Tuberculosis has been a scourge of mankind since pre-biblical times. From the
end of the 19th century, when the causative organisms were first identified (Mycobacterium tuberculosis and M.bovis), the disease was in steady decline in
the developed world. A combination of improved nutrition and social conditions,
pasteurisation of milk, the development of antibiotics and the use of both X-ray
screening and the BCG vaccine had virtually eradicated TB from western
Elsewhere in the world it was a different story. Even with the benefits of
the vaccine, M.tuberculosis continued to infect one third of the human
population and accounted for three million deaths every year.
Recently, however, however, TB has re-emerged worldwide as a major threat to
public health due to the development of multi-drug resistant strains of the
organism and the triggering of disease in individuals infected with HIV. In
1993, the World Health Organisation (WHO) declared TB a global emergency and
this has fuelled a worldwide increase in TB research.
Within the UK, the incidence of TB in people is still relatively low;
and is mainly confined to people who come into the UK from poor countries where
TB is rife; or where people live in cramped or unsanitary conditions.
So far as agriculture is concerned, DEFRA takes great pains to try and
control tuberculosis in cattle. Bovine TB is an important disease in its own
right and a small source of the disease for the human population. It has been
known for a hundred years that cattle also get TB and that in some cases the
disease can be transmitted to man (usually in a non-respiratory form) through
milk. In the 1930s it was estimated that around 2,500 deaths caused by TB in the
UK each year (5-10% of the total cases), were due to infected milk. The
introduction of DEFRA’s Attested Herds Scheme and the widespread use of
pasteurisation greatly reduced the levels of disease in cattle and man.
Although most of Great Britain remains free of bovine tuberculosis, specific
areas in the south-west of the country have shown an increasing incidence over
recent years. 1599 cases of tuberculosis were confirmed in individual cattle
from Great Britain in 1996, mostly as a result of tuberculin testing. This
geographical difference in disease incidence has been assumed to be because the
infection is present in certain wildlife species, which act as a reservoir for
DEFRA (and their predecessors, MAFF) have argued for a very long time that
the presence of TB in badgers in the South-West of England provides a very
significant cause of bTB infection in cattle. Other scientists (and pressure
groups) argue that, badgers tend to be the recipients of the disease; with the
vast majority (if not all) the blame for continued levels of bTB infections
being within cattle themselves.
That said, the first badger discovered to be suffering with TB,
was found as late as 1971. It might not be too much of a leap of the imagination
to suggest that badgers first became infected with TBs from cattle; rather than
Over the past few years, MAFF, and now DEFRA, have attempted to define a huge
experiment (in which tens of
thousands of badgers will be killed over hundreds of square miles of
countryside) to determine "once-and-for-all" whether badgers are the
cause of bTB in cattle. While significant arguments remain about the
scientific validity of the experiment, it seems highly unlikely that the cull will
produce any results which will be accepted as being accurate and scientifically
valid by both sides of the badger divide.
Pessimists in the badger community argue very strongly that research efforts
should take place to develop vaccines to prevent cattle, badgers and other
species from getting TB in the first place. In the long term, this is the ONLY
acceptable solution, unless, of course, you want a the Foot-and-Mouth-type slaughter on a repeated basis.