Adolescents make up one-sixth of the world’s population [1] [2] . Adolescents also make up more than half of the population in developing countries, particularly in sub-Saharan Africa [3] [4] . These teenagers need to be educated to lead fulfilling lives. Adolescents’ lack of knowledge about sexual and reproductive health has many consequences. According to WHO, 21 million girls aged 15 - 19 will become pregnant in these countries in 2019, and around 50% of these pregnancies will be unintended. Nearly 55% of unintended pregnancies among adolescents aged 15 - 19 years end in abortion [3] . According to UNICEF, nearly 170,000 adolescents aged 10 - 19 will be living with HIV in 2020, of whom 150,000 will be newly infected [5] . In the study by Kassa et al., which covered 24 countries from East, West, Central, North and Southern African sub-regions, the overall pooled prevalence of adolescent pregnancy in Africa was 18.8% and 19.3% in the Sub-Saharan African region [1] . Factors associated with adolescent pregnancy include rural residence, being married, not attending school, no maternal education, no father’s education and lack of parent-to-adolescent communication on sexual and reproductive health (SRH) issues [1] .

In sub-Saharan Africa, the frequency of unprotected sex at last intercourse varies widely, from 18% to 83% [6] . Contraceptive use among young women aged 15 - 24 in the region is low, at 14.7%. At the same time, HIV infection is high among young women in the region, accounting for 64% of new HIV infections in West and Central Africa among 15 - 24-year-olds. At the same time, HIV testing among young people in the region remains very low, at 12% [7] .

In Burkina Faso, as in other African countries, risky sexual behaviour persists, including early sexual debut, multiple sexual partners, economic and sexual exchange, and low condom and contraceptive use [7] . Over 90% of adolescents aged 15 - 19 years reported that they did not have access to enough detailed information to effectively protect themselves from unwanted pregnancy [7] . To improve adolescents’ sexual and reproductive health, a sound knowledge of the components of reproductive health and good sexual behaviour is essential. It is against this background that this study of adolescents’ sexual and reproductive health knowledge and behaviour was initiated, with the aim of proposing appropriate actions.

The study was conducted in the area of the Demographic and Health Surveillance System (DHSS) of the Nouna Health Research Centre in Burkina Faso.

It was a descriptive cross-sectional study. The method of data collection was prospective.

Data were collected in randomly selected households between 7 March and 4 April 2022.

The study population consisted of male and female adolescents aged 10 - 19 years in the Nouna SSDS area.

The inclusion criteria were:

Sample size was calculated using the Schwartz formula: n = [(Z² PQ)/δ²].

As no similar study was available in our context, we used a standard P of 0.5.

With a precision of 95%, the theoretical minimum number of adolescents for the study was 385. We randomly selected 1202 adolescents from the DHSS sampling frame.

Ten trained interviewers, supported by a supervisor, collected data during interviews with the teenagers using tablets equipped with Survey CTO mobile data collection software. All data collected was quickly downloaded to secure servers and checked for quality prior to analysis.

The study variables were:

Socio-economic level was measured using the McArthur scale. We divided it into 3 levels: low socio-economic level (0 to 3), medium socio-economic level (4 to 7) and high socio-economic level (8 to 10).

To ensure ethical compliance, we obtained approval from the institutional ethics committee of the Nouna Health Research Centre (NHRC) and the national ethics committee for health research in Burkina Faso. In addition, for all adolescents under the age of 18, parental or guardian consent and adolescent consent were required to participate in the study. For adolescents aged 18 and over, written informed consent was obtained before participation in the study. Confidentiality and anonymity of participants were also assured.

This study has limitations. It did not analyse the determinants of lack of knowledge about SRH and risk behaviour.

Only 58.15% of the participants had ever heard of HIV/AIDS. This situation could be explained by the youth of our study population, who have not yet had the opportunity to attend or listen to regular awareness-raising sessions on HIV/AIDS. Furthermore, the presence of terrorism in the area means that this opportunity is becoming increasingly rare. Also, as the majority of young teenagers are in primary school, the subject of HIV is less discussed at this level of education. It is generally not until secondary school that it is more widely discussed.

This result is lower than those found by Diarra et al. [8] in Mali and Touré et al. [9] in Côte d’Ivoire, who found 99.7% and 99.3% respectively. This difference could be explained by the fact that our study population was mainly rural and had a low level of education.

In terms of sources of information about HIV/AIDS, the school was the main source with 53.58%. This could be explained by the high proportion of adolescents attending school in our study (84.8% of participants). School is a privileged place to learn and acquire knowledge about HIV/AIDS. NGOs sometimes organize HIV/AIDS awareness sessions in schools, helping to improve knowledge about sexual and reproductive health.

This result shows that most parents do not educate their children about sexual and reproductive health, as it is still a taboo subject in our context.

Only 7% of the adolescents were aware of other types of STIs besides HIV/AIDS. This could be explained by the fact that STI awareness campaigns always focus on HIV/AIDS. This result is lower than that found by Segbedji et al. [10] in Lomé, who found that 92% of adolescents were aware of other STIs. This difference may be explained by the fact that their study included adolescents in secondary school. At the secondary level, the study of STIs is part of the life and earth sciences curriculum.

In terms of behaviour, only 15.8% of the adolescents had already had sexual relations. This result is similar to that found by Khermakhem et al. [11] in Tunisia, where 12.5% of adolescents were sexually active.

This low rate could be explained by the fact that the participants lived in rural or semi-rural areas. In these environments, they are less influenced by the media and social networks. The latter often broadcast sexual content that arouses teenagers’ curiosity about sexuality. In addition, cultural and religious norms, which are more respected in rural areas, do not encourage sexual activity among teenagers before marriage.

Our result is lower than those of Segbedji et al. [10] in Lomé, Kounta et al. [12] in Mali and Diallo et al. [13] in Conakry, who found frequencies of 27.6%, 54% and 45.2% respectively. This difference can be explained by the fact that their studies focused on adolescents in urban areas who were in secondary school, unlike ours, which focused on adolescents who had not attended school, in primary and secondary schools.

Contraceptive methods were used by 55.3% of adolescents. This relatively high rate of use could be explained by the availability of contraceptive methods in all health centres. The Ministry of Health has made contraceptive methods available free of charge throughout Burkina Faso.

This rate of 55.3% is much higher than those found by Diawara [14] in Bamako and Adohinzin et al. [15] in Bobo Dioulasso, who found 8.5% and 28.6% respectively. This could be explained by the fact that contraceptive prevalence is low in Mali and that the Adohinzin study targeted adolescents aged 15 - 19 years, most of whom were in couples.

In addition, some young people are unaware of the potential risks of unprotected sex. For other young people, condoms reduce pleasure, so they choose to have sex without condoms.

The condom is the most commonly used contraceptive method (44.37%). This is due to its accessibility, affordability and effectiveness in preventing both unwanted pregnancy and sexually transmitted infections. This rate of condom use is lower than that of Keita [16] in Mali, who found 92.4%. This difference could be explained by the fact that his study took place in an urban environment where condoms are easier to obtain.

More than 8 out of 10 adolescents (83.4%) have not had sexual relations. This could be explained by the respect for social values in our context. In fact, habits and customs are not in favour of sexual relations outside marriage. This rate is higher than that found by Mukadi et al. [17] in the Congo, who found 56% in their study. Their study was conducted in an urban environment. In this environment, moral decay is more pronounced and young people routinely engage in early sex without embarrassment.

Of the teenagers who had heard about HIV, only 4.3% had been tested, or 30 people, representing 2.5% of all young people. This low rate of HIV testing could be explained not only by the fact that most of the adolescents were virgins, but also by inadequate information about HIV/AIDS.

The screening rate in our series is lower than that of Segbedji et al. [10] in Lomé, who found 42.4%. The difference in the study setting could explain this situation. In rural areas, the subject remains taboo and the risk of HIV-related social stigma is high.

Adolescents in rural areas have insufficient knowledge about sexual and reproductive health. In fact, knowledge about HIV/AIDS and STIs is poor, and the rate of HIV screening is low. Few adolescents had started sexual activity, which is remarkable. However, those who had sexual partners were taking risks, as the majority of sexual relationships were unprotected. Despite this, condoms were the contraceptive method most commonly used by teenagers. These shortcomings should make it possible to take action in relation to adolescents. Emphasis should be placed on community education programs to reach those who do not attend school. A comprehensive approach that respects the rights of adolescents is needed to meet their needs and help them lead responsible and fulfilling sexual lives.