Global Health Challenges Social Analysis 76: Lecture 10

1. Global Health ChallengesSocial Analysis 76: Lecture 10 Harvard University Initiative for Global Health

2. Global Causes of Child Death Diarrhoeal Diseases Biology, Clinical Manifestations and Interventions Global Epidemiology History of Health System Response Respiratory Infections Biology, Clinical Manifestation and Interventions Global Epidemiology History of Health System Response Harvard University Initiative for Global Health

3. WHO Estimates Under-Five Deaths by Cause, 2002 Harvard University Initiative for Global Health

4. Global Causes of Child Death Diarrhoeal Diseases Biology, Clinical Manifestations and Interventions Global Epidemiology History of Health System Response Respiratory Infections Biology, Clinical Manifestation and Interventions Global Epidemiology History of Health System Response Harvard University Initiative for Global Health

5. Diarrhoea Diarrhoeal diseases are a complex of diseases that are characterized by diarrhoea. Diarrhoea can be divided into bloody diarrhoea, watery diarrhoea and epidemic diarrhoea. Although it is often difficult to isolate the pathogen, the main agents for watery diarrhoea are rotavirus, pathogenic E.coli, Campylobacter. The main cause of acute bloody diarrhoea is Shigella. Vibrio cholera is the major cause of epidemic diarrhoea. Diarrhoeas due to faecal-oral transmission Harvard University Initiative for Global Health

6. Dehydrating Diarrhoeal Disease Harvard University Initiative for Global Health

7. Diarrhoea Preventive Interventions • Breastfeeding – promotion of infant formula in 1970s was a cause of increased diarrhoea • Water, sanitation and personal hygiene – interrupt faecal-oral transmission • Complementary feeding • Zinc supplementation • Vitamin A supplementation • Rotavirus vaccination – two effective vaccines now licensed Harvard University Initiative for Global Health

8. Diarrhoea Treatment Interventions Standard therapy in a high-income countries is to give a dehydrated child intravenous fluids. These are costly and require access to health services. Research at the ICDDR,B lead to the development of oral rehydration therapy in the 1970s. A simple solution of sugar and salt in the right proportions has been demonstrated to provide effective rehydration and reduce diarrhoea case-fatality rates. ORT (oral rehydration therapy) has been promoted as a safe, low-cost therapy for home or clinic management of diarrhoea. Harvard University Initiative for Global Health

9. Diarrhoea Treatment Interventions Zinc has also been demonstrated to reduce severity of diarrhoeal episodes. For bloody diarrhoeas, there is also a role for antibiotic treatment. Harvard University Initiative for Global Health

10. Source: Kosek M, Bern C, Guerrant RL. The global burden of diarrhoeal disease, as estimated from studies published between 1992 and 2000. Bulletin of the World Health Organization, 2003,81(3). Harvard University Initiative for Global Health

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12. Trends in Diarrhoeal Disease Child mortality has declined in the 1990s. Direct evidence on causes of death is limited, but we suspect that deaths from diarrhoea declined. Little evidence on trends of diarrhoea due to different pathogens. Harvard University Initiative for Global Health

13. Diarrhoeal Disease Control • With the advent of ORT, WHO initiated a major effort in 1979 to • Raise awareness of the magnitude of diarrhoeal disease mortality • Demonstrate the effectiveness of ORS in different settings • Launch educational campaigns to teach mothers to use ORS at home and to encourage clinic workers to provide ORS to dehydrated children • In the 1980s, 110 countries developed control of diarrhoeal disease programs Harvard University Initiative for Global Health

14. Diarrhoeal Disease Control During 1980s and early 1990s, the WHO strategy for delivering oral rehydration therapy evolved. The initial focus was delivering preformulated packets of Oral Rehydration Salts (ORS) to peripheral facilities. With the recognition that most children with dehydrating diarrhoea never made it to a clinic, the emphasis was on recommended home fluids (home made sugar/salt solutions) and ORS. By the early 1990s, the emphasis had shifted to increased fluids and maintaining feeding. Harvard University Initiative for Global Health

15. ORT Coverage We suspect diarrhoeal disease mortality fell during the 1990s; was the decline due to ORT? Or improvement in nutritional status, better water supply, increased breastfeeding, Vitamin A? Comparable time-series data on ORS use is very limited. UNICEF Multiple-Indicator Cluster Surveys suggest that ORS coverage has reached one third to one half of children. Harvard University Initiative for Global Health

16. Estimated ORT Use (UNICEF Estimates) Harvard University Initiative for Global Health

17. IMCI Strategy Since 1992, WHO has focused efforts on the development of an integrated strategy to manage sick children. The logic is based on the similarity of symptom complexes for a number of childhood illnesses. Strictly “vertical”, one disease at a time approaches would miss the reality of clinical interaction for both sick children and health workers treating these children. Harvard University Initiative for Global Health

18. IMCI Strategy • Three components of the strategy: • Improve health worker diagnostic/treatment skills by training them to use evidence based standardized algorithms for managing dehydrating diarrhoea, malaria and acute lower respiratory infections. • Improve health systems support through district planning and management, increased drug availability, quality improvement and supervision, referral pathways, and health information systems. • Improve family and community health practices including promoting appropriate care-seeking, nutrition, and home case management. Harvard University Initiative for Global Health

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21. Global Causes of Child Death Diarrhoeal Diseases Biology, Clinical Manifestations and Interventions Global Epidemiology History of Health System Response Respiratory Infections Biology, Clinical Manifestation and Interventions Global Epidemiology History of Health System Response Harvard University Initiative for Global Health

22. Acute Respiratory Infection (ARI) Harvard University Initiative for Global Health

23. Acute Lower Respiratory Infections The major burden of respiratory infections are caused by lower respiratory infections, namely pneumonia. Pneumonia, infection of the tissue of the lung, can be caused by a range of organisms. The main identified causes are Streptococcus pneumoniae, Hemophilus influenzae type B (HiB) and respiratory syncitial virus (RSV). From the perspective of child health in developing countries, it is rare that a particular pathogen is isolated; huge uncertainty on the distribution of different etiologic agents of pneumonia remains. Harvard University Initiative for Global Health

24. Pneumonia Harvard University Initiative for Global Health

25. Acute Respiratory Infection Preventive Interventions • Breastfeeding – exclusive breast feeding for the first 4-6 months provides a protective effect. • Complementary feeding – improved nutritional status reduces case-fatality rates • Hemophilus influenza type B vaccination – already incorporated in GAVI new vaccine funds • Conjugate pneumococcal vaccine -- 7-serotype vaccine FDA licensed 2000; 9-valent tested in The Gambia with 16% reduction child mortality; many others being tested. • Zinc Harvard University Initiative for Global Health

26. Respiratory Infection Treatment Interventions Antibiotics for severe lower respiratory infections are essential to reduce the case-fatality rate. WHO uses a sensitive and relatively non-specific definition of pneumonia to govern antibiotic treatment: fast breathing or lower chest wall indrawing in a child presenting with cough or difficult breathing. Gold standard diagnosis is based on a chest X-ray. Harvard University Initiative for Global Health

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28. Trends in Acute Respiratory Infections As a major component of child mortality, we expect the decline in child deaths in the 1990s was in part due to declines in pneumonia. There is, however, little direct evidence to back up this claim. The average number of episodes of lower respiratory tract infections is much lower. Harvard University Initiative for Global Health

29. ARI Programme WHO launched a Programme for Control of Acute Respiratory Infections in 1984. Strategy was to promote early detection and treatment of pneumonia with antibiotics by first-level health facility workers. Standard treatments based on cotrimoxazole or amoxycillin. In 1992, diarrhoea and ARI programmes merged into Integrated Management of Childhood Illness strategy. Harvard University Initiative for Global Health

30. Coverage of Antibiotic Treatment for ARI (UNICEF MICS Surveys) Harvard University Initiative for Global Health

31. IMCI Evaluation IMCI evaluation undertaken in Bangladesh, Brazil, Peru, Tanzania and Uganda. IMCI programs successful in improving quality of care of sick children presenting at government health facilities. Except in Tanzania, only 5-20% of sick children visit a government health facility. Impact of IMCI very limited because utilization of care is low. No mortality impact except for a statistically non-significant reduction in Tanzania. Challenge for child survival is to reach children in the community using a strategy that does not depend on high utilization of health services for sick children. Harvard University Initiative for Global Health

32. IMCI and New Vaccines IMCI evaluation in Bangladesh 19% of sick children in the IMCI area were taken to a health worker compared with 9% in the non-IMCI area. Growing movement to reconsider IMCI as the main strategy for managing major illnesses for children in poor countries. Given that HiB and Pneumococcus are the largest contributors to pneumonia deaths, including these vaccines in GAVI and national vaccine programs is an important strategy for the future. Harvard University Initiative for Global Health

33. Global Initiatives Period of major increase in attention for child survival interventions. UNICEF has a new Executive Director, Ann Venneman who has declared that UNICEF will return to its 1980s focus on child survival. New Partnership for Maternal, Newborn and Child Health launched in January 2006. Norway and the Gates Foundation are developing an MDG4 (reduce child mortality) business plan. Harvard University Initiative for Global Health