No 21 - 2010

Acute and chronic hepatitis B 2009

2009 saw 22 notifications of acute hepatitis B virus (HBV) infection, including 14 males, Table 1. The median age was 40 years (range 13-75 years). A total of 18 (82%) were Danish-born, and ten (18%) were immigrants.

Fourteen patients (86%) were infected in Denmark, of whom 16 were Danish-born and three immigrants. Eight were infected via heterosexual contact, one by haemodialysis, two by intravenous drug use (IDU), one by homosexual contact and one by tattooing. In six cases, the source of infection was unknown.

Three patients were infected abroad (14%), including two Danish-born and one immigrant. In one case, the mode of infection was heterosexual contact and in the two others, the mode of infection was unknown.

Chronic hepatitis B 2009

In 2009, a total of 138 cases of chronic HBV infection were notified, Table 2. A total of 72 (52%) patients were males, Table 3.

The median age was 32 years (range 1-80 years). Among the notified cases, 21 (15%) were of Danish origin and 117 (85%) of foreign origin. The immigrant group counted a total of 44 nationalities, including 51 (44%) from Asia, 25 (21%) from Europe, 18 (15%) from Africa, 13 (11%) from Turkey, 11 (7%) from the MENA countries (the Middle East and North Africa) and two (2%) from Greenland.

The most frequent mode of infection was mother-to-child transmission, Table 4.

Two cases of Danish origin were infected at birth, one abroad and the other in Denmark, prior to the introduction of general HBV screening of pregnant women in 2005, EPI-NEWS 41/05.

Three children of mothers of foreign origin were infected in Denmark prior to the introduction of general screening of pregnant women. Five were notified as nosocomial infections. These were either infected abroad or in Denmark via blood products made prior to the introduction of screening of donor blood.

Hepatitis B screening of pregnant women

In 2009 the general screening of pregnant women identified 176 HBsAg positives, including five (3%) of Danish origin, Table 5.

A total of 12 pregnant women were adoptees, 11 from Korea and one from China.

Only 56 of the 176 women (32%) were notified to the Department of Epidemiology on form 1515 in accordance with physicians' obligation to notify infectious diseases.

Commentary

The number of notified HBV infections has remained at a constant, low level in recent years. The number of persons notified with chronic HBV infection is lower than in any other year since the infection became notifiable in 2000. The mean number of cases observed in the period was 180. The many cases observed in South Jutland are the result of improved reporting rather than a real increase in incidence.

HBV infection acquired by birth is the primary cause of chronic HBV infection. As chronic HBV infection acquired by birth is mostly characterised by an initial course of several asymptomatic years, it cannot be established if the decrease in the number of notifications is due to a decrease in the number of infected persons or a decrease in the number of diagnosed persons who are notified. In connection with screening of pregnant women, it was established that a considerable share of diagnosed pregnant women are not notified.

As from 1January 2010, HIV and syphilis have formed part of the general screening of pregnant women. It is essential that the physician of the pregnant woman pays attention to the test results provided with the blood type determination made at the initial pregnancy examination. Furthermore, it is important that midwives and obstetricians check if hepatitis B, HIV and syphilis status are ticked in pregnancy and hospital records.

(M. Malling, J.N. Rasmussen, S. Cowan, Department of Epidemiology)

Individually notifiable diseases and selected laboratory diagnosed infections  

26  May 2010