Table 1. Study characteristics and data summaries of the included publications.
| Quality assessment | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Author, year | County (city or district), Province | Year* when interrupted | Study period | Snails found** | Sero prevalence in local residents (sample size) | Sero prevalence in mobile population (sample size) | Research question | Definition of mobile population | Serological test† | Proportion from endemic areas ‡ | Score § |
| Fang et al, 2009 | Huangshan, Anhui | 1993 | 2007 | Yes | 0.25% (3576) | 0.47% (422) | Clear | Clear | IHA | 24.9% | 10 |
| Yan et al, 2012 | Longhai, Fujian | 1985 | 1989–2010 | Yes | 0–3.4% in children aged 7–14 years (41–328) | 0 (102; 410) | Clear | Quite clear | IHA | Unknown | 8 |
| Xu et al, 2013 | Huadu and Zengcheng, Guangdong | 1982 | 2006–2010 | No | 0% (200–600) | 0–3.17% (200–1027) | Clear | Clear | DIGFA | Unknown | 9 |
| Li et al, 2012 | Qingxin, Guangdong | 1984 | 2006–2010 | No | 0–4.2% in children (215–307) | 0.67–6.19% (100–1002) | Clear | Quite clear | DIGFA | Unknown | 8 |
| Gao et al, 2003 | Zengcheng and Huadu, Guangdong | 1982 | 1996–2000 | No | 2.3–4.8% in children (353–393) | 2.22–5.88% (45–102) | Clear | Clear | ID | Unknown | 8 |
| Gao et al, 2007 | Zengcheng and Huadu, Guangdong | 1982 | 2001–2005 | No | 0% in children (200–209) | 2.08–5.88% (48–102) | Clear | Clear | ELISA | Unknown | 8 |
| Zhou et al, 2008 | Shaoguan, Guangdong | 1985 | 2001–2006 | No | 0% in children (387–487) | 2.30–5.88% (51–98) | Clear | Clear | ELISA | Unknown | 9 |
| Su et al, 2014 | Zhaoqing, Guangdong | 1985 | 2008–2013 | No | 0.25–0.61% (313–595) | 1.16–1.84% (345–762) | Clear | Clear | DIGFA | AH 40.4%, HB 20.4%, HN 10%, JS 11.9%, JX 20.1%, SC 6.5%, YN 0.8% | 10 |
| Lin et al, 2009 | Counties, Guangxi | 1988 | 2008 | Yes | 3.46% (2428) | Clear | Clear | IHA | 48.2% | 10 | |
| Zhou et al, 2009 | Changshu, Jiangsu | 1990 | 2008 | No | 0.47% (1066) | 0 (124) | Clear | Clear | DDIA | AH 57.3%, SC 6.5%, JS 25.8% | 10 |
| Wu et al, 1994 | Changshu, Jiangsu | 1990 | 1992 | Unclear | 0.1% (21421) | 6.87% (9759) | Clear | Clear | IEST | AH 60%, SC 4% | 10 |
| Xue et al, 1997 | Jiangyin, Jiangsu | 1981 | 1995 | Unclear | 3.75% (1067) | Clear | Clear | IEST | AH 36.6%, SC 16.5% | 10 | |
| Zhou et al, 2011 | Tongzhou, Jiangsu | 1993 | 2002–2009 | No | 0.49–0.5% in children (200–205) | 0.79–1.45% (207–312) | Clear | Clear | DDIA | Unknown | 9 |
| Ji et al, 2000 | Tongzhou, Jiangsu | 1993 | 1996–1999 | No | 0.85–1.81% in children (332–468) | 0.95–5.65% (248–446) | Clear | Clear | ID | Unknown | 10 |
| Jin et al, 2006 | Jinshan, Shanghai | 1984 | 2005 | Yes | 0.59% (507) | 0 (103); 0.06% (11690) | Clear | Clear | IHA/COPT | 38.30% | 9 |
| Yang et al, 2007 | Jinshan, Shanghai | 1984 | 2006 | Yes | 4.47% (514) | 0.06% (12747); 3.56% (505) | Clear | Clear | IHA/IEST | Unknown | 8 |
| Yang et al, 2008 | Jinshan, Shanghai | 1984 | 2007 | No | 1% (501) | 0.05% (14300); 0.60% (504) | Clear | Clear | IHA/IEST | Unknown | 8 |
| Yu et al, 2009 | Jinshan, Shanghai | 1984 | 2008 | Yes | 1.66% (602) | Clear | Clear | IHA | All | 10 | |
| Zhou et al, 2007 | Minhang and Pudong, Shanghai | 1985 | 2004 | Yes | 4.71% (2931) | Clear | Clear | IHA | 66.12% | 10 | |
| Shi et al, 2012 | Minhang, Shanghai | 1985 | 1994–2009 | Unclear | 0.05–5.37% (8325–37393) | Clear | Clear | IEST | AH 37.2%, SC 18.5%, JS 12.2, HN 8.2% | 10 | |
| He et al, 2002 | Jinshan, Shanghai | 1984 | 1999 | Unclear | 4.45% (1281) | Clear | Clear | IEST | 63.90% | 10 | |
| Song et al, 2011 | Nanhui, Shanghai | 1985 | 2000–2009 | Yes | 0.13–1.01% (3671–11019) | Clear | Clear | IEST | AH 28.8%, JS 19.2%, ZJ 12.1%, SC 9.1%, JX 10%, HN 6.2% | 10 | |
| Jin et al, 2010 | Minhang, Pudong, Jiading, Songjiang and Jinshan, Shanghai | 1985 | 2008 | Yes | 2.14% (2992) | Clear | Clear | IHA | All | 10 | |
| Qiu et al, 2010 | Luwan, Shanghai | 1985 | 1995–2008 | Unclear | 0.10–2.32% (725–4635) | Clear | Clear | IEST | Unknown | 9 | |
| Song et al, 2005 | Nanhui, Shanghai | 1985 | 1994–2003 | Yes | 0–0.67% (2687–8487) | Clear | Clear | IEST | AH 27.9%, JS 18%, ZJ 12.3%, SC 8.6%, JX 9.8%, HN 6.8% | 10 | |
| He et al, 2006 | Qingpu, Shanghai | 1983 | 1995–2004 | No | 1.20–3.52% (5247–34228) | Clear | Clear | IEST | Unknown | 9 | |
| Dang et al, 2005 | Jinshan, Shanghai | 1984 | 2000–2002 | Yes | 0.32% (313) | Clear | Clear | DIGFA/ELISA | AH 53.7%, JS 16% | 9 | |
| Li et al, 1996 | Baoshan, Shanghai | 1984 | 1993 | Unclear | 5.61% (4809) | Clear | Clear | ID | AH 12.4%, JS 13.6%, ZJ 10.6%, SC 13.1%, JX 8%, HN 9.3% | 10 | |
| Yuan et al, 2002 | Baoshan, Shanghai | 1984 | 2000 | Unclear | 0.56% (4797) | Clear | Clear | IEST | AH 28%, JS 23.6%, SC 14% | 10 | |
| Zhang et al, 2011 | Changshan, Zhejiang | 1995 | 2005–2009 | Yes | 0.2–8.12% (501–530) | 0.85–21.97% (103–896) | Clear | Clear | IHA | Unknown | 9 |
| Li et al, 2007 | Yuhang, Zhejiang | 1994 | 2006 | Unclear | 0.33% (3307) | Clear | Clear | DIGFA | 73.80% | 10 | |
| Xie et al, 2010 | Zhuji, Zhejiang | 1994 | 2008–2009 | Unclear | 3.08% (1979); 5.33% (900) | Clear | Clear | IHA | All | 10 | |
| Zhu et al, 2012 | Jiaxing, Zhejiang | 1993 | 2008–2011 | Yes | 0.48–5.07% | 0.16–6.70% (723–2443) | Clear | Clear | IHA | Unknown | 9 |
| Chen et al, 2008 | Cixi, Zhejiang | 1981 | 2004–2007 | Unclear | 1.60–5.22% (690–13295) | Clear | Clear | IHA | Unknown | 9 | |
| Xu et al, 2009 | Cixi, Zhejiang | 1981 | 2007–2008 | No | 0.26% (12330) | Clear | Clear | DIGFA | Unknown | 9 | |
| Hu et al, 2014 | Cixi, Zhejiang | 1981 | 2008–2012 | No | 0–0.86% (200–296) | 0.99–2.98% (300–507) | Clear | Clear | IHA | Unknown | 9 |
| Xu et al, 2012 | Changshan, Zhejiang | 1995 | 2008–2011 | Yes | 1.21–4.79% (330–501) | 0.81–10.00% (124–536) | Clear | Clear | IHA | Unknown | 9 |
| Wang et al, 2013 | Jiaxing, Zhejiang | 1994 | 1995–2012 | Yes | 0.2–2.6% (283–50257) | 0.67–4.85% (9063–28050) | Clear | Clear | IHA/DIGFA/COPT/ELISA | Unknown | 8 |
| Zhou et al, 1998 | Jiaxing, Zhejiang | 1994 | 1997 | Yes | 5.24% (3361) | Clear | Clear | IEST | 62% | 10 | |
| Xu et al, 2009 | Yinzhou, Zhejiang | 1985 | 2006 | Unclear | 0.73% (19403) | Clear | Clear | IEST | AH 30.9%, JX 26.9%, JS 3.1%, SC 21.1%, HN 7.8%, HB9.2%, YN 1% | 10 | |
| Lou et al, 2001 | Yiwu, Zhejiang | 1994 | 1999 | Unclear | 1.88% (849) | Clear | Clear | DIGFA | Unknown | 9 | |
Note:
* At the level of county (city or district);
** Snails were found in the year or at least at the end of study period;
† IHA, Indirect Hemagglutination Assay; DIGFA, Dot Immuno-Gold Filtration Assay; ID, Intradermal Test; ELISA, Enzyme Linked Immunosorbent Assay; DDIA, Dye Dipstick Immuno-Assay; IEST, Immuno-Enzymatic Staining Test; COPT, Circum Oval Precipitation Test.
‡ AH, Anhui province; SC, Sichuan; JS, Jiangsu; JX, Jiangxi; HN, Hunan; HB, Hubei; ZJ, Zhejiang; YN, Yunnan.
§ Each item was scaled as 1 or 2: research question ('unclear' 1 or 'clear' 2); definition of the mobile population ('unclear' 1 or 'clear' 2); serological test (''two or more tests' 1, or 'one test' 2); origin of the mobile population in endemic areas (unknown proportion 1, or known proportion 2); and sample size of mobile population ('less than 50' 1 or 'equal or more than 50' 2).