Epidemiology of Acute diarrhoeal diseases.pptx

A brief description on Acute Diarrhoeal diseases. Its definition, types, epidemiology its prevention and control, vaccines available.

1. Acute diarrhoeal diseases (ADD)

2. Introduction Diarrhoea is defined as the passage of loose, liquid or watery stools more than three times a day It is the recent change in consistency and character of stools rather than the number of stools that is more important Intestinal and respiratory infections are a major cause of death in children under 5 yrs of age

3. Diarrhoea is a leading cause of death during natural disasters and other emergencies Displacement of population into overcrowded shelters, polluted water sources, inadequate sanitation, poor hygiene Lack of adequate health services, transport etc

4. Clinical types of diarrhoeal disease 1) Acute watery diarrhoea : usually lasts several hours to days; main danger is dehydration, weight loss. The usual pathogens are Vibrio cholerae, E.coli and Rotavirus 2) Acute bloody diarrhoea : also called “dysentery”. The main dangers are damage to intestinal mucosa, sepsis and malnutrition. It is marked by visible blood in stools. The common cause is Shigella.

5. 3) Persistent diarrhoea : lasts 14 days or longer. The main danger is malnutrition, sepsis. Persons with AIDS are more likely to develop persistent diarrhoea 4) Diarrhoea with severe malnutrition (marasmus and kwashiorkor) : the main dangers are severe systemic infection, dehydration, vitamin and mineral deficiency, heart failure

6. WHO Factsheet Diarrhoeal disease is the third leading cause of death in children 1–59 months of age. It is both preventable and treatable. Each year diarrhoea kills around 4,43,832 children under 5 and an additional 50,851 children aged 5 to 9 years. A significant proportion of diarrhoeal disease can be prevented through safe drinking-water and adequate sanitation and hygiene. Globally, there are nearly 1.7 billion cases of childhood diarrhoeal disease every year. Diarrhoea is a leading cause of malnutrition in children under 5 years old.

7. Epidemiological determinants - Agent Viruses - Rotavirus, Astrovirus, Adenovirus, Coronavirus, Enterovirus, Cytomegalovirus Bacteria - Campylobacter jejuni , Escherichia coli, Shigella, Salmonella, Vibrio cholerae, Vibrio parahaemolyticus, Staphylococcus aureus, Clostridium perfringens, Yersinia enterocolitica, Chlamydia, Neisseria gonorrhoeae Others - E. histolytica , Giardia intestinalis , Cryptosporidium, Cyclospora

8. Infections causing diarrhoea Rotaviruses - shed in high concentrations for many days in stool and vomit of infected individuals. Transmission occurs primarily by faeco-oral route Bacterial causes - (a) E. coli cause acute watery diarrhoea in adults and children. It is the most common cause of traveller’s diarrhoea (b) Salmonella cause inflammation of bowel epithelium (c) Shigella accounts for a high percentage of mortality due to diarrhoeal disease

9. Others - (a) Giardiasis is a recognised cause of diarrhoea. It flourishes in duodenum and jejunum (b) Cryptosporidium causes diarrhoea in infants, immunodeficient patients and domestic animals. It can cause persistent diarrhoea and wasting

10. Diarrhoea may be caused by parenteral infections like ENT infections, respiratory or urinary infections, malaria, bacterial meningitis etc. Malnutrition may lead to certain nutritional diseases like kwashiorkor, sprue, coeliac disease and pellagra which are all associated with diarrhoea

11. Reservoir of infection For E. coli, shigella, V cholerae, Giardia lamblia etc. man is the principal reservoir For other enteric pathogens, animals are reservoirs. Examples are C. jejuni , Salmonella

12. Host factors Diarrhoea is common in children between 6 months and 2 yrs of age when weaning occurs It occurs when there is decline of maternally acquired immunity, introduction of contaminated food, contact with faeces etc Malnutrition and diarrhoea for a vicious circle Poverty, immunodeficiency, lack of hygiene are contributory factors

13. Environmental factors In tropical areas, rotavirus diarrhoea occurs throughout the year whereas bacterial diarrhoea peak during rainy season

14. Mode of transmission Pathogenic organisms are transmitted by faeco - oral route - via water, food, fomites

15. Control of Diarrhoeal diseases The Diarrhoeal Diseases Control (DDC) Programme of WHO has advocated several intervention measures which centre around the practice of “Oral rehydration therapy” The intervention measures may be classified into : Short term- (a) Appropriate clinical management Long term- (a) Better MCH care practices (b) Preventive strategies (c) Preventing diarrhoeal epidemics

16. Clinical management Oral rehydration therapy:diarrhoea can often be cured solely with oral rehydration therapy. ORS (oral rehydration salt) is effective against dehydration as well as reduces the stool output Reduced osmolarity ORS gm/litre Sodium chloride 2.6 Glucose, anhydrous 13.5 Potassium chloride 1.5 Trisodium citrate 2.9 Total weight 20.5

17. Assessment of dehydration is done before ORS is given When obvious signs of dehydration exists, the water deficit is 50-100ml/kg body wt. The ORS solution required during initial 4 hrs may be calculated by multiplying patient’s weight (in kg) by 75ml/kg The actual amount given will depend on the patient’s desire to drink and by observing signs of dehydration

18. If the person vomits, wait for few minutes and then try again In case of children, give ORS in a teaspoon every 1-2 minutes and if being breast fed, nursing continued along with ORS Introduction of ORS has reduced cost of treatment and made possible treatment at homes by family members/ primary care workers

19. Assessment of dehydration Patient parameters Dehydration Mild Severe 1 Patient’s appearance Thirsty, alert, restless Drowsy, limp, cold, sweaty, comatose 2 Radial pulse Normal rate and volume Rapid, feeble, sometimes impalpable 3 Blood pressure Normal Less than 80 mm Hg ; may be unrecordable 4 Skin elasticity Pinch retracts immediately Pinch retracts very slowly 5 Tongue Moist Very dry 6 Anterior fontanelle Normal Very sunken 7 Urine flow Normal Little or none % body wt loss 4-5 % 10% or more Estimated fluid deficit 40-50ml/kg 100-110 ml/kg

20. 2) Intravenous rehydration:the solutions recommended by WHO for IV infusion are: (a) Ringer’s lactate solution (2) Diarrhoea treatment solution (DTS) 3) Maintenance therapy : after initial fluid and electrolyte deficit has been corrected, oral fluid is used for maintenance 4) Appropriate feeding: normal food intake should be promoted as soon as child is able to eat. This is relevant especially in breast fed babies

21. Treatment Plan for Rehydration Therapy Age First give 30ml/kg in Then give 70ml/kg in Infants 1 hour 5 hours Older 30 mins 2 ½ hours

22. Maintenance Therapy Amount of Diarrhoea Amount of oral fluid Mild diarrhoea (Not more than one stool every 2 hours or longer, or less than 5 ml stool/ kg/ hour) 100 ml/kg body weight/ day until diarrhoea stops Severe diarrhoea (More than one stool every 2 hours, or more than 5 ml of stool/ kg/ hour) Replace stool losses volume for volume; if not measurable, give 10 – 15ml/kg body weight/ hour

23. 5) Chemotherapy: antibiotic therapy should be considered only if cause of diarrhoea has been identified as shigella, typhoid or cholera. DOC of cholera – Doxicycline , Tetracycline. DOC of diarrhoea due to Shigella – Ciprofloxacin. 6) Zinc supplementation: It reduces the duration and severity of diarrhoea. Zinc supplements are given for 10 – 14 days to lower the incidence of diarrhoea in the following 2 to 3 months

24. MCH care practices Maternal nutrition: improve prenatal and postnatal nutrition Child nutrition: (a ) promotion of breast feeding (b) appropriate weaning practices (c ) supplementary feeding (d) Vitamin A supplementation

25. Preventive strategies Sanitation - improved hygiene, safe water supply, proper disposal of waste, hand hygiene practices Health education: convince people to adopt healthy practices Immunisation: Measles vaccine has a role in diarrhoea control Fly control

26. Rotavirus vaccine Rotarix – monovalent human rotavirus vaccine. It is administered orally in a 2-dose schedule to infants of approximately 2 and 4 months of age. Interval between the doses should be at least 4 weeks

27. Rota Teq – pentavalent bovine-human vaccine. The recommended schedule is 3 oral doses at ages 2, 4 and 6 months. The first dose administered between ages 6-12 weeks and subsequent doses at intervals of 4-10 weeks.

28. Diarrhoeal Diseases Control Programme in India

29. THE CASE MANAGEMENT PROCESS The case management process is presented on a series of charts, which show the sequence of steps and provide information for performing them. The charts describe the following steps: Assess the young infant or child Classify the illness Identify treatment Treat the infant or child Counsel the mother Give follow-up care

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