The relative transmissibility of shigellosis among male and female individuals in Hubei Province, China: a modelling study

Objective Shigellosis has been a heavy burden in China. However, its relative transmissibility in male and female individuals remains unclear. Method A sex-based Susceptible–Exposed–Infectious/Asymptomatic–Recovered (SEIAR) model was applied to explore the dataset of reported shigellosis cases built by Hubei Province from 2005 to 2017. Two indicators, secondary attack rate (SAR) and relative ratio of SAR between males and females, were developed to assess the relative transmissibility in males and females. Results The number of cases and reported incidences in males and females demonstrated a significant decreasing trend (Male trend: χ 2 = 11.268, P = 0.001, Female trend: χ 2 = 11.144, P = 0.001). SEIAR model had a great fitting effect with the data of shigellosis ( P < 0.001). Our simulation revealed that, when parameter β fm = 0, the greatest decrease in cases were obtained for different genders. The median value for SAR mm was 2.3225 × 10 −8 (Range: 1.7574 × 10 −8 – 3.8565 × 10 −8 ), SAR mf was 2.5729 × 10 −8 (Range: 1.3772 × 10 −8 – 3.2773 × 10 −8 ), SAR fm was 2.7630 × 10 −8 (Range: 1.8387 × 10 −8 – 4.2638 × 10 −8 ) and SAR ff was 2.1061 × 10 −8 (Range: 1.0201 × 10 −8 – 3.2140 × 10 −8 ). The median value of relative ratio calculated by SAR in mm versus (vs) mf was 0.93 (Range: 0.75 – 1.47), mm vs fm was 0.90 (Range: 0.41 – 1.81), mm vs ff was 1.07 (Range: 0.55 – 2.93), mf vs fm was 0.99 (Range: 0.32 – 1.25), mf vs ff was 1.17 (Range: 0.43 – 3.21) and ff vs fm was 0.75 (Range: 0.35 – 1.06). Conclusion Transmissibility of shigellosis is different among male and female individuals. Shigellosis seems to be more transmissible in males than in females. Author summary Shigellosis, also known as bacillary dysentery, is an infectious disease caused by the genus Shigella spp . Developing countries have high disease burden of shigellosis. However, its relative transmissibility in male and female individuals remains unclear. In this study, we employed a mathematical model to explore the dataset of reported shigellosis cases built by Hubei Province, China from 2005 to 2017. Two indicators, secondary attack rate (SAR) and relative ratio of SAR between males and females, were developed to assess the relative transmissibility in males and females. We found that shigellosis has medium transmissibility among male and female individuals. The disease seems to be more transmissible in males than in females.