Hepatitis A

Epidemiology of Hepatitis A in UK Travellers

Hepatitis A is the most commonly reported vaccine-preventable disease in travellers. Travellers from countries of low endemicity going to countries of high/intermediate endemicity are at high risk of contracting the disease as they have had no previous exposure to the virus and therefore not acquired any natural immunity. Figure 1 shows the total laboratory reports to the Health Protection Agency, Communicable Disease Surveillance Centre (CDSC) of hepatitis A by travel history (see link below) and figure 2 shows the statutory notifications of hepatitis A by presumed travel history.

Figure 1 Total laboratory Reports to CDSC of Hepatitis A in England and Wales by travel history 1990 - 2002*

Figure 2 Total notifications of Hepatitis A in England and Wales by presumed travel history 1990 - 2002*

For both the laboratory reports and notifications, there has been a significant decline in total hepatitis A cases seen in England and Wales over the period 1990 - 2002*. The majority of notifications of hepatitis A are presumed to be contracted in Great Britain. However, for laboratory reports, the majority have not had a travel history given so it is not possible to say where they were acquired. Figure 3 shows the laboratory reports to CDSC of hepatitis A with a history of travel and the notifications of hepatitis A cases presumed contracted abroad.

Figure 3 Laboratory reports of hepatitis A with a history of travel and notifications of hepatitis A presumed to be contracted abroad in England and Wales 1990 - 2002*

The number of cases notified or reported by laboratories has declined between 1990 and 2002, more consistently from laboratory data than from notifications. However, the proportion of laboratory reports for which no travel history has been given has increased over time and so the decline in laboratory reports may in part reflect poorer reporting rather than an actual decline in travel-associated disease.

Figure 4 shows the proportion of laboratory reports of cases of hepatitis A acquired in different regions in the world where information on recent travel abroad has been given.

Figure 4 Proportion of Laboratory reports of Hepatitis A in England and Wales by area of acquisition 1990 - 2002*

The proportion of laboratory reports of cases acquired in the Indian Sub-Continent has fallen from one third to a fifth between 1990 and 1997. Over the same period, the proportion of reports of cases acquired in European countries popular with UK travellers, have declined from 15% to 5%. Meanwhile, an increasing proportion of cases have been acquired in other countries in the rest of the world. More information is required about country of acquisition to be able to accurately determine trends in travel-associated hepatitis A and to investigate more fully the role of hepatitis A immunisation in preventing travel-associated hepatitis A.

Links

Hepatitis A Laboratory Reports, England and Wales, by Travel History, 1990 - 2002*