Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease characterized by a peripheral, symmetrical, progressive, and potentially destructive joint involvement [1]-[5]. It is the most common inflammatory rheumatism worldwide, with a prevalence of approximately 0.5% - 1% in the general population [6]-[9]. In sub-Saharan Africa, available data remain limited, but several studies suggest an increasing recognition of the disease, related to improvements in diagnostic capacity and the gradual establishment of specialized rheumatology services. [10]-[12].

In Chad, the management of rheumatic diseases has recently expanded with the opening of specialized services, including that of the Hôpital de la Refondation du Tchad in N’Djamena. However, RA is still often diagnosed at an advanced stage due to socioeconomic constraints, limited access to specialized care, and persistent lack of awareness of the disease in the general population. In this context, our study aims to describe the epidemiological, diagnostic, therapeutic, and evolutionary characteristics of RA at the Rheumatology Department.

Our series of 211 cases of rheumatoid arthritis (RA) represents one of the most substantial datasets reported in Central Africa. Its prevalence of 4.22% among 5000 rheumatology consultations is at the upper limit of African estimates, which generally range from 1.5% to 4% in specialized hospital studies [13]-[16]. This variability may reflect recruitment differences in specialized centres or a genuinely high RA burden in the Chadian population.

1) Epidemiological profile and diagnostic delay

The marked female predominance (86.3%) aligns with findings from Senegal, Benin, Congo, and North Africa, where women represent 75% to 90% of cases. [17][18]. The mean age at diagnosis (44.45 years) is similar to reports from Senegal (43 - 45 years), Congo (45 years), and Morocco (46 years) [19][20].

A major diagnostic delay—72 months—is one of the key features of our study. This delay is substantially longer than those reported in Morocco (36 - 48 months), Benin (36 - 48 months), and remains higher than Senegalese data (54 - 72 months) [21][22]. Such prolonged delays, typical of sub-Saharan Africa, may be explained by self-medication, limited specialist availability, restricted access to immunological testing, and lack of structured care pathways. As a consequence, advanced forms are common at diagnosis: deformities (61%), ankylosis (52.2%), and polyarticular involvement (93.8%). Similar findings have been reported in Senegal and Benin [23][24]. Comparative data from sub-Saharan African studies are presented in Table 4.

Table 4. Comparison of epidemiological data on rheumatoid arthritis in sub-Saharan Africa.

2) Extra-articular manifestations and immunological features

Extra-articular manifestations such as alopecia (12%), pulmonary involvement (3.4%), and myalgia (6.3%) fall within the African range 2% - 15% [25][26]. Immunological markers (RF 69%, ACPA 67.5%) are consistent with Senegalese and Moroccan data. These high positivity rates correlate with greater structural severity, as confirmed by our radiological findings [27][28].

3) Structural severity and radiographic outcomes

A predominance of Steinbrocker stage 3 (55.2%) and a high frequency of joint space narrowing (97.7%) and erosions (43.1%) illustrate a structurally severe disease. Similar levels of radiographic damage have been reported in Congo, Benin, and Morocco [29][30].

4) Evolutionary data: DAS28, SF-36, and NHP

a) Inflammatory activity (DAS28): Initial DAS28 scores were mostly high or moderate, reflecting substantial inflammatory activity. Similar profiles were observed in Senegal. Clinical improvement under methotrexate parallels findings from Benin and Morocco.

b) Quality of life (SF-36): Significant impairment was noted in physical functioning, pain, and activity limitation, consistent with Tunisian and Moroccan studies.

c) Functional impairment (NHP): Major impairments in pain, sleep, fatigue, and mobility were observed, similar to results in Senegal and Tunisia [31][32].

5) Therapeutic management: African context

Therapeutic strategies relied mainly on methotrexate (81.5%), hydroxychloroquine, sulfasalazine, low-dose corticosteroids, and NSAIDs, consistent with African practice. The absence of biologics remains a major limitation due to high cost, lack of health insurance, unavailability, and absence of national RA care programs [33]-[36].

This study has several limitations. Its monocentric and retrospective design exposes it to selection bias, particularly towards moderate-to-severe cases referred to a specialized rheumatology department. The availability of immunological tests was variable, which may have influenced the observed seropositivity rates. In addition, disease activity indices and functional scores were not systematically available for all patients because of socioeconomic constraints. Nevertheless, these limitations reflect real-life conditions in sub-Saharan Africa and underline the relevance of our data for routine clinical practice in the region.

RA in Chad is diagnosed late, clinically active, radiologically destructive, and functionally disabling. Early detection, continuous access to DMARDs, and progressive introduction of biologic therapies are necessary to improve patient outcomes.

This study, involving 211 cases of rheumatoid arthritis, represents one of the largest series reported in Chad. It reveals a disease that is often diagnosed at a late stage, with an average diagnostic delay of more than six years and a high frequency of severe, deforming, and disabling forms. Biological and immunological data confirm high disease activity, while radiological findings demonstrate advanced joint destruction. Management remains dominated by methotrexate, hydroxychloroquine, and low-dose corticosteroids, in a context marked by the total absence of biologic therapies and irregular treatment adherence. These findings highlight the urgent need to strengthen early detection through training of primary-care physicians to recognize early inflammatory arthritis and to refer patients promptly to rheumatology services. In parallel, patient education programs focusing on treatment adherence and early recognition of warning symptoms could help reduce diagnostic delays and prevent irreversible disability. Finally, expanding access to conventional DMARDs and progressively implementing national strategies for the introduction of biologic therapies should be considered a priority for improving the prognosis of rheumatoid arthritis in Chad.

All authors contributed significantly:

-Study conception and methodology: Garba Harine Abdel Aziz.

-Data analysis: All authors.

-Manuscript writing: Garba Harine Abdel Aziz.

-Critical revision: All authors.

All authors approved the final manuscript.

Data are available upon reasonable request from the corresponding author.

The study protocol was conducted with due regard for patient anonymity and confidentiality. Authorization to collect and use data was obtained from the management of the Refoundation Hospital of Chad and the research director of the Faculty of Human Health Sciences at the University of N'Djamena. Informed oral consent was obtained during consultations.