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Report 4 (of 5): Net Profit
- Tanzania
Introduction
Malaria is a life-threatening parasitic
disease transmitted through the bite of a female Anopheles
mosquito, which feed from dusk until dawn. Worldwide,
more than one million people die from malaria each
year, mostly children, and up to 500 million cases
of acute illness result from the disease. The greatest
impact is found in Africa where around 90 per cent
of cases occur. That's the equivalent of more than
2,400 deaths every single day. Malaria can cause severe
anaemia, miscarriage and death in pregnant women and
is responsible for almost one-third of preventable
low birth weight in newborn babies. It also poses
a risk to travellers and immigrants as treatment and
control have become more difficult with the spread
of drug-resistant strains of parasites and insecticide-resistant
strains of mosquito.
In Tanzania, almost a third of deaths
are caused by malaria. As a result, the country is
committed to controlling the disease with activities
developed and co-ordinated by the National Malaria
Control Programme within the Ministry of Health. This
has made Tanzania a world leader in research into
malaria prevention and in particular insecticide-treated
nets or ITNs. Population Services International (PSI),
an non-governmental organisation (NGO) is using social
marketing to promote ITNs in nine African countries
including Tanzania, to help prevent malaria and save
lives. In collaboration with ministries of health,
PSI has sold over one million nets and almost two
million treatment kits in Africa.
The development of the 'dip-it-yourself'
kit for home treatment, together with government elimination
of sales tax on ready-made nets in Tanzania, has resulted
in an increase in the sale of ITNs, which are being
hailed as the most promising available method of controlling
malaria in tropical countries. Recent field trials
have shown that treated nets can have a massive impact,
reducing child deaths by up to 25 per cent.
Mosquitoes
Mosquitoes have been around for 100
million years. In that time they have diversified
into 3,000 species that are very different from one
another.
The facts:
- Worldwide, mosquito-borne diseases
kill more people than any other single factor.
- Mosquitoes can be carriers of malaria,
yellow fever, and dengue fever.
- Malaria is transmitted to humans
by the bite of infected female mosquitoes.
- The average life span of a female
mosquito is 3 to 100 days, whereas the male lives
10 to 20 days.
- One female mosquito may lay 100
to 300 eggs at a time and may average 1,000 to 3,000
offspring during her life span.
- Most mosquitoes remain within a
1-mile radius of their breeding site.
- Mosquitoes breed in areas where
there is stagnant water such as swamps, and during
the rainy seasons in African countries.
An Anopheles mosquito
© Iowa State University Entomology Department
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Malaria
Malaria is a very serious disease.
The malaria parasite infects and kills red blood cells,
which carry oxygen from the lungs throughout the body.
The classic course of malaria consists
of bouts of fever accompanied by other symptoms and
alternating with periods of freedom from any feeling
of illness. The intermittent type of fever is usually
absent at the beginning of the disease, when headache,
malaise, fatigue, nausea, muscular pains, slight diarrhoea
and slight increase of body temperature are the predominant
and vague symptoms, often mistaken for influenza (flu)
or a gastro-intestinal infection. Most severe forms
of the disease result in organ failure, delirium,
impaired consciousness and generalised convulsions
followed by persistent coma and death.
Symptoms may occur 7 to 8 days after
infection, but often reappear months or years after
infection if not treated properly. The most common
forms of prevention include anti-malarial drugs (such
as chloroquine, mefloquine and Fansidar), that kill
malaria parasites, insect repellent and mosquito nets.
Treatment may be prescribed to protect
against clinical symptoms. The type of treatment depends
on the area, local species of malaria, local pattern
of anti-malarial drug resistance, and personal characteristics
such as allergies or pregnancy. It is always best
to contact your doctor about the exact treatment that
would be suitable for you. Adequately and promptly
treated, malaria is a curable disease.
Malaria Prevention
Malaria has the biggest impact on
poor people, particular those in rural areas of developing
countries. People living in poor quality housing are
especially at risk. Poor people are at greater risk
of complications and death, because their access to
effective treatment is so limited. Malaria also contributes
to poverty by reducing the productivity of infected
people and their carers.
There are numerous ways to avoid catching
malaria and to prevent the disease spreading. Protection
from biting mosquitoes is the first line of defence:
- Use screens over doors and windows.
If accommodation allows entry of mosquitoes, use
a mosquito net over the bed.
- Use anti-mosquito sprays or insecticide
dispensers that contain tablets impregnated with
insecticide, or burn insecticide mosquito coils
in bedroom at night.
- If possible, avoid going out between
dusk and dawn when mosquitoes commonly bite.
- Wear long-sleeved clothing and
long trousers when going out at night, and avoid
dark colours, which attract mosquitoes.
- Apply insect repellent to exposed
skin, choosing one with DEET (dimethylphthalate).
More long-term methods to prevent
catching and spreading malaria include:
- Control of mosquitoes by eliminating
stagnant water where they can breed and using pesticides
such as DDT (dichlorodiphenyltrichloroethane). Rain
gutters, tree holes, old buckets or tyres with stagnant
water are common examples of breeding sites.
- Limiting the chances of human exposure
to the infected mosquito by community-based intervention
such as distribution of window screens and treated
bednets.
- Prevention of disease through the
use of anti-malarial drugs, particularly effective
for travellers exposed to mosquitoes for a limited
period of time.
Prevention of human disease through
use of vaccines has proven a difficult challenge due
to the complexity of the organism, its ability to
change through its life cycle both in the human and
in the mosquito, and its ability to hide from the
immune system.
Population Services International
Social marketing uses commercial marketing
methods such as consumer research, market segmentation,
branding and mass media advertising, to create demand
for health products and services. Social marketing
aims to meet a social need whereas traditional marketing
aims to maximise profit. Social marketing usually
involves subsidising the products and services, and
seeks to achieve a balance between affordable prices
and cost recovery.
PSI has devised responsive social
marketing strategies to overcome the many challenges
faced by today's African ITN initiatives:
- Market Segmentation: PSI
sells several products at different prices through
diverse outlets to multiple target groups, increasing
access to ITNs while maximizing cost recovery. To
reach pregnant women, PSI sells lower priced nets
with a distinct colour through antenatal clinics
in rural areas.
- Forming partnerships: PSI
forms partnerships with commercial companies, NGOs,
and women's cooperatives to deliver ITNs through
multiple channels. PSI always works closely with
the malaria control program of each country's Ministry
of Health.
- Informing, educating, and communicating:
PSI's branded campaigns are complemented by broad
communications aimed at increasing awareness about
malaria risks. These messages are delivered by trained
interpersonal communicators, often working in remote
rural areas.
PSI is credited with increasing the
diversity of net products and decreasing their price-and
Tanzania was the first country in the world to social
market home treatment on a national scale. The Social
Marketing of Insecticide Treated Nets Project (SMITN)
by PSI has played a critical role in stimulating the
development of the Tanzanian private net market and
has helped forge important public-private partnerships
in the name of malaria control. SMITN has succeeded
in stimulating demand for nets and insecticide retreatment
through creative and persuasive advertising and promotional
campaigns. Many in the private sector have been encouraged
to develop and launch their own net retreatment kits
for the Tanzanian market.
Mosquito Nets
Fabric Polyester netting (a
man-made fibre) is the most common fabric for nets;
it is light and does not absorb much water. Cotton
cloth or netting soak up a lot of water but need the
same concentration of treatment as polyester. Polyethylene
(monofilament) is a very strong man-made fibre that
absorbs very little water.
Denier Denier is a measure
of the strength of the fibre used to make the mosquito
net. The strongest is 100 and anything below 70 is
usually too weak and tears easily.
Mesh size Mesh size can be
measured either in millimetres - 1.5 to 2 mm is normal
for mosquito nets - or in holes per square inch, for
example 196 (14 x 14). Some nets have larger holes
that allow better ventilation but will only offer
protection as long as they remain treated.
Shape The two most common shapes
are round (or conical) and rectangular. There is less
person-to-net contact under a rectangular net but
many people prefer the easy-to-hang conical net. Wedge-shaped,
triangular, and tent-like nets can also be made.
Insecticide-treated Nets (ITNs)
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Selling nets in Tanzania
© IDRC |
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Insecticide-treated nets or ITNs represent
one of the best malaria control measures for children.
While mosquito nets are a well known defence against
malaria and becoming more widely available in large
African towns, the insecticides (synthetic pyrethroids)
used to treat them are not. Pyrethroids are widely used
for controlling insects. They perform in a similar manner
to pyrethrins, derived from chrysanthemum flowers. Permethrin
is perhaps the best known of the synthetic pyrethroids,
which are the only group of chemicals recommended for
use on mosquito nets.
Using a net that is either pretreated
with a long-lasting insecticide or is regularly re-treated
is vital and can double its effectiveness against
mosquitoes. Insecticide-treated mosquito nets are
a simple, safe and cost-effective method of protection
against malaria. Peak biting time is after midnight
when most people are asleep, so if untreated nets
- which are more commonly used - are not tucked in
properly, have large holes, or are so small that legs
and arms come into contact with it, the mosquitoes
can enter or feed through it.
With treated nets, mosquitoes are
killed or repelled by contact with the insecticide.
The repellent effect of the insecticide means that
other people sleeping in the same room also benefit.
When the insecticides are handled, stored, diluted,
and used correctly, they are not harmful to humans.
They are toxic, however, and must be used carefully.
Some nets may smell for a few days after treatment,
but when the insecticides are used at the correct
dilution there should be no other effects. The insecticides
are also harmless to chickens, goats, and dogs. They
can however harm fish, so waste fluid from net dipping
should be poured down a pit latrine and NOT
into a river or pond.
Compounds may be sold under different
names but the most commonly used ones are permethrin
(Imperator, Peripel), deltamethrin (K-othrine),
and lambda-cyhalothrin (Icon). Insecticides
are potentially very hazardous if used incorrectly.
Always read the instructions for use and follow the
storage guidelines.
Nets can cost US$5 - $10, and re-treatment
US$0.50 - $1.00 per year. Polyester nets can last
up to five years and have to be re-dipped every six
months. At present, families who can afford it are
paying for anti-malarial drugs, insecticide sprays,
coils, or traditional control methods. For those who
cannot afford these measures, treated nets are a good
alternative because they are durable and can be re-dipped
in insecticide locally, making them much cheaper in
the long-run.
Treating Mosquito Nets with Insecticides
To calculate the quantities required,
it is important to use a consistent system of measurement.
It is simplest to use metric measurements: centimetre
(cm), metre (m), millimetre (mm) millilitre (ml) and
litre (l). All nets should be clean and dry.
- Calculate the area of the net,
in square metres:
Rectangular net
- Hang the net up.
- Measure the area at the top
= width x length.
- Measure the area around the
sides = height x total distance around base
of net.
- Add the two measurements together
to find the total area of the net.
An example of a rectangular
net for a double bed:
Top: width 1.83 m x length 2.13 m = 3.9 m2
Sides: height 0.84 m x (1.83 + 2.13 + 1.83 + 2.13)
= 6.65 m2
Total area: 3.9 + 6.65 = 10.55 m2
- Calculate the amount of water absorbed
by the net, in ml or litres:
Using a bucket and a measuring container, measure
two litres of water into the bucket. Soak the net
until it is totally wet. Carefully wring out the
net over the bucket. When the net has stopped dripping,
measure the water remaining in the bucket.
For example:
2 litres - 1.3 litres = 0.7 litres
(700 ml)
(original water in bucket minus remaining water
= water absorbed by the net)
- Calculate the amount of insecticide
required:
- Check the recommended dosage
of insecticide. Read the instructions on the
bottle.
- Check the concentration of
the insecticide. This follows the name of the
insecticide. For example, permethrin EC 50 contains
500 g of insecticide in each litre; this is
also known as a 50% solution (EC means emulsified
concentrate: the formulation contains a solvent
which has a characteristic smell, while the
insecticide itself is odourless).
- Dosages of commonly used insecticides:
(in mg of insecticides per square metre of polyester
material)
Permethrin = 200-500 mg/square metre
Deltamethrin = 15-25 mg/square metre
Lambda-cyhalothrin = 20 mg/square metre
Cyfluthrin (oil in water emulsion) = 30-50 mg/square
metre
Etofenprox = 200 mg/square metre
- To calculate the amount of insecticide
use the following formula:
Dosage (mg) × Area of net ÷ Concentration
of insecticide % × 10
For example:
If you want a dosage of 200 mg/m2 on
a 11 m2 net and you are using Permethrin
50 (a 50% concentration contains 500 g insecticide
per litre) you would calculate the amount required
as follows:
200 x 11 = 2200
divided by 50 x 10 = 4.4 ml insecticide
If you have found that this specific
net absorbs 0.7 litre (700 ml) of water, add this
amount of water to the insecticide to make a final
mixture.
- Measure the amount of water and
insecticide needed:
Wide-mouth containers, such as
an empty cooking fat container (1 kilo = approximately
1 litre), are best for measuring large amounts
of water.
Insecticide can be measured using
an empty 250 g container that can be scored inside
at 50 ml intervals. For small amounts of insecticide
a syringe could be used. The insecticide may dissolve
the markings on the syringe, so it is useful to
score the outside with a knife.
Treatment
- Protective gloves must be worn.
- Add the insecticide to the water
and mix well. Treatment should be performed outdoors
or in a well-ventilated area. If you are treating
a few individual nets you can place each net in
a carrier bag, add the insecticide and water solution,
knead well and let the owners carry their net home
in the bag.
- Dip the net in the solution until
it is thoroughly wet.
- Wring out the net over a bowl and
hang it up until it has stopped dripping.
- Dry the net. They can be laid on
beds and bedding (which will help to kill bedbugs)
or dried outdoors. Do not place them in direct sunlight
for more than a few hours.
- Wash your hands and all equipment
with soap and water.
- Pour any waste insecticide down
a pit latrine and NOT into a river or pond.
Worldwide Initiatives
Nearly 30 years ago, the World Health
Organization (WHO) predicted that malaria would never
be eradicated. Today, research is uncovering more
about the disease in the hope of controlling it. To
meet the growing challenge of malaria, the World Health
Organization (WHO), the United Nations Children's
Fund (UNICEF), The World Bank and the United Nations
Development Programme (UNDP) launched the Roll Back
Malaria (RBM) Initiative in 1998 at the request of
African countries who demanded increased progress
in controlling malaria. Its aim is to halve the number
of malaria-induced deaths by 2010 by supporting research
into better drugs and if possible a vaccine.
In the time it takes one Olympic athlete
to complete the gruelling test of human endurance,
the marathon (around 2 hours 12 minutes), as many
as 79,200 people will have contracted malaria. During
the Sydney Olympic Games in 2000, athletes from Ethiopia,
Nigeria, Senegal, South Africa and Tanzania joined
Roll Back Malaria to help raise awareness about the
disease. One of these was the Tanzanian Olympic marathon
runner Mr Fokasi Wilbroad Fullah.
Most adults in Tanzania, like Mr Fullah,
have had malaria at some point in their lives. They
need education about and better access to treatments
in villages and communities.
The disease effectively imposes a
huge tax on affected communities in terms of human
and economic development. Wage earners are not able
to work, lands cannot be used for farming, school
attendance drops and learning capacity of children
is hindered. The direct and indirect costs of malaria
in Africa are in excess of $2 billion a year.
Hope for the Future
While insecticide-treated nets have
proved to be the most promising malaria-control technology
currently available, much remains to be done if cost-effective,
sustainable programmes are to promote their use. Continued
research is bringing new methods of malaria prevention
to light and attempting to develop a vaccine. Until
an effective vaccine can be developed, however, malaria
control will largely be dependent on measures such
as improvements in housing construction, source reduction,
impregnated bednets and insecticide treatment.
For further information, please contact:
Population Services International
(PSI)
1120 19th Street NW
Suite 600
Washington, DC 20036
USA
Tel +1 (202) 785 0072
Fax +1 (202) 785 0120
Email: info@psi.org
Website: http://www.psi.org/ |
Information about malaria
Malaria Foundation International
213 Elm Street
Stonington, CT 06378
USA
Website: http://www.malaria.org/
The Foundation facilitates
the development and implementation of solutions
to the health, economic and social problems
caused by malaria. |
Malaria Consortium
Dr Sylvia Meek
Malaria Consortium LSHTM
Keppel Street
London WC1 7HT
United Kingdom
Tel +44 20 7927 2439
Fax +44 20 7580 9075
Email: smeek@lshtm.ac.uk
The consortium was jointly
developed by the London School of Hygiene
and Tropical Medicine and the Liverpool School
of Tropical Medicine. It draws together malaria
control expertise from the two schools, other
institutes and individuals throughtout the
UK, Europe and countries affected by malaria.
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Mosquito Solutions Ltd
Dr J Miller
PO Box 32137
Dar es Salaam
Tanzania
Tel/Fax +255 51 75732
Email: jem@costech.gn.adc.org
Mosquito Solutions Ltd offers
information and technical expertise concerning
the appropriate packaging of individual 'dip-it-yourself'
kits for treating mosquito nets. It can also
offer technical evaluation of currently available
methods of mosquito net treatment. |
Suppliers
www.pathcanada.org/english/content/section2.html
Lists suppliers of mosquito nets by country.
www.pathcanada.org/english/content/section3.html
Lists suppliers of insecticides by country.
www.pathcanada.org/english/content/section4.html
Lists suppliers of related products by country, such
as house-spraying insecticides and coils.
Websites
http://www.who.int/
The World Health Organization
www.who.int/tdr
The WHO's Special Programme for Research and Training
in Tropical Diseases (TDR)
http://www.rbm.who.int/
The Roll Back Malaria website
http://www.pathcanada.org/
PATH Canada is a non-profit, non-governmental organisation
whose goal is to improve health, especially the health
of women and children, in developing regions of the
world.
http://www.malaria-vaccines.org.uk/
The Malaria Vaccine Trials is a research group based
at the University of Oxford, UK.
http://www.malariavaccine.org/
The Malaria Vaccine Initiative (MVI) at PATH (Program
for Appropriate Technology in Health) is a focused
vaccine development programme created to accelerate
the development of promising malaria vaccine candidates
and ensure their availability and accessibility for
the developing world. PATH is an international, non-profit
organisation dedicated to improving health, especially
that of women and children. http://www.path.org/
http://www.amvtn.org/
African Malaria Vaccine Testing Network
http://www.malaria.org/
Malaria Foundation International
www.africonnect.com/mimcom
Multilateral Initiative on Malaria is an alliance
of organisations and individuals concerned with malaria.
The website contains a large number of resources including
journals and organisations.
Further Reading
Net Gain : A New Method for Preventing
Malaria Deaths
edited by Christian Lengeler, Jacqueline Cattani,
and Don de Savigny
£19.95, IDRC, 1996, ISBN 0-88936-792-2
This can be bought from ITDG Publishing or can be
downloaded free by going to:
www.idrc.ca/acb/showdetl.cfm?&DID=6&Product_ID=87&CATID=15
Studies conducted in The Gambia, Ghana, and Kenya
show that the insecticide-treated mosquito net reduced
the mortality rate of children under five years of
age by up to 63 per cent. Net Gain reviews and discusses
the development of the treated mosquito net, focusing
on the technology, its implementation, and its promotion.
This document is an output from
a project funded by the UK Department for International
Development (DFID) and the European Commission (EC)
for the benefit of developing countries. The views
expressed are not necessarily those of DFID or the
EC.
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