Gordon M A, Walsh A L, Chaponda M, Soko D, Mbvwinji M, Molyneux M E, Gordon S B
Wellcome Trust Research Laboratories, Universities of Malawi and Liverpool, College of Medicine, Blantyre, Malawi.
J Infect. 2001 Jan;42(1):44-9. doi: 10.1053/jinf.2000.0779.
The high seroprevalence of HIV in Malawi might be expected to alter the pattern of pathogens isolated from bacteraemic patients. We aimed to describe the frequency and seasonal pattern of bacterial isolates from blood, their antibiotic susceptibility, and patient outcome, in order to provide data on which to base empirical antibiotic therapy and further studies of pathogenesis.
Over a 12-month period, blood cultures were taken from all febrile adult medical admissions to Queen Elizabeth Central Hospital, Blantyre.
A total of 2789 out of 9298 adult general medical admissions had blood culture performed, of whom 449 (16.1%) grew significant pathogens. Non-typhi salmonellae (NTS) (37%) and Streptococcus pneumoniae (30%) were the two commonest isolates. Mortality was 18% among general medical admissions and 38% among bacteraemic patients. Mortality for individual pathogens was: NTS 33%; S. pneumoniae 36%; Escherichia coli 54%; Klebsiella spp. 58%; Neisseria meningitidis 44%; Salmonella typhi 17%. Despite an overwhelming association between the major pathogens and HIV infection (95% of S. pneumoniae cases and 92% of NTS cases were seropositive for HIV), a seasonal pattern was preserved. Streptococcus pneumoniae was more frequently isolated in the cold dry months, while STM isolates increased following a rise in temperature. A case of bacteraemia with Vibrio cholerae (serotype 01) was detected during a cholera outbreak in the rainy season. Although S. pneumoniae isolates were relatively susceptible to penicillin (88%) and chloramphenicol (74%), S. typhimurium isolates were fully susceptible only to chloramphenicol.
This large study confirms the dominance of NTS and S. pneumoniae in bacteraemia in an area affected by HIV-1 and allows comparison of mortality by individual pathogens. It demonstrates a preserved seasonal pattern of bacteraemia for these major pathogens, despite an overwhelming association with HIV infection.
马拉维较高的HIV血清阳性率可能会改变从菌血症患者中分离出的病原体模式。我们旨在描述血液中细菌分离株的频率和季节性模式、它们的抗生素敏感性以及患者的预后情况，以便为经验性抗生素治疗和进一步的发病机制研究提供数据依据。
在为期12个月的时间里，对布兰太尔伊丽莎白女王中央医院所有发热的成年内科住院患者进行血培养。
9298例成年内科住院患者中，共有2789例进行了血培养，其中449例（16.1%）培养出重要病原体。非伤寒沙门氏菌（NTS）（37%）和肺炎链球菌（30%）是最常见的两种分离株。在内科住院患者中死亡率为18%，在菌血症患者中死亡率为38%。个别病原体的死亡率分别为：NTS 33%；肺炎链球菌36%；大肠杆菌54%；克雷伯菌属58%；脑膜炎奈瑟菌44%；伤寒沙门氏菌17%。尽管主要病原体与HIV感染之间存在极强的关联（95%的肺炎链球菌病例和92%的NTS病例HIV血清呈阳性），但季节性模式仍然存在。肺炎链球菌在寒冷干燥的月份更频繁地被分离出来，而伤寒沙门氏菌分离株在温度升高后增加。在雨季霍乱暴发期间检测到1例霍乱弧菌（血清型01）菌血症病例。尽管肺炎链球菌分离株对青霉素（88%）和氯霉素（74%）相对敏感，但鼠伤寒沙门氏菌分离株仅对氯霉素完全敏感。
这项大型研究证实了在受HIV-1影响的地区，NTS和肺炎链球菌在菌血症中占主导地位，并允许对个别病原体的死亡率进行比较。它表明，尽管这些主要病原体与HIV感染存在极强的关联，但菌血症的季节性模式仍然存在。
