Critical analysis of deaths due to atypical pneumonia during the onset of the influenza A (H1N1) virus epidemic

Immunity to influenza: Impact of obesity

Obesity is a health concern that is recognized as a critical factor for vulnerability to influenza A/pdmH1N1 virus infection, with epidemiological and clinical impacts. In humans, obesity induces disturbances in inflammatory and immune responses to the influenza virus and in some cases, this leads to severe complications, with fatal outcomes. Obesity impairs immunity by altering the response of cytokines, resulting in a decrease in the cytotoxic cell response of immunocompetent cells which have a key anti-viral role. Additionally, obesity seems to disturb the balance of endocrine hormones, such as leptin, that affect the interplay between metabolic and immune systems. This contribution focuses on reviewing the current epidemiologic data for the immune response to immunity in obese humans and animal models. In doing so, we aim to provide potential mechanisms to enhance immunity to influenza A/pdmH1N1 virus infection and protective factors in obese people.

Rapid detection and clinical spectrum of the novel influenza H1N1 strain in a diabetic pediatric population

OBJECTIVES

H1N1 infection in diabetic patients is of special concern and serious interest since the virus can place individuals, especially children, at great possible risk of subsequently developing type 1 diabetes. This work aims to describe the demographic characteristics, clinical features, and severity of illness of children with type 1 diabetes mellitus (DM), compare the incidence of pandemic H1N1 virus in children with that of the general pediatric population with influenza-like symptoms, and identify the complications of H1N1 virus infection associated with glycemic control.

METHODS

The present study included 45 children and adolescents with type 1 diabetes, who were subject to clinical and laboratory investigations. Another 30 healthy adolescents and children with a mean age of 10.43 ± 4.38 years were included as a control group. H1N1 reverse-transcriptase quantitative PCR (RT-Q PCR) was tested for H1N1 virus detection.

RESULTS

Diabetic patients positive for (H1N1) showed significantly higher random blood sugar (RBS) levels than diabetic patients negative for (H1N1). Moreover, the H1N1-positive patients had significantly higher hemoglobin (Hb) g/dL, platelet counts, total leukocyte counts (TLCs), and CRP levels. Newly diagnosed patients who were tested positive for (H1N1) and diabetic ketoacidosis (DKA) had significantly higher RBS levels and TLCs than patients who were presented with hyperglycemia.

CONCLUSION

RT-PCR is a rapid and specific method for influenza A (H1N1) virus diagnosis. In addition, early administration of oseltamivir no later than 48 hours after the infection is highly recommended in either diabetic or DKA patients suspected of having H1N1.

Neuraminidase inhibitor therapy in a military population

BACKGROUND

Although neuraminidase inhibitors (NI) are the mainstay of treatment for influenza infection, prescribing practice for these agents is not well described. Additionally, benefit is contested.

OBJECTIVES

We examined provider prescriptions of NI during the 2009 pandemic and post-pandemic periods. We also evaluated the effectiveness of NI in reducing severity of influenza infection.

STUDY DESIGN

Data on NI prescription and severity of influenza infection were compiled in healthy pediatric and adult beneficiaries enrolled in a prospective study of influenza like illness conducted at five military medical centers over five years. Subjects underwent nasal swabs to determine viral etiology of their infection. Demographic, medication and severity data were collected. Subjects with positive influenza were included.

RESULTS

Two hundred sixty three subjects were influenza positive [38% [H1N1] pdm09, 38.4% H3N2, and 20.5% B); 23.9% were treated with NI. NI were initiated within 48h in 63% of treated subjects. Although NI use increased over the five years of the study, early use declined. Most measures for severity of illness were not significantly reduced with NI; adults treated within 48h had only a modest reduction in duration and severity of some of their symptoms.

CONCLUSIONS

NI use in our population is increasing, but early use is not. NI use resulted in no reduction in complications of illness. Resolution of symptoms and reduction in severity of some symptoms were slightly better in adults who were treated early. These modest benefits do not support routine treatment with NI in otherwise healthy individuals with influenza.

Neuraminidase inhibitors for influenza: a review and public health perspective in the aftermath of the 2009 pandemic

OBJECTIVES

The objectives of this study were to: (1) reflect on key stages in the discovery, development and pre-pandemic use of neuraminidase inhibitors (NAIs), (2) summarise the evidence of NAI effectiveness for treatment and prophylaxis of seasonal influenza prior to the 2009 pandemic, and (3) summarise the evidence base generated during the 2009 pandemic period.

DESIGN

A rapid systematic review of evidence published to June 2010 was conducted where existing high-quality systematic reviews formed a baseline and were supplemented with data from other reviews, randomised controlled trials (RCTs) and observational studies.

MAIN OUTCOME MEASURES

Severity and duration of symptoms; rates of severe illness, complications and death following treatment for influenza or influenza-like illness; rates of influenza and influenza-like illness following long-term prophylaxis or post-exposure prophylaxis of household contacts.

RESULTS

Prior to the 2009 pandemic, evidence from RCTs conducted in seasonal influenza epidemics indicated that NAIs used to treat laboratory-confirmed influenza in healthy adults reduced the duration of illness by one day. NAIs provide high levels of protective efficacy in adults when given long-term or in household-based post-exposure prophylaxis for seasonal influenza. Several 2009 pandemic period observational studies suggest that early treatment may reduce rates of hospitalisation and in-hospital mortality, but data from that period do not substantially increase the evidence base on prophylaxis, although they confirm effectiveness.

CONCLUSIONS

NAIs should be deployed during a future pandemic for either post-exposure prophylaxis or treatment depending on national policy considerations and logistics. The existing evidence base on effectiveness against severe outcomes requires supplementation.

Impact of neuraminidase inhibitor treatment on outcomes of public health importance during the 2009-2010 influenza A(H1N1) pandemic: a systematic review and meta-analysis in hospitalized patients

BACKGROUND

The impact of neuraminidase inhibitor (NAI) treatment on clinical outcomes of public health importance during the 2009-2010 pandemic has not been firmly established.

METHODS

We conducted a systematic review and meta-analysis, searching 11 databases (2009 through April 2012) for relevant studies. We used standard methods conforming to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using random effects models.

RESULTS

Regarding mortality we observed a nonsignificant reduction associated with NAI treatment (at any time) versus none (OR, 0.72 [95% CI, .51-1.01]). However we observed significant reductions for early treatment (≤48 hours after symptom onset) versus late (OR, 0.38 [95% CI, .27-.53]) and for early treatment versus none (OR, 0.35 [95% CI, .18-.71]). NAI treatment (at any time) versus none was associated with an elevated risk of severe outcome (OR, 1.76 [95% CI, 1.22-2.54]), but early versus late treatment reduced the likelihood (OR, 0.41 [95% CI, .30-.56]).

CONCLUSIONS

During the 2009-2010 influenza A(H1N1) pandemic, early initiation of NAI treatment reduced the likelihood of severe outcomes compared with late or no treatment.

PROSPERO REGISTRATION

CRD42011001273.

Knowledge, attitudes, practices and emotional reactions among residents of avian influenza (H5N1) hit communities in Vietnam

BACKGROUND

Awareness of individuals' knowledge and predicting their behavior and emotional reactions is crucial when evaluating clinical preparedness for influenza pandemics with a highly pathogenic virus. Knowledge, attitude, and practice (KAP) relating to avian influenza (H5N1) virus infection among residents in communities where H5N1 patients occurred in Vietnam has not been reported.

METHODS AND PRINCIPAL FINDINGS

Face-to-face interviews including KAP survey were conducted in Bac Kan province, located in the northeast mountainous region of Vietnam. Participants were residents who lived in a community where H5N1 cases have ever been reported (event group, n = 322) or one where cases have not been reported (non-event group, n = 221). Data on emotional reactions of participants and healthcare-seeking behavior after the event in neighboring areas were collected as well as information on demographics and environmental measures, information sources, and KAP regarding H5N1. These data were compared between two groups. Higher environmental risk of H5N1 and improper poultry-handling behaviors were identified in the event group. At the time of the event, over 50% of the event group sought healthcare for flu-like symptoms or because they were scared. Awareness of the event influenced KAP scores. Healthcare-seeking behavior and attention to H5N1 poultry outbreaks diminished in the event group as time passed after the outbreak compared with the non-event group. Factors that motivated participants to seek healthcare sooner were knowledge of early access to healthcare and the risk of eating sick/dead poultry, and perception of the threat of H5N1.

CONCLUSIONS

Awareness of H5N1 patients in neighboring areas can provoke panic in residents and influence their healthcare-seeking behavior. Periodic education to share experiences on the occurrence of H5N1 patients and provide accurate information may help prevent panic and infection and reduce mortality. Local conditions should be taken into account when emphasizing the need for early access to healthcare.

Socioeconomic factors influencing hospitalized patients with pneumonia due to influenza A(H1N1)pdm09 in Mexico

Background

In addition to clinical aspects and pathogen characteristics, people's health-related behavior and socioeconomic conditions can affect the occurrence and severity of diseases including influenza A(H1N1)pdm09.

Methodology and Principal Findings

A face-to-face interview survey was conducted in a hospital in Mexico City at the time of follow-up consultation for hospitalized patients with pneumonia due to influenza virus infection. In all, 302 subjects were enrolled and divided into two groups based on the period of hospitalization. Among them, 211 tested positive for influenza A(H1N1)pdm09 virus by real-time reverse-transcriptase-polymerase-chain-reaction during the pandemic period (Group-pdm) and 91 tested positive for influenza A virus in the post-pandemic period (Group-post). All subjects were treated with oseltamivir. Data on the demographic characteristics, socioeconomic status, living environment, and information relating to A(H1N1)pdm09, and related clinical data were compared between subjects in Group-pdm and those in Group-post. The ability of household income to pay for utilities, food, and health care services as well as housing quality in terms of construction materials and number of rooms revealed a significant difference: Group-post had lower socioeconomic status than Group-pdm. Group-post had lower availability of information regarding H1N1 influenza than Group-pdm. These results indicate that subjects in Group-post had difficulty receiving necessary information relating to influenza and were more likely to be impoverished than those in Group-pdm. Possible factors influencing time to seeking health care were number of household rooms, having received information on the necessity of quick access to health care, and house construction materials.

Conclusions

Health-care-seeking behavior, poverty level, and the distribution of information affect the occurrence and severity of pneumonia due to H1N1 virus from a socioeconomic point of view. These socioeconomic factors may explain the different patterns of morbidity and mortality for H1N1 influenza observed among different countries and regions.

Pneumonia in patients with novel influenza A (H1N1) virus in Southeastern Turkey

The objective of this study was to describe the clinical characteristics and the radiological and laboratory findings of the hospitalised patients who had novel, laboratory-confirmed, swine-origin influenza A virus (S-OIV) infection with pneumonia. Between October and December 2009, 56 patients hospitalised for pneumonia who were tested for S-OIV infection were retrospectively evaluated. Thirty-three patients had positive S-OIV infections. In addition, 23 of the 56 patients who had negative test results for S-OIV infection were compared with the positive group. The mortality rate amongst the patients with S-OIV infection was 24.2%. Of the 33 patients, 42.4% had at least one underlying medical condition and 4 (12%) patients were pregnant or postpartum. Fourteen patients (42.4%) with S-OIV infection were followed up in an intensive care unit. The most common symptom was dyspnea. The mean peak body temperature during hospital stay (39.42 ± 0.70) was higher in this group than in the negative group (38.51 ± 1.05) (p = 0.001). Thrombocytopenia, increased creatine kinase and elevated lactate dehydrogenase levels were statistically significant. Bilateral infiltration was more common in the patients with S-OIV infection. Although some laboratory, radiological and clinical data show a significant difference between the patients with S-OIV pneumonia and the negative group, each patient presenting with signs of pneumonia during pandemia should be tested for Influenza A.