An adverse event following 2009 H1N1 influenza vaccination: a case of acute disseminated encephalomyelitis / 소아과

Acute disseminated encephalomyelitis (ADEM) is an inflammatory demyelinating disease of the central nervous system that typically follows an infection or vaccination and has a favorable long-term prognosis. We describe the first reported case of ADEM after vaccination against novel influenza A (H1N1). A previously healthy 34-month-old boy who developed ADEM presented with a seizure and left-sided weakness 5 days after vaccination against novel influenza A (H1N1). Cerebrospinal fluid examination revealed elevated cell counts. T2-weighted images and fluid-attenuated inversion recovery images revealed multiple patchy hyperintense lesions in the frontal and parietal subcortical white matter and the left thalamus. After the administration of intravenous corticosteroid, the patient's clinical symptoms improved and he recovered completely without neurologic sequelae.

Evaluation of the Efficacies of Rapid Antigen Test, Multiplex PCR, and Real-time PCR for the Detection of a Novel Influenza A (H1N1) Virus / 대한진단검사의학회지

BACKGROUND: In April 2009, a novel influenza A (H1N1) virus was detected in the US, and at the time of conducting this study, H1N1 infection had reached pandemic proportions. In Korea, rapid antigen tests and PCR assays have been developed to detect the H1N1 virus. We evaluated the efficacies of rapid antigen test, multiplex PCR, and real-time PCR for detecting the H1N1 virus. METHODS: From August to September 2009, we tested 734 samples obtained from nasopharyngeal swab or nasal swab using rapid antigen test (SD Influenza Antigen, Standard Diagnostics, Inc., Korea) and multiplex PCR (Seeplex FluA ACE Subtyping, Seegene, Korea). We also tested 224 samples using the AdvanSure real-time PCR (LG Life Sciences, Korea) to compare the results obtained using real-time PCR with those obtained using multiplex PCR. Furthermore, 99 samples were tested using the AdvanSure real-time PCR and the AccuPower real-time PCR (Bioneer, Korea). RESULTS: In comparison with the results of multiplex PCR, the sensitivity and specificity of the rapid antigen test were 48.0% and 99.8%, respectively. The concordance rate for multiplex PCR and the AdvanSure real-time PCR was 99.6% (kappa=0.991, P=0.000), and that for the AdvanSure real-time PCR and the AccuPower real-time PCR was 97.0% (kappa=0.936, P=0.000). CONCLUSIONS: The rapid antigen test is significantly less sensitive than PCR assay; therefore, it is not useful for H1N1 detection; however multiplex PCR, the AdvanSure real-time PCR, and the Accu-Power real-time PCR can be useful for H1N1 detection.

Novel Influenza A (H1N1) Infection in Immunocompromised Patients / 대한진단검사의학회지

BACKGROUND: Since April 2009, novel influenza A (H1N1) infection is spreading throughout the world. This infection might be fatal for immunocompromised patients who are at a potentially high risk of developing infectious complications. We investigated the detection rate and features of H1N1 infection in immunocompromised patients. METHODS: Between August 2009 and February 2010, we examined 8,112 subjects, including 390 immunocompromised patients, for H1N1. Swab samples were taken from the nose and throat of the participants. Real-time PCR was performed to identify H1N1 viral genes. RESULTS: Positive results were obtained in 2,953/8,112 (36.4%) subjects and 46/390 (11.8%) immunocompromised patients. H1N1 was identified in 8.7% patients with solid cancer, 12.9% patients with hematologic malignancy, 16.7% patients with chronic renal disease, and 14.5% patients with kidney transplantation. The mean cycle threshold (Ct) value of PCR was significantly lower (P<0.05) in patients with hematologic malignancy as compared to that in patients with chronic renal disease and control subjects. Four patients died due to respiratory complications. CONCLUSIONS: The detection rate of H1N1 was significantly lower in immunocompromised patients than in other patients. The Ct value of patients with hematologic malignancy was significantly lower than that of other immunocompromised patients and control subjects.

Experience with a Simulation Drill for Novel Influenza A (H1N1) / 병원감염관리

BACKGROUND: It is important that hospitals conduct disaster drills to ensure prompt response in case of a pandemic and thereby prevent a biological disaster. METHODS: In a university hospital of Seoul, a drill was arranged by the members of the drill preparation team who were a part of the response team for infection control of novel influenza A (H1N1). The drill preparation team designed the scenario for the drill, made plans to resolve the potential problems that could occur during that scenario, and organized a survey team and a survey methodology. The scenario consisted of 2 modules: (1) for an intensive care unit and (2) for an emergency care center. The surveyors and field participants were evaluated after the drill exercise. RESULTS: This drill was conducted to improve the response to outbreaks of new infectious diseases. The drill event showed that the communication among the members responsible for the infection control was effective. However, the drill revealed certain drawbacks in the process; this drawbacks involved availability of adequate quarantine space, education on using personal protective equipments, assignment of medical and nonmedical staff, management of visitors, and installment of air-conditioners, heaters, and ventilation units in the areas with H1N1 outbreak. CONCLUSION: This drill helped to improve the process of infection control and overcome the drawbacks in the current process, and thereby helped in achieving positive outcome during the actual pandemic situation when the number of hospital visits and admissions because of H1N1 pandemic had rapidly increased. Although disaster plans and drills are not actively performed, the drill for infection control is essential because the risk for an outbreak of a new infectious disease is increasing.

Non-airborne transmission during outbreak of pandemic (H1N1) 2009 among tour group members, China, June 2009 / 中华流行病学杂志

Objective During June 2-8, 2009, 11 cases of the novel influenza A (H1N1)occurred in Sichuan Province, China. We investigated this outbreak to identify the source of infection,mode of transmission and risk factors for infection. Methods The primary case, a U.S. citizen,developed disease on June 2. From June 3 to 5, she joined Tour Group A for a trip to Jiuzhaigou. We telephoned passengers of the three flights on which the primary case had traveled in China, and members of Tour Group A. We asked whether they had any influenza-like symptoms during May 27 to June 12. Health authorities placed passengers whose seats were within three rows of the primary case on flights and members of Tour Group A on medical observation, and isolated individuals if they developed symptoms. We used real-time RT-PCR to test the throat swabs from symptomatic persons for the novel influenza virus and defined a confirmed case as one with influenza-like symptoms and laboratory confirmation. A retrospective cohort investigation to identify the risk factors for infection was conducted. We interviewed all members of Tour Group A about their detailed contact history with the primary case. Results During June 5 to 6, 9 (30%) of the primary case' s 30 fellow tour group members developed disease, compared with none of her 87 fellow passengers to Jiuzhaigou and 1 of her 87 fellow passengers on the returning trip (when several of the members of Tour Group A were symptomatic). 56% of the tourists who had talked with the primary case in close range ( ＜2 m) for ≥2 minutes developed disease, whereas none of the 14 other tour group members developed disease (RR= ∞; exact 95%CI: 2.0- ∞ ). Having conversed with the primary case for ≥ 10 minutes (vs. 2-9 minutes) increased the risk by almost five fold (RR=4.8, exact 95%CI: 1.3-180). Conversely, other kinds of contact, such as dining at the same table, receiving chewing gum from the primary case and sharing bus rides or planes with the primary case played no roles during this outbreak. Conclusion This novel influenza A (H1N1) outbreak was caused by an imported case, and transmitted mainly via droplet transmission when the primary case was talking with her fellow tourists during a tour. These findings highlight the importance of preventing droplet transmission during a pandemic.

Diagnosis and Management of Novel Influenza A (H1N1) / 가정의학회지

Since the World Health Organization has officially declared a global influenza pandemic, the number of human cases of pandemic influenza A (H1N1) in 2009 has been increasing in many countries. Especially from mid-October, the number of domestic cases of influenza A (H1N1) has been exponentially increasing, with the number of confirmed cases reaching over 100,000. The clinical symptoms of novel influenza A (H1N1) include fever, cough, sore throat, runny nose, myalgia, headache, chills and fatigue. Nucleic acid amplification tests, including real time RT-PCR assay specific for 2009 novel influenza A (H1N1) can be used in the patients with suspected influenza. Antiviral treatment by using neuraminidase inhibitors (oseltamivir, zanamivir) is recommended by Centers for Disease Control and Prevention for treatment of novel influenza A (H1N1) disease. Personal and public efforts to control the outbreak of novel influenza A (H1N1) disease are required. Vaccination against pandemic H1N1 is important for personal health, but also to build community-level immunity to novel influenza A.

Interpretation of Positive Result for Influenza A and Negative Result for Novel Influenza A/H1N1 in Reverse Transcriptase PCR for Novel Influenza A/H1N1 / 임상검사와정도관리

BACKGROUND: Real-time reverse transcriptase PCR (rRT-PCR) is widely used to detect novel influenza A/H1N1. We had observed several cases with positive result for influenza A and negative result for novel influenza A/H1N1 during a novel influenza A/H1N1 outbreak. The causes of those results were investigated in this study. METHODS: A total of 913 cases tested with rRT-PCR for novel influenza A/H1N1 (Real-time Ready Influenza A/H1N1 Detection Set, Roche Diagnostics, Germany) during 25 August 2009 to 8 September 2009 was enrolled in this study. Cases showing positive result for influenza A (M gene) and negative result for novel influenza A/H1N1 (H1 gene) were tested with multiplex RT-PCR for seasonal influenza and novel influenza A/H1N1 (Seeplex FluA ACE Subtyping kit, Seegene, Korea), and the amplicons were directly sequenced. RESULTS: One hundred and eleven cases (12.2%) were positive for novel influenza A/H1N1. Twenty-seven cases (3.0%) were positive for influenza A, but negative for novel influenza A/H1N1. Subtypes of influenza A were determined in 25 cases by multiplex RT-PCR and nucleotides sequencing. One novel influenza A/H1N1, six seasonal influenza A/H1N1, three seasonal influenza A/H3N2, and 15 influenza A/H9N2 were detected. CONCLUSIONS: Subtypes of influenza A were determined in most cases with positive result for influenza A and negative result for novel influenza A/H1N1. Several cases with seasonal influenza A were detected. Even if a nonepidemic period of seasonal influenza, tests for seasonal influenza A can help in the differential diagnosis of influenza.

The status of Novel Influenza A(H1N1)with secondary pulmonary infection / 中国实用内科杂志

In March,2009,novel influenza pandemic A(H1N1)virus emerged in Mexico and rapidly disseminated worldwide.Secondary pulmonary infection is a predominant contributor to the death of novel influenza A(H1N1),The most common causative pathogens of secondary pulmonary infection in novel influenza A(H1N1)include Streptococcus pneumoniae,Haemophilus influenzae and Staphylococcus aureus.The recognization of the pathogenesis of secondary pulmonary infection in novel influenza A(H1N1)is critically significant to the strategy in diagnosis and treatment of novel influenza A(H1N1).Therefore,we elaborate the current situation of secondary pulmonary infection in novel influenza A(H1N1)and provide insight into the clinical diagnosis and treatment of novel influenza A(H1N1).