Helicobacter gastroduodenitis is a serious chronic infectious disease
that is responsible for widespread morbidity and mortality. An underst
anding of the way in which it spreads is fundamentally important when
considering measures for its control. Its prevalence is highest in the
developing world and in individuals with a disadvantaged socio-econom
ic childhood. The disease is believed to be contracted during the earl
y years of life. A faeco-oral mode of transmission is considered by ma
ny to be the most likely mode of spread, however, the organism is diff
icult to culture both from faeces and from the environment and unlike
other enteric organisms Helicobacter does not give rise to a diarrhoea
l illness that would facilitate its transmission. An oro-oral route of
spread has also been suggested, however, Helicobacter cannot be cultu
red from saliva, and if it was spread orally there is no reason why ch
ildhood should be the most frequent age for its acquisition. A third p
ossibility is that the bacterium is transmitted gastro-orally. In favo
r of this hypothesis, the infection is easily acquired following gastr
ic intubation with inadequately disinfected equipment. Children have a
greater tendency to vomit than adults, and tend to explore with their
fingers and place foreign objects in their mouths. Initial Helicobact
er infection causes a dyspeptic illness characterised by mucousy vomit
ing, which may provide a vehicle for transmission. Furthermore, during
the acute infection the organism induces achlorhydria in the host, po
ssibly enabling the organism to survive longer in vomited mucus in the
absence of acid. This theory fits best with the epidemiological data.
Those most at risk are children living in an overcrowded environment
who share beds with one another and live in houses that do not possess
a fixed hot water supply (thus making cleaning up of vomit more diffi
cult). It is also commoner in institutionalized children and is associ
ated with school catchment areas.