Prevalence, incidence and residual risk of transfusion transmitted viruses (HBV, HCV and HIV infections) in Lithuanian blood donors from 2004 to 2018: The incidence/window-period model study.

INTRODUCTION: Estimation of hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV) transfusion risk in blood donors is essential for monitoring the safety of the blood supply and the impact of new screening tests. Due to improvements in donor selection and continuing progress in screening assays, residual risk of virus transmission has significantly decreased over the past years. It is not practical and sometimes even not possible to measure residual risk in blood donors directly and mathematical models are used. The aim of this study was to calculate the prevalence, incidence rates of HBV, HCV and HIV infections and analyse evolution of their transmission residual risk from 2004 to 2018 at the National Blood Center of Lithuania. MATERIALS AND METHODS: Data from the archives of the National Blood Center of Lithuania from 2004 to 2018 was retrospectively analysed. The residual risk was calculated for each virus and year by applying the incidence/window-period model suggested by World Health Organization. For the analysis of the residual risk yearly trends a linear regression was used. RESULTS: A total of 754,755 blood donors and 1,245,568 donations were included in the analysis and represented a 2.06 donations per donor over 15 years. Average residual risk for HBV, HCV and HIV respectively was 570.04, 807.14 and 35.72 per 1,00,000 donations. During the study period, there was statistically significant downward trend in the residual risk for every analysed virus. DISCUSSION: Residual risk of virus transmission has been steadily decreasing over past 15 years in Lithuanian donors, but the current risk remains quite high. It is difficult to establish how much the risk is affected by statistical assumptions or virus prevalence in general population. However, results of this study indicate the need of the population screening program of transfusion transmitted viruses.

Routine HIV testing program in the University Infectious Diseases Centre in Lithuania: a four-year analysis.

BACKGROUND: HIV transmission remains a major concern in Eastern Europe, and too many people are diagnosed late. Expanded testing strategies and early and appropriate access to care are required. Infectious disease departments might be targets for expanded HIV testing owing to the intense passage of key patient populations that carry indicators of HIV disease. Our objective was to evaluate the feasibility and clinical effectiveness of a fully integrated, opt-out routine, rapid HIV testing program. METHODS: A retrospective four-year study of a screening program was conducted from 2010 through 2014. The program was divided into two periods: from 2010 to 2012 (pilot study) and from 2013 to 2014. The pilot study consisted of routine HIV testing of patients aged 18-55 that were hospitalized in one department. In the second period, all inpatients aged 18-65 were eligible. Targeted testing was conducted in the other inpatient department during the pilot study and the outpatient department during both periods. RESULTS: During the pilot study, 2203 patients were hospitalized, 1314 (59.6%) were eligible, 954 (72.6%) were tested, and 3 (0.31%) were newly diagnosed HIV-positive. In the second period, 4911 patients were hospitalized, 3727 (75.9%) were eligible, 3303 (88.6%) were tested, and 7 (0.21%) were HIV-positive. In total, 2800 targeted tests were performed, and 4 (0.14%) patients tested positive with newly discovered HIV. All 14 newly diagnosed patients were provided with care. Comparing cumulative groups of routine and targeted testing, the HIV prevalence was 0.23% vs. 0.14% (p = 0.40) and was above the reported cost-effectiveness threshold of 0.1% (p = 0.012). A lower proportion of advanced disease and a higher proportion of heterosexually transmitted infection were found in the routine testing group. CONCLUSION: Routine HIV testing in admissions of infectious diseases is acceptable, feasible, sustainable and clinically effective. Compared to targeted testing, routine testing helped to discover more patients in earlier stages and those with heterosexually transmitted HIV infection.

Utility of propidium monoazide viability assay as a biomarker for a tuberculosis disease.

Reliable laboratory diagnosis of tuberculosis (TB), including laboratory biomarkers of cure, remains a challenge. In our study we evaluated the performance of a Propidium Monoazide (PMA) assay for the detection of viable TB bacilli in sputum specimens during anti-TB chemotherapy and its potential use as a TB biomarker. The study was conducted at three centres on 1937 sputum specimens from 310 adult bacteriologically confirmed pulmonary TB patients obtained before commencing anti-TB treatment and at regular intervals afterwards. Performance of the PMA assay was assessed using various readout assays with bacteriology culture results and time to positivity on liquid media used as reference standards. Treatment of sputum with N-acetyl-cysteine was found to be fully compatible with the PMA assay. Good sensitivity and specificity (97.5% and 70.7-80.0%) for detection of live TB bacilli was achieved using the Xpert(®) MTB/RIF test as a readout assay. Tentative Ct and ΔCt thresholds for the Xpert(®) MTB/RIF system were proposed. Good correlation (r = 0.61) between Ct values and time to positivity of TB cultures on liquid media was demonstrated. The PMA method has potential in monitoring bacterial load in sputum specimens and so may have a role as a biomarker of cure in TB treatment.

Truncated CXCL10 is associated with failure to achieve spontaneous clearance of acute hepatitis C infection.

UNLABELLED: The pathogenesis of hepatitis C virus (HCV) infection is strongly influenced by the nature of the host's antiviral immunity. Counterintuitively, elevated serum concentrations of C-X-C chemokine 10 (CXCL10), a potent chemoattractant for antiviral T-cells and NK-cells, are associated with poor treatment outcomes in patients with chronic HCV. It has been reported that an N-terminal truncated form of CXCL10, generated by the protease dipeptidylpeptidase 4 (DPP4), can act as chemokine antagonist. We sought to investigate CXCL10 antagonism in the clinical outcome and evolution of acute HCV infection. We collected serial blood samples from 16 patients, at the clinical onset of acute HCV infection and at 12 standardized follow-up timepoints over the first year. Intact and truncated CXCL10 and DPP4 activity were quantified in all longitudinal samples. In addition, NK-cell frequency/phenotype, and HCV-specific T-cell responses were assessed. Subjects developing chronicity (n = 11) had higher concentrations of CXCL10 (P < 0.001), which was predominantly in a truncated form (P = 0.036) compared to patients who spontaneously resolved infection (n = 5). Truncated CXCL10 correlated with HCV-RNA (r = 0.40, P < 0.001) and DPP4 activity (r = 0.53, P < 0.001). Subjects who resolved infection had a higher frequency of HCV-specific interferon-gamma (IFNγ)-producing T-cells (P = 0.017) and predominance of cytotoxic NK-cells (P = 0.005) compared to patients who became chronic. Patients who became persistently infected had higher proportions of cytokine-producing NK-cells, which were correlated with concentrations of truncated CXCL10 (r = 0.92, P < 0.001). CONCLUSION: This study provides the first evidence of chemokine antagonism during acute HCV infection. We suggest that the DPP4-CXCL10 axis inhibits antiviral innate and adaptive host immunity and favors establishment of viral persistence.

Two dog-related infections leading to death: overwhelming Capnocytophaga canimorsus sepsis in a patient with cystic echinococcosis.

Capnocytophaga canimorsus is a fastidious, capnophilic, fusiform, and filamentous gram-negative rod. It is part of the normal oral flora of dogs and cats and can cause an infection in humans, but is of generally low virulence in healthy individuals. A case of fatal sepsis due to Capnocytophaga canimorsus in a 46-year-old woman with clinically silent cystic echinococcosis discovered postmortem is present. She had been bitten by a dog 3 days before the symptoms appeared. The family had owned the dog for 4 years. A preliminary diagnosis of septic shock of unknown etiology with multisystem organ failure was established. Despite all the efforts, the patient died on the seventh day of hospitalization. Laboratory findings received postmortem showed Capnocytophaga canimorsus isolated from the blood culture after 7 incubation days. Autopsy showed a cyst in the liver with a fibrotic wall and necrotic eosinophilic interiors containing fragments of Echinococcus granulosus scolices. In conclusion, an interaction possibly established long ago between the host and Echinococcus granulosus conditioned immunosuppression mechanisms developed by the parasite in this case, which can explain such an aggressive course of the infection with Capnocytophaga. Two dog-related infections were fatal in the middle-aged dog owner considered healthy before this hospitalization. Vigilance concerning recent exposure to dogs or cats and potential immunosuppression risk factors must be maintained in a patient presenting with clinical features of fulminant sepsis.

Viral clearance or persistence after acute hepatitis C infection: interim results from a prospective study.

OBJECTIVE: Hepatitis C virus infection (HCV) has a high rate of chronic evolution; however, the underlying mechanisms remain to be elucidated. We investigated natural clinical, virological, and immunological course of acute HCV infection in order to identify possible prognostic factors of spontaneous resolution and to gain more understanding of early characteristics responsible for viral clearance or persistence. MATERIALS AND METHODS: Eight patients with acute symptomatic hepatitis C were prospectively followed up for more than 6 months (range, 8-14 months). None of the individuals received antiviral therapy during the study period. We analyzed biochemical, virological, and immunological parameters of these patients detected at different time-points of the follow-up. Plasma HCV RNA was quantitated using TaqMan real-time polymerase chain reaction. Virus-specific CD4(+) T cells were enumerated by interferon-gamma (IFN-gamma) ELISpot assay. RESULTS: Two of eight individuals resolved HCV spontaneously, while the remaining patients developed chronic HCV infection. HCV RNA became undetectable within 14 days of the study, followed by a rapid alanine aminotransferase normalization in patients with resolved infection. On the contrary, chronically infected subjects demonstrated persistent viremia or intermittently undetectable HCV-RNA, accompanied by polyphasic alanine aminotransferase profile throughout the study. Patients with self-limited hepatitis C displayed the strongest virus-specific CD4(+) T (IFN-gamma) cell reactivity within the first weeks of the follow-up, while persistently infected subjects initially showed a weak antiviral CD4(+) T (IFN-gamma) cell response. CONCLUSIONS: In most cases, acute hepatitis C progresses to chronic disease. Viral clearance within the first month after clinical presentation accompanied by monophasic alanine aminotransferase profile could predict recovery. Early and strong CD4(+)/Th1 immune response against HCV might play an important role in the disease resolution.

Characterization of HCV strains in an oncohematological pediatric department reveals little horizontal transmission but multiple introductions by un-screened blood products in the past.

Because several children were found infected with hepatitis C virus (HCV) at a pediatric oncohematological department in Vilnius, 474 children were tested for anti-HCV. Fifty-eight percent of 96 children treated with blood and plasma products manufactured before the introduction of anti-HCV screening of blood in Lithuania in 1994 were positive for anti-HCV versus 3.4% of those treated after 1994. The possible route of transmission for 45 of these was investigated by phylogenetic analyses within the NS5B region. Children treated before 1995 were infected with a multiplicity of strains of different subtypes, predominantly 1b found in 21 cases, 3a in 5 cases, 2 in 3 cases, 1a in 1 case, and not subtypeable genotype 1 strains in 2 cases. Children who had received blood products after 1994 were infected with only two subtypes, 1b in six and 3a in seven. Genetic analysis showed multiple introductions of HCV before 1995 and that horizontal spread between patients had occurred only to a minor extent at the department. However, two transmission chains involved children treated before 1995. Another chain involved five children treated after 1994. Since the most important risk factor for acquiring hepatitis C was blood products manufactured before the introduction of donor screening for anti-HCV, the spread between children would not have been revealed without molecular tools. These and the background strains provide the first reported sequence data on Lithuanian HCV strains. In general, these were shown to form autochthonous clades, except the 3a strains that were related to strains from the former USSR.

Neuraminidase inhibitors reduce nitric oxide production in influenza virus-infected and gamma interferon-activated RAW 264.7 macrophages.

The influenza virus (influenza) infection causes an intense infiltration of pulmonary tissues by macrophages, which abundantly generate a free radical, nitric oxide (NO) resulting in lung damage. Neuraminidase inhibitors (NIs) restrict influenza virus replication but whether they can suppress NO production within macrophages is unknown. RAW 264.7 macrophages were exposed to interferon-gamma (IFN-gamma), live influenza (A/PR/8/34) or a combination of both and were treated with NIs (oseltamivir or zanamivir). Results revealed that the drugs reduced a synergy between influenza and IFN-gamma in NO synthesis within the cells at all of the used concentrations (0.01, 0.1, 1 microg/ml). In contrast to zanamivir, this effect occurred in a concentration-dependent manner with oseltamivir treatment. On the other hand, all concentrations of zanamivir significantly suppressed NO production in comparison to that upon the combined exposure only (p < 0.05). Both compounds also considerably decreased NO generation in the IFN-gamma-stimulated macrophages, and zanamivir in the influenza-infected cells as well. However, neither of the drugs inhibited iNOS mRNA expression in the cells containing these stimulants. Additionally, the data indicate that a prodrug oseltamivir can be activated in vitro within the macrophage cultures. These findings are important for designing treatment approaches to limit pulmonary inflammation during influenza infection.

Inhaled zanamivir versus rimantadine for the control of influenza in a highly vaccinated long-term care population.

BACKGROUND: Despite vaccination, influenza commonly causes morbidity and mortality in institutional settings. Influenza control with rimantadine and amantadine is limited by emergence and transmission of drug-resistant influenza A variants, ineffectiveness against influenza B, and toxicity. This study evaluated the efficacy and tolerability of zanamivir versus rimantadine for influenza outbreak control in long-term care facilities. METHODS: This double-blind, randomized, controlled study prospectively enrolled nursing home residents for 3 influenza seasons (1997 to 2000). Vaccine was offered to all subjects. Following influenza outbreak declaration, subjects were randomized to inhaled zanamivir 10 mg or standard of care (rimantadine 100 mg for influenza A or placebo for influenza B) once daily for 14 days. The proportion of randomized subjects developing symptomatic, laboratory-confirmed influenza during prophylaxis was the primary endpoint. RESULTS: Of 482 randomizations (238 zanamivir, 231 rimantadine, 13 placebo), 96% of subjects were elderly or had high-risk conditions; over 90% were vaccinated. Symptomatic, laboratory-confirmed influenza occurred in 3% of zanamivir subjects and 8% of rimantadine subjects during chemoprophylaxis (P = .038; additional protective efficacy for zanamivir over rimantadine = 61%). Since only 25 subjects were randomized during 2 influenza B outbreaks and none developed influenza, the influenza B data were excluded from further analysis. Zanamivir was well tolerated and unassociated with emergence of resistant virus; rimantadine-resistant variants were common. CONCLUSIONS: This is the first prospective, controlled study demonstrating effectiveness of chemoprophylaxis for influenza outbreak control. Zanamivir prevents symptomatic, laboratory-confirmed influenza more effectively than rimantadine, is unassociated with resistant virus, and has a favorable safety profile. Zanamivir is an appropriate alternative for influenza outbreak control among institutionalized vaccinated elderly.

Inhaled zanamivir versus placebo for the prevention of influenza outbreaks in an unvaccinated long-term care population.

BACKGROUND: Antiviral chemoprophylaxis effectiveness for influenza control has not been prospectively established for unvaccinated residents of long-term care facilities. This study evaluated the efficacy and tolerability of zanamivir against the standard of care (no intervention, ie, placebo) for influenza outbreak control in a largely unvaccinated institutionalized population. OBJECTIVE: To evaluate the efficacy and tolerability of zanamivir versus placebo for influenza outbreak control in long-term care facilities. METHODS: This double-blind, randomized, placebo-controlled study prospectively enrolled/followed residents of long-term care facilities (LTCF) at 12 centers for 1 to 3 influenza seasons (1997 to 2000). Following influenza outbreak declaration, asymptomatic subjects were randomized for prophylaxis to inhaled zanamivir 10 mg or inhaled placebo given once daily for 14 days. The proportion of randomized subjects who during prophylaxis developed symptomatic, laboratory-confirmed influenza (SLCI) was the primary end point. RESULTS: Influenza outbreaks were explosive. The attack rates varied from 9.5 to 14.8 per 100 residents. Of 1763 consents given and resulting in 494 randomizations, 49% received zanamivir and 51% placebo; 66% were elderly and 9% were vaccinated. SLCI occurred in 6% of zanamivir and 9% of placebo subjects (P = .355; protective efficacy for zanamivir = 29%, 95% confidence interval 31% to 62%), and symptomatic influenza confirmed by culture in 2% and 6%, respectively (P = .052; protective efficacy = 65%, 95% confidence interval 8.5% to 86%). Zanamivir use was also associated with a 70% (95% confidence interval 13% to 89%) reduction in laboratory-confirmed influenza with fever (2% vs 6%, P = .043). Influenza B was not detected. Zanamivir was well tolerated. No virus isolate demonstrated zanamivir resistance. CONCLUSIONS: The protective efficacy of zanamivir versus placebo for SLCI was marginal, for all laboratory confirmed illnesses, but significant against culture proven and febrile influenza, suggesting zanamivir can be effective for outbreak control and symptom reduction of unvaccinated institutionalized residents. Zanamivir had an acceptable safety profile in elderly, high-risk LTCF residents and was not associated with the emergence of resistant strains.