McGarvey Stephen T, Carabin Hélène, Balolong Ernesto, Bélisle Patrick, Fernandez Tomas, Joseph Lawrence, Tallo Veronica, Gonzales Ryan, Tarafder Mushfiqur R, Alday Portia, Willingham Arve Lee, Olveda Remigio
International Health Institute, Brown University, Providence, RI 02912, USA.
Bull World Health Organ. 2006 Jun;84(6):446-52. doi: 10.2471/blt.05.026427. Epub 2006 Jun 21.
To estimate the association between the intensity of animal infection with Schistosoma japonicum and human infection in Western Samar province, the Philippines.
We conducted an observational cross-sectional study of 1425 households in 50 villages. Stool samples were collected on each of 1-3 days from 5623 humans, 1275 cats, 1189 dogs, 1899 pigs, 663 rats and 873 water buffalo. Intensity of infection with S. japonicum was measured by the number of eggs per gram (EPG). Egg counts were done using the Kato-Katz method. We used a Bayesian hierarchical cumulative logit model, with adjustments for age, sex, occupation and measurement error.
The adjusted proportions of humans lightly infected (classified as 1-100 EPG) was 17.7% (95% Bayesian credible interval = 15.3-20.2%); the proportion classified as at least moderately infected (>100 EPG) was 3.2% (2.2-4.6%). The crude parasitological results for animals indicated that 37 cats (2.9%), 228 dogs (19.2%), 39 pigs (2.1%), 199 rats (30.0%) and 28 water buffalo (3.2%) were infected. In univariate analyses the odds ratios corresponding to a unit increase in the mean number of EPG at the village-level in dogs was 1.05 (1.01-1.09), in cats 1.35 (1.02-1.78), in pigs 1.16 (0.24- 5.18) and in rats 1.00 (1.00-1.01). Mean EPG values in cats, dogs, pigs and rats were correlated with one another. This confounding made interpreting the odds ratios difficult, but the odds ratios for dogs and cats were more consistent.
S. japonicum is endemic in areas of the Philippines despite implementation of control programmes. This may be due to the association of infections in dogs and cats with human infections. Infection control in dogs and cats is challenging, and there is a need to develop new methods to control transmission across all species.
评估菲律宾西萨马省动物日本血吸虫感染强度与人类感染之间的关联。
我们对50个村庄的1425户家庭进行了一项观察性横断面研究。在1至3天内，从5623名人类、1275只猫、1189只狗、1899头猪、663只大鼠和873头水牛身上采集粪便样本。通过每克粪便中的虫卵数（EPG）来测量日本血吸虫的感染强度。虫卵计数采用加藤厚涂片法。我们使用了贝叶斯分层累积对数模型，并对年龄、性别、职业和测量误差进行了调整。
经调整后，轻度感染（定义为1 - 100 EPG）的人类比例为17.7%（95%贝叶斯可信区间 = 15.3 - 20.2%）；至少中度感染（>100 EPG）的比例为3.2%（2.2 - 4.6%）。动物的原始寄生虫学检测结果表明，37只猫（2.9%）、228只狗（19.2%）、39头猪（2.1%）、199只大鼠（30.0%）和28头水牛（3.2%）受到感染。在单变量分析中，村级犬类平均EPG每增加一个单位对应的比值比为1.05（1.01 - 1.09），猫为1.35（1.02 - 1.78），猪为1.16（0.24 - 5.18），大鼠为1.00（1.00 - 1.01）。猫、狗、猪和大鼠的平均EPG值相互关联。这种混杂情况使得比值比难以解释，但犬类和猫类的比值比更为一致。
尽管实施了控制项目，但日本血吸虫在菲律宾部分地区仍为地方病。这可能是由于犬类和猫类感染与人类感染之间存在关联。控制犬类和猫类的感染具有挑战性，因此需要开发新的方法来控制所有物种间的传播。
