Syphilis infection in pregnant women can have disastrous consequences for their babies. Screening and treatment during pregnancy can prevent these adverse effects. But most pregnant women in Africa are not screened for syphilis. Research involving the London School of Hygiene and Tropical Medicine assessed the cost effectiveness of maternal syphilis screening in Mwanza, Tanzania.

In 1999, the prevalence of syphilis in sub-Saharan Africa ranged from 2.5 % in Burkina Faso to 17.4 % in Cameroon. Maternal syphilis is linked to spontaneous abortion, stillbirth, low birth weight, premature delivery and congenital syphilis. It may contribute to 29 % of perinatal deaths, 11 % of neonatal deaths and 26 % of stillbirths around the world. Syphilis screening and treatment could have a major impact in sub-Saharan Africa. But cost-effectiveness is a key concern in the competition for scarce healthcare resources.

Some 8 % of pregnant women in Mwanza have active syphilis. The prevalence of HIV is around 10 %. The antenatal programme there offers on-site syphilis screening and treatment with a single dose of benzathine penicillin. An economic analysis shows that:

• The financial cost of the intervention is US$ 1.44 per woman screened, US$ 20 per woman treated and US$ 187 per adverse birth outcome averted (stillbirths and low birth weight births averted).
• Personnel and supplies account for 91 % of total costs. More than 60 % of capital costs are start-up costs.
• The cost per DALY saved (an index of the impact of interventions for different diseases) is US$ 110 with low birth weight as the only adverse outcome. When stillbirth is included, it is only US$ 10.56 per DALY saved.
• The cost per DALY saved (including stillbirth) from three previous studies ranged from US$ 3.97 to US$ 18.73. Even after adjusting for study design differences, all the estimates are under US$ 193, the upper limit for ‘cost effectiveness’ given in the World Development Report, 1993.
• The cost per DALY saved decreases as prevalence increases. But it remains cost effective even at prevalences as low as 2 % (US$ 33 per DALY saved).

How does this compare with other public health interventions? The costs per DALY saved have been estimated at US$ 11 for nevirapine treatment to prevent mother-to-child transmission of HIV (MTCT), US$ 17 to 42 for immunisations and US$ 7 to 28 for oral rehydration therapy.

To policy-makers faced with the choice of where to allocate scarce resources, the researchers point out that:

• there is an urgent need to scale up syphilis screening and treatment in high prevalence areas
• syphilis screening and treatment gives an opportunity to identify and counsel couples who may have a high risk for HIV infection and so may reduce the spread of HIV
• the choice between implementing MTCT or syphilis screening programmes should take into account the prevalence of each disease
• where syphilis screening or MTCT programmes are already in place, it may be possible to provide the other service in combination at a lower cost than operating the two independently.

Source(s):
‘Is antenatal syphilis screening still cost effective in sub-Saharan Africa’, Sexually Transmitted Infections 79: 375-381, by F. Terris-Prestholt, D. Watson-Jones, K. Mugeye, L. Kumaranayake, L. Ndeki, H. Weiss, J. Changalucha, J. Todd, F. Lisekie, B. Gumodoka, D. Mabey and R. Hayes, 2003
'Syphilis in pregnancy in Tanzania I. The impact of maternal syphilis on outcome of pregnancy', Journal of  Infectious Diseases 186: 940-947, by D. Watson-Jones, J. Changalucha, B. Gumodoka et al, 2002
' Syphilis in pregnancy in Tanzania II. The effectiveness of antenatal syphilis screening and single dose benzathine penicillin treatment for the prevention of adverse pregnancy outcomes', Journal of Infectious Diseases 186: 948-57, by D. Watson-Jones, B. Gumodoka, H. Weiss et al, 2002

Funded by: Wellcome Trust; UK Medical Research Council; UK Department for International Development

id21 Research Highlight: 19 January 2004

Further Information:
Fern Terris-Prestholt
HIVTools Research Group
Health Policy Unit
London School of Hygiene and Tropical Medicine
Keppel Street
London WC1E 7HT
UK

Tel: +44 (0) 20 7612 7886
Fax: +44 (0) 20 7637 5391
Contact the contributor: Fern.Terris-Prestholt@lshtm.ac.uk

London School of Hygiene and Tropical Medicine, UK

Other related links:
'Screen test: detecting and treating syphilis in pregnant women in Tanzania' >