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No inoculations are compulsory for entry to The
Gambia, but it is recommended that prospective
travellers take medical advice at least three
weeks before departing for the country. Recommended
vaccinations include Typhoid, Yellow Fever, Meningitis
A, Hepatitis A and Polio. Anti-malarial medication
is generally advised. Visitors are advised to
carry with them preparations for dehydration,
stomach upsets, insect bites and cuts, as well
as mosquito repellent and sun block, because these
are not readily available in The Gambia. Food
poisoning is a major risk in The Gambia and travellers
are advised to make sure their food and water
are safe; drink only bottled water, ensure meat
and vegetables are well cooked and avoid unpeeled
fruit and vegetables. Travel insurance is recommended.
You must discuss your own particular needs
and contraindications to vaccines or tablets with
your doctor or practice nurse. Advice can change
so check again for future visits.
Ensure you are fully insured for medical emergencies
including repatriation. The T6 leaflet
(from Post Offices) gives details of health care
agreements between countries and an application
form for care within EC countries, which must
be completed before departure
Confirm those recommended for use in Britain are
up to date, especially those for children and adult
boosters of tetanus.
- Courses or boosters usually advised: hepatitis
A; typhoid; diphtheria; yellow fever.
- Vaccines sometimes advised: hepatitis B; poliomyelitis;
rabies; tuberculosis; meningococcal A &
C.
- Yellow fever certificate required if over
1 year old and entering from an endemic or infected
area .
NOTES ON THE DISEASES
MENTIONED BELOW
Malaria is a serious and sometimes fatal disease
transmitted by mosquitoes. You cannot be vaccinated
against malaria.
MALARIA PRECAUTIONS
Malaria precautions are essential in all areas,
all year round. Avoid mosquito bites by covering
up with clothing such as long sleeves and long
trousers especially after sunset, using insect
repellents on exposed skin and, when necessary,
sleeping under a mosquito net.
Check with your doctor or nurse about suitable
antimalarial tablets.
(Mefloquine OR doxycycline OR Malarone is usually
recommended).
Prompt investigation of fever is essential. If
travelling to remote areas, a course of emergency
'standby' treatment should be carried.
Tetanus is contracted through dirty cuts and
scratches and poliomyelitis spread through contaminated
food and water. They are serious infections of
the nervous system.
Typhoid and hepatitis A are spread through contaminated
food and water. Typhoid causes septicaemia and
hepatitis A causes liver inflammation and jaundice.
In risk areas you should be immunised if good
hygiene is impossible.
Tuberculosis is most commonly transmitted via
droplet infection. Those going to countries where
it is common, especially those mixing closely
with the local population and those at occupational
risk, e.g. health care workers, should ensure
that they have previously been immunised. Check
with your doctor or nurse.
Meningococcal meningitis and diphtheria are also
spread by droplet infection through close personal
contact. Vaccination is advised if close contact
with locals in risk areas is likely.
Yellow fever is spread by mosquito bites. It
is uncommon in tourist areas but can cause serious,
often fatal illness so most people visiting risk
areas are immunised.
Hepatitis B is spread through infected blood,
contaminated needles and sexual intercourse, It
affects the liver, causes jaundice and occasionally
liver failure. Those visiting high risk areas
for long periods or at social or occupational
risk should be immunised.
Rabies is spread through bites or licks on broken
skin from an infected animal. It is always fatal.
Vaccination is advised for those going to risk
areas that will be remote from a reliable source
of vaccine. Even when pre-exposure vaccines have
been received urgent medical advice should be
sought after any animal bite.
Hepatitis A
Cause: Hepatitis A virus, a member of the picornavirus
family. Transmission: The virus is acquired directly
from infected persons by the faecal-oral route
or by close contact, or by consumption of contaminated
food or drinking water. There is no insect vector
or animal reservoir (although some non-human primates
are sometimes infected). Nature of the disease:
An acute viral hepatitis with abrupt onset of
fever, malaise, nausea and abdominal discomfort,
followed by the development of jaundice a few
days later. Infection in very young children is
usually mild or asymptomatic (e.g. causes no symptoms);
older children are at risk of symptomatic disease.
The disease is more severe in adults, with illness
lasting several weeks and recovery taking several
months; case-fatality is greater than 2% for those
over 40 years of age and 4% for those over 60.
Geographical distribution: Worldwide, but most
common where sanitary conditions are poor and
the safety of drinking water is not well controlled.
Risk for travellers: Non-immune travellers to
developing countries are at significant risk of
infection. The risk is particularly high for travellers
exposed to poor conditions of hygiene, sanitation
and drinking water control. Prophylaxis (protective
treatment): Vaccination. Precautions: Travellers
who are non-immune to hepatitis A (i.e. have never
had the disease and have not been vaccinated)
should take particular care to avoid potentially
contaminated food and water. Source: WHO.
Malaria
General considerations: Malaria is a common and
life-threatening disease in many tropical and
subtropical areas. It is currently endemic in
over 100 countries, which are visited by more
than 125 million international travellers every
year. Each year many international travellers
fall ill with malaria while visiting countries
where the disease is endemic, and well over 10,000
fall ill after returning home. Fever occurring
in a traveller within three months of leaving
a malaria-endemic area is a medical emergency
and should be investigated urgently. Cause: Human
malaria is caused by four different species of
the protozoan parasite Plasmodium: Plasmodium
falciparum, P. vivax, P. ovale and P. malariae.
Transmission: The malaria parasite is transmitted
by various species of Anopheles mosquitoes, which
bite mainly between sunset and sunrise. Nature
of the disease: Malaria is an acute febrile illness
with an incubation period of 7 days or longer.
Thus, a febrile illness developing less than one
week after the first possible exposure is not
malaria. The most severe form is caused by P.
falciparum, in which variable clinical features
include fever, chills, headache, muscular aching
and weakness, vomiting, cough, diarrhoea and abdominal
pain; other symptoms related to organ failure
may supervene, such as: acute renal failure, generalized
convulsions, circulatory collapse, followed by
coma and death. It is estimated that about 1%
of patients with P. falciparum infection die of
the disease. The initial symptoms, which may be
mild, may not be easy to recognize as being due
to malaria. It is important that the possibility
of falciparum malaria is considered in all cases
of unexplained fever starting at any time between
the seventh day of first possible exposure to
malaria and three months (or, rarely, later) after
the last possible exposure, and any individual
who experiences a fever in this interval should
immediately seek diagnosis and effective treatment.
Early diagnosis and appropriate treatment can
be life-saving. Falciparum malaria may be fatal
if treatment is delayed beyond 24 hours. A blood
sample should be examined for malaria parasites.
If no parasites are found in the first blood film
but symptoms persist, a series of blood samples
should be taken and examined at 6-12-hour intervals.
Pregnant women, young children and elderly travellers
are particularly at risk. Malaria in pregnant
travellers increases the risk of maternal death,
miscarriage, stillbirth and neonatal death. The
forms of malaria caused by other Plasmodium species
are less severe and rarely life-threatening. Prevention
and treatment of falciparum malaria are becoming
more difficult because P. falciparum is increasingly
resistant to various antimalarial drugs. Of the
other malaria species, drug resistance has to
date been reported for P. vivax, mainly from Indonesia
(Irian Jaya) and Papua New Guinea, with more sporadic
cases reported from Guyana. P. vivax with declining
sensitivity has been reported for Brazil, Colombia,
Guatemala, India, Myanmar, the Republic of Korea,
and Thailand. P. malariae resistant to chloroquine
has been reported from Indonesia. Geographical
distribution: The risk for travellers of contracting
malaria is highly variable from country to country
and even between areas in a country. In many endemic
countries of Latin America and the Caribbean,
Asia and the Mediterranean region, the main urban
areas, but not necessarily the outskirts of towns,
are free of malaria transmission. However, malaria
can occur in main urban areas in Africa and India.
There is usually less risk of the disease at altitudes
above 1,500 metres, but in favourable climatic
conditions it can occur at altitudes up to almost
3,000 metres. The risk of infection may also vary
according to the season, being highest at the
end of the rainy season. There is no risk of malaria
in many tourist destinations in South-East Asia,
Latin America and the Caribbean. Source: WHO.
Meningococcal disease
Cause: The bacterium Neisseria meningitidis,
of which 12 serogroups are known. Most cases of
meningococcal disease are caused by serogroups
A, B and C; less commonly, infection is caused
by serogroups Y and W-135. Epidemics in Africa
are usually caused by N. meningitidis type A.
Transmission: occurs by direct person-to-person
contact, including aerosol transmission and respiratory
droplets from the nose and pharynx of infected
persons, patients or carriers. There is no animal
reservoir or insect vector. Nature of the disease:
Most infections do not cause clinical disease.
Many infected people become asymptomatic (i.e.
cause no symptoms) carriers of the bacteria and
serve as a reservoir and source of infection for
others. In general, susceptibility to meningococcal
disease decreases with age, although there is
a small increase in risk in adolescents and young
adults. Meningococcal meningitis has a sudden
onset of intense headache, fever, nausea, vomiting,
photophobia and stiff neck, plus various neurological
signs. The disease is fatal in 5-10% of cases
even with prompt antimicrobial treatment in good
health care facilities; among individuals who
survive, up to 20% have permanent neurological
sequelae. Meningococcal septicaemia, in which
there is rapid dissemination of bacteria in the
bloodstream, is a less common form of meningococcal
disease, characterized by circulatory collapse,
haemorrhagic skin rash and high fatality rate.
Geographical distribution: Sporadic cases are
found worldwide. In temperate zones, most cases
occur in the winter months. Localized outbreaks
occur in enclosed crowded spaces (e.g. dormitories,
military barracks). In sub-Saharan Africa, in
a zone stretching across the continent from Senegal
to Ethiopia (the African "meningitis belt"),
large outbreaks and epidemics take place during
the dry season (November-June). Risk for travellers:
Generally low. However, the risk is considerable
if travellers are in crowded conditions or take
part in large population movements such as pilgrimages
in the Sahel meningitis belt. Localized outbreaks
occasionally occur among travellers (usually young
adults) in camps or dormitories.Prophylaxis (protective
treatment): Vaccination is available for N. meningitidis
types A, C, Y and W-135. Precautions: Avoid overcrowding
in confined spaces. Following close contact with
a person suffering from meningococcal disease,
medical advice should be sought regarding chemoprophylaxis.
Source: WHO.
Typhoid fever
Cause: Salmonella typhi, the typhoid bacillus,
which infects only humans. Similar paratyphoid
and enteric fevers are caused by other species
of Salmonella, which infect domestic animals as
well as humans. Transmission: Infection with typhoid
fever is transmitted by consumption of contaminated
food or water. Occasionally direct faecal-oral
transmission may occur. Shellfish taken from sewage-polluted
beds are an important source of infection. Infection
occurs through eating fruit and vegetables fertilized
by night soil and eaten raw, and milk and milk
products that have been contaminated by those
in contact with them. Flies may transfer infection
to foods, resulting in contamination that may
be sufficient to cause human infection. Pollution
of water sources may produce epidemics of typhoid
fever, when large numbers of people use the same
source of drinking water. Nature of the disease:
Typhoid fever is a systemic disease of varying
severity. Severe cases are characterized by gradual
onset of fever, headache, malaise, anorexia and
insomnia. Constipation is more common than diarrhoea
in adults and older children. Without treatment,
the disease progresses with sustained fever, bradycardia,
hepatosplenomegaly, abdominal symptoms and, in
some cases, pneumonia. In white-skinned patients,
pink spots (papules), which fade on pressure,
appear on the skin of the trunk in up to 50% of
cases. In the third week, untreated cases develop
additional gastrointestinal and other complications,
which may prove fatal. Around 2-5% of those who
contract typhoid fever become chronic carriers,
as bacteria persist in the biliary tract after
symptoms have resolved. Geographical distribution:
Worldwide. The disease occurs most commonly in
association with poor standards of hygiene in
food preparation and handling and where sanitary
disposal of sewage is lacking. Risk for travellers:
Generally low risk for travellers, except in parts
of north and west Africa, in south Asia and in
Peru. Elsewhere, travellers are usually at risk
only when exposed to low standards of hygiene
with respect to food handling, control of drinking
water quality, and sewage disposal. Prophylaxis
(protective treatment): Vaccination. Precautions:
Observe all precautions against exposure to foodborne
and waterborne infections. Source: WHO.
Yellow fever
Cause: The yellow fever virus, an arbovirus of
the Flavivirus genus. Transmission: Yellow fever
in urban and some rural areas is transmitted by
the bite of infective Aedes aegypti mosquitoes
and by other mosquitoes in the forests of south
America. The mosquitoes bite during daylight hours.
Transmission occurs at altitudes up to 2,500 metres.
Yellow fever virus infects humans and monkeys.
In jungle and forest areas, monkeys are the main
reservoir of infection, with transmission from
monkey to monkey carried out by mosquitoes. The
infective mosquitoes may bite humans who enter
the forest area, usually causing sporadic cases
or small outbreaks. In urban areas, monkeys are
not involved and infection is transmitted among
humans by mosquitoes. Introduction of infection
into densely populated urban areas can lead to
large epidemics of yellow fever. In Africa, an
intermediate pattern of transmission is common
in humid savannah regions. Mosquitoes infect both
monkeys and humans, causing localized outbreaks.
Nature of the disease: Although some infections
are asymptomatic, most lead to an acute illness
characterized by two phases. Initially, there
is fever, muscular pain, headache, chills, anorexia,
nausea and/or vomiting, often with bradycardia.
About 15% of patients progress to a second phase
after a few days, with resurgence of fever, development
of jaundice, abdominal pain, vomiting and haemorrhagic
manifestations; half of these patients die 10-14
days after onset of illness. Geographical distribution:
The yellow fever virus is endemic in some tropical
areas of Africa and central and south America.
The number of epidemics has increased since the
early 1980s. Other countries are considered to
be at risk of introduction of yellow fever due
to the presence of the vector and suitable primate
hosts (including Asia, where yellow fever has
never been reported). Risk for travellers: Travellers
are at risk in all areas where yellow fever is
endemic. The risk is greatest for visitors who
enter forest and jungle areas. Prophylaxis (protective
treatment): Vaccination. In some countries, yellow
fever vaccination is mandatory for visitors. Precautions:
Avoid mosquito bites during the day as well as
at night. Endemic Countries: The World Health
Organization considers the following countries
to be endemic for yellow fever: Angola, Benin,
Bolivia, Brazil, Burkino Faso, Burundi, Cameroon,
Central African Republic, Chad, Colombia, Congo,
Congo, Côte d'Ivoire, Democratic Republic
of the Congo, Ecuador, Equatorial Guinea, Ethiopia,
French Guyana, Gabon, Gambia, Ghana, Guinea, Guinea-Bissau,
Guyana, Kenya, Liberia, Mali, Niger, Nigeria,
Panama, Peru, Rwanda, Sao Tome and Principe, Senegal,
Sierra Leone, Somalia, Sudan, Suriname, Togo,
Trinidad and Tobago, Uganda, United Republic of
Tanzania and Venezuela. Source: WHO.
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