Ian
Williamson takes a look at whch regions in the world to avoid
if
you don’t want to catch some pretty nasty diseases.
The world
is shrinking as global travel becomes the norm. Expatriates,
too, do not just stick to the tried and tested destinations
of the past. Some will live and work in what in a previous
age might have been called ‘exotic locations’
– which means you don’t have to go far to be at
potential risk from a travel-related illness. However, with
sensible planning and behaviour, the world soon becomes a
safer place to visit.
Estimates suggest that 80 per cent of travellers to developing
countries suffer diarrhoea or feel unwell due to their journey.
For significant illnesses, such as HIV, typhoid, cholera and
meningococcal disease, the figure falls to less than 0.1 per
cent of 100,000 travellers per month. So, clearly, precautions
should be tailored to the risk. Watch out for drinking the
local water, if you want to avoid the former unpleasantness.
For the latter, more serious threats, there are a few things
to bear in mind.
Last year a man died from rabies in the UK after contracting
the disease while visiting his family in the Philippines.
Despite being given the rabies vaccine to boost his immune
system’s response to the virus within an hour of being
admitted to hospital, he succumbed to the disease.
The last case of rabies in the UK was in the 1960s. Although
scientists in the USA claimed late last year that new drugs
had been effective in treating full-blown rabies, they are
not commonly available and once rabies symptoms appear, there
is no cure for the disease. Rabies attacks the central nervous
system, and acts a little like a neuro-toxin.
The only way to act once you have been bitten by an animal
you suspect might be infected is to get to hospital immediately.
A series of vaccinations can prevent the disease getting hold
of your nervous system. But once it has appeared in full-blown
form, there is little hope for cure. Apart from a few islands
– Hawaii and the UK are notable – rabies is common
throughout the world. So, be very aware of the risk.
One of the problems with trying to pin down disease hot spots
at any one time is that outbreaks of a disease move across
the globe in an ever-changing pattern.
Take the case of anthrax in Zimbabwe. A year ago, no one would
have associated Zimbabwe with this disease but with the unrest
following the farm takeovers by war veterans, herds of different
breeds of cattle have been mixed together. Veterinary inspectors
have been denied access to the new mixed herds. As a result,
there has been an outbreak of anthrax in the country.
Travellers could be at risk if they eat infected animals –
although anthrax has other mechanisms of transmission such
as through inhalation and, in some cases, through the skin.
Anthrax spores can remain active in the soil for years. Anyone
visiting other anthrax regions – such as Asia, the Middle
East, Iran, Russia and parts of Africa – should avoid
contact with raw animal products including meats, carcasses
and hides. Treatment for Anthrax is much like that for rabies:
prior to the onset of symptoms, antibiotics are generally
effective. But once the disease has taken hold, the prognosis
is poor.
Another re-emerging infection is dengue fever, a viral disease
transmitted by mosquitoes. With increasing travel through
tropical and semi-tropical regions, this disease is now second
only to malaria as the most prevalent insect-borne disease
in the tropics – even including areas where it was once
thought to have been eradicated.
There is currently no vaccine available against dengue fever,
so it is best to take precautions to avoid being bitten by
mosquitoes in the first place. Prevention of mosquito bites
should be the prime consideration for any traveller in less-well-developed
regions.
Yellow fever, another mosquito-borne virus, remains on the
list of major world health concerns for travellers as one
infected person can introduce it to a new area and trigger
an epidemic. The mosquito is found mainly in tropical South
America and Africa from the Sahara desert southwards, down
through Nigeria, Angola and Kenya. International law now requires
those leaving infected areas to show proof of vaccination
before being allowed entry into countries concerned about
the yellow fever risk. Like dengue fever, preventing bites
by mosquitoes is crucial.
HIV infection remains a constant threat and nowhere more so
than in central Africa. Up to one in seven of the population
are HIV-positive and the vast majority through heterosexual
intercourse. In Thailand and India there is up to an 80 per
cent infection rate among prostitutes, making unprotected
sex a greater danger than Russian roulette. Clearly, unprotected
sex is a big no-no in such regions.
Northern Europe is not immune to its own disease hotspots
but the incidence of communicable diseases in most areas are
unlikely to provide a health hazard to the international traveller
greater than that found in his home country. However, the
incidence of certain food-borne diseases such as salmonella
and campylobacter, is significantly increasing in some countries.
And rabies remains endemic in wild animals (especially foxes)
in rural areas of northern Europe.
In other parts of the world, where rabies is a significant
risk, there may be a shortage of the rabies vaccine and immunoglobulin,
so always obtain a series of three anti-rabies injections
before you travel; this greatly simplifies any post-bite rabies
treatment you may need.
When it comes to international travel, especially to less
developed parts of the world, a little prior knowledge can
prove invaluable and sometimes be a lifesaver.
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