274 Typhoid Fever and other Salmonellosis Metl J Indones Quantitative bacteriology of Tlphoid fever P-15 in Vietnam P.V. Bay, J. Wain, H. Vinh, N.T. Chinh, S.T. Diep, N.T. Hoa, A. Walsh, C. Parry, V.A. Ho, N.J. White Abstrak Terdapat kekurangan informasi mengenai jr.tmlah bakteria di dalam darah dan sumsum tulang pada pasien demam tifuid dan hubungan antara junilah bakteria dan gambaran klinis. Telah dilakukan penghitungan jumlah bakteria di dalam darah, btffy coat, buffy coatyang dilisiskan, aspirat sumsum tulang dari pasien demam enterik dengan kuhur positif menggunakan metode plat tuang. Median jumLah bakteri di dalam darah dari 375 pasien adalah I cfilml (kisaran IQ <0,3-5). Pacla 29Vo pasien, terdapat I cfu/5 ml darah, maka diperlukan 13 ml darah untuk 95Vo kultur positif rate pada infeksi S. typhi. Pacla 187/375, 100 p.I lapisan buffy coat dipisahkan dari I ml darah. Sebanyak j7,5%o (95Vo Cl 32,9-42,1) dari total bakteria terkonsentrasi pada lapisan ini. Pada 81/375 pasien, median jumlah bakteria per sel terinfeksiyang terdapat pada lapisan buffy coat yang dilisiskan tlengan digitonin aclalah 1,3 cfu per sel. Di stunsum tulang 78 pasien terdapat rata-rata 4 kali lebih banyak bakteria daripada tli dalam darah pada pasien yang sama pada volume yang sana. Terdapctt korelasi negatif yang bermakna (p<0,05) antara jumlah bakteria dan ttmur dan lamanya demam sebelum masuk rumah sakit. Terdapat korelasi positif yang bennakna (p=0,05 ) antara jumlah bakteria clan suhu, waktu demam lurun seteLah pengobatan, clar-t resistensi multipel dari setiap isolat bakteria, walaupun tertlapat riwayat pengobatan yctng sama sebelumnya. Sebagai ringkasan, apabila dilakukan kultur darah untuk menegakkan diagnosis, maka paling sedikit dibutuhkan 13 ml darah. Kuman S. typhi terkonsentrasi tli dalamlapisanbuffycoatsehinggalapisaninirnerupakanspesimenyangbaikuntukisolasiS.typhi. Sumsumtulangmerupakanspesimen terbaik untuk kttltur S. typhi. S. typhi yang mubi resisten berada dalam jr.mlah lebih banyak di dalam darah tlaripada strain yang masih sensitif. Terdapat korelasi langsung antarajumlah bakteria dan perubahan klùtis saat pengobatan. Abstract There is paucity of information on the number of bacteria in the blood and bone marrow of typhokl patients, and the relationship between bacterial load and clinical outcome. We have countecl the bacteria in whole blootl, buffy coats, lysecl btffi coats, and bone marrow aspirates from culture positive enteric fever pcttients using the pour plate methocl. The nrcdian number of bacteria in whole blood front 375 patients was lcfi.t/ml (lQ range<0.3-5). In 29Vo of patients tlrcre was 1cfii/5mls blood and so l3mls of blood is requiredfor a 95Vo culture positive rate in S. typht infections. In 187/375, 100 1.tl comprising tlrc buffy coat laye4, was separatetlfrom lml of whole blood. 37.5Vo (95Vo CI 32.9-42.1) of the total bacteria were concentrated in this layer In 8l/375 patients for the metLian numbers of bacteria per infecteil cell were found, by digitonin lysis of buffy coats, to be 1.3 cfu per cell. In the bone marcow of 78 patients there were ct,x averange of four times e$ nxany bacteria as from the blood of the satne patients for equal volurnes. There was a negatùte, sigttificant correlation (p<0.005) between counts anxd age, and duration of fever preceeding hospital atlmission. There was a positive significant correlation (p=0.05) between counts and temperature, fever clearance time after treatment, and muLti-dntg resistance of the bacteriaL isoLate, despite similar preteatment histories. In summary if blood culture is used to establish a diagnosis at least I3 mls must be culturecl. Tfte S. typhi is concentated in the buffy coat layer which provides a reliable specinten for the isolation o/ S. typhi. Bone marrow is the best specimen from which ro reliably cubure of S. typlti. MultidrL,g resistant S. typhi is present in higher numbers in the bloocl than is found with fully sensitit,e strains. There is a direct correlation betvveen bacterial load and clinical response to treatnxent. INTRODUCTION Typhoid fever is characterised by bacteraemia with Salmonella typhi a highly evolved parasite bacterium that infects only man. Although blood culture is the mainstay of laboratory diagnosis, there is little infor- Dong Thap Provincial Hospital Cao Lanh, Dong Thap, The Centre for Tropical Diseases Ho Chi Minh City, University of Oxford Wellcome Trust Clinical Research Unit, Vetnam mation on the numbers of bacteria circulating in the blood or their distribution between plasma and phagocytic cells. Previous studies have shown that ^S. typhi is present only in the white cell and platelet fraction of the bloodt. Using standard broth cultures S. typhi is found in the blood or bone marrow of 30- 90Vo of clinically suspected cases of enteric fever. The propotion of positive cultures depends on the specimen collected and duration of preceding illness 2, and the laboratory methods used3. Although a re- duction in isolation rate, with increasing duration of fever, is described3-s and is attributed to a reduction