Table 4.
Prevalence and intensity of parasite infections among the participants enrolled in the cross-sectional survey in Hanoi, stratified by five exposure groups in the Than Tri district, Hanoi, between April and June 2014
| Prevalence of infection/Exposure groupsa | Com peri-urban | Com urban | Farmer peri-urban | Farmer urban | Worker HSDC | Chi-square test | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| N = 101 | N = 170 | N = 129 | N = 153 | N = 128 | |||||||
| n | %d | n | %c | n | %c | n | %c | n | %c | P-value | |
| Intestinal parasiteb | 7 | 6.9 | 17 | 10.0 | 39 | 30.2 | 17 | 11.1 | 13 | 10.2 | < 0.001 |
| Soil-transmitted helminthc | 6 | 5.9 | 16 | 9.4 | 39 | 30.2 | 15 | 9.8 | 11 | 8.6 | < 0.001 |
| Intestinal protozoa | 1 | 1.0 | 1 | 0.6 | 2 | 1.6 | 2 | 1.3 | 2 | 1.6 | 0.932 |
| Hookworm | 4 | 4.0 | 6 | 3.5 | 32 | 24.8 | 11 | 7.2 | 5 | 3.9 | < 0.001 |
| Light infection (1–1,999 epg) | 4 | 4.0 | 6 | 3.5 | 32 | 24.8 | 11 | 7.2 | 4 | 3.1 | < 0.001 |
| Moderate infection (2,000–3,999 epg) | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 1 | 0.8 | |
| Trichuris trichiura | 2 | 2.0 | 9 | 5.3 | 7 | 5.4 | 4 | 2.6 | 9 | 7.0 | 0.281 |
| Light infection (1–999 EPG) | 2 | 2.0 | 9 | 5.3 | 7 | 5.4 | 4 | 2.6 | 8 | 6.3 | 0.384 |
| Moderate infection (1,000–9,999 epg) | 0 | 0.0 | 0 | 0.0 | 0 | 0 | 0 | 0 | 1 | 0.8 | |
| Ascaris lumbricoides | 0 | 0.0 | 2 | 1.2 | 0 | 0 | 0 | 0 | 2 | 1.6 | 0.252 |
| Light infection (1–4,999 epg) | 0 | 0.0 | 2 | 1.2 | 0 | 0 | 0 | 0 | 1 | 0.8 | < 0.001 |
| Moderate infection (5,000–49,999 epg) | 0 | 0.0 | 0 | 0.0 | 0 | 0 | 0 | 0 | 0 | 0.0 | < 0.001 |
| Giardia intestinalis | 0 | 0.0 | 1 | 0.6 | 0 | 0 | 0 | 0 | 1 | 0.8 | 0.612 |
| Entamoeba coli | 0 | 0.0 | 1 | 0.6 | 1 | 0.8 | 2 | 1.3 | 1 | 0.8 | 0.833 |
| Entamoeba histolytica/E. dispar | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | na |
| Balantidium coli | 1 | 1.0 | 0 | 0.0 | 1 | 0.8 | 0 | 0.0 | 0 | 0.0 | 0.403 |
aExposure groups: Com peri-urban: people living in the peri-urban commune Duyen Ha, 5 km away from the city along the Red River; Com urban: people living in the urban area of Hanoi, in Bang B village or Tam Hiep commune along the To Lich River and potential exposed to wastewater; Farmer peri-urban: peri-urban farmers living in Duyen Ha commune using the irrigation water from Red River, wells or local drains, which are not contaminated with the city’s wastewater; Farmer urban: urban farmers living in Bang B village or Tam Hiep commune reusing wastewater from To Lich River; and Worker HSDC: workers from Hanoi Sewerage and Drainage Company (HSDC) maintaining drainage channels and operating the Yen So treatment plants
bIntestinal parasitic infection includes: Ascaris lumbricoides, Trichuris trichiura, hookworm and any intestinal protozoa
cSoil-transmitted helminth infection includes: Ascaris lumbricoides, Trichuris trichiura, hookworm
dPrevalence rate is calculated out of the results of the examination of a single stool sample by means of duplicate Kato-Katz and the formalin-ether concentration method, infection intensity by the examination via duplicate Kato-Katz
Abbreviation: epg, eggs per gram; na, not applicable