Congenital syphilis rate (live births and stillbirth)
Export Indicator
Reported congenital syphilis cases per 100 000 live births in the 12-month reporting period
What it measures
Progress in eliminating vertical transmission of syphilis
Rationale
Untreated syphilis infection in pregnancy can result in stillbirth, neonatal death and congenital disease (collectively defined as “congenital syphilis”).
Untreated syphilis infection in pregnancy also increases the risk of vertical transmission of HIV. Given the high efficacy, appropriate simplicity and low cost of syphilis testing and treatment, global and regional initiatives to eliminate the vertical transmission of syphilis are well established. The rate of congenital syphilis is a measure of national surveillance and the impact of programmatic interventions to eliminate vertical transmission of syphilis.
Numerator
Number of reported congenital syphilis cases (live births and stillbirths) in the past 12 months
Denominator
Number of live births in the past 12 months
Calculation
Numerator/denominator
Method of measurement
Routine health information systems.
Measurement frequency
Annual
Disaggregation
None
Additional information requested
It is important to indicate in the comments section the case definition of congenital syphilis used in your country for reported cases. In particular, countries should note whether the reported data include stillbirths. Please comment on the extent to which the data are deemed representative of the national population. If a country is unable to report on the denominator, WHO will use the denominator from the United Nations Population Division.
Strengths and weaknesses
Diagnosing congenital syphilis is most reliable when specific diagnostic tests are used, but unfortunately these are seldom available. In most countries, therefore, diagnosis relies on clinical history of maternal testing and treatment and clinical examination of the infant, which makes surveillance challenging.
Given the difficulties in diagnosing congenital syphilis—and depending on the case definition used—underreporting and overreporting can be a problem. The likely magnitude of such reporting errors should always be considered when looking at rates of congenital syphilis over time.
Further information
Global guidance on criteria and processes for validation: elimination of mother-to-child transmission of HIV, syphilis and hepatitis B virus. Geneva: World Health Organization; 2021 (https://iris.who.int/bitstream/handle/10665/349550/9789240039360-eng.pdf...).