No 14/15 - 2012

Hepatitis B, HIV & syphilis screening of pregnant women, 2011

Screening of pregnant women for hepatitis B was introduced on 1 November 2005, EPI-NEWS 41/05, and screening for HIV and syphilis was initiated on 1 January 2010, EPI-NEWS 27-33/10.

In 2011, a total of 63,976 blood type analyses were performed in pregnant women. Among these, 63,229 (99%) were tested for hepatitis B (HBsAg), 63,104 (99%) for HIV and 62,678 (98%) for syphilis, Figure 1.

HBsAg positive pregnant women

Of the 63.229 tests, a total of 181 were positive (0.3%) which is at par with the level observed in previous years.
A total of 114 women tested HBsAg-positive for the first time in 2011. Among these, 108 (95%) were reported to the statutory national hepatitis B notification system.

The remaining 67 women (36%) had already tested HBsAg-positive as part of the general screening during previous pregnancies.
HBeAg, a marker for disease activity, was detected in 25 (14%) of the women. HBeAg occurrence was higher among women from South-East Asia, Table 1.

HIV positive pregnant women

Among 63,104 HIV tests, 39 (0.06%) were positive. Twelve women had newly detected HIV and 27 were known HIV positives. All were notified via the statutory national HIV notification system. Two of the twelve women with newly detected HIV were Danes, Table 2.

Among the ten foreign women with newly detected HIV, five had immigrated within 1-3 years, one in 2011 and another 13 years ago. The group also comprised two tourists and a student temporarily staying in Denmark.

Pregnant women with syphilis

Among the 62,678 tests, a total of 150 were positives. Subsequently, 137 of the 150 (91%) were re-tested using confirmatory serological examination: six of these tested positive for current syphilis, corresponding to 0.01% of the total group of tested pregnant women. Among the six who tested positive, two were Danes, one was from the Middle East, one from Eastern Europe and one was African. Five of these were notified via the statutory national syphilis notification system.

Commentary

As previously, the majority of the pregnant women who test positive for hepatitis B (HBV), HIV or syphilis as part of the pregnancy screening belong to risk groups; but as was seen last year, a small number of pregnant women not belonging to any risk group also tested positive for HBV, HIV or syphilis.

The share of pregnant women who were screened for HIV and syphilis has risen substantially since the introduction of pregnancy screening in 2010, EPI-NEWS 15/11. For HIV, the share of tested persons increased from 95% in 2010 to 99% in 2011, and for syphilis the share increased from 94% to 98%. For HBV, the share decreased marginally, but remained high at 99%, Figure 1.

After the initial years with general screening, when the Department of Epidemiology was in contact with GPs as well as maternity wards concerning every single HBV carrier, the share of HBV carriers notified via the statutory national hepatitis B notification system decreased.

In 2010, only 64% of multigravidas and 41% of monogravidas were notified, EPI-NEWS 15/11.

In 2011 the Department of Epidemiology sent notification forms to physicians who had not previously notified any pregnant HBV carriers to the statutory national notification system. This yielded a nearly complete notification percentage for 2011, when 95% of monogravidas  were notified.

Six in every seven newly diagnosed HIV positive immigrants had resided in Denmark for several years. These women should have been diagnosed upon arrival to Denmark, as this would have speeded up treatment and possibly improved their prognosis. The National Board of Health recommends testing of immigrants from countries with a high HIV incidence as soon as possible after they arrive to Denmark, EPI-NEWS 46/09.

According to the guidelines on pregnancy screening from the National Board of Health, EPI-NEWS 27-33/10, pregnant women who test positive at screening should undergo full serological examination to exclude false positives. The occurrence of false-positive screening results remains high as only 4% of the re-tested currently had syphilis.

Thirteen pregnant women who tested positive to syphilis during screening have not currently been re-tested. Among these, a limited number may have syphilis.

One effect of the general screening of pregnant women is that mother-to-child infection with the three diseases may be avoided in most cases; furthermore, newly diagnosed pregnant women may be offered diagnosis and treatment. It is therefore important that the treating physician refers any pregnant women diagnosed with one of the three diseases in the screening programme to the relevant specialist departments. The pregnant woman's partner and remaining children should be called in for blood sample testing and referred as appropriate provided they test positive. Children and partners may be vaccinated against HBV at no cost if they test negative in the above-described test.

(O. Wojcik, S. Cowan, A.H. Christiansen, B. Søborg, Dept. of Infectious Disease Epidemiology, S. Hoffmann, DBMP)

11 April 2012