Clinical Cysticercosis epidemiology in Spain based on the hospital discharge database: What's new?

Background
Cysticercosis (CC) is a tissue infection caused by the larval cysts of the pork tapeworm Taenia solium. It is usually acquired by eating contaminated food or drinking water. CC Cysts can develop in the muscles, the eyes, the brain, and/or the spinal cord. T. solium is found worldwide, but its prevalence has decreased in developed countries due to stricter meat inspection and better hygiene and sanitation. Nevertheless, CC is still a leading cause of seizures and epilepsy. In Spain, The disease is not nationally reportable and data on CC infected animals are also missing, despite the European Directive 2003/99/EC.
Methodology/Principal findings
We performed a retrospective descriptive study using the Spanish Hospitalization Minimum Data Set (CMBD). Data with ICD-9 CM cysticercosis code (“123.1”) placed in first or second diagnostic position from 1997 to 2014 were analyzed. Hospitalization rates were calculated and clinical characteristics were described. Spatial distribution of cases and their temporal behavior were also assessed. A total of 1,912 hospital discharges with clinical cysticercosis were identified. From 1998 to 2008, an increasing trend in the number of CC hospitalizations was observed, decreasing afterwards, in parallel with a decrease in the external migration rate. The Murcia region had the highest median hospitalization rate (13.37 hospitalizations/100,000 population), followed by Navarra and Madrid. The 16–44 age group was the most represented (63.6%). The three most frequent associated diagnoses were epilepsy and convulsions (49.5%), hydrocephalus (11.8%) and encephalitis/myelitis/meningitis (11.6%).
Conclusions/Significance
There is a need for a common strategy on data collection, monitoring and reporting, which would facilitate a more accurate picture on the CC epidemiological scenario. Even if most cases might be imported, improving the human and animal CC surveillance will result useful both in gaining extended disease knowledge and reducing morbidity and related-costs.

【背景】囊尾蚴病（Cysticercosis, CC）是由猪肉绦虫（Taenia solium）幼虫囊泡引发的组织感染性疾病，通常经食用受污染食物或饮用受污染水源而感染。其囊泡可寄生于肌肉、眼部、脑部及/或脊髓。猪肉绦虫呈全球分布，但在发达国家，随着肉类检疫标准趋严、卫生条件改善，其流行率已有所下降。尽管如此，囊尾蚴病仍是引发癫痫发作与癫痫的首要病因之一。在西班牙，该病未被纳入全国法定报告病种，且即便存在《欧洲指令2003/99/EC》，相关的囊尾蚴病感染动物数据仍存在缺失。

【方法学与主要结果】本研究依托西班牙住院患者最低数据集（Spanish Hospitalization Minimum Data Set, CMBD）开展回顾性描述性研究，分析了1997年至2014年间，以ICD-9-CM囊尾蚴病编码"123.1"作为第一或第二诊断顺位的病例数据。研究计算了住院率，对临床特征进行了描述，并评估了病例的空间分布与时间变化趋势。本研究共识别出1912例临床确诊囊尾蚴病的出院病例。1998年至2008年间，囊尾蚴病住院病例数呈上升趋势，此后则随外来移民率下降而同步回落。穆尔西亚（Murcia）地区的住院率中位数最高，达13.37例/10万人口，其次为纳瓦拉（Navarra）与马德里（Madrid）。16~44岁年龄段为主要发病人群，占比达63.6%。最常见的3项伴随诊断依次为癫痫与惊厥（49.5%）、脑积水（11.8%）以及脑炎/脊髓炎/脑膜炎（11.6%）。

【结论与意义】亟需建立一套统一的数据收集、监测与报告策略，以更精准地勾勒囊尾蚴病的流行病学图景。即便多数病例可能为输入性病例，加强人与动物的囊尾蚴病监测仍有助于深化对该病的认知，并降低其发病率与相关医疗成本。