Lecture 1: Introduction to course and assignment theory
Isolation and quarantine are different in the choice you give someone. Quarantine is on the
suspicion of a disease, while isolation is when you know that someone is sick. Quarantine is
less used in NL, because it is indirect against the freedom of a person.
HIV/aids led to a variety of containment approaches,
- VCT (voluntary counselling and testing)
- treatment campaigns
- MTCT (Mother-to-Child-transformation)
- micro-credits
- self-help groups
- BEHAVIOUR change programs
- global fund
Contagious diseases can be air born, vector born, water/food born, STD, zoonoses.
We can eliminate diseases, or we can control them because elimination is impossible.
Evidence informed decision making (EIDM)
- Evidence matters,
o related to the agent, its causes, and the effectiveness of the solution.
- Context matters
o what contextual issues contribute to the problem? What solutions work from
where.
- Integration of Evidence, Epistemological justice (TDR)
Precede/Proceed model – Green and Keuter
Precede is development.
Proceed is implementation and evaluation.
,Intervention mapping – Bartholomew et al.
Behaviour changes and communication models
- Theory of plan behaviour
- Health belief model
Designing an intervention framework. You should understand behaviour – knowing what to
change. Also, for technology-based interventions, behaviour matters.
5 steps in health intervention
1. What is the problem?
2. What factors cause the problem?
3. How can these factors be changed?
4. What overall interventions strategies are most appropriate and cost effective?
5. What needs to be done to reach the goals? With what populations shall work be
done, and in what sequence, to solve the problem?
1. What is the problem? (Is it a priority health problem?)
Burden of disease + potential burden.
There are many different measures,
- mortality/morbidity
- DALY, developed by WHO
- global burden of disease
- Socio-economic impact (economic and social costs). When you’re sick, how are you
still able to participate in society?
, - For whom?
In practice this phase, in practice is not purely a desk study. It requires data collection
among/with target group: participation of stakeholders, end-users Needs assessment.
Use the following research methods:
- Routine information: national census data, death certification and registers, hospital
and clinic records, disease notification systems, lab tests
- Epidemiological data: cross-sectional study
- Community appraisals: questionnaires, interviews, focus groups, visualisation, and
diagramming.
2. What factors cause the problem?
Neglected tropical diseases – as a global community we do not invest enough in them. We
have no research in them, and we don’t address them (that’s why they’re neglected).
Understanding the problem is 80% of solving the problem. Tools to identify causes – epi
triangle, problem tree literature and common sense.
The epi triangle helps us understand the occurrence of a
disease. It unruffles all the causes. It will enable us to
think of ways to break the chain of transmission. How can
we intervein and come up with solutions.
vector
It is an interaction between the agent (the cause of the
disease), the host (the person who gets sick), within an
environment. To identify the cause of the disease and to
identify how to intervene.
AGENT – cause of the disease – think about the
transmissibility, incubation period, in extend we can treat it. It can be parasites, bacteria,
viruses etc. another important thing is the pathogenicity/virulence. To what extend can it
cause disease and to what extend can it cause death?
HOST – susceptibility – a person or an animal who carries the agent. Why is a certain host
susceptible? Due to biological factors? Immunity, genes, vaccinations, nutritional status. But
also behavioural, some hosts are more acceptable due to their behaviour. Sexual behaviour,
distance etc. it is the product of the attitude of people. But not always our behaviour is on
purpose. Some people for instance work in an environment where there is more risk, such as
doctors or nurses.
ENVIRONMENT – favourable – the physical environment, some diseases are places in the
world, this can be due to climate etc. Also dependent on the socio-economic environment,
the man-made environment. Think about the health system, how is the vaccination system
organized? But also, less health related, what is the main mode of public transport?
Ideological /cultural factors, what are attitudes towards vaccination?
VECTOR – some diseases are not transmitted directly but through a vector. In that specific
case it is important to analyse what important factors of the vector are relevant to the
disease. This can be biological, the mosquito or it can be mechanical, the needle.
Disease occurrence is the result of an interaction between host, agent, and/or environment.
, Social determinants of health ecological models:
3. How can all those factors be changed?
5 basic strategies to intervene:
1. Change/kill the agent, can be done by for example using disinfect.
2. Raise host resistance, make host less susceptible for the disease. This can be done by
a vaccination program. How can we change their behaviour, maybe with knowledge.
3. Modify the environment, less out brakes. Setting up a surveillance system, or by
removing mosquito breeding places etc.
4. Separate agent from host (isolation for example)
5. Interrupt transmission (infected to non-infected individual)
Example:
Intervention Diarrhoea
Change the agent Disinfection
Raise host resistance Proper nutrition
Modify the environment Enforcing sanitary standards
Separate agent from host Don’t let children play among animals
Interrupt transmission Special sanitary care for the sick
Socio-ecological models help us to identify the occurrence of infectious diseases. It can be an
alternative.
Preventive programs deal with a complex web of aetiology (causation). Hence, a web of
interventions is needed in many conditions. This has often a risk factor strategy, reducing
risks and increasing protective factors. This requires intersectional cooperation, and personal
and collective behavioural change.
4. What overall intervention strategies are most appropriate and cost effective?
Intervention analysis, using research methods similar to problem analyses. Make a list of
relevant interventions and review them. Look at:
- Medical-technical effectiveness
- Organisational effectiveness
- Social, cultural, and political feasibility
- Financial feasibility