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Abstract. Thrombocytopenia is a common finding in malaria, but its prognostic value has not been addressed in children. The relationship between thrombocytopenia (platelet count < 100,000/mm 3 on admission) and severity and outcome was investigated prospectively in children hospitalized with falciparum malaria in Dakar, Senegal, an area that is hypoendemic for malaria. Of 288 falciparum cases, 215 matched the 2000 World Health Organization definition of severe malaria. Median platelet counts were lower (98,000/mm 3 versus 139,000/mm 3 ; P < 0.02) among severe cases than in mild cases, and in children who died than among those who recovered (68,500/mm 3 versus 109,000/mm 3 ; P < 0.002). In severe cases, children presenting with a platelet count < 100,000/mm 3 were more likely to die (odds ratio [OR] ‫ס‬ 6.31, 95% confidence interval [CI] ‫ס‬ 2.0-26.0). Moreover, multivariate analysis identified thrombocytopenia as an independent predictor of death (OR ‫ס‬ 13.3, 95% CI ‫ס‬ 3.2-55.1). Our data show an association between thrombocytopenia and either severity or prognosis in childhood falciparum malaria.

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Rickettsia slovaca and Rickettsia raoultii have been associated with a syndrome characterized by scalp eschar and neck lymphadenopathy following tick bites. However, in many cases, the causative agent remains undetermined. We report 3 cases of this syndrome caused by Bartonella henselae, and we propose the term "SENLAT" to collectively describe this clinical entity.

We present muon spin relaxation measurements performed on crystals of the heavy fermion superconductor UPt3. In zero applied field, contrary to a previous report, we do not observe an increase of the internal magnetic field in the lower superconducting phase (the B phase). Our result gives an experimental upper bound of the magnetic field that could be associated with the superconducting state.PACS numbers : 74.70. Tx, 75.20.Hr, 76.75.+i The unconventional nature of superconductivity in the hexagonal heavy fermion superconductor UPt 3 is now well established [1]. This was first convincingly demonstrated by the occurence in zero magnetic field of two superconducting phase transitions at T C+ ≃ 0.50 K and T C * ≃ 0.45 K. Despite intense experimental and theoretical activities, the nature of superconductivity in UPt 3 is still unknown. Even the question of the symmetry of the superconducting order parameter is not resolved [2,3].Recently Luke et al. have reported zero field muon spin relaxation (µSR) measurements which show that the relaxation rate increases when crossing T C * from above [4,5]. This observation has been taken as a proof that the B phase (the low temperature superconducting phase below T C * ) breaks time reversal symmetry and is characterized by triplet Cooper pairs. This remarkable result has attracted much interest [6,7,2,8,3].The physical properties of heavy fermion metals are well known to be extremely dependent on the sample quality. High quality crystals are now available. These two facts have been our original motivation for performing new µSR measurements, the results of which are presented in this letter.The samples were prepared from two large single crystals of UPt 3 grown by the Czochralski method under ultrahigh vacuum from zone-refined depleted uranium. The as-grown crystals were annealed for several days at 1200 • C -1300 • C (see Ref.[9]), and then spark-cut or wire-sawed. The cut plates were annealed for an additional week at 950 • C, improving the sharpness of the resistivity transition (an example is presented at Fig. 1 of Ref. [10]). The resistivity of our samples, measured on long samples (8 mm length, 0.3 × 0.4 mm 2 cross section) obeys ρ(T ) = ρ(0) + AT 2 perfectly below 1.1 K, with ρ c (0) = 0.28 µΩcm, ρ a (0) = 0.51 µΩcm and A c = 0.90 µΩcmK −2 , A a = 1.46 µΩcmK −2 for current parallel to c and a. These low residual resistivities, which are comparable with recently published values [11], are a proof of the high quality of our samples.The µSR measurements were carried out on two samples which differ by the orientation of the crystal axes relative to the sample plane : either c or a * (≡ b) is perpendicular to it. Each sample is a disk of ∼ 18 mm diameter and ∼ 0.4 mm thickness, comprising of a mosaic of ∼ 10 aligned slices of the same single crystal carefully glued to a 5N silver plate (40 × 40 mm 2 ). To ensure good thermal contact at low temperature, each slice is ultrasonically bonded to a gold wire clamped to the silver plate. This method allows to reach low tempera...