Clinical symptoms, immune factors, and molecular characteristics of an adult male in Shenzhen, China infected with influenza virus H5N1

Abstract

On December 29, 2011, a man infected with a subclade of the H5N1 virus was confirmed in Shenzhen, China. The clinical symptoms and immune factors of the patient were investigated and the phylogenetic and molecular characteristics of the virus were analyzed. High fever, rapid development of serious pneumonia and multi-organ failure were the main clinical symptoms. Arterial blood gas analysis showed that PaCO2 rose sharply and PO2 decreased. Leukocyte and platelet counts decreased rapidly. Peripheral blood lymphocyte counts indicated lymphopenia and inverted ratios of CD4(+) to CD8(+) cells. Cytokine analysis showed that the levels of serum IL-6, IL-10, and IFN-r continued to increase, whereas the levels of IL-12 and TNFs decreased during the clinical course. MCP-1 and IP-10 remained at a high level after infection. Phylogenetic analysis confirmed that the virus A/Shenzhen/1/2011 belongs to the new subclade 2.3.2.1. An Arg (R) insertion at P6 and an RP8I substitution in the HA cleavage site motif were detected in the virus. Compared to the vaccine strain, 16 specific substitutions occurred in the HA1 protein. Some of them were located on the receptor-binding site, glycosylation site and the region of the antigenic determinant. In summary, serious complications and immune system disorders were the main features of the infection with H5N1. Gene variation did not weaken the highly pathogenic features of viruses and the pathogenicity and antigenicity of the new subclade virus were changed.

Protective Efficacy of Passive Immunization with Monoclonal Antibodies in Animal Models of H5N1 Highly Pathogenic Avian Influenza Virus Infection

“…5G). Consistent with some human cases previously described [38,39], these results suggested that increases of IL-6 in the serum and lungs might be associated with systemic inflammatory responses leading to death. While increased production of TNFa and IL-1b were also seen in the macaques with severe disease, the other cytokines tested were unlikely correlated with disease severity of the macaques (Figs.…”

A Detailed Epidemiological and Clinical Description of 6 Human Cases of Avian-Origin Influenza A (H7N9) Virus Infection in Shanghai

“…The above evidence implies that smoking, drinking, and underlying diseases may be related to the prognosis of H7N9 infection; dyspnea, decreased platelet counts, elevated CK levels, and hypoxemia may be associated with poor prognosis. The time to initiation of antiviral therapy seems to have no impact on prognosis, whereas the presence of complications may be associated with poor prognosis [10]. …”

“…Of the 6 patients, 2 emerged from a single family, suggesting that aggregation exists to some extent. In addition, H7N9 avian influenza and H5N1, both of which are fatal, show similar clinical symptoms and disease progression [10,11]. Therefore, early diagnosis and treatment, with an improved cure rate are important to control these infections [11].…”

Molecular pathogenesis of H5 highly pathogenic avian influenza: the role of the haemagglutinin cleavage site motif

“…H5 replication in humans is mainly supported in alveolar epithelium and alveolar macrophages, which is reflected by the observed clinical signs . Manifestation of human H5N1 infection includes fever, broncho‐interstitial pneumonia, acute respiratory distress syndrome with associated hypoxaemia and multiple organ failure . In the absence of respiratory involvement, infection may also present as a gastrointestinal infection or encephalopathy .…”