Graf Paul C F, Chretien Jean-Paul, Ung Lady, Gaydos Joel C, Richards Allen L
Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, Maryland, USA.
Clin Infect Dis. 2008 Jan 1;46(1):70-7. doi: 10.1086/524018.
Most epidemiologic studies of tick-borne rickettsial diseases in the United States are small and have limited demographic scope, making broader risk assessment difficult.
We conducted a seroprevalence study of spotted fever group rickettsiae and Anaplasma phagocytophilum, the agent of human granulocytic anaplasmosis. Specimens were selected randomly from the Department of Defense Serum Repository for 10,000 diverse military personnel at various stages in their careers who were serving with active duty status in 1997. Antibody testing included enzyme-linked immunosorbent assay for Rickettsia rickettsii and A. phagocytophilum, and Western blot confirmation for A. phagocytophilum. Risk factors were assessed using logistic regression.
Subjects were mostly male and young and were diverse ethnically and geographically. Spotted fever group rickettsiae seropositivity was 6.0% (95% confidence interval, 5.5%-6.4%). In univariable logistic regression, seroprevalence was significantly higher among older subjects, men (6.5%, compared with 3.3% among women), black individuals (8.7%, compared with 5.6% among white individuals), subjects from states with above-average Rocky Mountain spotted fever incidence, and subjects in ground combat specialties. Associations remained significant in multivariable analysis for age, sex, black versus white race, home state with high incidence, and ground combat specialty. Among 696 subjects with serum samples obtained within 7 days after entering the military, the rate of seropositivity was 3.4% (95% confidence interval, 2.1%-4.8%). Seroprevalence was nonsignificantly lower in men (3.4%, compared with 3.7% in women ) and in black individuals (3.4%, compared with 4.1% in white individuals). A. phagocytophilum seropositivity, as determined by by enzyme-linked immunosorbent assay and Western blot, was 2.6% and 0.11% (95% confidence interval, 0.05%-0.18%), respectively. Western blot seropositivity was not significantly associated with subject characteristics in univariable analysis.
Spotted fever group rickettsiae exposure was common and A. phagocytophilum exposure was rare in a US population with broad demographic diversity.
美国大多数关于蜱传立克次体病的流行病学研究规模较小，且人口统计学范围有限，难以进行更广泛的风险评估。
我们开展了一项关于斑点热群立克次体和嗜吞噬细胞无形体（人类粒细胞无形体病病原体）的血清阳性率研究。样本是从国防部血清库中随机选取的1997年现役的10000名处于不同职业阶段的多样化军事人员。抗体检测包括针对立氏立克次体和嗜吞噬细胞无形体的酶联免疫吸附测定，以及针对嗜吞噬细胞无形体的免疫印迹确认。使用逻辑回归评估风险因素。
受试者大多为男性且年轻，在种族和地域上具有多样性。斑点热群立克次体血清阳性率为6.0%（95%置信区间，5.5% - 6.4%）。在单变量逻辑回归中，年龄较大的受试者、男性（6.5%，女性为3.3%）、黑人（8.7%，白人个体为5.6%）、来自落基山斑疹热发病率高于平均水平州的受试者以及地面作战专业的受试者血清阳性率显著更高。在多变量分析中，年龄、性别、黑人与白人种族、高发病率的家乡州以及地面作战专业之间的关联仍然显著。在696名入伍后7天内采集血清样本的受试者中，血清阳性率为3.4%（95%置信区间，2.1% - 4.8%）。男性（3.4%，女性为3.7%）和黑人个体（3.4%，白人个体为4.1%）的血清阳性率略低，但无显著差异。通过酶联免疫吸附测定和免疫印迹确定的嗜吞噬细胞无形体血清阳性率分别为2.6%和0.11%（95%置信区间，0.05% - 0.18%）。在单变量分析中，免疫印迹血清阳性率与受试者特征无显著关联。
在人口统计学具有广泛多样性的美国人群中，斑点热群立克次体暴露较为常见，而嗜吞噬细胞无形体暴露较为罕见。
