Prevalence of human intestinal protozoan infections in Sichuan Province in 2015

doi:10.12140/j.issn.1000-7423.2019.05.013

Abstract

Abstract:

Objective To understand the current status of human intestinal protozoan infections in Sichuan Province. Methods An epidemiological survey was carried out in Sichuan Province according to the Protocol of National Survey Scheme on Major Human Parasitic Diseases from April to June, 2015. Total 45 survey sites were selected from 15 counties (cities and districts) within 5 ecological zones of Sichuan by using a stratified sampling method. No less than 250 rural permanent villagers in each site were enrolled in the survey and the fecal sample was collected from each participant. The protozoan cysts in the feces were examined by Lugol’s iodine staining method(one check for each sample). The protozoan trophozoites were examined only in the fresh diarrheal or bloody fecal samples using saline direct smear method(one check for each sample). Each fecal sample was examined once. SPSS 23.0 software was used for statistical analysis. The prevalence difference among the different groups of people was compared by χ² test. Results Total 11 403 people were investigated. The overall prevalence of intestinal protozoan infections was 2.0% (223/11 403) province-wide. Total 9 protozoan species were identified in infected people including Entamoeba histolytica (0.2%, 22/11 403), E. coli (0.7%, 78/11 403), Gardia lamblia (0.1%, 9/11 403）, Blastocystis hominis (0.5%, 60/11 403）, E. hartmani (0.2%, 17/11 403）and Endolimax nana(0.6%, 67/11 403). Two cases of Balantidium coli, one case of each Iodamoeba butschlii and Embadomonas intestinalis were identified. The highest prevalence of intestinal protozoan infections was identified in areas of Source of rivers-Southern Gansu ecological zone (6.5%, 148/2 278),and the lowest prevalence was identified in Sichuan basin zone (0.4%, 10/2 289). There was a significant difference in the prevalence of protozoan infections among different ecological zones (P < 0.01). The highest prevalence of intestinal protozoan infections was identified in Markam County (10.2%, 102/1 001), followed by Ganzi County (6.1%, 46/755). There was significant difference in the prevalence of intestinal protozoa among different counties (cities and districts) (P < 0.01). The prevalence of intestinal protozoa in males and females were 1.9% (97/5 247) and 2.1% (126/6 156), respectively, without significant difference (P > 0.05). People with age 20-29 had the highest prevalence of intestinal protozoa and no protozoa infection was found in people with age of 80 or older, however, there was no significant difference in the prevalence of intestinal protozoa among different age groups (P > 0.05). Regarding the education, people with no education (illiteracy) had the highest prevalence (3.2%, 73/2 317) and no infection was identified in people with education of college and above, with significant difference among people with different education(P < 0.01). In terms of occupation, the highest prevalence of protozoan infections occurred in herdsmen (4.8%, 20/421) followed by students (2.0%, 30/1 491), however, there was no significant difference in the prevalence among different occupations (P > 0.05). In terms of ethnic groups, the highest prevalence was found in Tibetan population (5.3%, 149/2 381) followed by Han population (0.9%, 74/7 857) with significant difference in the prevalence of protozoan infections among different nationalities (P < 0.01). Conclusion Source of rivers Gannan ecological zone and Markam County kept relatively high prevalence of protozoan infections in which more prevention and control measures should be adopted. The people with low education and Tibetan are the main population for the control of intestinal protozoan infections.

Key words: Intestinal protozoa, Infection status, Sichuan Province

CLC Number:

R532.1

Jing-wen LUO, Hong-chun TIAN, Hong XIE, Bo ZHONG, Yang LIU, Yi-lan CHEN, Li LI. Prevalence of human intestinal protozoan infections in Sichuan Province in 2015[J]. CHINESE JOURNAL OF PARASITOLOGY AND PARASITIC DISEASES, 2019, 37(5): 583-587.

Figures/Tables 2

Table 1

Human intestinal protozoan infection in 15 counties within 5 ecological zones in Sichuan Province in 2015

生态区Ecological zone	县（市、区）County (city and district)	检查人数 No. exam’d	感染人数 No. infected	感染率/% Prevelence/%	标化感染率/% Standardized prevelance/%	9种肠道原虫感染例数No. infected cases with 9 intestinal protozoa
生态区Ecological zone	县（市、区）County (city and district)	检查人数 No. exam’d	感染人数 No. infected	感染率/% Prevelence/%	标化感染率/% Standardized prevelance/%	溶组织阿米巴E.histolytica	结肠内阿米巴E. coli	蓝氏贾第鞭毛虫 G. lamblia	人芽囊原虫 B.hominis	结肠小袋纤毛虫 B. coli	哈门氏内阿米巴 E. hartmani	微小内蜒阿米巴 E. nana	布氏嗜碘阿米巴 I. butschlii	肠内滴虫 R. intestinalis
四川盆地Sichuan basin	邛崃市Qionglai	1 004	0	0	0	0	0	0	0	0	0	0	0	0
	岳池县Yuechi	1 012	10	1.0	0.8	0	5	0	5	0	0	0	0	0
	宣汉县Xuanhan	273	0	0	0	0	0	0	0	0	0	0	0	0
	小计Subtotal	2 289	10	0.4	0.5	0	5	0	5	0	0	0	0	0
藏东-川西 Easter Tibet-Western Sichuan	泸定县Luding	1 014	29	2.9	4.9	1	15	0	17	0	0	1	1	1
	汶川县Wenchuan	750	0	0	0	0	0	0	0	0	0	0	0	0
	天全县Tianquan	509	0	0	0	0	0	0	0	0	0	0	0	0
	小计Subtotal	2 273	29	1.3	1.2	1	15	0	17	0	0	1	1	1
江河源区-甘南Source of rivers-Southern Gansu	马尔康县Barkam	1 001	102	10.2	10.4	10	17	3	11	0	17	65	0	0
	若尔盖县Ruoergai	522	0	0	0	0	0	0	0	0	0	0	0	0
	甘孜县Ganzi	755	46	6.1	6.4	1	31	5	13	0	0	0	0	0
	小计Subtotal	2 278	148	6.5	5.9	11	48	8	24	0	17	65	0	0
秦巴山地 Qinba mountains	旺苍县Wangcang	263	2	0.8	0.8	0	0	1	0	0	0	1	0	0
	通江县Tongjiang	1 019	3	0.3	0.6	0	1	0	2	0	0	0	0	0
	青川县Qingchuan	1 024	11	1.1	1.6	2	4	0	3	2	0	0	0	0
	小计Subtotal	2 306	16	0.7	0.8	2	5	1	5	2	0	1	0	0
川西南-滇中北山地Southwest Sichuan-North Yunnan Mountains	米易县Miyi	752	9	1.2	1.3	0	1	0	8	0	0	0	0	0
	石棉县Shimian	750	11	1.5	1.1	8	4	0	1	0	0	0	0	0
	雷波县Leibo	755	0	0	0	0	0	0	0	0	0	0	0	0
	小计Subtotal	2 257	20	0.9	0.3	8	5	0	9	0	0	0	0	0
合计Total		11 403	223	2.0	0.9	22	78	9	60	2	17	67	1	1

Table 1

Table 2

特征 Feature	检查人数 No. exam’d	感染人数 No. infected	感染率/% Prevalence/%	特征 Feature	检查人数 No. exam’d	感染人数 No. infected	感染率/% Prevalence/%
性别Gender				职业Occupation
男Male	5 247	97	1.9	农民 Farmer	8 475	156	1.8
女Female	6 156	126	2.1	牧民 Herdsman	421	20	4.8
年龄组/岁Age group/Year				学生 Student	1 491	30	2.0
0~9	1 328	24	1.8	学龄前儿童 Preschool children	779	14	1.8
10~19	1 074	25	2.3	家庭妇女、待业人员 Housewives, unemployed people	90	1	1.1
20~29	813	23	2.8	其他 Others	147	2	1.4
30~39	1 200	26	2.2	民族Ethnic groups
40~49	2 217	44	2.0	汉族Han	7 857	74	0.9
50~59	1 584	32	2.0	蒙古Mongolian	10	0	0
60~69	1 938	33	1.7	回族Hui	21	0	0
70~79	1 034	16	1.5	藏族Zang	2 831	149	5.3
≥ 80	215	0	0	苗族Miao	1	0	0
文化程度Education				彝族Yi	389	0	0
文盲Illiteracy	2 317	73	3.2	侗族Dong	1	0	0
小学Primary school	5 338	105	2.0	白族Bai	5	0	0
初中Junior high school	2 550	28	1.1	畲族She	1	0	0
高中、中专 Senior high school and secondary technical school	346	3	0.9	羌族Qiang	287	0	0
				大专、大学及以上 College and above	73	0	0
				学龄前儿童Preschoolers	779	14	1.8

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