GIT Epidemiology Flashcards
What is the most common outcome of a gastrointestinal infection?
diarrhea
What is gastroenteritis?
Syndrome characterised by gastrointestinal symptoms of nausea, vomiting, diarrhoea and abdominal discomfort
What is diarrhea?
loose watery stools that occur at least 3 times in a day
Describe diarrhea?
- an increase in the number and volume and water content of stools 2. Having loose or watery stool at least three times per day 3. usually resulting from disease of the small intestine
What is dysentery?
- an inflammatory disorder of the gastrointestinal tract ;associated with blood and pus in the faeces 2. accompanied by symptoms of pain, fever, abdominal cramps; usually resulting from disease of the large intestine
What is enterocolitis?
inflammation involving the mucosa of both the small and large intestine
What is the clinical classification of diarrhea?
- Acute watery diarrhoea - loose or watery stools without visible blood of duration less 14 days 2. acute bloody diarrhoea - loose watery stools with visible blood of duration less than 14 days 3. Persistent diarrhoea - loose watery stools without visible blood of duration over 14 days
How long does acute diarhhea last?
5 to 7 days
What are the casues of diarrhea?
- viral 2. bacterial 3. protozoa 4. parasitic
What are the most common viral causes?
- rotavirus 2. adenoviruses 3. astroviruses 4. norovirus
Describe the epidemiology of the rotavirus?
- Leading cause of acute diarrhoea in children
- Leading cause of diarrhea mortality in children aged <5 years: 128,515 deaths
- persons of all ages 228,047 deaths
- Account for 40% of hospital admissions in children under the age of five worldwide
- Causes 527,000 deaths each year among children
Name the common bacterial causes of diarrhea?
- E. coli 2. Vibrio cholerae 3. Shigella 4. Campylobacter jejuni 5. Salmonella 6. Clostridium difficile 7. staphylococci
Name the common parasitic casues of diarrhea?
- Entamoeba histolytica 2. Giardia lamblia 3. Cryptosporidium 4. Isospora
Describe the global burden of diarrhea?
- highest in children under 5 2. Eighth leading cause of death among all ages: 1,655,944 deaths
Describe the epidemiology of the burden in children under 5?
2.5 billion cases in children under five years each year – 1. Incidence highest in the first 2 years of life 2. Africa and south east Asia with the greatest burden 3. Fifth leading cause of death among children younger than 5 years: 446,000 deaths
Describe diarrhea - related mortality?
22.4 deaths per 100,000 1. Children aged ≤5 years 70.6 deaths per 100,000 – 2. adults >70 years 171.7 deaths per 100,000
What are the leading risk factors of death in children under 5?
- childhood wasting (low weight for height score): 80.4% 2. unsafe water: 72.1% 3. poor sanitation :56.4%
Describe the burden of diarrhea in Malawi?
- 22 % of U-5s (26% in urban vs 21% in rural) 2. prevalence peaks between 6-24 months of age
Describe the burden in rural vs urban children?
- Rural children with diarrhoea are more likely to be taken for advice or treatment than urban children (67% versus 60%) 2. Children are less likely to be taken for advice or treatment if their mothers have no education (58%), compared with children whose mothers have a primary (68%) or secondary education (65%)
Describe the transmission of diarrhea?
- Mostly through fecal-oral route
- Nosocomial transmission possible (clostridium)
- Person-to person contact in Shigella
Describe the faecal-oral route?
- Ingestion of faecally contaminated water or food
- Person-to-person transmission
- Direct contact with faecal material
- Through vectors-Flies
Describe the faecal-oral transmission?
faeces → fluids/fingers/flies/fields → food → new host
What are the risk factors for diarrhea?
- lack of breast feeding 2. malnutrition 3. lack of food hygiene 4. poor weaning practices 5. lack of sufficient water 6. inadequate sanitation 7. poor personal and domestic hygiene
What risky behaviours increases the likelihood of diarrhea?
- Failed exclusive breast feeding for 4-6 months 2. Failure to breast feed for at least a year 3. Using infant bottles 4. Contaminated water 5. Failure to wash hands 5. Failure to dispose of faeces - infant faeces can be full of infectious viruses and bacteria 6. Storing cooked food at room temperature
How do you treat diarrhea?
- fluid replacement to prevent dehydration 2. zinc treatment 3. Oral rehydration therapy
How do you prevent diarrhea?
- rotavirus and measles vaccinations 2. promotion of early and exclusive breastfeeding and vitamin A supplementation 4. promotion of hand washing with soap 5. improved water supply quantity and quality, including treatment and safe storage of household water 6. community-wide sanitation promotion
Describe water, sanitation and hygiene with regards to diarrhea?
88% of diarrhoeal deaths attributed to unsafe water, inadequate sanitation and poor hygiene
Describe interventions with regards to water, sanitation and hygiene?
- Disposal of human excreta in sanitary manner 2. Washing hands with soap 3. Increasing access to safe drinking water 4. Improving water quality at source 5. Treating household water and storing it safely
Improved sanitation causes a mean reduction in diarrhea incidence by?
36%
Hand washing with soap causes a mean reduction in diarrhea by?
40%
Improved water quality at source, household water treatment and safe storage?
47%
Improved excreta disposal?
22%
Describe adequate nutrition as a risk factor in diarrhea?
- Undernourished children at higher risk of having more severe, prolonged and frequent episodes of diarrhoea 2. Repeated diarrhoeal episodes increases risk of malnutrition 3. Diarrhoea associated with stunting
Describe the diarrhea and malnutrition interaction?
diarrhea (which can be caused by early weaning, contaminated food, water and milk) → diminished absorption food → malnutrion (which can be caused by poverty ignorance, inequitable distribution of food in the family) → atrophy of gut mucosa and diminished resistance to infection → proliferation of enteric bacteria → diarrhea
Describe the burden of adequate nutrition in the world today?
- 129 million children under the age of five in the developing world are underweight (80% of them in Africa and South Asia) 2. 40 % of children in Africa stunted and about 50% in Asia
Describe the burden of adequate nutrition in Malawi today?
- 37 % of children under five stunted 2. 3 % of children are wasted
Importance of breastfeeding?
- Breastmilk contains nutrients, antioxidants, and antibodies 2. Six fold greater risk of death from infectious diseases in the first 2 months of life in infants not breastfed
Describe breastfeeding practices in Malawi?
61 % of children under six months are exclusively breastfed in 2010 MDHS 1. Only 34% of infants age 4-5 months 2. 80% of infants age 0-1 month 3. 69% of infants age 2-3 months
What micronutrient supplementation is necessary?
- vitamin A 2. adequate zinc intake
Importance of vitamin A?
- Mortality reduction ranging from 19-54% 2. Associated with reductions in diarrhoea and measles 3. Also been shown to reduce duration, severity and complications associated with diarrhoea
Describe the immunization from the Rotavirus in Malawi and SA?
- Vaccine efficacy 61.2% 2. Malawi (49.4% ) and South Africa(76.9%) 3. Efficacy against all-cause severe GE; 30.2% – episodes of severe rotavirus GE prevented per 100 infants vaccinated 4. 6.7 in Malawi and 4.2 in South Africa
Describe the immunization from the Rotavirus in Latin America?
- GE-associated mortality reduction of 22-41% 2. GE-associated hospitalization reduction of 17-51% 3. Rotavirus hospitalization reduction of 59-81%
