Hainv Gao

Human infections with the emerging avian influenza A H7N9 virus from wet market poultry: clinical analysis and characterisation of viral genome

Summary Background Human infection with avian influenza A H7N9 virus emerged in eastern China in February, 2013, and has been associated with exposure to poultry. We report the clinical and microbiological features of patients infected with influenza A H7N9 virus and compare genomic features of the human virus with those of the virus in market poultry in Zhejiang, China. Methods Between March 7 and April 8, 2013, we included hospital inpatients if they had new-onset respiratory symptoms, unexplained radiographic infiltrate, and laboratory-confirmed H7N9 virus infection. We recorded histories and results of haematological, biochemical, radiological, and microbiological investigations. We took throat and sputum samples, used RT-PCR to detect M, H7, and N9 genes, and cultured samples in Madin-Darby canine kidney cells. We tested for co-infections and monitored serum concentrations of six cytokines and chemokines. We collected cloacal swabs from 86 birds from epidemiologically linked wet markets and inoculated embryonated chicken eggs with the samples. We identified and subtyped isolates by RT-PCR sequencing. RNA extraction, complementary DNA synthesis, and PCR sequencing were done for one human and one chicken isolate. We characterised and phylogenetically analysed the eight gene segments of the viruses in the patients and the chickens isolates, and constructed phylogenetic trees of H, N, PB2, and NS genes. Findings We identified four patients (mean age 56 years), all of whom had contact with poultry 3–8 days before disease onset. They presented with fever and rapidly progressive pneumonia that did not respond to antibiotics. Patients were leucopenic and lymphopenic, and had impaired liver or renal function, substantially increased serum cytokine or chemokine concentrations, and disseminated intravascular coagulation with disease progression. Two patients died. Sputum specimens were more likely to test positive for the H7N9 virus than were samples from throat swabs. The viral isolate from the patient was closely similar to that from an epidemiologically linked market chicken. All viral gene segments were of avian origin. The H7 of the isolated viruses was closest to that of the H7N3 virus from domestic ducks in Zhejiang, whereas the N9 was closest to that of the wild bird H7N9 virus in South Korea. We noted Gln226Leu and Gly186Val substitutions in human virus H7 (associated with increased affinity for α-2,6-linked sialic acid receptors) and the PB2 Asp701Asn mutation (associated with mammalian adaptation). Ser31Asn mutation, which is associated with adamantane resistance, was noted in viral M2. Interpretation Cross species poultry-to-person transmission of this new reassortant H7N9 virus is associated with severe pneumonia and multiorgan dysfunction in human beings. Monitoring of the viral evolution and further study of disease pathogenesis will improve disease management, epidemic control, and pandemic preparedness. Funding Larry Chi-Kin Yung, National Key Program for Infectious Diseases of China.

Clinical Findings in 111 Cases of Influenza A (H7N9) Virus Infection

BACKGROUND During the spring of 2013, a novel avian-origin influenza A (H7N9) virus emerged and spread among humans in China. Data were lacking on the clinical characteristics of the infections caused by this virus. METHODS Using medical charts, we collected data on 111 patients with laboratory-confirmed avian-origin influenza A (H7N9) infection through May 10, 2013. RESULTS Of the 111 patients we studied, 76.6% were admitted to an intensive care unit (ICU), and 27.0% died. The median age was 61 years, and 42.3% were 65 years of age or older; 31.5% were female. A total of 61.3% of the patients had at least one underlying medical condition. Fever and cough were the most common presenting symptoms. On admission, 108 patients (97.3%) had findings consistent with pneumonia. Bilateral ground-glass opacities and consolidation were the typical radiologic findings. Lymphocytopenia was observed in 88.3% of patients, and thrombocytopenia in 73.0%. Treatment with antiviral drugs was initiated in 108 patients (97.3%) at a median of 7 days after the onset of illness. The median times from the onset of illness and from the initiation of antiviral therapy to a negative viral test result on real-time reverse-transcriptase-polymerase-chain-reaction assay were 11 days (interquartile range, 9 to 16) and 6 days (interquartile range, 4 to 7), respectively. Multivariate analysis revealed that the presence of a coexisting medical condition was the only independent risk factor for the acute respiratory distress syndrome (ARDS) (odds ratio, 3.42; 95% confidence interval, 1.21 to 9.70; P=0.02). CONCLUSIONS During the evaluation period, the novel H7N9 virus caused severe illness, including pneumonia and ARDS, with high rates of ICU admission and death. (Funded by the National Natural Science Foundation of China and others.).

Comparison of patients hospitalized with influenza A subtypes H7N9, H5N1, and 2009 pandemic H1N1.

Hospitalization with H7N9 virus infection is associated with older age and chronic heart disease, and patients have a longer duration of hospitalization than patients with H5N1 or pH1N1. This suggests that host factors are an important contributor to H7N9 severity.

Angiotensin II plasma levels are linked to disease severity and predict fatal outcomes in H7N9-infected patients

A novel influenza A (H7N9) virus of avian origin emerged in eastern China in the spring of 2013. This virus causes severe disease in humans, including acute and often lethal respiratory failure. As of January 2014, 275 cases of H7N9-infected patients had been reported, highlighting the urgency of identifying biomarkers for predicting disease severity and fatal outcomes. Here, we show that plasma levels of angiotensin II, a major regulatory peptide of the renin–angiotensin system, are markedly elevated in H7N9 patients and are associated with disease progression. Moreover, the sustained high levels of angiotensin II in these patients are strongly correlated with mortality. The predictive value of angiotensin II is higher than that of C-reactive protein and some clinical parameters such as the PaO2/FiO2 ratio (partial pressure of arterial oxygen to the fraction of inspired oxygen). Our findings indicate that angiotensin II is a biomarker for lethality in flu infections. Supplementary information The online version of this article (doi:10.1038/ncomms4595) contains supplementary material, which is available to authorized users.

The Serum Profile of Hypercytokinemia Factors Identified in H7N9-Infected Patients can Predict Fatal Outcomes

The novel avian origin influenza A (H7N9) virus has caused severe diseases in humans in eastern China since the spring of 2013. Fatal outcomes of H7N9 infections are often attributed to the severe pneumonia and acute respiratory distress syndrome (ARDS). There is urgent need to discover biomarkers predicting the progression of disease and fatal outcome of potentially lethal flu infections, based on sound statistical analysis. We discovered that 34 of the 48 cytokines and chemokines examined in this study were significantly elevated in the plasma samples from patients infected with H7N9. We report for the first time that the levels of MIF, SCF, MCP-1, HGF, and SCGF-β are highly positively linked to disease severity and the profile of mediators MIF, SCF, MCP-1, HGF, SCGF-β, IP-10, IL-18, and IFN-γ is an independent outcome predictor.

Adjuvant Corticosteroid Treatment in Adults With Influenza A (H7N9) Viral Pneumonia.

Objective:To determine the impact of adjuvant corticosteroids administered to patients hospitalized with influenza A (H7N9) viral pneumonia. Design:The effects of adjuvant corticosteroids on mortality were assessed using multivariate Cox regression and a propensity score-matched case-control study. Nosocomial infections and viral shedding were also compared. Setting:Hospitals with influenza A (H7N9) viral pneumonia patient admission in 84 cities and 16 provinces of Mainland China. Patients:Adolescent and Adult patients aged >14 yr with severe laboratory-confirmed influenza A (H7N9) virus infections were screened from April 2013 to March 2015. Interventions:None. Measurements and Main Results:The study population comprised 288 cases who were hospitalized with influenza A (H7N9) viral pneumonia. The median age of the study population was 58 years, 69.8% of the cohort comprised male patients, and 51.4% had at least one type of underlying diseases. The in-hospital mortality was 31.9%. Two hundred and four patients (70.8%) received adjuvant corticosteroids; among them, 193 had hypoxemia and lung infiltrates, 11 had chronic obstructive pulmonary disease, and 11 had pneumonia only. Corticosteroids were initiated within 7 days (interquartile range, 5.0–9.4 d) of the onset of illness and the maximum dose administered was equivalent to 80-mg methylprednisolone (interquartile range, 40–120 mg). The patients were treated with corticosteroids for a median duration of 7 days (interquartile range, 4.0–11.3 d). Cox regression analysis showed that compared with the patients who did not receive corticosteroid, those who received corticosteroid had a significantly higher 60-day mortality (adjusted hazards ratio, 1.98; 95% CI, 1.03–3.79; p = 0.04). Subgroup analysis showed that high-dose corticosteroid therapy (> 150 mg/d methylprednisolone or equivalent) significantly increased both 30-day and 60-day mortality, whereas no significant impact was observed for low-to-moderate doses of corticosteroids (25–150 mg/d methylprednisolone or equivalent). The propensity score–matched case-control analysis showed that the median viral shedding time was much longer in the group that received high-dose corticosteroids (15 d), compared with patients who did not receive corticosteroids (13 d; p = 0.039). Conclusions:High-dose corticosteroids were associated with increased mortality and longer viral shedding in patients with influenza A (H7N9) viral pneumonia.

Decreased Osteopontin Expression as a Reliable Prognostic Indicator of Improvement in Pulmonary Tuberculosis: Impact of the Level of Interferon-gamma-Inducible Protein 10.

Background/Aims: Osteopontin (OPN) expression is increased during the course of various chronic inflammatory diseases, including tuberculosis (TB). However, its prognostic value in TB management remains unclear. This study aimed to determine whether OPN could associate with other cytokines serving as a reliable biomarker for evaluating the effectiveness of early anti-TB treatments. Methods: Smear-positive pulmonary TB patients (n = 20) were recruited, and the plasma levels of OPN, IP-10, TNF-α, and IL-12 were measured by ELISA before initiation of anti-TB therapy and after sputum smear conversion. The C-reactive protein (CRP) levels and erythrocyte sedimentation rate (ESR) were also tracked during anti-TB treatment. Results: OPN expression was significantly elevated in patients with smear-positive pulmonary TB, and was closely related with disease severity. Monitoring during the treatment course revealed that its expression, along with that of IFN-γ-induced protein 10 (IP-10), decreased significantly only after sputum smear conversion. Moreover, OPN levels positively correlated with CRP levels before and after anti-TB treatment. Furthermore, OPN markedly promoted IP-10 expression in peripheral blood mononuclear cells. Conclusion: Association between OPN and IP-10 may serve as a reliable prognostic indicator for improvement during the early treatment of pulmonary TB, and may help clinicians in tailoring an effective TB treatment regimen.

Clinical findings of 40 patients with nocardiosis: A retrospective analysis in a tertiary hospital

To the best of our knowledge, no Chinese case studies concerning Nocardia infection have been published to date. Therefore, the present study aimed to retrospectively evaluate the risk factors, clinical features, imaging results, laboratory abnormalities, treatments and outcomes of nocardiosis in a Chinese tertiary hospital. Data collected from patients with laboratory-confirmed nocardiosis were retrospectively analyzed. A total of 40 patients who had a positive culture of Nocardia were included. The median time between the onset of symptoms and diagnosis was 42 days. Underlying diseases were identified in 72.5% of the patients of which diabetes was the most common (32.5%). The most important risk factor was corticosteroid administration. Fever and cough were common clinical symptoms. The pleuropulmonary (85%) were the most frequently involved sites and the disseminated disease rate was 30.0%. Frequent chest computed tomography scans revealed the presence of airspace opacities, nodules and masses, in addition to cavitary lesions that were particularly common among the study group. Brain images revealed lesions associated with abscesses. The majority of the patients (71.1%) were treated with trimethoprim sulfamethoxazole alone or in combination with other drugs. The in-hospital mortality rate was 15.0%. Disseminated disease, immunocompromised patients, an older age, brain involvement and concomitant infections were associated with a poor prognosis. Nocardiosis is an uncommon but emerging disease. The present study reports the first case series on nocardiosis from China and provides important information on the clinical features and risk factors of nocardiosis. Early recognition of the disease and the initiation of appropriate treatment are essential for a good prognosis.

Functional variants regulating LGALS1 (Galectin 1) expression affect human susceptibility to influenza A(H7N9)

The fatality of avian influenza A(H7N9) infection in humans was over 30%. To identify human genetic susceptibility to A(H7N9) infection, we performed a genome-wide association study (GWAS) involving 102 A(H7N9) patients and 106 heavily-exposed healthy poultry workers, a sample size critically restricted by the small number of human A(H7N9) cases. To tackle the stringent significance cutoff of GWAS, we utilized an artificial imputation program SnipSnip to improve the association signals. In single-SNP analysis, one of the top SNPs was rs13057866 of LGALS1. The artificial imputation (AI) identified three non-genotyped causal variants, which can be represented by three anchor/partner SNP pairs rs13057866/rs9622682 (AI P = 1.81 × 10−7), rs4820294/rs2899292 (2.13 × 10−7) and rs62236673/rs2899292 (4.25 × 10−7) respectively. Haplotype analysis of rs4820294 and rs2899292 could simulate the signal of a causal variant. The rs4820294/rs2899292 haplotype GG, in association with protection from A(H7N9) infection (OR = 0.26, P = 5.92 × 10−7) correlated to significantly higher levels of LGALS1 mRNA (P = 0.050) and protein expression (P = 0.025) in lymphoblast cell lines. Additionally, rs4820294 was mapped as an eQTL in human primary monocytes and lung tissues. In conclusion, functional variants of LGALS1 causing the expression variations are contributable to the differential susceptibility to influenza A(H7N9).

Monitoring of human cytomegalovirus glycoprotein B genotypes using real-time quantitative PCR in immunocompromised Chinese patients

Based on sequence variation in the N-terminus of glycoprotein B (gB), human cytomegalovirus (HCMV) can be classified into four gBn genotypes, and these genotypes are associated with different clinical outcomes. The distribution of gBn genotypes and the level of gBn DNA load were examined in immunocompromised Chinese patients using real-time quantitative PCR. In addition, the PCR and pp65 antigenemia results were compared. In 1480 specimens, 81.4% were antigen-positive, 12.6% were PCR-positive. The gB genotype distribution was as follows among PCR-positive samples: gBn1, 63.1%; gBn2, 13.4%; gBn3, 8.6%; gBn4, not detected; mixed genotypes, 14.9% (gBn1 and gBn3, 14.4%; gBn2 and gBn3, 0.5%). The gBn3 and gBn1 genotypes had the highest and lowest copy numbers, respectively (p<0.05). The quantity of gBn DNA found in PCR-positive, pp65-negative samples was significantly lower than that found in PCR-positive, pp65-positive samples (p<0.05). The PCR and antigenemia results did not differ among bone marrow transplant patients, solid organ transplant patients, and immunocompromised patients without transplantation (p>0.05). HCMV gBn genotyping using real-time quantitative PCR was established successfully, and the distribution of gBn genotypes in immunocompromised Chinese patients was investigated. This method may help to understand better the relationship between gBn genotype and clinical outcome and aid in clinical detection.