Between 1925 and 2018, 11,789 leprosy patients were diagnosed in Shaanxi province, 10,270 cases have been cured, and 502 patients relapsed (data from LEPMIS). The prevalence rates of leprosy in over 95% of regions, counties, or districts in Shaanxi were controlled below 1/100,000 population, reaching our national target of basically eliminating leprosy. According to data above, 477 new diagnosed leprosy cases and 65 relapsed patients were found in Shaanxi between 1998 and 2018, 542 cases in total. The annual detection rate dropped from 0.092/100,000 population in 1998 to 0.029/100,000 population in 2018. The detection rate and prevalence rate of leprosy showed an impressively significant downward trend over the past 20 years, which indicated that we have achieved good results in the prevention and control of leprosy.
In 477 newly diagnosed patients, the male-female ratio is 2.46:1, which was basically consistent with previous reports in some other areas in China[15, 16]. This result was consistent with previous results conducted in other regions of our country. Male patients still accounted for a relatively high proportion of the new diagnosed cases in each year, which may be related to different genetic susceptibility in different genders. However, this ratio in China was different from that in some other countries of the world. That may be because females got more skin consultations than males, and males may be more easily exposed to leprosy bacilli related to behavioral and cultural factors. Culture, life, and genetic differences between races may be related to this difference, but to date, no studies have been published on this, and it would have been interesting to explore this aspect.
The average age of the newly detected was 45.2 years old, which changed little in different years. In terms of newly diagnosed cases, the age distribution in different years were similar. However, the average age of prevalent cases was getting higher. The Leprosy Control Handbook mentioned that it is generally believed that the average age of patients tends to rise as the incidence of leprosy declined (the prevalence of leprosy is controlled). This was also an evidence for the relatively low epidemic situation of leprosy in Shaanxi. However, this may also be related to the long delay period in diagnosis, suggesting that the ability to detect new leprosy patients in Shaanxi still needed improvement. In terms of current leprosy cases, the average age during 21 years was relatively high, which may be related to the large number of MB leprosy cases in our province and the long MDT course. Disability degree is an indicator of the ability to diagnose and monitor leprosy of health service departments, and patients classified as grade 1 or grade 2 disability were related to delayed diagnosis or monitoring failure. This suggested that we should pay attention to the treatment and rehabilitation of current leprosy cases. From 1998 to 2018, only two children under 15 years old were diagnosed with leprosy, which on one hand may be related to the long incubation period and/or low transmission, on the other hand may be related to the relatively low prevalence in Shaanxi. In terms of regional distribution, leprosy epidemic was mainly in Southern Shaanxi and the Central Shaanxi Plain. These areas above were also areas with high incidence rate of leprosy in history. The source of infection has not been completely and effectively controlled, suggesting that we should continue to improve prevention and control work in these areas.
83.6% of the new cases were MB and 16.4% were PB, with a ratio of 5.1:1, which was higher than related reports in some other regions in China, indicating that the number of MB cases was too high and there were potential risks. MB leprosy patients have more severe symptoms, more complications, and need longer period of MDT. In Shaanxi, the proportion of MB patients was relatively higher than other provinces, this resulted in leprosy patients in Shaanxi may have more severe symptoms, more complications, and be cured at an older age on average. However, previous studies showed that the type ratio will rise in the low prevalence area of leprosy, which may indicate that leprosy in Shaanxi was in a low epidemic state and under effective control. The type ratio of newly detected cases between 1998 and 2018 was relatively high (83.7%). The grade 2 disability rate of new cases in Shaanxi between 1998 and 2018 was about 31.0%, which may be related to the longer delay in diagnosis and less newly detected cases. The average delay period of newly diagnosed patients was 46 months, which was much higher than that reported in relevant literatures in some other areas in China, such as Guangdong province, indicating that leprosy cases in Shaanxi took a longer time from onset to diagnosis. This situation may be related to latent symptoms and atypical clinical manifestations in the early stage, low attention to patients, and lack of primary prevention and treatment experience, etc., suggesting that our province should further carry out leprosy monitoring and strengthen the ability of early detection and diagnosis.
In order to improve diagnostic delay and reduce deformity rate in Shaanxi province, we should take advantage of China’s health system reform, comprehensively improve the LEPMIS, strengthen the training of dermatologists, vigorously promoting the community health consultation on leprosy, and actively carry out early leprosy diagnosis technology research.