention: cholera vaccine. •Control: notification to local health authorities and to the WHO, isolation in fever hospital, management of dehydration, chemoprophylaxis by tetracycline, release of cases after 3 successive negative stool cultures with 2-3 days apart. • Cholera should be excluded if the returning pilgrims died within 1 month. Dysentery • Definition: inflammation of large intestine characterized by diarrhea (with blood and mucus), tenesmus, and abdominal pain. • Infectious agent: Bacterial (bacillary): shigella, salmonella, E coli, campylobacter. Protozoa (amebic): entameba histolytica. • Source of infection: human (cases or carriers). • Portal of exit: human feces. • Mode of transmission: 1) feco-oral, 2) ingestion of contaminated food or milk. • Portal of entry: mouth. • Incubation period: few days (bacillary dysentery), few weeks (amebic dysentery). • Symptoms: frequent motions of loose stool (with blood and mucus), tenesmus, and abdominal pain. • Period of communicability: 2 – 3 weeks. Dysentery Amebic Dysentery Bacillary Dysentery Agent entameba histolytica shigella, salmonella, E coli, campylobacter Incubation period 3-4 weeks 1-7 days Fever (usually) absent moderate or high Stool watery, bulky loose, scanty Motions/day 6–8 More than 10 Tenesmus rare present Abdominal pain less squeezing Course (usually) chronic acute Treatment Anti-protozoal drugs Antibiotics