Effectiveness of 1 Dose of 2009 Influenza A (H1N1) Vaccine at Preventing Hospitalization With Pandemic H1N1 Influenza in Children Aged 7 Months-9 Years

We use data on confirmed cases of pandemic influenza A(H1N1), disseminated by the United States Centers for Disease Control and Prevention(US CDC), to fit the parameters of a seasonally forced Susceptible, Infective, Recovered (SIR) model. We use the resulting model to predict the course of the H1N1 influenza pandemic in autumn 2009, and we assess the efficacy of the planned CDC H1N1 vaccination campaign. The model predicts that there will be a significant wave in autumn, with 63% of the population being infected, and that this wave will peak so early that the planned CDC vaccination campaign will likely not have a large effect on the total number of people ultimately infected by the pandemic H1N1 influenza virus.

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Clinical impact of influenza – lessons learnt from the pandemic influenza A (H1N1) 2009

Microbiology Australia ◽

10.1071/ma11029 ◽

2011 ◽

Vol 32 (1) ◽

pp. 29

Author(s):

Alex Dierig ◽

Gulam Khandaker ◽

Robert Booy

Keyword(s):

Clinical Features ◽

Pandemic Influenza ◽

Influenza A ◽

Influenza Pandemic ◽

Gastrointestinal Symptoms ◽

H1n1 Influenza ◽

World Health ◽

Pandemic H1n1 ◽

Pandemic H1n1 Influenza ◽

Influenza A H1n1

Influenza is generally an acute, self-limiting, febrile illness without further complications in the majority of people. However, it can be associated with severe morbidity and mortality and the burden of the disease on society is likely to be underestimated. In 2009 an outbreak of H1N1 influenza A virus infection was detected in Mexico with further cases soon observed worldwide. Subsequently, in June 2009, the first influenza pandemic of the 21st century due to influenza A (H1N1) was declared by the World Health Organization (WHO). There were many uncertainties regarding the virulence, clinical symptoms and epidemiological features of this newly evolved influenza A strain. Over time, many similarities, but also some differences between the pandemic H1N1 influenza A and seasonal influenza were identified. We recently performed a systematic review of the literature, looking at articles published between 1 April 2009 and 31 January 2010, to identify the epidemiological and clinical features of the pandemic H1N1 influenza. In this current article we compare our findings with others from the international literature. There was more severe impact on young and healthy adults, children, pregnant women and the obese. Clinical features in general were similar between seasonal and pandemic influenza; however, there were more gastrointestinal symptoms associated with pandemic H1N1 influenza. Shortness of breath was characteristic of more severe pH1N1 2009 infection with a higher possibility of being admitted to an intensive care unit (ICU).

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Hospitalizations associated with 2009 influenza A (H1N1) and seasonal influenza in Saurashtra region, India

The Journal of Infection in Developing Countries ◽

10.3855/jidc.1049 ◽

2010 ◽

Vol 4 (12) ◽

pp. 834-841 ◽

Cited By ~ 5

Author(s):

Rajesh K Chudasama ◽

Umed V Patel ◽

Pramod B Verma

Keyword(s):

Influenza Virus ◽

Median Time ◽

Influenza A ◽

Seasonal Influenza ◽

H1n1 Influenza ◽

Pandemic H1n1 ◽

H1n1 Influenza Virus ◽

Pandemic H1n1 Influenza ◽

Influenza A H1n1 ◽

Epidemiological Characteristics

Introduction: This study investigated the clinico-epidemiological characteristics of patients who were hospitalized with 2009 pandemic H1N1 influenza virus infection and seasonal influenza in the Saurashtra region of India. Methodology: From September 2009 to February 2010, a total of 773 patients with influenza virus attending different hospitals in Rajkot city were studied. Real-time reverse-transcriptase-polymerase-chain-reaction (RT-PCR) testing was used to confirm infection; the clinico-epidemiological features of the disease were closely monitored. Results: Of the 733 patients, 35.4% (274/773) were cases of 2009 pandemic H1N1 influenza and 64.6% (499/773) were cases of seasonal influenza. Of the 274 patients with 2009 pandemic H1N1 influenza, the median age was 29.5 years, and 51.5% were males. Only 1.1% positive patients had recent travel history to an infected region. A median time of five days was observed from onset of illness to influenza A (H1N1) diagnosis, and a median time of six days was reported for hospital stay. All admitted influenza A (H1N1) patients received Oseltamivir drug, but only 16.1% received it within two days of onset of illness. One fourth of the admitted positive patients died. The most common symptoms were cough, fever, sore throat, and shortness of breath. The coexisting conditions were diabetes mellitus, hypertension, chronic pulmonary diseases, and pregnancy (p = 0.001). Chest radiography revealed 93% of the positive patients had pneumonia. Conclusion: The clinical course and outcomes of the 2009 pandemic (H1N1) influenza virus are comparable to those of the currently circulating seasonal influenza, with high mortality in influenza A (H1N1) patients.

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Prior Infections With Seasonal Influenza A/H1N1 Virus Reduced the Illness Severity and Epidemic Intensity of Pandemic H1N1 Influenza in Healthy Adults

Clinical Infectious Diseases ◽

10.1093/cid/cir809 ◽

2011 ◽

Vol 54 (3) ◽

pp. 311-317 ◽

Cited By ~ 21

Author(s):

R. B. Couch ◽

R. L. Atmar ◽

L. M. Franco ◽

J. M. Quarles ◽

D. Nino ◽

...

Keyword(s):

Influenza A ◽

Seasonal Influenza ◽

H1n1 Virus ◽

H1n1 Influenza ◽

Illness Severity ◽

Healthy Adults ◽

Pandemic H1n1 ◽

Pandemic H1n1 Influenza ◽

Influenza A H1n1

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Prolonged shedding of influenza A(H1N1)v virus: two case reports from France 2009

Eurosurveillance ◽

10.2807/ese.14.49.19434-en ◽

2009 ◽

Vol 14 (49) ◽

Author(s):

H Fleury ◽

S Burrel ◽

C Balick Weber ◽

R Hadrien ◽

P Blanco ◽

...

Keyword(s):

Symptom Onset ◽

Influenza A ◽

Case Reports ◽

Resistance Mutation ◽

Neuraminidase Inhibitor ◽

H1n1 Influenza ◽

Pandemic H1n1 ◽

Pandemic H1n1 Influenza ◽

Influenza A H1n1 ◽

Emergence Of Resistance

We observed a prolonged shedding of virus 14 and 28 days after symptom onset in two patients with pandemic H1N1 influenza, who did not have immunodepression and were treated with neuraminidase inhibitor. This prolonged shedding was not associated with the emergence of resistance mutation H275Y in the viral neuraminidase gene.

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Approach to Pandemic 2009 influenza: first report from a main referral hospital for Pandemic H1N1 influenza care in Iran

The Journal of Infection in Developing Countries ◽

10.3855/jidc.1195 ◽

2010 ◽

Vol 4 (10) ◽

pp. 629-635 ◽

Cited By ~ 3

Author(s):

Simin Dashti-Khavidaki ◽

Hossein Khalili ◽

Farid Gholamalipour ◽

Abdolreza Soudbakhsh ◽

Azita Hajhossein Talasaz ◽

...

Keyword(s):

Influenza A ◽

Adverse Reactions ◽

Gastrointestinal Symptoms ◽

H1n1 Influenza ◽

Cross Sectional Study ◽

World Health ◽

Pandemic H1n1 ◽

Cross Sectional ◽

Pandemic H1n1 Influenza ◽

Influenza A H1n1

Introduction: Pandemic H1N1 influenza A (pdmH1N1) was a major health threat worldwide. Methodology: A prospective cross-sectional study was conducted at Imam Khomeini Hospital in Iran. Cases of suspicious pdmH1N1 patients referred to the emergency ward of the hospital were enrolled in the study, regardless of whether the final location of treatment was the community, the hospital ward, or the intensive care unit. Oseltamivir was administered within three hours of the patient's admission. The median length of stay for hospitalized patients was 3 days. Results: Gastrointestinal symptoms (nausea [164/434; 37.8%] and vomiting [98/434; 22.6%]) were the most common adverse reactions to oseltamivir in the study population, followed by dizziness (74/434; 17.1%). Out of 434 patients, 209 (48.2%) were treated in the community, 201 (46.3%) were admitted to the general ward in the hospital, and 24 (5.5%) were admitted to an ICU. Conclusions: This study provided insight on the effectiveness of oseltamivir in treating pandemic influenza A, as well as possible adverse reactions to the drug. The study further drew attention to a variety of pdmH1N1 complications, in particular secondary bacterial pneumonia. We also determined that 2009 influenza A (H1N1) infection-related critical illness and mortality affected fewer elderly than younger patients. Additionally, it was shown that our approach to patients with suspected Influenza A/H1N1 virus in our hospital was compatible with World Health Organization pandemic flu guidelines in our country.

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The 2009 pandemic H1N1 influenza and indigenous populations of the Americas and the Pacific

Eurosurveillance ◽

10.2807/ese.14.42.19366-en ◽

2009 ◽

Vol 14 (42) ◽

Cited By ~ 80

Author(s):

G La Ruche ◽

A Tarantola ◽

P Barboza ◽

L Vaillant ◽

J Gueguen ◽

...

Keyword(s):

Influenza A ◽

Influenza Infection ◽

Severe Disease ◽

H1n1 Influenza ◽

Indigenous Populations ◽

Chronic Obstructive ◽

Pandemic H1n1 ◽

Pandemic H1n1 Influenza ◽

The Pacific ◽

Influenza A H1n1

There are few structured data available to assess the risks associated with pandemic influenza A(H1N1)v infection according to ethnic groups. In countries of the Americas and the Pacific where these data are available, the attack rates are higher in indigenous populations, who also appear to be at approximately three to six-fold higher risk of developing severe disease and of dying. These observations may be associated with documented risk factors for severe disease and death associated with pandemic H1N1 influenza infection (especially the generally higher prevalence of diabetes, obesity, asthma, chronic obstructive pulmonary disease and pregnancy in indigenous populations). More speculative factors include those associated with the risk of infection (e.g. family size, crowding and poverty), differences in access to health services and, perhaps, genetic factors. Whatever the causes, this increased vulnerability of indigenous populations justify specific immediate actions in the control of the current pandemic including primary prevention (intensified hygiene promotion, chemoprophylaxis and vaccination) and secondary prevention (improved access to services and early treatment following symptoms onset) of severe pandemic H1N1 influenza infection.

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