week 2

Question 1

what growth measures are routinely collected in UK children

Answer 1

weight - baby, school age and sometimes pre school age
head circumference - only as a baby
length - only as a baby and if they cannot stand
height - after age 2
BMI - after age 2

Question 2

how is weight measured

Answer 2

using clincal grade electronic scales
wearing light indoor clothes and no shoes
babies weighed naked

Question 3

how is head circumference measured

Answer 3

using a non-elastic plastic tape

measured 3 times or more - until at least 2 are the same

Question 4

how is length measured

Answer 4

using a stiff or rigid board

Question 5

how is height measured

Answer 5

using rigid measure with t piece or stadiometer

shoes off, feet flat

Question 6

what does it mean if a patient is outside +2SD or -2SD on a growth chart

Answer 6

not healthy at all

Question 7

standard centile lines

Answer 7

lines on the growth chart are evenly spaced at 2/3 SD and include extreme outer centiles

Question 8

what does a height on the 25th centile mean

Answer 8

should be around 25 children shorter and 75 taller

Question 9

how did WHO build an ideal growth chart

Answer 9

6 different cohorts from around the world using the same protocol and criteria:
child healthy
breastfed for first 4 months and impartially for a year
no smoking
prosperous mothers

Question 10

how to tell if an individuals growth is normal

Answer 10

both weight and height tend to track within one centile space
weight commonly varies over short term in pre school years due to illness
height may show wide variation due to measurement error

Question 11

what makes a child short

Answer 11

genetic - polygenic inheritance 
rate of maturation - some grow faster than others
severe chronic illness and treatment
chromosomal anomolies: turners, downs
growth hormone deficiency 
chronic undernutrition

Question 12

describe the 3 severities of malnutrition

Answer 12

severe acute malnutrition - below 3 standard deviations of median weight or height, visible severe wasting or presence of nutritional oedema
moderate malnutrition - weight loss and 2 to 3 SDs below the median weight or height
acute malnutrition - 1 to 2 SDs below median weight or height

Question 13

3 types of malnutrition

Answer 13

mineral deficiency
protein energy malnutrion
avitaminosis

Question 14

BMI for an obese adult

Answer 14

> 30 for obesity

>25 for overweight

Question 15

what medical problems is obesity associated with

Answer 15

type II diabetes
ischaemic heart disease
cerebrovascular disease
osteoarthritis 
hypertension 
some cancers
psychological problems

Question 16

social problems associated with obesity

Answer 16

body image dichotomy
difficulty engaging in some common social activities eg gym or employment
stigma

Question 17

economic problems associated with obesity

Answer 17

sick leave

costs to NHS

Question 18

causes of obesity

Answer 18

genetic predispositions
leptin and appetite control
insulin production and fat deposition
individual diet and exercise patterns
deprivation, learning disability, gender and race
obesogenic environment
technological progress

Question 19

what is an obesogenic environment

Answer 19

readily available, cheap and heavily marketed energy rich foods
increase in labour saving devices eg lifts
increase in passive and motorised personal transport eg cars instead of walking
decreased participation i nactive leisure pursuits and total energy expenditure

Question 20

milk-producing cells

Answer 20

lactocytes

Question 21

function of oxytocin in breastmilk

Answer 21

stimulates myoepithelial cells to contract, pushing the milk into lactiferous ducts and towards the nipple

Question 22

function of montgomery tubercles

Answer 22

glands which secrete a sebaceous fluid that lubricates the nipple and protects the skin
fluid has an individual aroma attracting infant to the mother

Question 23

control of lactation

Answer 23

suckling sends powerful stimulus via higher sensors in the hypothalamus to posterior pituitary - secretes oxytocin
this acts on smooth muscle in alveoli which contract and inject milk into the lactiferous ducts
same stimulus acts on anterior pituitary to produce lactin - stimulates lactocytes to secrete milk for the next feed
milk contains feedback inhibitor of lactation which inhibits milk production when it accumulates

Question 24

protein in human milk

Answer 24

main one is alpha lactalbumin and is associated with the destruction of over 40 types of cancer cells

Question 25

carbohydrate in milk

Answer 25

Lactose is the main primary carbohydrate - provides 40% of total calories improves the absorption of calcium and promotes growth of healthy bacteria

Question 26

components of human milk not in formula

Answer 26

``` stem cells growth factors immunoglobulins leukocytes lactoferrin oligosaccharides human milk lipids IL-7 ```

Question 27

describe colostrum

Answer 27

``` first milk produced from breasts from 16 weeks of pregnancy consists of thick, yellowish fluid rich in vit A antibodies and anti-infective proteins ```

Question 28

benefits of breastfeeding

Answer 28

immune protection: breastfeeding activates broncho-entero-mammary pathway - when mother inhales pathogens, lymph nodes in the lungs and small intestine manufacture specially sensitised lymphocytes which migrate to the breasts and create antibodies promotes development of the brain: contains long-chain polyunsaturated fatty acids such as docosahexaenoic which support brain development and intelligence promotes maturation of gut: epidermal GF promotes healing, neuronal GFs promote development of peristalsis - help reduce chance of necrotising enterocolitis protects mothers health: protects against postpartum haemorrhage and depression, ovarian and breast cancers, heart disease and type II diabetes

Question 29

importance of skin to skin contact

Answer 29

triggers lactation and mothering hormones triggers calming hormones in the baby stimulates digestion stimulates instinctive feeding behaviors enables infants skin to become colonised by protective bacteria from mothers skin

Question 30

positioning during breastfeeding

Answer 30

``` CHIN keep baby Close baby will tilt Head back baby's head and body should be In line Nose to nipple ```

Question 31

role of oxytocin in babies

Answer 31

when they feel secure they release oxytocin | vital for brain development

Question 32

doctors role in breastfeeding

Answer 32

encourage and discuss importance encourage skin to skin contact acknowledge mother may need support avoid advising supplementary bottle feeds just to allay anxiety dont prescribe medication without checking safety for lactation

Question 33

breastfeeding as a societal issue

Answer 33

breasts still seen as sexual little support for breast feeding in public or long-term breastfeeding media portrays bottle feeding

Question 34

breastfeeding as an economical issue

Answer 34

not breastfeeding is associated with lower intelligence and economic losses failing to breastfeed costs global economy

Question 35

aim of an immunisation programme

Answer 35

to protect those at highest risk (selective immunisation stategy) or to eradicate, eliminate or contain disesae (mass immunisation strategy)

Question 36

describe selective vaccination

Answer 36

``` vaccine does not need to be given to all, only those at increased risk of disease: travel high risk groups occupational risk outbreak control ```

Question 37

describe mass vaccination

Answer 37

eradication - disease and causal agent removed worldwide elimination - disease disappeared from one WHO region but remains elsewhere containment - disease no longer constitutes a significatn public health problem

Question 38

aim of an ideal vaccine

Answer 38

to produce the same immune protection which usually follows natural disease but without causing the disease to generate long-lasting immunity to interrupt spread of infection

Question 39

contradictions and precautions of vaccinations

Answer 39

those with primary or acquired immunodefiency those on immunosuppressives, including biological therapy pregnant women infants born to a mother who received immunosuppressive biological therapy during pregnancy those in contact with an individual with immunodeficiency, current recent immunosuppressive including biological therapy

Question 40

what are live vaccines

Answer 40

attenuated (weakened) strains which replicate in host act like natural infection closest to actual infection and therefore elicit good, strong, long-lasting immune responses

Question 41

examples of live vaccines

Answer 41

MMR BCG yellow fever

Question 42

what are inactivated vaccines

Answer 42

do not contain a pathogen capable of replicating and causing disease

Question 43

live v inactivated vaccines

Answer 43

``` live: longer lasting immunity strong immune response evoked can revert to virulence poor stability cannot use in pregnancy or immunosupressed inactivated: shorter lasting immunity adjuvant needed unable to cause infection stable constituents clearly defined less contradictions need several doses local reactions common ```

Question 44

describe herd immunity

Answer 44

for. each disease there is a certain level of immunity in the population which protects the whole population because the pathogen stops spreading within the community provides indirect protection of unvaccinated individuals

Question 45

examples of vaccine preventable diseases

Answer 45

``` bacterial: diphtheria tetanus TB pertussis (whooping cough) meningococcal c disease pneumococcal disease viral: measles mumps rubella HPV varicella Hep b influenza poliomyelitis ```

Question 46

what is passive immunity

Answer 46

provides protection at, or around the time of exposure to a specific pathogen given to individuals who are at high risk of severe disease or of developing severe complications from the disease they provide immediate but temporary protection does no stimulate the immune system to make any antibodies

Question 47

example of passive immunity

Answer 47

transplacental - most important source in newborn

Question 48

types of antibody preparations

Answer 48

human source - pooled blood preparations from donors (plasma or immunoglobulin) monoclonal animal source

Question 49

examples of antibodie preparations from human sources

Answer 49

hepatitis b immunoglobulin human rabies immunoglobulin tetanus immunoglobulin

Question 50

antibody preparation pros and cons

Answer 50

pros: rapid, preventative, can be given to those where vaccine is contradicted cons: expensive, potential for adverse events, limited evidence base for some, no lasting immunity

Question 51

factors influencing a vaccine

Answer 51

``` benefit to others fidelity (keep commitments) autonomy no harm transparency (reasons behind) justice utility (helping great amount of people) trust privacy (sharing of data) risk effectiveness reciprocity (taking vaccine when healthy - some become unhealthy) ```

Question 52

questions to consider when developing a vaccine programme

Answer 52

is there a need for the vaccine? - does it cause a significant health problem is a suitable vaccine available that is safe and effective? can the programme be delivered in a safe, effective and cost-effective manner? what is the aim of the programme?

Question 53

what is surveillance of a vaccine programme

Answer 53

the ongoing, systematic collection, recording, analysis, interpretation and disseminaton of data

Question 54

when does surveillance of a vaccine programme need to occur

Answer 54

``` pre-implementation: to estimate burden of disease to decide vaccine strategy post implementation: to monitor effectiveness of vaccine strategy ```

Question 55

issues in vaccine policy decisions

Answer 55

``` disease incidence, vaccine safety, efficacy from surveillance aim of programme cost of programme population accessibility cultural attitudes and practices facilities available for delivery ```

Question 56

symptoms of pertussis

Answer 56

``` initially: cold-like symptoms followed by: gradually worsening cough paroxysms of coughing characteristic whoop post-tussive vomiting conjuctival haemorrhage ```

Question 57

complications of pertussis

Answer 57

respiratoy - majority of cases involve a collapsed lung and/or pneumonia neurological - lack of oxygen leading to altered consciousness, convulsions, permanent brain damage, death severe weight loss and dehydration due to vomiting sudden death

Question 58

history of pertussis vaccines

Answer 58

whole cell vaccine used until 2004 rates dropped to 30% in 1975 due to anxiety about safety epidemics between 1977 and 1983 acellular vaccine added to preschool booster in 2001 and replaced whole cell vaccine in 2004

Question 59

current issues with pertussis

Answer 59

some evidence of vaccine waning with age pertussis remains the most common vaccine preventable disease in <1y with highest mortality 2012 temporary programme to offer vaccine to pregnant women weeks 28 and 32 - 2014 programme extended for at least 5 years 2016 advice changed so vaccine given from week 16

Question 60

challenges of global immunisation

Answer 60

``` funding, coverage, uptae surveillance different priorities, different vaccines multiple agencies: bill and melinda gates, UNICEF suspicion, mistrust violence - war, civil unrest ```

Question 61

difference between active immunity and passive immunity

Answer 61

active - protection produced by a persons own immune system by natural infection or artificial immunisation means passive - protection transferred from another person or animal as antibody. can be natural (transplacental) or artifical (immunoglobulin)

Question 62

vaccine definition

Answer 62

induced immunity using vaccine

Question 63

immunisation definition

Answer 63

vaccine induced immunity and the transfer of antibodies/immunoglobulins

Question 64

antigen definition

Answer 64

a live or inactivated substance capable of producing an immune response or any substance than be bound by an antibody

Question 65

antibody definition

Answer 65

immunoglobulin produced by b lymphocytes to help eliminate a pathogen

Question 66

polysaccharide v conjugate vaccines

Answer 66

polysaccharide: t-cell independent less immunogenic in under 2s no booster response - immune response after 2nd dose is similar to 1st dose conjugate: polysaccharide antigen linked to a protein antigen (strong anitgen with weak antigen - strong immune response to weak antigen) conjugates can include toxoids, CRM197 designed to enhance immune response, particularly in children under 2y/o

Question 67

components of a vaccine

Answer 67

stabilisers - prevent components adhering to side of vial trace components preservatives antibiotics adjuvants - substance that enhances immune response in presence of an antigen

Question 68

purpose of intervals between vaccines

Answer 68

to allow each immune response to develop | to avoid immune interference

Question 69

primary v secondary vaccine failure

Answer 69

primary - no/limited response | secondary - immunity wanes over time

Question 70

frequency of adverse events in live and inactivated vaccines

Answer 70

live - reduces with additional dose | inactive - increases with additional dose

Question 71

timing of adverse events in live and inactivated vaccines

Answer 71

live - depends on time for pathogen to replicate | inactive - generally within 48 hours of vaccine

Question 72

what is the reproduction number

Answer 72

r = the effective reproduction number number of secondary infections produced by a typical infective r0 = basic reproduction number number of secondary infections produced by a typical infective in a totally susceptible population R0>1 = epidemic possible

Question 73

herd immunity threshold

Answer 73

HIT = 1 - (1/R0) how many people we need to vaccinate to prevent epidemic also called critical vaccine threshold