HPV, STI and AMR in West Africa: estimating population burden and understanding exposures to accelerate vaccine impact and drive new interventions

United Nations Sustainable Development Goal 3 (SDG3) sets ambitious targets for improving health and wellbeing globally by 2030. This includes targets for reducing the number of people dying early from cancer, and the number of newborns dying for preventable reasons. It includes targets for dramatically reducing the number of hepatitis B and hepatitis C infections, and for stopping all cases of HIV being passed from a mother to baby. The goal also calls for universal access to sexual and reproductive health care. Many of these areas disproportionately impact on the health and wellbeing of women and make gender inequality worse. This conflicts with the aims of SDG5 which aims to reduce such inequality.

If the targets for women in The Gambia and other parts of West Africa are to be achieved, a dramatic increase in progress is essential. A recent review highlighted that one of the main reasons that progress has been too slow so far, is a lack of reliable information on the burden of given health conditions. This was found to be a particular problem in West Africa compared to other parts of the world. The proposed survey will specifically address this and aims to drive improvements in key areas for the health and wellbeing of women in The Gambia and other parts of West Africa as follows:

Human papillomavirus (HPV), which is sexually transmitted, causes cervical cancer, one of the most common causes of cancer death in women in Africa. There is already a vaccine against HPV which has been shown to be very good at preventing cancer in women in high income countries. The vaccine is going to be introduced in The Gambia and it is now essential to be able to monitor how good it is in West Africa too. Measuring how much HPV females in The Gambia have before the vaccine is introduced is critical for this and is an important aim of the survey. It may be that there are better, or easier, ways to give HPV vaccines and that improved vaccines become available too. The information from the survey is essential if we are to predict and measure this and ultimately reduce the number of women dying early from cervical cancer in West Africa.

Other sexually transmitted infections (STIs), including syphilis, gonorrhoea, and chlamydia, are important causes of preventable deaths in newborns, of stillbirths, of infertility and of other sexual and reproductive health problems. For infections like gonorrhoea, resistance to many antibiotics is increasing too in some parts of the world. We do not know how big a problem this is in West Africa. The survey will measure how common STIs and antibiotic resistance are in females in The Gambia. This information will first, improve the way we treat STIs in The Gambia and other parts of West Africa and second, drive the development of new tests for the infections, and new vaccines to prevent them.

Hepatitis B and C are the leading causes of liver cancer in West Africa. Hepatitis B is preventable by vaccination and providing the vaccine to newborns in the first 24 hours of life prevents the infection being transmitted from mother to baby. Medicines that can cure hepatitis C are available. It is also possible to prevent HIV being transmitted from mother to baby. To do this it is essential the mother knows she has the infection during pregnancy and that the baby is given medicines when it is born. The survey will measure how common these three infections are in women of childbearing age. It also aims to identify those factors in the Gambian health system that mean the effective prevention and treatment strategies which exist are either not available or not implemented correctly.

In summary, information from the planned survey aims to accelerate progress towards SDG3 in key areas and thus will have much needed positive impact on the health and wellbeing of women in West Africa.

This multi-stage, probability-based, cluster survey will be undertaken within an established Health and Demographic Surveillance System in The Gambia. It will generate key data on the population prevalence of human papilloma viruses - associated with cervical cancer, other sexually transmitted infections, viral hepatitis, and HIV; also, on associated risk factors in 15 to 49-year-old females. These data are expected to accelerate progress towards achieving the targets set out in relation to Sustainable Development Goal 3 - addressing health and wellbeing, in females in West Africa. Specifically, baseline prevalence data on HPV, at the point of national vaccine rollout, are essential if vaccine impact is to be predicted, measured, and maximized, through considering alternative vaccination schedules, and new vaccines as they become available. Data on sexually transmitted infections, important causes of neonatal death, stillbirth, and infertility and on their antimicrobial resistance patterns, will allow syndromic treatment guidelines to be adapted to the setting - thus reducing the drivers of further resistance. The data are also expected to provide advocacy for the implementation of strategies, such as for the prevention of congenital syphilis, which are known to be effective but not currently provided as part of antenatal care in The Gambia and other countries is West Africa. Quantifying the ongoing burden of hepatitis B in women of child-bearing age, despite a well-established vaccination programme, will determine progress toward elimination targets, and drive work to improve the timeliness of neonatal hepatitis B vaccination. Prevalence data on hepatitis C and HIV both amendable to prevention and treatment strategies, will be complemented by a study of health systems factors which aims to identify the barriers to implementation of proven interventions in The Gambia and sub-region.