Epidemiology of anemia

This ppt describes about the epidemiology of anemia globally and in India

1. Epidemiology of Anemia
Dr. Jayaramachandran S
Assistant Professor
Department of Community Medicine
10.04.2018

2. Content
•Definition of epidemiology
•Introduction
•Global overview
•Indian burden
•Social determinants of anemia
•Thalassemia & Sickle cell anemia

3. Define Epidemiology?
EpidemiologyDistribution
Determinants
Health related states
or events
Specified population
Application
Control of health
problems

5. Introduction
•Over the past decade, anemia has emerged as a risk factor that is
associated with a variety of adverse outcomes
•The epidemiology of anemia and aging, in general, is particularly
challenging because of increased heterogeneity in the distribution of
social and biological risk factors with advancing age.
•Anaemia, a manifestation of under-nutrition and poor dietary intake
of iron is a serious public health problem among pregnant women,
infants, young children and adolescents.

7. Diagnosis & Assessment of Severity
Age No anemiaMildModerateSevere
6–59 months≥ 1110–10.97–9.9 <7
5–11 years≥ 11.511–11.48–10.9 <8
12–14 years≥ 1211–11.98–10.9 <8
Female >14 years≥ 1211–11.98–10.9 <8
Pregnant women≥ 1110–10.97–9.9 <7
Male >14 years≥ 1311–12.98–10.9 <8
Source: Haemoglobin concentration for the diagnosis of anaemia and assessment of severity. WHO

8. Public health significance of anaemia
Public health
problem
Number of countries
Preschool-age
children
Pregnant
women
Non-pregnant
women
None 2 0 1
Mild 40 33 59
Moderate81 91 78
Severe 69 68 54
Source: de Benoist B et al., eds.Worldwide prevalence of anaemia 1993-
2005.WHO Global Database on Anaemia Geneva, World Health Organization, 2008.

9. Adolescent enters reproductive age with
low iron stores (Pre-pregnant women)
Pregnant women with
anemia
Lactating women with
anemia
Baby with low iron & Hb levels (Infancy
& pre school child)
Uncorrected anemia in
Childhood
Adolescent with low iron & Hb
levels + menstrual loss
Vicious cycle
of anemia in
females

10. Global overview
•WHO Global Database on Anaemia for 1993–2005, estimated the
prevalence of anaemia worldwide at 25%.
•Estimated prevalence
•High development countries –9%
•Low development countries –43%.
•Africa and Asia account for more than 85% of the absolute anaemia
burden in high-risk groups

11. Global overview
1.62
billion
293 million children
of preschool age
56 million pregnant
women
468 million non-
pregnant women

12. Global overview
47 %
Child 1 –5 years
42%
Pregnant women
30%
Non-pregnant women
Children and women of reproductive age are most at risk

13. Population group
Prevalence of anaemiaPopulation affected
Percent95% CI(in million)95% CI
Preschool-age 47.445.7-49.1293 283-303
School-age 25.419.9-30.9305 238-371
Pregnant41.839.9-43.856 54-59
Non-pregnant30.228.7-31.6468 446-491
Men12.78.6-16.9260 175-345
Elderly23.918.3-29.4164 126-202
Total 24.822.9-26.716201500-1740
Source: de Benoist B et al., eds.Worldwide prevalence of anaemia 1993-2005.WHO Global
Database on Anaemia Geneva, World Health Organization, 2008

20. India
•India is among the countries with high prevalence of anaemia in the world.
•7 out of every 10 children aged 6 –59 months are anaemic.
•Children aged 6 –59 months
•3% are severely anaemic
•40 % are moderately anaemic
•26%are mildly anaemic
•Itis estimated that anaemia directly causes 20 per cent of maternal deaths
in India and indirectly accounts for another 20 per cent of maternal deaths.

25. Iron deficiency Anemia

26. Iron deficiency anemia –Global burden
Country Pregnant Non pregnant
India 88 74
Africa 50 40
Latin America40 30
•Developing countries: 2/3
rdof pregnant & ½ of non-pregnant women
•Developed countries: 4 –12% of women of child bearing age group

28. Anemia among children & AdultsUrbanRural Total
Children age 6-59 months (<11.0) 55.959.455.8
Non-pregnant women age 15-49 years (<12.0)51.054.3 53.1
Pregnant women age 15-49 years (<11.0) 45.752.1 50.3
All women age 15-49 years (%) 50.854.253.0
Men age 15-49 years (<13.0) 18.425.222.7
Indian Scenario

30. Anemia among children & AdultsUrbanRural Total
Children age 6-59 months (<11.0) 44.145.844.6
Non-pregnant women age 15-49 years (<12.0)53.055.0 53.6
Pregnant women age 15-49 years (<11.0) * * (21.6)
All women age 15-49 years who are anaemic (%)51.8 54.252.5
Men age 15-49 years who are anaemic (<13.0)16.3 12.615.0
Puducherry

31. Iron deficiency anemia
•Contributes to more than 50 % of anemia in our country

32. Determinants of Anemia

33. Age
•Iron deficiency commonly develops after six months of age if
complementary foods do not provide sufficient absorbable iron, even
for exclusively breastfed infants.
•Peak during preschool years & puberty
•2
ndpeak during old age
•More the birth order more is the incidence of anemia

34. Gender
•Following menarche, adolescent females often do not consume
sufficient iron to offset menstrual losses.
•As a result, a peak in the prevalence of iron deficiency frequently
occurs among females during adolescence.

35. Education
•Lower the literacy higher the chance of developing anemia

36. Socio economic status
•Iron deficiency is most common among groups of low socioeconomic
status

37. Environmental factors
•Poor hygiene
•Poor sanitation
•Bare foot walking
•Unsafe drinking water
•Rural > urban

38. Social factors
•Early marriage
•Median age of marriage = 17.7years
•Percent married by 18 years = 58%
•Median age at first birth = 20years
•Percentage of adolescents who have begun childbearing = 16

39. Host factors
•Given diet may be low in iron or may contain adequate amounts of
iron which are of low bioavailability
•Other nutrients necessary for haematopoiesis may also be deficient.
These include folic acid, vitamins A,B12, and C, protein, and copper
and other minerals
•Malabsorption

40. Host factors –Infant / Preschool / Children
•Low iron stores at birth due to anaemia in mother
•Non-exclusive breastfeeding
•Too early introduction of inappropriate complementary food
(resulting in diminished breast milk intake, insufficient iron intake,
and heightened risk of intestinal infections)
•Late introduction of appropriate (iron-rich) complementary foods

41. Host factors –adolescent & women in
reproductive age group
•Insufficient intake of quality & quantity iron rich foods
•Iron loss during menstruation
•Iron loss from post-partum haemorrhage

42. Host factors –Pregnancy
•Increased need of about 700-850 mg in body iron over the whole
pregnancy.
•Lactation results in loss of iron via breast milk

43. Host factors –infections / others
•Malaria by haemolysis
•Parasitic infections, e.g. hookworm, trichuriasis, amoebiasis, and
schistosomiasis
•Genetic factors, e.gthalassemia, sickle cell trait, and glucose-6-
phosphate dehydrogenase deficiency (G6PD)

44. Host factors –Food habits
•Excessive quantity of “iron inhibitors” in diet, especially during
mealtimes (e.g.,tea, coffee; calcium-rich foods)

45. Adolescent enters reproductive age with
low iron stores (Pre-pregnant women)
Pregnant women with
anemia
Lactating women with
anemia
Baby with low iron & Hb levels (Infancy
& pre school child)
Uncorrected anemia in
Childhood
Adolescent with low iron & Hb
levels + menstrual loss
Vicious cycle
of anemia in
females

46. Take home message
•How? Prevent –improving hygiene & prophylaxis
•Recognise –early diagnosis –clinical examination / biochemical test
•Treat –WIFS / National Iron
+initiative /
•Whom? all those high risk group in our country
•Why? It will reduce the direct and indirect causes of morbidity and
mortality

47. IDA –Adolescent girls –Population profile
Adolescent population
•226 million (20.5%)
Adolescent girls (10-19 years)
•109.4 million (48.4%)
Adolescent girls in school (15-19
years)
•16.4 million (15%)
Adolescent girls out of school
(15-19 years)
•38.2 million (35%)
Indian population

48. Anemia prevalence
•IDA prevalence reported to vary from 56% -90.1%
•67.8 –98.5 million adolescent girls are anemic

50. Thalassemia & sickle cell anemia : Global
•Estimated that around 3,00,000 to 4,00,000 babies with a severe
haemoglobin disorder are born each year.
•World-wide 56,000 conceptions would have a major thalassemia
disorder and among them around 30,000would have βthalassemia
major, the majority of babies being born in middle and low income
countries
•Thalassemia: Most children are born in low-income countries

51. Thalassemia & sickle cell anemia
•Around 1.1% of couples worldwide are at risk for having children
with a haemoglobin disorder and 2.7 per 1000 conceptions are
affected.
•Most affected children born in high-income countries survive with a
chronic disorder
•In low-income countries children die before the age of 5 years:
haemoglobin disorders contribute the equivalent of 3.4% of mortality
in children aged under 5 years worldwide.

52. Thalassemia -Global
•At least 5.2% of the world population (and over 7% of pregnant
women) carry a significant variant.
•Haemoglobin S accounts for 40% of carriers but causes over 80% of
disorders because of localized very high carrier prevalence: around
85% of sickle-cell disorders, and over 70% of all affected births occur
in Africa.
•In addition, at least 20% of the world population carry
α
+thalassaemia.

53. Thalassemia –India
•βthalassemia syndrome –1,00,000 patients
•The average prevalence of βthalassemia carriers is 3 –4% which
translates to 35 to 45 million carriers

54. Thalassemia –India
•Prevalence of pathological haemoglobinopathies in India is 1.2 per
1000 live births
•32,400 babies with a serious haemoglobin disorder born each year
based on 27 million births per year in India
•10,000 to 12,000 thalassemic children are born annually in India

55. Thalassemia –India
•The rate of homozygosity per 1000 births annually was 0.28 in
Maharashtra and 0.39 in Gujarat.
•HbEis prevalent in the north-eastern and eastern region where the
frequencies of HbEcarriers range from 3 to over 50%
•HbSis predominantly seen among the scheduled tribes, scheduled
castes and other backward casteswith carrier frequencies varying
from 5 to 35% in many groups

56. Sickle cell anemia
•Mostly prevalent among black
•Malaria incidence is high
•Haemoglobin S is carried by 8% of American blacks
•1 out of 400 births of American black

57. Sickle cell anemia
•Sickle cell disease –1,50,000 cases
•Sickle-cell disorders: In high-income countries that provide neonatal
diagnosis and care for patients, most survive well into adult lifeand,
because there is limited use of prenatal diagnosis, numbers of
patients are rising steadily