BackgroundAs China approaches the elimination of measles, outbreaks of measles continue to occur. Healthcare workers (HCWs) are known to be at high risk of infection and transmission of measles virus. A measles outbreak occurred in a hospital in Xinjiang Uighur Autonomous Region of the People’s Republic of China. We report an investigation of this outbreak and its implications for measles elimination and outbreak preparedness.MethodsWe conducted a retrospective search for measles cases using hospital records. Information on cases was collected by interview, and was used to determine epidemiological linkages. We surveyed HCWs to determine their demographic characteristics, disease history and vaccination status, and knowledge about measles.ResultsWe identified 19 cases, ages 18 to 45 years, in Hospital W between December 2015 and January 2016; 14 were laboratory-confirmed, and 5 were epidemiologically linked. The primary case was a 25-year-old neurology department nurse who developed a rash on 22 December 2015 that was reported on 11 January 2016. She continued working and living with her workmates in a dormitory during her measles transmission period. Among the 19 infected HCWs, 2 had received a dose of measles-containing vaccine (MCV) before the outbreak, and 16 had unknown vaccination status. Outbreak response immunization activities were started on 8 January in a non-selective manner by offering vaccine regardless of vaccination history; 605(68%) of 890 HCWs were vaccinated. The HCW survey had a 73% response rate (646/890); 41% of HCWs reported that they had received MCV before outbreak, and 56% exhibited good knowledge of measles symptoms, transmission, complications, and vaccination.ConclusionsLow MCV coverage, low measles knowledge among HCWs, delayed reporting of measles cases, and absence of proper case management were associated with this outbreak. Training and vaccinating HCWs against measles are essential activities to prevent measles virus transmission among HCWs.

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Dilution enthalpies of six α-amino acid enantiomers (L-alanine vs D-alanine, L-serine vs D-serine, and L-proline vs D-proline) in pure water were determined at T = (288.15 to 323.15) K by isothermal titration calorimetry (ITC). Homochiral enthalpic pairwise interaction coefficients (h xx ) at each temperature were evaluated according to the McMillan−Mayer theory. The h xx values of α-alanine and α-proline enantiomers are all positive (h LL > h DD > 0), while those of α-serine enantiomers are all negative (h LL < h DD < 0). In both cases, the h xx values increase uniformly and gradually with elevating temperatures. A slight but significant enthalpic discrimination effect is found in the homochiral pairwise interactions of these α-amino acid enantiomers. The positive growth of h xx values indicates that increasing temperature promotes the predominance of hydrophobic interactions in the binary aqueous solutions studied. ■ INTRODUCTIONAs is well-known, the stability of biological macromolecules like proteins is controlled by various weak nonbonding interactions between α-amino acid residues and other biochemical components in aqueous solutions. 1−3 Homotactic or heterotactic enthalpic pairwise interaction coefficients (h xx or h xy ) obtained from the framework of the McMillan−Mayer theory are particularly useful for understanding solute−solute and solute−solvent noncovalent interactions. 4,5 Over the past several decades, great efforts have been made by many research groups to gain insight into the thermodynamics of complex nonbonding interactions in biological model solution systems. 6−14 However, most of the studies have been carried out only at T = 298.15 K, and therefore the temperature dependences of h xx or h xy coefficients and the relevant mechanisms have remained unknown or not very clear, though some attempts have been made for this problem. 15−20 Considering that the first derivative of enthalpic pairwise interaction coefficient (h 2 ) on temperature T ((∂h 2 /∂T) p ) equals the second virial coefficient of isobaric heat capacity (c p,2 ), and the latter seems to be more sensitive to the structural change of water in the hydration shell of solutes, 21 it is of greater interest to investigate the temperature dependence of h 2 . Recently, we have paid much attention to the solvent and substituent effects on homotactic enthalpic pairwise interactions of small biochemical compounds in aqueous mixed solvents containing highly polar cosolvents like dimethylformamide (DMF) or dimethyl sulfoxide (DMSO) at 298.15 K, and the phenomena of enthalpic discrimination in these systems has been explored. 22−34 In the present work, we have measured the dilution enthalpies of six enantiomers of typical α-amino acids (Scheme 1) in pure water at different temperatures by isothermal titration calorimetry (ITC), and the temperature dependences and enthalpic discrimination of homochiral pairwise interactions are discussed mainly. We hope to gain insight into how the studied α-amino acids play key roles on the stability of pro...