Virological, epidemiological, clinic, and molecular genetic features of the influenza epidemic in 2015-2016: prevailing of the influenza A(H1N1)09 pdm virus in Russia and countries of the Northern hemisphere

This work describes the specific features of the influenza virus circulating in the period from October 2015 to March 2016 in 10 cities of Russia, the basic laboratories of CEEI at the D.I. Ivanovsky Institute of Virology "Federal Research Centre of Epidemilogy and Microbiology named after the honorary academician N.F. Gamaleya" of the Ministry of Health of the Russian Federation. The increase in the morbidity caused by influenza viruses was detected in January-February 2016. The duration of the morbidity peak was 4-5 weeks. The most vulnerable group included children at the age from 3 to 6; a high rate of hospitalization was also detected among people at the age of 15-64 (65%). In clinic symptoms there were middle and severe forms with high frequency of hospitalization as compared with the season of 2009-2010, but much higher in comparison with the season of 2014-2015. Some of the hospitalized patients had virus pneumonias, half of which were bilateral. Among these patients, 10% were children; 30%, adults. The mortality in the intensive care unit of the hospital was 46%. Almost all lethal cases were among unvaccinated patients in the case of late hospitalization and without early antiviral therapy. The predominance of the influenza A(H1N1)09pdm virus both in the Russian Federation and the major part of the countries in the Northern hemisphere was noted. The results of the study of the antigenic properties of influenza strains of A(H1N1)pdm09 virus did not reveal any differences with respect to the vaccine virus. The sequencing data showed the amino acid substitutions in hemagglutinin (receptor binding and Sa sites) and in genes encoding internal proteins (PA, NP, M1, NS1). Strains were sensitive to oseltamivir and zanamivir and maintained resistance to rimantadine. The participation of non-influenza ARI viruses was comparable to that in preliminary epidemic seasons.

[Anaerobic gas-producing clostridial endogenic infection in patient with salmonellosis]

Anaerobic gas-producing clostridial infection is one of most severe complications of mainly gunshot wound of war period, in peace time occurs very seldom. The rare clinical case of anaerobic gas-producing clostridial endogenic infection with fulminant course in patient with salmonellosis produced by group B salmonella typhimurium. The disease was finished with fatal outcome in 8.5 hours after appearance of pain syndrome in right thigh with consequent fulminant development of gas gangrene with arterial hypotension on 4th day after onset of gastroenteric form of medium severity salmonellosis. Clinical, microbiological and postmortem data are represented.

[Acute myocarditis caused by ECHO virus]

Enteroviral infection is characterized by clinical polymorphism. One of its clinical manifestation is myocarditis, which is usually caused by Coxsackie virus. ECHO viruses cause the disease mostly in childhood. The article presents a case of enteroviral (ECHO) infection complicated by pneumonia and focal myocarditis in a 41-year-old patient, hospitalized during a season of influenza and acute respiratory infections. Acute myocarditis was moderate and the patient recovered by day 23.

[Clinical implications of impaired microcirculation and hemodynamics in acute respiratory viral infections and their pharmacological correction]

Microcirculation, hemocoagulation and blood viscosity were studied in 377 of 1033 inpatients with influenza and other acute respiratory viral infections. The new data show that it is feasible to improve the course, outcomes and results of the treatment. Microcirculation disorders persist throughout the disease, but in convalescence, intravascular alterations are leading. The microcirculatory changes manifest themselves with advanced erythrocyte aggregation, activation of vascular-platelet and plasmic links of hemostasis, and high blood viscosity at low shift velocities. In the presence of concomitant pathology (ischemic heart disease, hypertensive disease, diabetes mellitus) and development of complications, especially acute pneumonia, these disturbances are still greater and tend to increase to the period of decline of clinical and toxic manifestations. These patients should take acetylsalicylic acid (aspirin) as an antiaggregant and other medicines improving blood rheology.

[Cardio-vascular system condition in respiratory mycoplasmosis]

The study enrolled 53 patients (29 males, 24 females) with respiratory mycoplasmosis aged 15-88 years. Most of them were 59 years of age and younger. In 1/3 of the patients the diseases started with symptoms of acute respiratory viral infection, in 2/3 of them--with pulmonary affection. Pneumonia was diagnosed in 50 patients (94.3%), acute bronchitis--in 3 patients. ECG changes were registered in about half of the examinees who had no cardiac complaints. 25 of them had alterations in the end part of the ventricular ECG complex; rhythm and conduction disturbances occurred rarely. Mycoplasmosis patients suffering from ischemic heart disease (IHD) had stable ECG changes while in those free of IHD the changes were short. Myocardial necrosis foci were absent. Cardiac damage comparison in patients with respiratory mycoplasmosis and in other acute respiratory infections has found that cardiovascular system suffers less in acute mycoplasmosis. These data are useful in differential diagnosis of myocardial infections.

[Microcirculation, hemostasis, and hemorheology in influenza and acute respiratory viral infections in patients with hypertension]

AIM

To study microcirculation (MC), hemostasis (HS) and blood viscosity (BV) in influenza and acute respiratory viral infection (ARVI) in hypertensive patients.

MATERIAL AND METHODS

The study group consisted of 67 hypertensive patients with influenza or ARVI. 45 influenza and ARVI normotensive subjects served control. HS and BV tests were made, conjunctival biomicroscopy was performed.

RESULTS

Patients with influenza and ARVI in the acute period had distinct perivascular and vascular abnormalities, sludge phenomenon in the majority of postcapillary venules and capillaries. In convalescence microcirculation improved. HS in the acute stage of infections was characterized by fast coagulation, depression of fibrinolysis; in convalescence, a significantly enhanced platelet aggregation was seen. The highest BV occurred at low shift speeds. Hypertensive patients had higher vascular permeability and more severe intravascular changes which presented with disseminated intravascular red cell aggregation, slowing down of blood flow, its partial block. In hypertension there was also significantly higher platelet aggregation, lower disaggregation, higher BV increase in convalescence.

CONCLUSION

Hypertensive patients with influenza or ARVI had serious disorders of microcirculation, HS and BV threatening cardiovascular complications in such patients.

[Microcirculation and hemostasis in influenza and acute viral respiratory infections complicated with pneumonia]

AIM

To study microcirculation (MC), hemostasis and blood viscosity (BV) in influenza and acute respiratory viral infections (ARVI) complicated by pneumonia.

MATERIAL AND METHODS

Conjunctival biomicroscopy, hemostasis and BV were studied in 232 patients with influenza and ARVI. In 91 of them the disease complicated with acute pneumonia (AP), in 87--with obstructive bronchitis.

RESULTS

Irrespectively of the disease course, patients with influenza and ARVI showed intravascular changes in MC system, hypercoagulation, deterioration of fibrinolysis. In convalescence platelet aggregation increased, fibrinolytic blood activity enhanced. In influenza and ARVI complicated with AP intravascular changes and hypercoagulation were most pronounced. In uncomplicated influenza and ARVI accompanied by bronchitis such changes are less severe. BV was the highest in development of AP.

CONCLUSION

MC and hemostatic disorders arising in influenza and ARVI seem to be essential pathogenetic links provoking development of AP. In intravascular aggregation of platelets and red cells, activation of plasmic hemostasis differentiated treatment with desaggregants and anticoagulants are indicated.

[On the manifestation of diabetes mellitus in a patient with severe course of acute Flexner's dysentery]

Diabetes mellitus (DM) was diagnosed in a 54-year-old man with acute Flexner's dysentery (AFD). A severe course of AFD impedes early clinical diagnosis of DM detected only upon appearance of life-threatening ketoacidosis.

[On changes in the cardiovascular system of patients with respiratory syncytial infection]

Cardiovascular status was evaluated in 36 adult patients with respiratory syncytial infection, part of these coronary patients and the other part not. Respiratory syncytial infection had a negative impact on the cardiovascular system, particularly so in coronary patients, exacerbating the course of coronary disease and causing focal changes in the myocardium.

[Microcirculatory and hemostatic disturbances in patients with influenza and respiratory infections aggravated with coexisting diseases]

Microcirculatory disorders (MD) and hemostasis (HS) were studied in patients with influenza and acute respiratory viral infection (ARVI). The patients also suffered from ischemic heart disease (IHD), essential hypertension (EH) and diabetes mellitus (DM). Among 241 patients 63.9% were middle-aged and old. 45 patients under 60 years of age without coexisting diseases served control. In acute influenza and ARVI the majority of the postcapillary veins and capillaries were affected with sludge syndrome, there were marked perivascular and vascular changes. Convalescence was accompanied with reduced permeability and intravascular aggregation of erythrocytes, microvessels improved tonicity. HS responded to the acute infections with depression of fibrinolysis, in convalescence platelet aggregation activated. IHD patients had disseminated intravascular red cell aggregation, slowing of the microflow, hypercoagulation. Patients with postmyocardial infarction cardiosclerosis (PIC) had more severe affection of microcirculation and hemostasis in convalescence. In hypertensive patients microcirculation and hemostasis were similar to those with IHD. In diabetics platelet aggregation improved but sludge phenomenon and slow blood flow persisted. Thus, ARVI for IHD, EH DM patients are a risk factor for the disease aggravation. In influenza and ARVI, IHD patients, especially with PIC and EH are contraindicated active physical exercise, intake of dysaggregant drugs is desirable. Diabetics should take drugs improving blood rheology early in acute period of ARVI.

[Clinico-anatomic parallels of cardiac lesion in sporadic influenza]

Data on 40 patients (21 men, 19 women) who died in hospital of influenza in 1975-1990 are analysed. The age of the patients ranged from 47 to 92 years, 37 patients were over 60. 31 deceased had ischemic heart disease (IHD), of them 13 survived myocardial infarction; 11 patients had essential hypertension, 1--lymphoid leukemia, 1--pollenosis. Influenza caused by virus of A type (H3N2) was diagnosed in 27 patients. Influenza virus type B was detected in 13 patients. The disease ran a hypertoxic, severe and moderate course in 3, 20 and 17 patients, respectively. Influenza complicated with pneumonia in 23 cases, with hemorrhagic edema in 4 patients. The lethal outcome was caused by acute cardiovascular failure (n = 20) including acute myocardial infarction (n = 9), pulmonary edema (n = 9), pulmonary artery thromboembolism (n = 8). Influenza remains a serious disease especially for the elderly with IHD.

[Hemostatic changes in various clinical courses of influenza]

Data are given on the changes in the hemostatic system in 42 patients with uncomplicated influenza and in complications (pneumonia, bronchitis, aggravation of ischemic heart disease). In the acute period of the disease they were characterized by hypercoagulation which was most pronounced in patients with influenza complicated by pneumonia. In cases of aggravation of ischemic heart disease functional platelet activity during convalescence decreases but the plasma link of hemostasis remains activated and fibrinolytic blood activity inhibited. Functional platelet activity in dynamics of the disease increases which should be taken into consideration in pathogenetic therapy.