Irwin James, Tredoux Deon, Mills Graham
Department of General Medicine, Waikato Hospital, Pembroke Street, Private Bag 3200, Hamilton 3240, New Zealand.
N Z Med J. 2013 May 10;126(1374):56-66.
This prospective observational study aimed to identify what proportion of patients presenting to Waikato Hospital with undifferentiated symptoms of an acute febrile illness (USFI) have leptospirosis or murine typhus infection, and to identify factors at presentation predictive of each infection. It also aimed to identify infecting rickettsial organism(s) causing murine typhus in the region.
Between 15/10/2009-15/10/2010 all adult patients presenting with USFI of greater than and equal to 72 hours with no clear diagnosis on presentation were invited to participate in the study. A structured questionnaire and examination were administered and acute and convalescent serology was performed. For patients returning positive murine typhus serology, rickettsial PCR analysis was performed on stored acute blood samples.
Fifty-seven patients were recruited. Nine were diagnosed with leptospirosis, five with murine typhus, three with Epstein-Barr virus (EBV), two with cytomegalovirus (CMV), five with bacterial sepsis and six with other diagnoses. Twenty seven had an acute febrile illness for which no diagnosis was found. A low platelet count (p<0.001) was associated with murine typhus infection, and rural occupation (p<0.001) and a low lymphocyte count (p=0.001) with leptospiral infection. There was a trend towards rural residence being associated with murine tyhpus infection (p=0.059). Two of four patients with positive murine typhus serology returned positive PCR analysis for Rickettsia typhi.
A significant proportion of patients presenting to Waikato Hospital with USFI had leptospirosis or murine typhus infection. A low platelet count and rural residence were associated with murine typhus infection, and rural occupation and a low lymphocyte count with leptospiral infection. R. typhi was identified as a rickettsial organism causing rickettsial fever in the Waikato region.
这项前瞻性观察性研究旨在确定出现急性发热性疾病（USFI）未分化症状前往怀卡托医院就诊的患者中，感染钩端螺旋体病或鼠型斑疹伤寒的比例，并确定就诊时可预测每种感染的因素。该研究还旨在确定该地区引起鼠型斑疹伤寒的感染立克次体微生物。
在2009年10月15日至2010年10月15日期间，邀请所有出现USFI且持续时间大于或等于72小时、就诊时无明确诊断的成年患者参与研究。进行结构化问卷调查和体格检查，并进行急性期和恢复期血清学检测。对于鼠型斑疹伤寒血清学检测呈阳性的患者，对储存的急性期血液样本进行立克次体PCR分析。
招募了57名患者。9例被诊断为钩端螺旋体病，5例为鼠型斑疹伤寒，3例为EB病毒（EBV）感染，2例为巨细胞病毒（CMV）感染，5例为细菌性败血症，6例为其他诊断。27例患有急性发热性疾病但未确诊。血小板计数低（p<0.001）与鼠型斑疹伤寒感染相关，农村职业（p<0.001）和淋巴细胞计数低（p=0.001）与钩端螺旋体感染相关。农村居住与鼠型斑疹伤寒感染存在关联趋势（p=0.059）。4例鼠型斑疹伤寒血清学检测呈阳性的患者中有2例对伤寒立克次体的PCR分析呈阳性。
大量出现USFI前往怀卡托医院就诊的患者感染了钩端螺旋体病或鼠型斑疹伤寒。血小板计数低和农村居住与鼠型斑疹伤寒感染相关，农村职业和淋巴细胞计数低与钩端螺旋体感染相关。伤寒立克次体被确定为怀卡托地区引起立克次体热的立克次体微生物。
