Host cytokine storm is associated with disease severity of severe fever with thrombocytopenia syndrome.

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging viral disease in China, caused by SFTS virus (SFTSV). Severe SFTS patients can quickly proceed to multiorgan dysfunction and death; however, underlying pathogenic mechanisms remain unclear. METHODS: Serum samples from 15 fatal and 44 nonfatal SFTS cases were subjected to multiplex-microbead immunoassays to detect a broad spectrum of cytokines. The viral load and virus-specific IgG titers were also tested by real-time PCR and ELISA, respectively. RESULTS: Cytokines IL-1RA, IL-6, IL-10, G-CSF, IP-10, and MCP-1 were elevated in SFTS patients and produced at robust levels in fatal cases. In contrast, cytokines PDGF-BB and RANTES decreased in SFTS patients. These cytokines reverted to normal ranges during the convalescent phase of SFTSV infection. Cytokines IL-1ß, IL-8, MIP-1α, and MIP-1ß showed a unique pattern of elevation in fatal cases but not in nonfatal cases. However, these cytokines increased in the convalescent phase of nonfatal SFTS cases. Our regression analysis revealed that the serum viral load correlated with these cytokines. Moreover, levels of these cytokines correlated with various clinical parameters and virus-specific IgG titers. CONCLUSION: The study demonstrates that SFTSV infection induces a cytokine storm with abnormally expressed cytokine profiles, which are associated with the disease severity.

Clinical progress and risk factors for death in severe fever with thrombocytopenia syndrome patients.

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by the SFTS virus (SFTSV) with an average fatality rate of 12%. The clinical factors for death in SFTS patients remain unclear. METHODS: Clinical features and laboratory parameters were dynamically collected for 11 fatal and 48 non-fatal SFTS cases. Univariate logistic regression was used to evaluate the risk factors associated with death. RESULTS: Dynamic tracking of laboratory parameters revealed that during the initial fever stage, the viral load was comparable for the patients who survived as well as the ones that died. Then in the second stage when multi-organ dysfunction occurred, from 7-13 days after disease onset, the viral load decreased in survivors but it remained high in the patients that died. The key risk factors that contributed to patient death were elevated serum aspartate aminotransferase, lactate dehydrogenase, creatine kinase, and creatine kinase fraction, as well as the appearance of CNS (central nervous system) symptoms, hemorrhagic manifestation, disseminated intravascular coagulation, and multi-organ failure. All clinical markers reverted to normal in the convalescent stage for SFTS patients who survived. CONCLUSIONS: We identified a period of 7-13 days after the onset of illness as the critical stage in SFTS progression. A sustained serum viral load may indicate that disease conditions will worsen and lead to death.

[Effect of comprehensive care for chronic filariasis patients with lymphedema].

OBJECTIVE: To evaluate the effect of chronic filariasis patients with lymphedema after comprehensive cared. METHODS: A total of 386 chronic filariasis patients with lymphedema received the comprehensive care including soaking feet by TCM, washing feet by single Chinese medicine or clear water, preventing and eliminating invasive wound, physical training, raising the limb, and wearing suitable shoes. The attack frequency of inflammation of lymphatic vessels, the stage of lymphedema disease, and leg circumference were observed before and after the care. RESULTS: After the comprehensive care, the attack rates of inflammation of lymphatic vessels decreased from 9.65% to 4.67%, and there was a significant difference (χ2 =7.34, P=0.0067). The proportion of the patients with high stage of lymphedema disease decreased significantly (all P <0.01), and the average leg circumference decreased of 1.06 cm. The skin appearance improved significantly. Other signs, such as pitting edema, ulcer, and skin folds also improved significantly (all P <0.01). CONCLUSION: The comprehensive care for chronic filariasis patients with lymphedema has a remarkable effect and is worthy of further application.

[Longitudinal surveillance of intestinal nematodiasis in Yinghu Village of Wujiang City].

OBJECTIVE: To understand the epidemic dynamics of intestinal nematodiasis in Wujiang City. METHOD: The residents of Yinghu Village of Wujiang City were investigated with Kato-Katz technique for the infections of intestinal nematodes, and the persons with the infections were administered with anthelmintics and they also received the health education. RESULTS: Of the 5 757 residents, 147 persons were infected with intestinal nematodes, with the average infection rate of 2.55%. The infection rates of hookworm, Ascaris lumbricoides and Tricuris trichiura were 1.96%, 0.49% and 0.24%, respectively. The repeated infection rate was 20.30%, that was 10.36 times higher than the new infection rate (1.96%). CONCLUSIONS: There are still regions and populations with high infection rates of intestinal nematodes in Wujiang City where the intestinal nematodiasis has been controlled. Therefore, it is necessary to strengthen the monitoring, prevention and control work.