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The SNP rs12252-C allele alters the function of interferon-induced transmembrane protein-3 increasing the disease severity of influenza virus infection in Caucasians, but the allele is rare. However, rs12252-C is much more common in Han Chinese. Here we report that the CC genotype is found in 69% of Chinese patients with severe pandemic influenza A H1N1/09 virus infection compared with 25% in those with mild infection. Specifically, the CC genotype was estimated to confer a sixfold greater risk for severe infection than the CT and TT genotypes. More importantly, because the risk genotype occurs with such a high frequency, its effect translates to a large population-attributable risk of 54.3% for severe infection in the Chinese population studied compared with 5.4% in Northern Europeans. Interferon-induced transmembrane protein-3 genetic variants could, therefore, have a strong effect of the epidemiology of influenza in China and in people of Chinese descent.

Background Acute human immunodeficiency virus type 1 (HIV-1) infection is a major contributor to transmission of HIV-1. An understanding of acute HIV-1 infection may be important in the development of treatment strategies to eradicate HIV-1 or achieve a functional cure. Methods We performed twice-weekly qualitative plasma HIV-1 RNA nucleic acid testing in 2276 volunteers who were at high risk for HIV-1 infection. For participants in whom acute HIV-1 infection was detected, clinical observations, quantitative measurements of plasma HIV-1 RNA levels (to assess viremia) and HIV antibodies, and results of immunophenotyping of lymphocytes were obtained twice weekly. Results Fifty of 112 volunteers with acute HIV-1 infection had two or more blood samples collected before HIV-1 antibodies were detected. The median peak viremia (6.7 log10 copies per milliliter) occurred 13 days after the first sample showed reactivity on nucleic acid testing. Reactivity on an enzyme immunoassay occurred at a median of 14 days. The nadir of viremia (4.3 log10 copies per milliliter) occurred at a median of 31 days and was nearly equivalent to the viral-load set point, the steady-state viremia that persists durably after resolution of acute viremia (median plasma HIV-1 RNA level, 4.4 log10 copies per milliliter). The peak viremia and downslope were correlated with the viral-load set point. Clinical manifestations of acute HIV-1 infection were most common just before and at the time of peak viremia. A median of one symptom of acute HIV-1 infection was recorded at a median of two study visits, and a median of one sign of acute HIV-1 infection was recorded at a median of three visits. Conclusions The viral-load set point occurred at a median of 31 days after the first detection of plasma viremia and correlated with peak viremia. Few symptoms and signs were observed during acute HIV-1 infection, and they were most common before peak viremia. (Funded by the Department of Defense and the National Institute of Allergy and Infectious Diseases.)

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The spike (S) protein of severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV) is not only responsible for receptor binding and virus fusion, but also a major Ag among the SARS-CoV proteins that induces protective Ab responses. In this study, we showed that the S protein of SARS-CoV is highly immunogenic during infection and immunizations, and contains five linear immunodominant sites (sites I to V) as determined by Pepscan analysis with a set of synthetic peptides overlapping the entire S protein sequence against the convalescent sera from SARS patients and antisera from small animals immunized with inactivated SARS-CoV. Site IV located in the middle region of the S protein (residues 528–635) is a major immunodominant epitope. The synthetic peptide S603–634, which overlaps the site IV sequence reacted with all the convalescent sera from 42 SARS patient, but none of the 30 serum samples from healthy blood donors, suggesting its potential application as an Ag for developing SARS diagnostics. This study also provides information useful for designing SARS vaccines and understanding the SARS pathogenesis.

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A worldwide outbreak of severe acute respiratory syndrome (SARS) had been reported. Over 8439 SARS cases and 812 SARS-related deaths were reported to the World Health Organization from 32 countries around the world up to 5 July 2003. The mechanism of transmission of SARS-CoV has been limited only to close contacts with patients. Attention was focused on possible transmission by the sewage system because laboratory studies showed that patients excreted coronavirus RNA in their stools in Amoy Gardens in Hong Kong. To explore whether the stool of SARS patients or the sewage containing the stool of patients would transmit SARS-CoV or not, we used a style of electropositive filter media particle to concentrate the SARS-CoV from the sewage of two hospitals receiving SARS patients in Beijing, as well as cell culture, semi-nested RT-PCR and sequencing of genes to detect and identify the viruses from sewage. There was no live SARS-CoV detected in the sewage in these assays. The nucleic acid of SARS-CoV was found in the sewage before disinfection from both hospitals by PCR. After disinfection, SARS-CoV RNA could be detected from some samples from the 309th Hospital of the Chinese People's Liberation Army, but not from Xiao Tang Shan Hospital after disinfection. In this study, we found that the virus can survive for 14 days in sewage at 4 degrees C, 2 days at 20 degrees C, and its RNA can be detected for 8 days though the virus had been inactivated. In conclusion, this study demonstrates that the RNA of SARS-CoV could be detected from the concentrates of sewage of both hospitals receiving SARS patients before disinfection and occasionally after disinfection though there was no live SARS-CoV; thus much attention should be paid to the treatment of stools of patients and the sewage of hospitals receiving SARS patients.