Transcript Slide 1
Anaemia in a Rural Community Ian Couper Professor of Rural Health Objective Discuss intervention strategies for addressing anaemia in rural communities Aim To explore multiple causative factors of anaemia in a rural context and possible intervention strategies to address these. Ms Dorah Mahlangu 24 years old Lives in rural Kosi Bay area Presents to you with tiredness Tiredness Many causes • Physiological • Physical (organic) • Psychological Acute vs. Chronic Ms Dorah Mahlangu 24 years old Lives in rural Kosi Bay area Presents to you with tiredness. • Also shortness of breath on exertion, palpitations, headache. On examination, her mucous membranes are very pale Anaemia Definition: • “abnormally low levels of haemoglobin in the blood” What is abnormal? • <14g% in men; <12g% in women Need to confirm: how? • FBC • Haemoglobinometer ( “finger prick Hb”) • Copper sulphate solution Ms Dorah Mahlangu 24 years old Lives in rural Kosi Bay area Presents to you with tiredness (etc) On exam, mucous membranes very pale • Also, pitting oedema of legs, soft ejection systolic murmur Hb = 4.3g% Is this a diagnosis? No! • Anaemia is a sign of disease, like fever Acute versus chronic • Implications of such a low Hb (severe anaemia) • Both dangerous in different ways: Acute: Shock Chronic: Decompensation • Compatible with ongoing life? Adaptation dependent on • • • • Severity rapidity of onset age pre-existing disease (especially cardiovascular) Types of anaemia What are causes? • What kind of anaemia is it? • Classification: Pathophysiological • Impaired Hb production Nutritional deficiencies Disturbances of bone marrow function Secondary to other conditions (e.g. infections, malignancies, etc) • Increased Hb loss (haemorrhage) • Increased Hb destruction (haemolysis) Morphological (red cell size) • Microcytic • Macrocytic • Normocytic Ms Dorah Mahlangu 24 years old Lives in rural Kosi Bay area Presents to you with tiredness (etc) O/E mucous membranes very pale, etc HB = 4.3g% Microcytic anaemia Microcytic anaemia Caused by iron deficiency anaemia • Can confirm by measuring serum iron, other iron studies, serum ferritin, etc. Not normally done in a rural hospital Need to exclude anaemia of chronic disorders and thalassaemia syndromes • Is this a diagnosis? What are the causes of her iron deficiency? Causes of iron deficiency anaemia Inadequate iron intake • Dietary deficiency • Impaired iron absorption (gastric lesions and malabsorption syndromes) Iron use exceeds intake • Loss due to bleeding Acute vs. chronic Sites of chronic blood loss • genital tract e.g. excessive menstrual loss • urinary tract e.g. haematuria • GI tract e.g. piles, parasites • Excessive requirements Infancy pregnancy Ms Dorah Mahlangu History: Menorrhagia • We have found a cause: are we now ready to treat? • What is causing the menorrhagia? Examination: Bleeding piles (haemorrhoids) • We have found 2 causes: are we now ready to treat? • What is causing the piles? Urine dipsticks • Haematuria • What is causing the haematuria? Stool microscopy • Hookworm Ms Dorah Mahlangu So … • Tiredness anaemia iron deficiency blood loss menorrhagia (hormonal imbalance) piles (since last child born) haematuria (due to urinary bilharzia = Schistosoma haematobium infection) hookworm infestation (Ancylostoma duodenale and Necator americanus) Treatment? Treatment Treat symptoms • Analgesic, e.g. paracetamol, for headache, etc Treat superficial cause • Dietary advice Animal foods (eggs, fish, meat, etc) Green vegetables (beans, peas, spinach, etc) • Iron supplementation E.g. ferrous sulphate 200mg 3X daily • Transfusion? Treatment Treat underlying causes • Hormonal regulation E.g. oral contraceptive pill • Piles E.g. dietary advice, local preparations • Hookworm E.g. albendazole 2 tablets • Bilharzia E.g. praziquantel Prevention Dietary advice (as above) Ongoing supplementation (FeSO4 at lower dose) Educate re bowel habits Avoiding contaminated water sources Knowing the signs – getting treatment early Hygiene What about the community? Ms Mahlangu’s community Poor rural community • Few people have cattle Sandy soil: • Parasites common (intestinal worms and S. hamatobium) • Difficult to grow vegetables • VIP latrines difficult to build No reticulated water: • Streams used for washing clothes, bathing, water for consumption, etc • Impact on sanitation Sub-tropical • Malaria common High fertility rate • Early age of first pregnancy High infant mortality • Increased number of pregnancies Treating the community An example of one project: Manguzi School Health Programme Nutritional intervention Iron supplementation Treatment of worms Treatment of bilharzia Education of students and families Dilemmas: dealing with conflicting knowledge Example 1: Bilharzia Correct advice: avoid contaminated water Problem: • All water in the community is contaminated • Climate very hot A solution: offer regular treatment Dilemmas: dealing with conflicting knowledge Example 2: Anaemia in antenatal patients in Kosi Bay Very common Causes • • • • Physiological Diet Parasites (intestinal and urinary) Malaria Dilemmas: dealing with conflicting knowledge Example 2: Anaemia in antenatal patients in Kosi Bay (cont) Problems: • Patients not responding • Dangerous (haemorrhage and maternal death) • Patients more at risk of complicated malaria (due to pregnancy and anaemia) • albendazole (for worms) and praziquantel (for bilharzia) not advised in pregnancy Action: • Iron (and folate) supplementation • Treatment of all patients for parasites after 1st trimester Causality One cause-one disease model is too simple Illness in an individual results from a multitude of prior circumstances Causal factors differ among individuals with the same illness Criteria for evaluating causality: • • • • • Temporality of association (time factor) Strength of association Specificity of association Consistency of association Biological plausibility Epidemiological understanding of causality Cause = stimulus that produces an effect or outcome Statistically significant association between 2 factors. Relationship may be causal or noncausal (e.g. living in Kosi Bay area and anaemia) Casual relationships may be: • direct e.g. menorrhagia anaemia • indirect e.g. pregnancy increased requirements for iron anaemia (in absence of increased intake) • sometimes they are both e.g. pica (i.e. eating sand) Fe deficiency anaemia, in 2 ways: directly, by decreasing availability of Fe and indirectly via parasitic infection Multiple causation Concept of multiple causes • Multiple causes of symptoms/illness E.g. anaemia • Multiple causes of single diseases E.g. chronic diseases Multiple causes: meanings • Multiple factors involved in inducing the mechanism that causes the disease • Each factor in disease causation has its own set of determinants • Identical diseases may be caused by different sets of factors Concept of a web of causation Web of causation: Anaemia in a Rural Community Nutritional • Diet poor in iron Environmental • Worms common in soil • Bilharzia common in water Infectious diseases • Malaria • HIV Fertility rate • Many pregnancies with poor recovery between Other illnesses common • Chronic disease Why is it a problem? (Is there a need to intervene?) Increased incidence of infection • The malnutrition-infection cycle. Increased mortality from malaria Increased risk of maternal and neonatal death Poor school performance • Impact on future nutrition • Impact on health seeking behaviour • etc Intervention Must be multifactorial Dealing with individuals only does not solve the problem Community wide approaches e.g. • • • • • • Water programmes Sanitation programmes Spraying for mosquitoes Education Fortification of foods Community wide supplementation Principles Always determine the cause of anaemia (any illness) before treating it Clinical reasoning: Always ask “why?” Illness often has multiple causes: causation is not simple and linear We cannot always know all the causes. Treatment and prevention cannot be separated Management of individuals is often insufficient: • Systematic approaches (cf. antenatal clinic example) • Community level action (cf. school health example)