Influenza A(H1N1)pdm09 and postpandemic influenza in Lithuania

Infectious disease-associated encephalopathies

Infectious diseases may affect brain function and cause encephalopathy even when the pathogen does not directly infect the central nervous system, known as infectious disease-associated encephalopathy. The systemic inflammatory process may result in neuroinflammation, with glial cell activation and increased levels of cytokines, reduced neurotrophic factors, blood-brain barrier dysfunction, neurotransmitter metabolism imbalances, and neurotoxicity, and behavioral and cognitive impairments often occur in the late course. Even though infectious disease-associated encephalopathies may cause devastating neurologic and cognitive deficits, the concept of infectious disease-associated encephalopathies is still under-investigated; knowledge of the underlying mechanisms, which may be distinct from those of encephalopathies of non-infectious cause, is still limited. In this review, we focus on the pathophysiology of encephalopathies associated with peripheral (sepsis, malaria, influenza, and COVID-19), emerging therapeutic strategies, and the role of neuroinflammation.

Coding-Complete Genome Sequences of Six Influenza Type A Strains Circulating in Lithuania in the 2009-2010 Epidemic Season

Here, we report the coding-complete genome sequences of six influenza A(H1N1) strains that were detected in Vilnius, Lithuania, among patients exhibiting influenza-like symptoms during the 2009–2010 epidemic season, in a national influenza surveillance. Several mutations were found in genes encoding hemagglutinin and neuraminidase, in comparison with the A/California/07/2009 reference strain (GenBank accession numbers NC026433 and NC026434).

Here, we report the coding-complete genome sequences of six influenza A(H1N1) strains that were detected in Vilnius, Lithuania, among patients exhibiting influenza-like symptoms during the 2009–2010 epidemic season, within national influenza surveillance. Several mutations were found in genes encoding hemagglutinin and neuraminidase, in comparison with the A/California/07/2009 reference strain (GenBank accession numbers NC_026433 and NC_026434).

Neurological complications of pandemic A(H1N1)2009pdm, postpandemic A(H1N1)v, and seasonal influenza A

OBJECTIVES

Not much is known about influenza-associated neurological complications. We aimed to describe the case series of hospitalized patients who were confirmed with influenza A and presented with neurological symptoms in order to capture the broad spectrum of influenza clinical manifestation and suggest including influenza diagnostic in some neurological conditions.

MATERIALS AND METHODS

The inclusion criteria were age ≥ 18 and laboratory-confirmed influenza presenting with neurological symptoms. Influenza-associated neurological complication was described as a development of neurological symptom with no other origin. The outcomes were classified into 5 categories: 1. recovery with no significant disability; 2. minor disability (able to manage on their own); 3. moderate disability (requiring some help but able to walk without assistance); 4. severe disability (unable to walk without assistance and perform daily activities); 5. death.

RESULTS

In total, 12 patients (five women and seven men) were enrolled, with age range 18-71 years old. Neurological complications of pandemic A(H₁ N₁ )2009pdm influenza developed in seven out of 69 (10.1%) hospitalized patients. The most common neurological complication was encephalopathy. Neurological complications developed in two out of 24 (8.3%) hospitalized patients during postpandemic (H₁ N₁ )_V period. One patient presented with encephalopathy, another with meningoencephalitis. During the 2018 influenza season, there was one patient who has developed influenza A neurological complications. Overall, two out of 104 (1.9%) influenza A patients developed influenza-associated neurological complications in 2019.

CONCLUSIONS

Every patient with unexplained neurological symptoms and signs similar to aseptic and septic meningitis/encephalitis has to be tested for influenza virus during epidemics and pandemics.

Clinical Features of Fatal Pandemic Influenza A/H1N1 Infection Complicated by Invasive Pulmonary Fungal Infection

Background

Severe pneumonia caused by influenza virus infection can be secondary to invasive pulmonary fungal (IPF) infection.

Objectives

This study aimed to summarize the incidence of IPF infection secondary to influenza virus infection and further explore its etiologic mechanism and high-risk factors.

Methods

All adult patients with confirmed influenza A (H1N1) virus infection admitted to the intensive care units (ICUs) of Nanjing Drum Hospital from November 2017 to March 2018 were retrospectively selected. The differences in baseline factors, risk factors, immune function and outcome parameters were studied between patients with and without IPF.

Results

Of the 19 critically ill patients with H1N1 infection, 11 (57.9%) developed IPF infection after 7 days of ICU admission. Two patients had proven and nine probable IPF infection. A difference in human leukocyte antigen–DR isotype (△HLA-DR; day 7–day 1) was found between the two groups. △HLA-DR (day 7–day 1) was higher in patients with no IPF infection than in those with IPF infection [(14.52 ± 14.21)% vs ( − 11.74 ± 20.22)%, P = 0.019]. The decline in HLA-DR indicated impaired immune function secondary to fungal infection in patients with H1N1 infection.

Conclusions

IPF infection was diagnosed in 57.9% of critically ill patients with H1N1 virus infection after a median of 7 days following ICU admission. A continuous decline in immune function could lead to the development of IPF infections. Dynamic monitoring of immune function may help in the early detection of IPF infection.