Hemorrhagic Fever with Renal Syndrome, Russia.

In Russia, 131,590 cases of hemorrhagic fever with renal syndrome caused by 6 different hantaviruses were reported during 2000-2017. Most cases, 98.4%, were reported in western Russia. The average case-fatality rate was 0.4%, and strong regional differences were seen, depending on the predominant virus type.

Cases of Hemorrhagic Fever with Renal Syndrome in Russia during 2000-2022.

During 2000-2022, a total of 69 of Russia's 85 administrative regions reported 164,580 hemorrhagic fever with renal syndrome (HFRS) cases, with an annual average rate of 4.9 cases/100,000 population (105 popul.). European Russia reported 162,045 (98.5%) cases in 53/60 regions with 9.7 cases/105 popul. Asian Russia reported 2535 (1.5%) cases in 16/25 regions with 0.6 cases/105 popul. In the same period, Russia reported 668 (0.4%) fatal HFRS cases, and 4030 (2.4%) cases among children under the age of 14 years. Most HFRS cases occurred during autumn and winter. The incidence among rural residents was 6.7 per 105 popul., higher than the urban 4.4 per 105 popul.; however, among HFRS patients, rural and urban residents account for 35% and 65%, respectively. Six hantaviruses, causing HFRS of different clinical severity, were recognized as pathogens: Hantaan (HTNV) and Amur (AMUV) of Orthohantavirus hantanense species, Seoul (SEOV) of Orthohantavirus seoulense species, Puumala (PUUV) of Orthohantavirus puumalaense species, and Kurkino (KURV) and Sochi (SOCV) of Orthohantavirus dobravaense species, with the principal hosts Apodemus agrarius coreae, Apodemus peninsulae, Rattus norvegicus, Myodes glareolus, Apodemus agrarius agrarius, and Sylvaemus ponticus, respectively. It was found that 97.7% of HFRS cases are caused by PUUV, therefore, this virus plays the main role in the HFRS morbidity structure in Russia.

Pre-Clinical Studies of Inactivated Polyvalent HFRS Vaccine.

Hemorrhagic fever with renal syndrome (HFRS) is the most common natural focal disease in the Russian Federation with about 6-12 thousand cases annually. 97.7% of all HFRS cases in Russia are caused by the Puumala virus, 1.5%-by the Hantaan, Amur, Seoul viruses, and about 0.8% by the Kurkino and Sochi viruses. There are no licensed vaccines for the prevention of HFRS in the European Region; there are no specific therapeutic to treat orthohantavirus infections. Here we report the results of candidate polyvalent HFRS vaccine preclinical studies. The vaccine was produced on the basis of three viruses: Puumala, strain PUU-TKD/VERO, Hantaan, strain HTN-P88/VERO, and Sochi, strain DOB-SOCHI/VERO. These viruses were inactivated with ß-propiolacton, purified by gel filtration and aluminum hydroxide adsorbed. 18-20 g female BALB/c mice were immunized intramuscularly 2 or 3 times with a 2-week intervals and blood was taken 2 weeks after immunization. FRNT50 performed for virus specific antibodies determination. ELISA kits (Bender MedSystems, Cusabio) were used for detection of cytokines IL-1ß, IL-12, INF-É£. Neutralizing antibodies geometric mean titers to the Puumala, Hantaan, and Sochi viruses were: 9.22 ± 0.31, 9.17 ± 0.26, 8.96 ± 0.34 log2/ml. Up to 1/32 vaccine dilution neutralizing antibodies were identified in 10/10 immunized mice with titers ≥ 3,32 log2/ml. IL-12 and INF-É£ increased after immunization in average 5.5 and 2.8 times respectively, that reflects the Th1 type immunity stimulation. IL-1ß slightly increased, that may suggest vaccine low reactogenicity. According to our preclinical investigations, the candidate polyvalent HFRS vaccine elicits balanced immune response to the Puumala, Hantaan and Sochi viruses.

Various Adjuvants Effect on Immunogenicity of Puumala Virus Vaccine.

Various adjuvant effects on the immunogenicity of the candidate inactivated Puumala virus vaccine were detected in BALB/c mice. Adjuvants under study were: aluminum hydroxide, spherical particles of Tobacco mosaic virus coat protein, B subunit of heat-labile enterotoxin of Escherichia coli, and low endotoxic lipopolysaccharide of Shigella sonnei. Aluminum hydroxide (1 mg/ml) did not affect neutralizing antibodies' induction and vaccine stability during storage compared to immunization with the vaccine without adjuvant. B subunit of heat-labile enterotoxin (0.2 µg/ml), low endotoxic lipopolysaccharide (50 µg/ml), and plant virus-based spherical particles (300 µg/ml) significantly enhance the humoral immune response of vaccine (p < 0.0001). Pronounced stimulation of IL-12 and IFN-É£ was observed when mice were immunized with vaccines both with adjuvants (except of aluminum hydroxide) and without adjuvants. It has been shown that low endotoxic lipopolysaccharide contributes not only to enhance the immune response but also to stabilize vaccine immunogenicity during at least 1 year storage.

Genetic and antigenic analyses of a Puumala virus isolate as a potential vaccine strain.

Puumala virus (PUUV), a causative agent of hemorrhagic fever with renal syndrome (HFRS), is prevalent in Europe and European Russia. No vaccine has been developed for PUUV-associated HFRS, primarily because of the low viral yield in cultured cells. A PUUV strain known as DTK/Ufa-97 was isolated in Russia and adapted for growth in Vero E6 cells maintained in serum-free medium. The DTK/Ufa-97 strain produced a higher viral titer in serum-free medium, suggesting that it may prove useful in the development of an HFRS vaccine. When PUUV-infected Vero E6 cells were grown in serum-free medium, the DTK/Ufa-97 strain yielded more copies of intracellular viral RNA and a higher viral titer in the culture fluid than did the Sotkamo strain. Phylogenetic analysis revealed that PUUVs can be classified into multiple lineages according to geographical origin, and that the DTK/Ufa-97 strain is a member of the Bashkiria-Saratov lineage. The deduced amino acid sequences of the small, medium, and large segments of the DTK/Ufa-97 strain were 99.2% to 100%, 99.3% to 99.8%, and 99.8% identical, respectively, to those of the Bashkirian PUUV strains and 96.9%, 92.6%, and 97.4% identical, respectively, to those of the Sotkamo strain, indicating that the PUUVs are genetically diverse. However, DTK/Ufa-97 and other strains of PUUV exhibited similar patterns of binding to a panel of monoclonal antibodies against Hantaan virus. In addition, diluted antisera (i.e., ranging from 1:160 to 1:640) specific to three strains of PUUV neutralized both homologous and heterologous viruses. These results suggest that the DTK/Ufa-97 strain is capable of extensive growth and is antigenically similar to genetically distant strains of PUUV.

Prednisolone plus S-adenosil-L-methionine in severe alcoholic hepatitis.

PURPOSE/BACKGROUND: Severe alcoholic hepatitis (AH) is a life-threatening liver disease with a potential of 30-40 % mortality at 1 month. While steroids remain to be a first line therapy, they provide only about 50 % survival benefit. The aim of the study was to evaluate the efficacy of glucocorticoids plus S-adenosylmethionine (SAMe), as compared to glucocorticoids alone, in patients with severe alcoholic hepatitis. METHODS: Forty patients with severe AH were randomized in two groups and enrolled in the prospective trial. Group 1 (n = 20) patients received prednisolone 40 mg/daily per os, and group 2 (n = 20) patients were managed with prednisolone 40 mg/daily per os plus SAMe 800 mg i.v. TREATMENT: Duration was 28 days. RESULTS: The response rate assessed by Lille model was significantly higher in the prednisolone plus SAMe group (19 of 20; 95 %) than in the prednisolone group (13 of 20; 65 %), p = 0.044. Two (10 %) patients died, both from the prednisolone group. There were no lethal outcomes in the prednisolone plus SAMe group. The Kaplan-Meier method showed no significant differences between the two groups (p = 0.151, log-rank). Hepatorenal syndrome (HRS) occurred in 20 % in the prednisolone group (4 of 20 patients) while no HRS cases were registered in the prednisolone plus SAMe group (p = 0.035). CONCLUSIONS: Management of severe alcoholic hepatitis with prednisolone plus SAMe was associated with better therapy response (p = 0.044) and less frequent HRS occurrence (p = 0.035). Mortality was not significantly lower in the prednisolone-SAMe group than in the prednisolone-only group at 28 days (10 vs. 0 %, p = 0.151).