Incidence and determinants of extrapulmonary tuberculosis in Egypt: a retrospective cohort study

Abstract

Tuberculosis (TB) is a significant global public health concern. The incidence of extrapulmonary tuberculosis (EPTB) is increasing; however, comprehensive data on its epidemiological and clinical characteristics remain limited, especially among populations who are co-infected with human immunodeficiency virus (HIV) or hepatitis C virus (HCV). This study aimed to assess the incidence and predictors of EPTB in patients co-infected with HIV or HCV in Egypt. We conducted a retrospective cohort study on patients infected with TB who are treated in Egyptian chest hospitals from January 1 to December 31, 2023. Patients were categorized into pulmonary TB (PTB) and EPTB. Clinical data, including HIV or HCV co-infection status, were analyzed to identify risk factors and comorbidities associated with EPTB. Multilevel logistic regression was employed to examine predictors of EPTB. Among 7,245 TB patients, 42.5% were diagnosed with EPTB. Determinant of EPTB were HIV-positive (OR = 0.46, 95% CI: 0.30-0.71, p < 0.001), being male (OR = 0.31, 95% CI: 0.27-0.35, p < 0.001 ), age (particularly children under 5 years) (OR = 4.75, 95% CI: 2.29-9.84, p < 0.001 ), urban residency (OR = 1.05, 95% CI: 0.87-1.27, p < 0.05), and comorbidities (OR = 0.59, 95% CI: 0.35-0.98, p < 0.05). The most common sites for EPTB were the lymph nodes (27.10%) and pleural cavity/effusion (24.60%). EPTB represents a substantial proportion of TB cases in Egypt, particularly among younger individuals and females. Despite the low percentage of HIV or HCV co-infection in EPTB cases, further analysis and diagnostic testing of undiagnosed patients are required. These findings underscore the need for targeted interventions and comprehensive care models for TB patients, especially in the context of HIV co-infection.

Keywords: Co-infection; Extrapulmonary tuberculosis; Hepatitis C; Human immunodeficiency virus; Pulmonary tuberculosis.

Fig. 1

Flowchart showing the assessment of EPTB incidence among TB patients with and without HIV or HCV co-infections in Egypt from January 1 to December 31, 2023. * PTB with both HIV and HCV = 12 and ** EPTB with both HIV and HCV = 2. (N.B. HCV test not performed for 6,184 patients, and HIV test not performed for 2,846 patients)

Fig. 2

A bubble plot showing the percentage of EPTB patients across 25 Egyptian governorates. Each bubble represents the percentage of EPTB in a specific governorate, with the size and color intensity of the bubbles corresponding to the percentage of affected patients.

Fig. 3

EPTB site distribution among studied populations, these numbers were mutually exclusive. (a) Distribution of EPTB cases across anatomical sites. (b) Distribution of HIV and HCV-positive EPTB cases. GIT: Gastrointestinal tract; ENT: Ear, nose, and throat.

Fig. 4

The predicted probabilities of EPTB diagnosis patients with random effect intercept.