Kurtis Jonathan D, Friedman Jennifer F, Leenstra Tjalling, Langdon Gretchen C, Wu Hai-Wei, Manalo Daria L, Su Li, Jiz Mario, Jarilla Blanca, Pablo Archie O, McGarvey Stephen T, Olveda Remigio M, Acosta Luz P
Center for International Health Research, Rhode Island Hospital, Brown University School of Medicine, Providence, RI 02903, USA.
Clin Infect Dis. 2006 Jun 15;42(12):1692-8. doi: 10.1086/504326. Epub 2006 May 12.
In communities where Schistosoma species are endemic, the prevalence and intensity of schistosomiasis is disproportionately high among children, compared with adults. This epidemiologic pattern is consistent with either the slow development of resistance or the requirement of host developmental changes for the expression of resistance.
We enrolled 87 individuals aged 7-18 years who did not have Schistosoma japonicum infection and 641 individuals aged 7-30 years with S. japonicum infection, all of whom reside in 3 villages in Leyte, Philippines. At baseline, S. japonicum infection was assessed by Kato-Katz thick-smear stool examination, and the levels of the pubertal hormone dehydroepiandrosterone sulfate (DHEA-S) in serum were determined. Individuals with S. japonicum infection were treated with praziquantel, after which stool examination and DHEA-S level measurement were performed every 3 months for 18 months.
In cross-sectional analyses, the intensity of infection among individuals with high DHEA-S levels was 43% lower (28 eggs per g, n = 243), compared with individuals with low DHEA-S levels (50 eggs per g, n = 242), even after adjusting for age, sex, and village (P = .01). Following praziquantel treatment, increased DHEA-S levels were associated with resistance to reinfection (P = .006). The intensity of reinfection among individuals with high DHEA-S levels was 42% lower, compared with individuals with low DHEA-S levels, even after adjusting for age, baseline intensity of S. japonicum infection, village, sex and water contact (P < .001).
Increased DHEA-S levels in serum, a marker for adrenal development, is associated with reduced S. japonicum infection and reinfection, even after adjusting for age and, by proxy, cumulative exposure. These data suggest that an intrinsic property of host pubertal development mediates, in part, the resistance to infection observed in older individuals.
在血吸虫流行的社区中，与成年人相比，儿童血吸虫病的患病率和感染强度异常高。这种流行病学模式与抵抗力发展缓慢或宿主发育变化对抵抗力表达的要求一致。
我们招募了87名7至18岁未感染日本血吸虫的个体以及641名7至30岁感染日本血吸虫的个体，他们均居住在菲律宾莱特省的3个村庄。在基线时，通过加藤厚涂片粪便检查评估日本血吸虫感染情况，并测定血清中青春期激素硫酸脱氢表雄酮（DHEA-S）的水平。对感染日本血吸虫的个体用吡喹酮进行治疗，之后每3个月进行一次粪便检查和DHEA-S水平测量，持续18个月。
在横断面分析中，即使在调整年龄、性别和村庄因素后，DHEA-S水平高的个体的感染强度比DHEA-S水平低的个体低43%（每克28个虫卵，n = 243）（每克50个虫卵，n = 242）（P = 0.01）。吡喹酮治疗后，DHEA-S水平升高与再感染抵抗力相关（P = 0.006）。即使在调整年龄、日本血吸虫感染基线强度、村庄、性别和水接触因素后，DHEA-S水平高的个体的再感染强度比DHEA-S水平低的个体低42%（P < 0.001）。
血清中DHEA-S水平升高是肾上腺发育的标志物，即使在调整年龄以及间接的累积暴露因素后，也与日本血吸虫感染和再感染减少相关。这些数据表明，宿主青春期发育的内在特性部分介导了年长者中观察到的抗感染能力。
