Diagnosis Of Flu Research Articles

Pediatric Respiratory Infections ‎After the COVID-19 Pandemic: A Single-Center Experience.

Background Pediatric respiratory infections, mainly bronchiolitis, are a substantial clinical burden. The most common etiology is respiratory syncytial virus (RSV). Other viruses include human rhinovirus, human metapneumovirus, influenza, adenovirus, coronavirus, and parainfluenza viruses. Objective We aimed to study the epidemiology and clinical characteristics of children with confirmed viral bronchiolitis and flu after the COVID-19 pandemic season and compare the behavior of each virus. Methods This retrospective observation study was done over seven months, from October 2022 to April 2023. All children (0-14) were included in the study if they met the clinical diagnosis of bronchiolitis or flu. Viral etiology is confirmed by PCR, using the respiratory panel available in our center which included the detection of four viruses: COVID-19, RSV, influenza A, and B. Clinical data, lab results, and X-rays were collected and correlated with each viral infection for all admitted patients. Results We recruited 237 children with bronchiolitis and flu symptoms from October 2022 to April 2023. The peak of infections (41%) was in November. Seasonal variations for each virus showed distinct patterns across the year. RSV peaked at the beginning of the season, gradually declining after that. In contrast, influenza A and B maintained a relatively consistent presence throughout the season. Meanwhile, COVID-19 reached its peak during March and April. One hundred forty-four (60%) of the patients were under two years of age. RSV was predominant in 150 patients (63.3%). COVID-19 was only detected in 25 patients (10%), whereas influenza A and B were equally isolated in 31 (13%) patients each. Fifty-one children (21%) were initially sick and required pediatric intensive care unit (PICU) admission, with no deaths reported. Notably, COVID-19 had a milder disease course, a shorter length of stay (LOS) in the hospital (two days) and a shorter duration of illness (five days) compared to other viruses. RSV infection was linked to more profound hypoxia and more sick children with more extended hospital stays. Conclusion Our study showed that, following the pandemic and the release of lockdown measures, there was another peak of upper respiratory tract infections (URTI) and flu, which was more aggressive, primarily due to other viruses, especially RSV. This resurgence was associated with more severe respiratory symptoms and an increased need for hospitalization. Notably, children with COVID-19 were in better condition compared to those with RSV.

Nanoengineered phosphorus doped graphitic carbon nitride based ultrasensitive biosensing platform for Swine flu detection.

In the present study, we developed an amino-polyindole modified phosphorus doped graphitic carbon nitride nanomaterial (APIN/P-g-C3N4) based immunosensing biochip for Serum amyloid A (SAA) biomarker towards early diagnosis of Swine flu. The P-g-C3N4 was synthesis via polycondensation and functionalized with APIN. Further, the biochip was fabricated by modifying the working area of SPE with APIN/P-g-C3N4 using drop cast method, APIN introduced the larger loading of -NH2 group moieties onto P-g-C3N4 matrix and benefitted to reinforced the biomolecules via covalent linkages. The monoclonal anti-SAA was conjugated onto APIN/P-g-C3N4/SPE using EDC-NHS chemistry and BSA was added for non-specific site blocking. The structural, chemical, composition and morphological characteristics of the synthesized, functionalized nanomaterial and fabricated biochips were investigated by XRD, XPS, FT-IR spectroscopy, SEM, FE-SEM and TEM techniques. Further, the electrochemical characterization and response studies of fabricated biochip were analyzed using the CV and DPV techniques. Based on the analytical performance of the proposed immunosensing biochip i.e. BSA/anti-SAA/APIN/P-g-C3N4/SPE, it is capable to detect SAA protein with ultra sensitivity of 79.5 μA log (mL ng-1) cm-2, ultralow limit of detection of 5ngmL-1 and wider linear detection range of 5ngmL-1-500μgmL-1 with quick response time of 10min. Moreover, the fabricated immunosensing biochips was used to analyse SAA protein in spiked serum samples and the achieved results demonstrated the good agreement with the electrochemical response observed in standard SAA protein samples in analytical solution. The proposed biochip can provide insights for developing a wide range of clinical screening tools for detecting various contagious diseases.

Tomato flu: need to look beyond the frame

Tomato flu: need to look beyond the frame

Outbreak of tomato flu in India raising concerns: is it a false alarm or are we welcoming a new pandemic?

Outbreak of tomato flu in India raising concerns: is it a false alarm or are we welcoming a new pandemic?

When a Headache Is More than the Flu: A Case Report.

IntroductionWhen influenza (flu) season arrives, it is easy for emergency department clinicians to anchor on the diagnosis of flu, sending patients on their way with or without anti-influenza medication. It is important not to miss the outlier – the patient who seems to have typical symptoms of influenza but with certain subtleties that should make one consider expanding the differential diagnosis.Case ReportWe describe an 11-year-old previously healthy male who presented with eight days of fever, myalgias, cough, congestion, and headache in the context of positive influenza exposure. The length and severity of his symptoms prompted laboratory and imaging investigation. He was positive for influenza type B with elevated inflammatory markers but otherwise normal laboratory workup and normal chest radiograph. He complained of a headache and was given fluids and antipyretics, and was admitted for overnight observation. He specifically did not have any forehead swelling. The next day during his inpatient stay he developed right frontal forehead edema and appeared ill. He was taken for a sinus computed tomography, which showed changes consistent with frontal bone osteomyelitis. Even after drainage by neurosurgery and otolaryngology, the patient subsequently developed repeat abscesses and ultimately a superior sagittal sinus thrombosis.ConclusionOther sources of infection should be considered in patients who have flu-like symptoms that last longer than expected, present with focality, or appear ill.

Multiple Attribute Decision Making Based on Interval-Valued Neutrosophic Trapezoidal Fuzzy Numbers and its Application in the Diagnosis of Viral Flu

Decision-making technique (DMT) is mostly used in artificial intelligence and cognitive sciences to elaborate individual and social perception. So, one of the most important strategies in DMT evolved in medical diagnosis scrutiny regarding the connection of symptoms and diagnosis of diseases due to uncertainty and fuzziness in the relevant information. The focus of this article is to develop a diagnostic decision making strategy for the diagnosis of Viral diseases with close related symptoms using the Interval-valued trapezoidal neutrosophic fuzzy Numbers (IVTrNFN) w.r.t multiple attribute decision making (MADM) strategy where, the attribute value is evolved to Interval-valued trapezoidal neutrosophic fuzzy number and the attribute weight is unknown and can be related to the GRA (Grey relational analysis projection) technique. In this research several operational laws are developed as well as the expected value and the hamming distance between two IVTrFNs are introduced. Moreover, the information entropy method is used to determine the attributes weights and the grey relational analysis as well as the projection method are involved too in the proposed framework. The ranks of the alternative decisions are evaluated by their relative closeness to PIS (Positive Ideal Solutions), which combine the grey relational projection values from positive and negative ideal solutions associated with each alternative. Finally, a Viral disease example is given to verify the developed approach and to demonstrate its practicality and effectiveness.

Medical decision-making support system based on bayesian networks in medical diagnostics

Modern level of medical science development provides the attending doctor with thousands of various diagnostic and therapeutic techniques as well as medicines. Practically applicating them, the clinician has to take into account a variety of factors: indications and contraindications of the method or modalities of treatment, characteristics of the patient and the course of the disease, compatibility or strengthening of the influence of certain examination methods, medications on each other, individual drug intolerance and contraindications in the patient. It becomes more difficult to keep all this in memory and make error-free, correct and timely decisions. Moreover, the situation is rapidly aggravated by the fact that the volume of knowledge in medicine is growing incrementally, and the time for a doctor to make an appropriate decision when making a diagnosis does not increase. In this regard, the question of creating a system that will minimize the time for a doctor to make a decision on the presence of a particular disease arises.
 AIM: To develop a medical decision-making support system based on Bayesian networks in diagnosing patients.
 RESULTS: A variant of the medical decision support system for the diagnosis of cold, flu and coronavirus are considered. A Bayesian network model using the GeNIe Academic software is proposed. The results of the percentages of possible diseases of the patient based on the existing symptoms are obtained.
 CONCLUSION: The approach to the decision support system construction considered in the article is intended to assist doctors in making a diagnosis to a patient based on his anamnesis. It should be noted that the constructed Bayesian network can be modified by adding other symptoms with their conditional probabilities and adjusting the existing ones after expert judgment (6 figs, bibliography: 6 refs).

Selective detections of single-viruses using solid-state nanopores

Rapid diagnosis of flu before symptom onsets can revolutionize our health through diminishing a risk for serious complication as well as preventing infectious disease outbreak. Sensor sensitivity and selectivity are key to accomplish this goal as the number of virus is quite small at the early stage of infection. Here we report on label-free electrical diagnostics of influenza based on nanopore analytics that distinguishes individual virions by their distinct physical features. We accomplish selective resistive-pulse sensing of single flu virus having negative surface charges in a physiological media by exploiting electroosmotic flow to filter contaminants at the Si3N4 pore orifice. We demonstrate identifications of allotypes with 68% accuracy at the single-virus level via pattern classifications of the ionic current signatures. We also show that this discriminability becomes >95% under a binomial distribution theorem by ensembling the pulse data of >20 virions. This simple mechanism is versatile for point-of-care tests of a wide range of flu types.

Clinical aspects and outcome of patients with swine flu among survivors and non-survivors

Background: Swine flu is an infective disease caused by any one of the several types of Influenza viruses. The world saw its first pandemic of swine flu this century in the year 2009 when the WHO raised a world-wide pandemic alert to level 6 on June 11, 2009. In India, first few cases (index cases) of swine flu were reported from Pune, Maharashtra. The most recent outbreak of this dreaded infection was reported during late winter of 2015.Methods: The present study was retrospective study. In order to collect the data, we reviewed medical charts of patients who were hospitalized in our hospital during the study period. Diagnosis of swine flu was confirmed after sending the blood-samples to Government approved laboratories in Pune and Mumbai. Real time, Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) method was employed for serological diagnosis. Forty-five confirmed cases of swine flu were included in this retrospective study. The primary objective of this study was to highlight the differences in the clinical profile as well as outcome between the patients who survived the attack of swine flu and those who did not.Results: Forty-five of these patients tested positive for H1N1 amounting to a positivity rate of 52.94%. Cough (93.3%) was the most common symptom followed by fever (88.8%) and breathlessness (82.2%). Patients who did not survive were more likely to have associated co-morbid conditions like Hypertension, Diabetes, cardio-vascular disease, pre-existing lung disease and pregnancy though this was not statistically significant ( p=0.189). Acute Respiratory Distress Syndrome (ARDS), Multi-Organ Dysfunction (MOD) and secondary bacterial infections were among the most common conditions that lead to death.Conclusions: Early detection of swine flu through meticulous screening in the community with a high index of suspicion followed by prompt and adequate treatment can go a long way in preventing another pandemic. Creating awareness among the lay people about personal as well as public hygiene is also vital to prevent the spread of this viral illness.

Vacunación frente a la gripe estacional en las personas mayores. Evaluación de la vacuna adyuvada: Informe de posicionamiento

Flu is a major public health problem, particularly for older people, and creates an important clinical and economic burden. A high mortality rate was reported in Spain during the period 2015 to 2016; 3,101 serious cases were hospitalised with a confirmed diagnosis of flu, of which 11% died (352 cases). Furthermore, financial and health costs are greatly increased by the complications of flu; people aged over 65 years represent approximately 64% of the total costs. Seasonal flu vaccination is the fundamental strategy, as demonstrated by cost-benefit and cost-effectiveness studies. A priority objective is to improve the vaccine's immune response and the search for and inclusion of adjuvants and immunostimulants in vaccines is a major line of research. This positioning report evaluates vaccination for older people and the importance of the adjuvanted vaccine in the elderly in strengthening immunogenicity, by means of a critical review of the literature based on the best evidence available on its immunogenicity and effectiveness, and an economic assessment.

A case report of parapneumonic pleural effusion caused by Streptococcus pneumoniae serotype 19A in a child immunized with 13-valent conjugate pneumococcal vaccine

BackgroundSimple parapneumonic effusion is a pleural effusion associated with lung infection (i.e., pneumonia). Streptococcus pneumoniae remains the most common pathogen causing parapneumonic effusions. In Morocco, the pneumococcal conjugate vaccine 13-valent (PCV13) was introduced in the national immunization program in October 2010 in 2 + 1 schedule for prevention of pneumococcal disease, and replaced by the PCV10 in July 2012 in the same schedule. We report a case of parapneumonic pleural effusions caused by S. pneumoniae serotype 19A in a child immunized with 3 doses of PCV13.Case presentationThis is a 2.5 years old previously healthy Moroccan female, fully vaccinated by PCV13 and immunocompetent, admitted to a private medical clinic with a six months history of persistent asthma. On arrival (7 February 2015), she was febrile to 40.3 °C with a brutal flu syndrome, chills, dry cough and serous rhinitis, for which she received symptomatic treatment. A biological assessment was done that confirmed the clinical diagnosis of flu. Seven days after, she presented a progressive deterioration of its general condition and the onset of severe abdominal pain. She was hospitalized and a second biological assessment, computed tomography scans and chest radiography were done that confirmed a diagnosis of a pneumococcal parapneumonia with abscess of the left lower lobe with encysted empyema. Microbiological analysis of the pleural fluid showed a S. pneumoniae serotype 19A with susceptibility intermediate to penicillin. The patient was treated by antibiotics including amoxicillin, cefixime ceftriaxone and vancomycin.ConclusionsWe reported a case of parapneumonic pleural effusions caused by a vaccine serotype pneumococcal 19A occurring in an immunocompetent child immunized with 3 doses of PCV13.

Performance evaluation of direct fluorescent antibody, Focus Diagnostics Simplexa™ Flu A/B & RSV and multi-parameter customized respiratory Taqman® array card in immunocompromised patients

BackgroundMolecular assays for diagnosis of Flu A, Flu B, and RSV with short turn-around-time (TAT) are of considerable clinical importance. In addition, rapid and accurate diagnosis of a large panel of viral and atypical pathogens can be crucial in immunocompromised patients. ObjectivesFirst, to evaluate the performance of the Simplexa™ Direct assay system in comparison with direct fluorescent antibody (DFA) and customized Taqman® Array Card (TAC) testing for RSV, Flu A, and Flu B in immunocompromised patients. Second, to evaluate different algorithms for the detection of respiratory pathogens in terms of cost, turn-around-time (TAT) and diagnostic yield. Study designWe collected 125 nasopharyngeal swabs (NTS) and 25 BAL samples from symptomatic immunocompromised patients. Samples for which Simplexa™ and TAC results were discordant underwent verification testing. The TAC assay is based on singleplex RT-PCR, targeting 24 viruses, 8 bacteria and 2 fungi simultaneously. ResultsThe overall sensitivity was significantly lower for DFA testing than for the two molecular methods (p<0.05). Performance characteristics of Simplexa™ testing were not significantly different compared to TAC testing (p>0.1). For BAL samples only, the sensitivity and specificity of the Simplexa™ assay was 100%.In total, 6.7, 16 and 18% of samples were positive for Flu A, Flu B or RSV by DFA, Simplexa™ and TAC testing, respectively. When considering not only these pathogens but also all results for TAC, the method identified 93 samples with one or more respiratory pathogens (62%). A co-infection rate of 15.3% was found by TAC.The estimated costs and TAT were 8.2€ and 2h for DFA, 31.8€ and 1.5h for Simplexa™ and 55€ and 3h for TAC testing. ConclusionsPerforming the Simplexa™ test 24h a day/7 days a week instead of DFA would considerably improve the overall sensitivity and time-to-result, albeit at a higher cost generated in the laboratory. Performing the TAC would increase the diagnostic yield and detection of co-infections significantly.

Procalcitonin for clinical decisions on influenza-like illness in emergency department during influenza a(H1N1)2009 pandemic

Purpose: We aimed to determine whether serum procalcitonin (PCT) values could help in identifying flu in patient admitted to the emergency department (ED) with influenza-like illness (ILI) during influenza A(H1N1)2009 pandemic.Methods: An observational retrospective cohort study was performed in a referral ED for emerging infectious diseases. All patients tested for influenza A(H1N1)2009 by Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) and procalcitonin between June 2009 and January 2010 were analyzed. PCT was studied for its negative predictive value of bacterial infection. Patients PCT−/RT-PCR + were considered as true positive.Results: On the 80 patients included, 16 were positive for influenza A(H1N1)2009 RT-PCR, all but one of them had low PCT concentrations. Conversely, 19 (30%) of the 64 patients with negative RT-PCR had elevated PCT concentrations. For a PCT threshold <0.25 μg/L, sensitivity was 0.94, specificity 0.30, positive predictive value 0.25 and negative predictive value 0.95 for the diagnosis of flu.Conclusion: In the context of an influenza pandemic, serum PCT measurement may be useful for clinical decisions in the ED as most of RT-PCR confirmed patients have low PCT values. Patients with PCT above 0.25 μg/L are unlikely to have a unique diagnosis of flu.

Delay in diagnosis of influenza A (H1N1)pdm09 virus infection in critically ill patients and impact on clinical outcome.

BackgroundPatients infected with influenza A (H1N1)pdm09 virus requiring admission to the ICU remain an important source of mortality during the influenza season. The objective of the study was to assess the impact of a delay in diagnosis of community-acquired influenza A (H1N1)pdm09 virus infection on clinical outcome in critically ill patients admitted to the ICU.MethodsA prospective multicenter observational cohort study was based on data from the GETGAG/SEMICYUC registry (2009–2015) collected by 148 Spanish ICUs. All patients admitted to the ICU in which diagnosis of influenza A (H1N1)pdm09 virus infection had been established within the first week of hospitalization were included. Patients were classified into two groups according to the time at which the diagnosis was made: early (within the first 2 days of hospital admission) and late (between the 3rd and 7th day of hospital admission). Factors associated with a delay in diagnosis were assessed by logistic regression analysis.ResultsIn 2059 ICU patients diagnosed with influenza A (H1N1)pdm09 virus infection within the first 7 days of hospitalization, the diagnosis was established early in 1314 (63.8 %) patients and late in the remaining 745 (36.2 %). Independent variables related to a late diagnosis were: age (odds ratio (OR) = 1.02, 95 % confidence interval (CI) 1.01–1.03, P < 0.001); first seasonal period (2009–2012) (OR = 2.08, 95 % CI 1.64–2.63, P < 0.001); days of hospital stay before ICU admission (OR = 1.26, 95 % CI 1.17–1.35, P < 0.001); mechanical ventilation (OR = 1.58, 95 % CI 1.17–2.13, P = 0.002); and continuous venovenous hemofiltration (OR = 1.54, 95 % CI 1.08–2.18, P = 0.016). The intra-ICU mortality was significantly higher among patients with late diagnosis as compared with early diagnosis (26.9 % vs 17.1 %, P < 0.001). Diagnostic delay was one independent risk factor for mortality (OR = 1.36, 95 % CI 1.03–1.81, P < 0.001).ConclusionsLate diagnosis of community-acquired influenza A (H1N1)pdm09 virus infection is associated with a delay in ICU admission, greater possibilities of respiratory and renal failure, and higher mortality rate. Delay in diagnosis of flu is an independent variable related to death.

Influenza-like-illness and clinically diagnosed flu: disease burden, costs and quality of life for patients seeking ambulatory care or no professional care at all.

This is one of the first studies to (1) describe the out-of-hospital burden of influenza-like-illness (ILI) and clinically diagnosed flu, also for patients not seeking professional medical care, (2) assess influential background characteristics, and (3) formally compare the burden of ILI in patients with and without a clinical diagnosis of flu. A general population sample with recent ILI experience was recruited during the 2011–2012 influenza season in Belgium. Half of the 2250 respondents sought professional medical care, reported more symptoms (especially more often fever), a longer duration of illness, more use of medication (especially antibiotics) and a higher direct medical cost than patients not seeking medical care. The disease and economic burden were similar for ambulatory ILI patients, irrespective of whether they received a clinical diagnosis of flu. On average, they experienced 5–6 symptoms over a 6-day period; required 1.6 physician visits and 86–91% took medication. An average episode amounted to €51–€53 in direct medical costs, 4 days of absence from work or school and the loss of 0.005 quality-adjusted life-years. Underlying illness led to greater costs and lower quality-of-life. The costs of ILI patients with clinically diagnosed flu tended to increase, while those of ILI patients without clinically diagnosed flu tended to decrease with age. Recently vaccinated persons experienced lower costs and a higher quality-of-life, but this was only the case for patients not seeking professional medical care. This information can be used directly to evaluate the implementation of cost-effective prevention and control measures for influenza. In particular to inform the evaluation of more widespread seasonal influenza vaccination, including in children, which is currently considered by many countries.

Laboratory diagnosis of swine flu: a review

Human swine influenza A [H1N1], also referred to as “swine flu,” is highly transmissible. The emergence of new strains will continue to pose challenges to public health and the scientific communities will have to prepare to detect them for appropriate treatment. Most sophisticated methods include immunofluorescence staining and antigen subtyping based on hemagglutination inhibition (HI). Another standard method is RT-PCR targeting hemagglutinin and neuraminidase genes. The recent availability of rapid, reliable, and easy-to-perform tests for detecting influenza virus infections has introduced rapid viral diagnosis. This review thus summarizes the current information on the present diagnostic methods for influenza virus H1N1.

Development of a Plastic-Based Microfluidic Immunosensor Chip for Detection of H1N1 Influenza

Lab-on-a-chip can provide convenient and accurate diagnosis tools. In this paper, a plastic-based microfluidic immunosensor chip for the diagnosis of swine flu (H1N1) was developed by immobilizing hemagglutinin antigen on a gold surface using a genetically engineered polypeptide. A fluorescent dye-labeled antibody (Ab) was used for quantifying the concentration of Ab in the immunosensor chip using a fluorescent technique. For increasing the detection efficiency and reducing the errors, three chambers and three microchannels were designed in one microfluidic chip. This protocol could be applied to the diagnosis of other infectious diseases in a microfluidic device.

Rapid Flu Diagnosis Using Silicon Nanowire Sensor

Influenza epidemics worldwide result in substantial economic and human costs annually. However, rapid and reliable flu diagnosis methods are significantly lacking. Here we have demonstrated the selective detection of influenza A viruses down to 29 viruses/μL in clinical exhaled breath condensate (EBC) samples (diluted by 100-fold) within minutes using silicon nanowire (SiNW) sensor devices. For 90% of the cases, we have observed that EBC samples tested positive or negative by gold standard method RT-qPCR generated corresponding positive or negative SiNW sensor responses. High selectivity of SiNW sensing was also demonstrated using H1N1 viruses, 8 iso PGF 2a, and inert nanoparticles. Finally, magnetic beads were shown capable of enhancing SiNW sensing directly for low level viruses and 8 iso PGF 2a. When calibrated by virus standards and EBC controls, our work suggests that the SiNW sensor device can be reliably applied to the diagnosis of flu in a clinical setting with 2 orders of magnitude less time compared to the gold standard method RT-qPCR.

Valeurs des signes cliniques et d’un test de diagnostic rapide dans le diagnostic de la grippe A (H1N1) nouveau variant aux urgences pédiatriques

To evaluate the values of clinical signs and the rapid diagnostic test (RDT) in the diagnosis of influenza H1N1 new variant in the pediatric emergency room. From 18 August to 1st December 2009, children admitted to the pediatric emergency department of CHU Nord (Marseille, France) and suspected of flu according to French guidelines, were tested for influenza using both an influenza RDT and a polymerase chain reaction (PCR) assay specific for H1N1. From 3 November to 3 December, clinical signs were also noted (fever, headaches, myalgia-arthralgia, shivers, diarrhea). A total of 1122 children were tested: 367 children (32.1%) had a positive specific PCR. The RDT value was: sensitivity 65.2% [55.8-73.6], specificity 99.5% [98.1-100], positive predictive value (PPV) 97.5% [91.8-100], negative predictive value (NPV) 91.2% [90.3-91.5], positive likelihood ratio (LRP) 153.7 [53.5-452.9] and negative likelihood ratio (LRN) 0.393 [0.387-0.411]. Clinical data were available for 504 children (328 over 2 years of age). In children more than 2 years of age and in multivariate analysis, headaches were the only sign significantly associated with a positive PCR (aOR=2.53 [1.25-5.12]). Overall, headaches and/or myalgia-arthralgia were valuable indicators for clinical diagnosis of flu, with a 75.8% NPV. Among children with a positive PCR, diarrhea was more frequent in children under 2 years of age (OR=2.76 [1.19-6.40]). The sensitivity of the RDT improved (90.9% [85.2-94.6]) when flu signs were also present. Associating clinical signs and RDT for the diagnosis of influenza A (H1N1) new variant in a pediatric emergency room improves selection of children requiring appropriate antiviral treatment.

Comparison of the efficacies of amantadine treatment of swine-origin influenza virus A H1N1 and seasonal influenza H1N1 and H3N2 in Japan (2008–2009)

Amantadine is not thought to be effective for the treatment of swine-origin influenza virus (S-OIV) based on an analysis of genetic sequences of the M2 protein. However, the actual clinical efficacy of amantadine has not been well documented. Here, we were able to compare the efficacies of amantadine and neuraminidase inhibitors. Subjects consisted of 428 patients, including 144 with seasonal influenza (flu) identified between 2008 and 2009, and 284 with S-OIV identified between July 1 and November 30, 2009. Diagnosis of flu was established using a rapid diagnostic kit obtained commercially in Japan. Body temperature sheets were obtained from 95% of the S-OIV patients. Times required to recover normal body temperature were compared among subjects using different antiviral drugs. Genetic abnormalities in the M2 protein were also investigated in 66 randomly selected subjects from within the patient pool. Overall, the average hours required to recover normal body temperature in S-OIV patients treated with amantadine (160 cases), with oseltamivir (59 cases), or with zanamivir (65 cases) were 33.9±20.7, 31.7±16.0, or 36.3±21.6, respectively. These differences were not statistically significant. The N31S abnormality was found in all 14 samples taken from the H3N2 patients and in all of the 23 samples taken from in S-OIV patients. However, this abnormality was not found in any of the 30 samples taken from seasonal H1N1 patients. Amantadine was found to be equally effective in treating S-OIV patients as neuraminidase inhibitors. The genetic abnormality resulting in S31N amino acid conversion identified in some of the H3N2 and S-OIV patients is thought to alter the function of M2 protein only mildly.