THE KILLER THAT HAS EVERYONE BAFFLED

The unknown disease wiping out Glasgow heroin addicts may not be a
one-off. Jean West reports

As a microbiologist, Dr Penelope Reading was familiar with the body's
standard physiological response to infection. So alarm bells rang when
two of her patients - both young female heroin addicts - deteriorated
rapidly after presenting with what appeared to be straightforward skin
infections.

Abscesses are familiar to the staff at Glasgow's Royal Victoria
Infirmary, who deal with many addicts. Drained and treated with
fast-acting antibiotics, they usually heal swiftly. But these women
were different. They quickly went into downward spirals and died.

"I realised we may have a problem on our hands when we witnessed what
appeared to be an overwhelming bacterial infection in these patients.
People in intensive care had never seen people die so fast in this
way. I contacted the health board and explained that we might have
something nasty on our hands," says Reading.

When she looked at the women's white blood cell counts, she found
something serious and dangerous. Without infection one might have
expected a count of about 3,000 to 8,000. Reading found levels of
between 40,000 and 150,000 cells caused by fighting the bacterium.

Antibiotics were useless. The women went into shock as their blood
pressure plummeted, then suffered respiratory and heart failure and
died with terrifying speed.

Dr Laurence Gruer, head of addiction services with Greater Glasgow
Health Board, was immediately alerted. He too was astonished: "In
these cases, the white cell count was incredible. Doctors had never
seen anything like that before. The only other situation where you
might get these levels are in rare forms of leukaemia."

Further fatalities followed. The patients seemed to die from toxins
released by a mystery micro-organism. To date, 33 addicts in Britain
and Ireland have died of the condition, 15 of them in Glasgow. One
homeless man who died last Monday is the subject of a complaint by the
Big Issue Magazine, who claim he was sent home by staff at the
Victoria. Two more people have died in Grampian and one in
Lanarkshire.

International networking through the European communicable diseases
early warning system brought to light a further 15 cases in Ireland,
eight fatal, and 14 in England and Wales, seven of whom died.

Glasgow needed help. The board contacted the Centre for Disease
Control and Prevention in Atlanta, Georgia, the world leader in the
investigation of unexplained outbreaks of illness, which first
identified legionnaires' disease in 1976. The Communicable Diseases
Surveillance Centre at Colindale, north London, is also involved in
tracking down the mystery bacterium, as is the Department of Health's
centre for applied microbiology and research at Porton Down, Wiltshire.

Anthrax, an early possibility, has been ruled out along with the
contamination of the citric acid used by addicts to dissolve heroin.
What remains is the heroin itself.

The mystery has wider implications. Many new, re-emerging or mutating
diseases threaten the human race. Recent years have seen outbreaks of
ebola, legionnaires' disease, Brazilian purpuric fever, lyme disease,
lassa fever and killer strains of old familiars such as malaria and
dengue fever.

Cheaper, swifter air travel means once exotic destinations are within
reach. Distant microbes can be at our physiological doorsteps within
24 hours. As the Spanish conquistadors wiped out so many Aztecs with
their gift of smallpox, so 21st-century maladies are passed by tourists.

Infections can also cross species. A recent Hong Kong flu outbreak
originated in chickens. The HIV pandemic is understood to have come
from chimpanzees. American Dr Richard Krause, editor of the book
Emerging Infections, agrees: "We are quite sure that in the last
several hundred years it mutated to infect humans who were exposed to
it because they ate chimp meat."

A rapidly mutating virus can increase a disease's transmissibility, as
in the case of HIV. In a similar way tuberculosis and yellow fever -
rendered virtually extinct in the west by mass-vaccination programmes
- - are returning. Ebola is difficult to contract, but genetic
reconstruction could theoretically see it re-emerge with the infection
rate of the common cold.

"I would say most so-called emerging or re-emerging infectious
diseases are in fact old friends that have returned in a new setting -
under various cultural or climactic, agricultural or behavioural
circumstances," says Krause.

He cites the example of a pulmonary and skin infection attacking HIV
sufferers in Thailand. It was caused by a microbial fungus related to
penicillium. It had always been around causing distress among the
general community, but the specific health profile of HIV patients
caused it to proliferate.

Parallels can be drawn with what is happening in Britain. The disease
has so far been confined to heroin addicts. It does not appear to be
transmissible person-to-person, as influenza or HIV might be. It
appears to affect those hard-bitten addicts, who, in the absence of
suitable veins, inject the drug in muscle tissue. This creates an
environment that allows only certain types of bacteria to thrive.

Clostridia, a group of bacteria that can cause conditions like
tetanus, botulism and gas gangrene, are under scrutiny by British
scientists. These organisms have been isolated from a number of cases
but, because there are thousands of different strains, there is still
a long way to go.

These are anaerobic bacteria - they can only survive in environments
devoid of oxygen. Pumping heroin, and the large amounts of citric acid
used to dissolve it, into muscle effectively destroys the tissue's
oxygen content. The bugs multiply in this habitat in the same way
legionella spreads in air-conditioning units and whirlpool spas.

"The fact that it is anaerobic means that growing it in a laboratory
has been notoriously difficult," says Gruer.

One breakthrough has been made. Antibiotics, which were thought to be
ineffective, may have been eliminating the bacterium, so there was
nothing left at autopsy. This has left researchers with little access
to the strain.

The general public does not seem to be at risk from this infection.
But, sooner or later, another emerging disease could cause a health
crisis - this time for everybody.

Box - Diseases on the rise

Ebola virus: first discovered 1976. Symptoms include high fever
nausea, abdominal pain, flaky rash and an altered mental state. 70% of
cases die, usually within a fortnight

Legionnaires disease: caused by breathing in droplets of water
contaminated by bacterium. Groups at greater risk include heavy
smokers and drinkers, diabetics, males over 50.

Lyme disease: acute inflammatory disease that results in joint damage,
skin changes, muscle paralysis and flu-like symptoms, caused by
bacterium transmitted by the bite of a deer tick. Symptoms mimic other
diseases making it difficult to diagnose, such as red rash at the site
of bite. Can be cured with antibiotics if diagnosed in the early
stages, but if left untreated problems can occur to the joints, heart
and nervous system.

Lassa fever: acute viral illness first identified in the 1950s. Found
mainly in west Africa, transmitted to humans from wild rats. Symptoms
include fever, nausea, headaches, sore throat, coughing, vomiting,
diarrhoea, muscular pain, and miscarriage in pregnant women. Fatal in
15% of cases, deafness occurs in 25%

Malaria: caused by parasite carried by mosquitoes, found in
over 100 countries and as much as 40% of the world's
population is at risk. More than 1m die each year. Symptoms
include fever, headache, muscle aches, nausea, kidney
failure, seizures. Parasites can lie dormant in the human
liver for up to 4 years

Dengue fever: also carried by mosquitoes, and also known as "breakbone
fever" due to the severe muscle and joint pains that can result. No
known vaccine or preventative medicine