HIV (human immunodeficiency virus) is a virus that attacks the immune system, weakening the body’s ability to fight infections and certain diseases [1]. It is primarily transmitted through sexual contact, blood, or from mother to child [2]. Without treatment, it can progress to AIDS, an advanced stage of infection characterized by severe opportunistic infections, and an increased risk of mortality [3]. Globally, approximately 41.0 million people were living with HIV at the end of 2025, with 64% located in the African region [4]. In 2024, approximately 570,000 people died from HIV-related causes, and 1.2 million were newly infected [4]. However, between 2010 and 2024, new infections fell by 40% and deaths by 54% (UNAIDS 2024). These notable successes were achieved through behavioral changes, the prevention of mother-to-child transmission, and, above all, antiretroviral treatment [5]. The long-term efficacy of antiretroviral treatment leads to viral load suppression, thereby yielding beneficial effects at both individual and community levels by eliminating the risk of transmission [4]. According to UNAIDS, antiretroviral therapy helped prevent approximately 1.8 million AIDS-related deaths in 2024. Since 1996, access to antiretroviral therapy is estimated to have prevented approximately 26.9 million deaths worldwide [6]. However, failure to adhere to prescribed antiretroviral treatment remains a major obstacle to treatment efficacy.

Despite the progress made, non-adherence to HIV treatment remains a global issue, particularly in Africa. Overall, rates of non-adherence vary significantly across regions and studies, with some figures indicating non-adherence levels of around 23% in Africa and 36% in a combined Africa-North America dataset [7]. Challenges regarding treatment adherence can be linked to social, psychological, economic, and therapeutic factors [8]. Several studies have shown that non-adherence to treatment poses a major obstacle to effective viral load control, fostering the emergence of drug resistance, progression to AIDS, and increased morbidity and mortality [9][10].

Senegal is one of the countries in the region that committed early to the fight against the HIV pandemic. The Senegalese Initiative for Access to Antiretrovirals (ISAARV) was launched as early as 1998, and a 2003 presidential decree guaranteed the availability and free provision of antiretrovirals nationwide [11]. Thanks to these efforts, the country has made notable progress, seeing a steady decline in new infections and deaths [12]. However, long-term treatment non-adherence remains a challenge. Data on non-adherence in Senegal vary, with reported rates ranging from 20% to 73.33%, depending on the populations studied and the assessment methods used [13][14]. The Department of Infectious and Tropical Diseases at the Fann University Hospital (CHNU de Fann) serves as a national reference center for the care of people living with HIV (PLHIV). It operates a hospital pharmacy that not only dispenses antiretrovirals (ARVs) but also assists physicians with patient monitoring. Under the National Strategic Plan for an integrated multisectoral response to AIDS, tuberculosis, viral hepatitis, and STIs (2023-2030), optimizing the quality of screening, treatment, care, and support services is a key priority. To achieve this, it is essential to assess treatment adherence among PLHIV in order to better tailor adherence support strategies. It is against this backdrop that we conducted this study to determine the prevalence of non-adherence over the past six months and to identify the reasons associated with it.

The majority of our patients were on a dolutegravir (DTG)-based therapeutic regimen (93.50%). This trend aligns with data published by Loosli et al. [15], where 91.6% of patients were on a DTG-containing regimen. The widespread use of this regimen reflects 2018 first-line recommendations from ISAARV and the WHO, which advocate using this combination therapy as the initial treatment for all HIV-infected adults and adolescents [16]. For three-quarters of the patients, the reminder method was psychological; 18.00% used an alarm. In a study conducted in China, the majority of patients (89.75%) used a telephone reminder [17]. Mobile phone reminders (SMS and calls) improve treatment adherence and efficacy, as demonstrated in numerous studies [18]-[20]. Therefore, it is necessary to promote the use of electronic reminder methods among our patients.

More than half of the patients (60.00%) reported at least one adverse event during follow-up. Weight gain was observed in 43.30% of patients, and vomiting in 9.20%. No serious adverse events leading to a change in treatment were reported in our study. This may be explained by the therapeutic regimen most commonly used in our study. Dolutegravir-based regimens are better tolerated than other first-line treatment regimens [21][22]. However, dolutegravir and other integrase inhibitors are associated with greater weight gain in individuals receiving antiretroviral therapy [23][24]. Individuals experiencing significant weight gain while on dolutegravir-based antiretroviral therapy should be screened for metabolic syndrome and treated accordingly. This weight gain should be managed through lifestyle modifications and other appropriate interventions [23]. We used three separate methods to measure treatment adherence: prescription refill compliance, adherence to the prescribed regimen, and the pill count method, which served as our reference standard. The latter revealed that approximately 10.00% of patients were non-adherent. Similar proportions were found in other studies, such as those by Liu et al. in China [17] (9.82%), Keou et al. in Cameroon [25] (8%), and Byabene et al. in Senegal [13] (10%). Higher figures were reported by Eribo et al. in Nigeria (17%), Guira et al. in Burkina Faso [26] (32.8%), and Been et al. among African immigrants in the Netherlands [27] (53.4%). This difference compared to our rate may be explained by variations in adherence assessment methods (remaining pills vs. self-reporting), as well as by our sampling approach, which focused exclusively on patients attending follow-up appointments. Forgetting (40.00%) and travel (25.00%) were the most frequently cited reasons. Forgetting and travel were the primary reasons cited, consistent with other studies [17][25][28]. Forgetting was one of the most common causes of treatment non-adherence. It can be attributed to several factors, often acting in combination. In our study, this could be explained by the fact that most of our patients (three-quarters) relied on mental reminders to take their medication, a practice that may lead to missed doses. The female predominance observed in our population (57.00%) also warrants consideration when analyzing treatment adherence. Women living with HIV may face specific constraints related to family responsibilities, domestic and professional activities, and childcare, all of which can influence the regularity of medication intake [8]. Forgetting could also be influenced by age. Our cohort included a significant proportion of older individuals, the 40 - 59 age groups were the most represented, at 47.00%. In elderly patients, certain challenges such as memory or concentration issues, fatigue, and the concomitant use of other medications can affect the daily management of antiretroviral therapy and increase the likelihood of missed doses [29].

More broadly, patient-related factors include a high mental load (work, studies, stress, family issues), attention deficits, a lack of understanding regarding the treatment’s importance, fatigue, or depression [30]. Other factors, particularly those related to the treatment itself, have been identified, such as long treatment duration and schedules that are restrictive or incompatible with daily life [8]. Organizational factors such as the absence of a daily routine and a lack of reminders (alarms, pill organizers, or support from a loved one)—have also been highlighted [8]. To reduce instances of missed doses, strategies should include simplifying treatment regimens; using tools like pill organizers, alarms, and mobile apps; providing clear and repeated patient education; involving family or loved ones; and tailoring dosing schedules to the patient’s lifestyle [31]. Travel-related factors may include changes to daily routines leading to missed doses; jet lag causing confusion or delays in administration; prolonged travel without immediate access to medication; forgotten, lost, or stolen luggage; and underestimating the trip’s duration (resulting in an insufficient supply of medication) [32]-[34]. Travel-related non-adherence may also stem from psychosocial factors, such as the fear of stigma (e.g., reluctance to take medication in public or in front of others), group travel or family stays encouraging excessive discretion, and travel-related fatigue (e.g., long drives or overnight flights) [35]. Studies conducted in East Africa have shown that certain forms of mobility and migration are associated with increased treatment non-adherence, particularly when travel leads to interruptions in follow-up care or a stay in an environment where one’s serostatus is unknown [36].

A lack of financial resources (5.00%) and transportation difficulties (5.00%) were also causes of non-adherence within our study population. These issues can be linked to where our patients lived; indeed, 38.00% of patients came from outlying regions, and 42.50% resided in the Dakar suburbs. For these patients, the distance to the care facility could lead to increased travel costs. A study conducted in sub-Saharan Africa also reports that financial constraints specifically a lack of transportation pose a significant barrier to adherence to antiretroviral therapy [37]. Similarly, research in Uganda has shown that a lack of funds for travel to care centers can result in missed appointments and missed doses [38].

Our study has several strengths. It enabled us to assess the frequency of non-adherence and identify its main causes, particularly forgetfulness and travel. It also allowed us to propose practical measures tailored to the difficulties patients face such as the use of alarms, telephone reminders, and pill organizers to prevent missed doses. However, the study has certain limitations, particularly regarding the methods used to assess treatment adherence. We relied on patient self-reporting, which could introduce biases (such as recall bias) likely to lead to an overestimation of adherence rates. Furthermore, biological methods such as measuring viral load or assaying protease inhibitor levels would have helped validate our questionnaire.

At the conclusion of our study conducted at the Infectious and Tropical Diseases Department of the CHNU de Fann among patients living with HIV, we observed generally satisfactory adherence to antiretroviral therapy. The majority of patients adhered to prescription renewal schedules and took their medication as prescribed; however, a small proportion remained non-adherent. Forgetting to take medication and traveling were the most frequently cited reasons. These results highlight the need to strengthen personalized approaches aimed at improving therapeutic adherence.

Conceptualization, Mouhamadou THIAM., Aboubakar Sidikh Badiane., and Mouhamadou Baïla Diallo.; methodology, Mouhamadou THIAM.; software, Mouhamadou THIAM., Aboubakar Sidikh Badiane; validation, Moussa Seydi., Mouhamadou Baïla Diallo., Judicaël Malick Tine.; formal analysis, Aboubakar Sidikh Badiane.; investigation,Mouhamadou THIAM Abdou Faye., Mame Diarra Diouf., Nogaye Diouf., Maguette Sene., Ndella Dieye., Amath Faye., Aby Sow.; data curation, Mouhamadou THIAM.; Aboubakar Sidikh Badiane., writing—original draft preparation, Mouhamadou THIAM.; writing—review and editing, Mouhamadou THIAM., Aboubakar Sidikh Badiane.; Mouhamadou Baïla Diallo., Abdou Faye., Harouna Ousmane Sow.; Mouhamadou Moustapha Gueye.; Daouda Thioub.; supervision, Moussa seydi., Aboubakar Sidikh Badiane. All authors have read and agreed to the published version of the manuscript.