Anonymous unlinked testing as a sentinel approach: experience in Germany.
OBJECTIVE
To establish a laboratory sentinel as a supplementary instrument for monitoring the seroprevalence of HIV among childbearing women as a proxy to the heterosexually active population.


METHODS
Anonymous unlinked testing of neonatal dried blood spots has been performed in central laboratories of three federal states since 1993. The survey uses residual dried blood spots collected on Guthrie cards for screening of infants for metabolic disorders. These are eluted and tested for HIV antibodies. Data retained with the specimen are only district of residence along with year and month of birth.


METHODS
Because maternal IgG crosses the placenta before birth, the presence of antibodies in newborns reflects the infection status of the mother. Childbearing women are fairly representative for the heterosexually active general population.


RESULTS
The observed HIV prevalence in childbearing women of less than 1 per thousand confirms the assumption of a low rate of HIV infection in the general population. Significant time trends could not be detected, but HIV prevalence was higher in metropolitan compared with rural areas.


CONCLUSIONS
Laboratory sentinels in general and the anonymous unlinked testing of neonatal dried blood spots in particular can supply additional information on HIV seroprevalence. This surveillance system could be expanded to utilise residual samples of other sources as well as to monitor the immunity against specific vaccine preventable diseases and other infectious diseases of public health relevance.
Siedler
A
A
Robert Koch-Institut, Berlin, Germany.
Hamouda
O
O
Schwartländer
B
B
D000293:Adolescent; D000328:Adult; D004992:Ethics, Medical; D005260:Female; D005858:Germany / Q000453:epidemiology; D015658:HIV Infections / Q000097:blood*; D015528:HIV Seroprevalence; D006801:Humans; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008297:Male; D008661:Metabolism, Inborn Errors / Q000175:diagnosis; D011247:Pregnancy; D018571:Sentinel Surveillance