Bao’an District used to be the leprosy epidemic area. After decades of efforts, the number of new leprosy patients decreased year by year. According to WHO’s criteron of disease elimination [18], Bao’an District had achieved the goal of elimination of leprosy as a public health problem in 1993. Multiple stragegies were made to early detection and reducing the number of new patients diagnosed with G2D. The detection rate of leprosy maintained at less than 0.5/100,000 while the prevalence rate maintained at less than 1/100,000 over the last three decades. It was reported 0.168/100,000 in 1991 while 0.029/100,000 in 2020, indicating more than 80% decline. As to prevalence rate, it was reported 0.673/100,000 in 1991, while it was only 0.295/100,000 in 2020, indicating a reduction of 56.2%. Our findings demonstrate a long duration of symptomatic illness (median, 31 months). It is interesting to note that this mean delay was higher in local patients (4 patients, median, 37.5 months). In Guangdong province, the mean delay in diagnosis was 26.37 months [19]. Factors can significantly affect delay in diagnosis including older, higher level of education, BL and LL, MB, people who had reaction or neuritis. The increased proportion of MB reflects a situation of low endemicity and indicates delays in detection [20]. New case had a reaction or neuritis was more likely to delay in diagnosis. We did not observe an association between nerve damage and delay in diagnosis, consistent with a previous study of leprosy patients at a United State clinic [21]. Factors that may affect the length of symptoms before diagnosis include patients having inadequate awareness of the disease, weak willingness to seek care for non-painful and non-itching skin lesions, not seeking care for fear of being isolated from the community, not having health insurance. Misdiagnosis and missed diagnosis of leprosy occur occasionally due to the insidious onset, long incubation period, and diverse characteristics of skin lesions.
The amount of fund given from 2011 to 2020 by the local government was 10.37 million CNY (US $1.6 million). The leprosy control strategies include suspicious sign and symptom surveillance, contact chasing, focused survey, extensive training to sustain leprosy capacity among health staff, health education, effective referral system, monitoring system to test possible adverse drug reactions, self-care activities supplying counselling and disability care information. In the late 1990s, case-finding activities among mobile populations were implemented in Shenzhen. An increase in the detection of new cases was observed from 2002 to 2013 in Bao’an; this resulted from a widespread case finding attempt (the integration of leprosy services into general health service) implemented in 2000. The activities include training health staff, such as dermatologists, neurologists, general practitioner in Social Health Centre and physical examination physician, establishing and improving an effective leprosy referral system, formulating an evaluating system and reward system for primary health care and medical institution, et al. In 2020, more than 1400 health workers can offer leprosy referral service and the physician training rate is over 90%. In the past 3 decades, about 93.0% of new cases of leprosy in Baoan District originated from other provinces and cities. There is no new child cases and relapses. 9.5% (9/95) of new mobile cases population were detected through self-reporting, 4.2% were detected through community health center referral and 6.3% were through Pathology laboratory referral. It means that 89.5% of newly detected leprosy cases were detected through passive modes, active case-finding in this area is insufficient,
It is notable that 61.1% of patients had nerve damage at diagnosis, higher than the 36.4% rate of nerve damage reported in the literature [21]. MB disease, presence of neuritis and reactions were identified as contributing factors of nerve damage [22]. These numbers show the large burden of peripheral nerves damage. With the progress of the disease, sensory changes may become irreversible and eventually leads to the appearance of disabilities. A causal relationship between nerve damage and D2G has been showed in the past [23–25], thorough neurological examination is essential at diagnosis and at each follow-up visit thereafter. Some of D2G, such as claw hand, monkey's hand, and foot drop caused by nerve impairment, may be irreversible. However, one patient in our study happened Foot drop in the course of treatment and recovered finally owe to timely discovery and treatment. Regular follow-up, improving patient’s understanding of the influence of leprosy on peripheral nerve, reporting any illness changes timely, may prevent the deformity caused by neuritis or make the deformity residual improvement during the treatment process. In most cases, the examination and assessment of neuritis or nerve damage depend on experienced doctors in the practice of leprosy. Nerve function was assessed monthly in patients under MDT treatment and repeated every three months in patients released from MDT.Quantitative assessment means or smart tools have not applied to detect the severity of nerve damage, which may influence the accuracy of assessment results. Compared with other areas, the proportion of cases with grade-2 disabilities among newly detected cases has been low in Bao’an [4–5]. The proportion of new cases with G1D increased from 25.0%during 1991 to 1995, to 31.8% during 2016 to 2020, while the proportion of new cases with G2D decreased from 25.0–13.6%, representing a reduction of 45.6%. The findings of this research indicated that the new case detection and disability rehabilitation of leprosy has achieved success. Patients were detected and treated in an early stage, which may prevent further aggravation of deformity. Early detection, early diagnosis and early treatment are still the key measures to prevent deformity.
Records of WHO grade of disability and EHF score provide a crude measure of the effectiveness of disability prevention activity, some patients deteriorated. Factors that could have affected prevention effect including bacterial density index greater than 4, long length of symptoms before diagnosis, substandard treatment process and lepromatous leprosy subtype. Positive is that nerve damage and impairment show improvement significantly after RFT.
Challenges to achieving the goal of NLEP are early detection and management of reactions, neuritis and disabilities among mobile leproy. Both the number and proportion of newly detected cases diagnosed among transient and mobile populations have increased since 1991. More than 90% were mobile leprosy cases in recent ten years. Transient and mobile leprosy almost had no fixed abode and job, it is a challenge for specialists to carry out regular follow-up, monitoring contacts and surveillance. Mobile leprosy cases are young, with high working intensity and poor compliance with physical examination and medical treatment, it is difficult for early discovery and treatment of neuritis, leprosy reactions and disabilities. Another challenge is that majority (75.8%) of newly detected leprosy was MB cases. Both the absolute number and proportion of MB cases among newly detected leprosy increased since 1991, from 7 and 58% at time period 1 (1991-2000) to 24 and 80% at time period 3 (2011-2020), respectively. The situation may indicate delays in detection or reflect the continually adjusted WHO clinical definition of MB and PB [20, 26].
The main limitation is the fact that no case interview is conducted which results in information bias as patients’ perception about the disease, treatment and recovery do not known.
For the next stage in the better mobile leprosy control in Baoan District, the following problems should be resolved. First, skills in detecting and management leprosy patients among general health staffs are inadequate while newly detected leprosy cases decreased year by year at low endemic situation. Second, leprosy administrative staffs are instable, personnel welfare benefits have not been well implemented, and lack of clinical professionals in leprosy prevention and control. Third, insufficient leprosy knowledge in public and social discrimination persists. Fourth, government commitment to leprosy control is low.