RATIONALE FOR SURVEILLANCE

Having decreased after the introduction of penicillin treatment in 1946, syphilis re-emerged in the end of the sixties and has remained at high incidence levels in developing countries. Developed countries are now also experiencing outbreaks and countries in economic transition are experiencing a marked and widespread recrudescence.

Syphilis prevalence data in pregnant women provide information about both latent and symptomatic syphilis in this group, and minimize the problems associated with general reporting of sexually transmitted syndromes. Subject to variations in health care seeking behaviour, this can be considered an approximation of syphilis prevalence in the general population.

RECOMMENDED CASE DEFINITION

Clinical description

The signs and symptoms of syphilis are multiple. The primary stage usually, but not necessarily, involves ulceration of the external genital organs and local lymphadenopathy; secondary and tertiary syphilis show mainly dermatological and systemic manifestations. For surveillance purposes, only confirmed cases (see below) will be considered.

Confirmed case

A person with a confirmed positive serology for syphilis (Rapid Plasma Reagin (RPR) or VDRL confirmed by TPHA (Treponema pallidum haemagglutination antibodies) or FTA (fluorescent treponemal antibody-absorption).

Case classification

 

Congenital syphilis: An infant with a positive serology, whether or not the mother had a positive serology during the pregnancy.

Acquired syphilis: All others.

RECOMMENDED TYPES OF SURVEILLANCE

Only confirmed cases should be reported to intermediate and central level by:

 

• Routine case-based or aggregate reporting
• Periodic surveillance reports

Laboratory-based surveillance through screening of pregnant women Routine reporting from antenatal (AN) clinics and sentinel sites of AN clinics Active case finding from prevalence surveys in pregnancy

RECOMMENDED MINIMUM DATA ELEMENTS

Aggregated data

Number of cases of positive serology for syphilis by age group, month, geographical area.

Number of cases of congenital syphilis by age group, gravidity, years, geographical area.

Performance indicators

False-positive rate at sentinel sites according to type of test (TPHA/FT-AB).

RECOMMENDED DATA ANALYSES, PRESENTATION, REPORTS

Cases/incidence by geographical area, age, parity.

Comparisons with age group and geographical area in previous years (line graph).

Rate of congenital syphilis by geographical area by year (line graph).

Annual surveillance summaries to be produced nationally and regionally and fed back.

PRINCIPAL USES OF DATA FOR DECISION-MAKING

 

• Document syphilis prevalence by screening pregnant women as a surrogate for general population
• Monitor trends in disease incidence
• Advocate syphilis control, and interventions
• Identify high risk areas for further targeting intervention
• Identify areas and populations where HIV prevention activities should be enhanced

SPECIAL ASPECTS

 

• The prevalence rate among pregnant women in developing countries varies between 3% and 19%. Maternal syphilis is associated with congenital syphilis (one third of births from such pregnancies), and with spontaneous abortion and stillbirth. Because the primary lesion is often painless and secondary syphilis is usually not diagnosed, women are mainly identified through serological screening. Syphilis surveillance is thus best performed in pregnant women

• In order to screen all pregnant women as per national policy guidelines, women should attend early for antenatal care. Clinic staff should take blood and send it to laboratory; laboratory staff should report results to clinic; women should attend for next visit and receive results and clinic staff should provide treatment and health education

• Syphilis in cases of genital ulcer should be reported separately in countries with access to laboratory facilities, in order to avoid double-counting

CONTACT

Regional Offices

See Regional Communicable Disease contacts on section "Communicable disease contacts in Regional Offices".

Headquarters: 20 Avenue Appia, CH-1211 Geneva 27, Switzerland

Initiative on HIV/AIDS and Sexually Transmitted Infections (HSI)

E-mail: gerbasea@who.ch /Surveillancekit@who.ch
Tel: (41 22). 791 4459/2111
Fax: (41 22) 791 4834 attn HSI