Genome-Wide Association Study of COVID-19 Outcomes Reveals Novel Host Genetic Risk Loci in the Serbian Population.

Host genetics, an important contributor to the COVID-19 clinical susceptibility and severity, currently is the focus of multiple genome-wide association studies (GWAS) in populations affected by the pandemic. This is the first study from Serbia that performed a GWAS of COVID-19 outcomes to identify genetic risk markers of disease severity. A group of 128 hospitalized COVID-19 patients from the Serbian population was enrolled in the study. We conducted a GWAS comparing (1) patients with pneumonia (n = 80) against patients without pneumonia (n = 48), and (2) severe (n = 34) against mild disease (n = 48) patients, using a genotyping array followed by imputation of missing genotypes. We have detected a significant signal associated with COVID-19 related pneumonia at locus 13q21.33, with a peak residing upstream of the gene KLHL1 (p = 1.91 × 10-8). Our study also replicated a previously reported COVID-19 risk locus at 3p21.31, identifying lead variants in SACM1L and LZTFL1 genes suggestively associated with pneumonia (p = 7.54 × 10-6) and severe COVID-19 (p = 6.88 × 10-7), respectively. Suggestive association with COVID-19 pneumonia has also been observed at chromosomes 5p15.33 (IRX, NDUFS6, MRPL36, p = 2.81 × 10-6), 5q11.2 (ESM1, p = 6.59 × 10-6), and 9p23 (TYRP1, LURAP1L, p = 8.69 × 10-6). The genes located in or near the risk loci are expressed in neural or lung tissues, and have been previously associated with respiratory diseases such as asthma and COVID-19 or reported as differentially expressed in COVID-19 gene expression profiling studies. Our results revealed novel risk loci for pneumonia and severe COVID-19 disease which could contribute to a better understanding of the COVID-19 host genetics in different populations.

Association of Vitamin D, Zinc and Selenium Related Genetic Variants With COVID-19 Disease Severity.

Background: COVID-19 pandemic has proved to be an unrelenting health threat for more than a year now. The emerging amount of data indicates that vitamin D, zinc and selenium could be important for clinical presentation of COVID-19. Here, we investigated association of genetic variants related to the altered level and bioavailability of vitamin D, zinc and selenium with clinical severity of COVID-19. Methods: We analyzed variants in genes significant for the status of vitamin D (DHCR7/NADSYN1 rs12785878, GC rs2282679, CYP2R1 rs10741657, and VDR rs2228570), zinc (PPCDC rs2120019) and selenium (DMGDH rs17823744) in 120 Serbian adult and pediatric COVID-19 patients using allelic discrimination. Furthermore, we carried out comparative population genetic analysis among European and other worldwide populations to investigate variation in allelic frequencies of selected variants. Results: Study showed that DHCR7/NADSYN rs12785878 and CYP2R1 rs10741657 variants were associated with severe COVID-19 in adults (p = 0.03, p = 0.017, respectively); carriers of DHCR7/NADSYN TG+GG and CYP2R1 GG genotypes had 0.21 and 5.9 the odds for developing severe disease, OR 0.21 (0.05-0.9) and OR 5.9 (1.4-25.2), respectively. There were no associations between selected genetic variants and disease severity in pediatric patients. Comparative population genetic analysis revealed that Serbian population had the lowest frequency of CYP2R1 rs10741657 G allele compared to other non-Finish Europeans (0.58 compared to 0.69 and 0.66 in Spanish and Italian population, respectively), suggesting that other populations should also investigate the relationship of CYP2R1 variant and the COVID-19 disease course. Conclusion: The results of the study indicated that vitamin D related genetic variants were implicated in severe COVID-19 in adults. This could direct prevention strategies based on population specific nutrigenetic profiles.

Safety and immunogenicity of a seasonal trivalent inactivated split influenza vaccine: a double blind, phase III randomized clinical trial in healthy Serbian adults.

This study was a phase III, multicenter, double-blind, randomized, placebo-controlled trial to evaluate the safety and immunogenicity of a seasonal trivalent split, inactivated influenza vaccine (TIV) in healthy Serbian adults between the ages of 18 and 65 years. This egg-based vaccine was manufactured by the Institute of Virology, Vaccines and Sera, Torlak, Belgrade, Serbia. A total of 480 participants were assigned randomly in a ratio of 2:1 to receive a single intramuscular dose (0.5 ml) of the vaccine (15 µg of hemagglutinin per strain) or placebo (phosphate-buffered saline). Participants were monitored for safety, including solicited and unsolicited adverse events (AEs) and serious adverse events (SAEs). No SAEs related to vaccination were reported. Injection site pain (51.3%), injection site tenderness (40.4%), tiredness (17.0%), and headache (15.1%) were the most commonly reported solicited events in the vaccine group. Incidence of related unsolicited AEs was low (1.3%) among vaccinees. Hemagglutinin inhibition (HAI) titers were measured before and 21 days after vaccination in 151 participants. Overall, HAI seroconversion rates to H1 and H3 were observed in 90.1% and 76.2% of vaccinees, respectively. For B antigen, it was 51.5%, likely due to high pre-vaccination titers. Post-vaccination seroprotection rates were in the range of 78.2-95.0% for the three antigens. Post-vaccination geometric mean titers (GMT) were at least 3.8 times higher than baseline levels for all the three strains among vaccinees. Overall, the study showed that the vaccine was safe and well tolerated, and induced a robust immune response against all three vaccine strains. ClinicalTrials.gov identifier: NCT02935192, October 17, 2016.

Influenza A H1N1 virus infection among pregnant women in a tertiary hospital in Belgrade, Serbia.

INTRODUCTION: Pregnant women are at higher risk of developing severe influenza. Our aim was to analyze clinical course and risk factors for fatal outcome in pregnant women with influenza (H1N1) infection. METHODOLOGY: This retrospective study enrolled eleven pregnant women with confirmed Influenza A (H1N1) infection treated in the Clinic for Infectious and Tropical Diseases, Belgrade, Serbia in a 6-years period. RESULTS: The mean age of pregnant women was 28.9 ± 5.2 years, and mean gestational age was 23.1 ± 7.0 weeks. Nine (81.8%) pregnant women had pneumonia (six had interstitial and three had bacterial pneumonia). Pregnant women developed pneumonia more often than other women in the reproductive period, but without statistical significance (81.8% vs. 65.7%, p = 0.330, OR (95% CI) 2.35 (0.47-11.80)). Nine (81.8%) pregnant women recovered. None of them experienced preterm delivery or abortion. Two women (18.2%) died due to acute respiratory distress syndrome. In one of them fetal death occurred one day before she died. The other one was performed caesarean section three days before death. Her newborn and children of all recovered women were healthy at birth. Prolonged time to initiation of oseltamivir and higher body mass index were statistically significantly associated with fatal outcome (p = 0.002, and p = 0.007, respectively). Gestational week of pregnancy, the etiology of pneumonia and comorbidity were not found to be risk factors for death (p = 0.128, p = 0.499 and p = 1.000, respectively). CONCLUSION: Pregnant women with H1N1 infection are at higher risk of pneumonia and death than other women in the reproductive period. Early antiviral therapy reduces the risk of unfavorable outcome.

Safety and immunogenicity of a seasonal trivalent inactivated split influenza vaccine: a phase I randomized clinical trial in healthy Serbian adults.

This study was a phase I double-blind, randomized, placebo-controlled trial to evaluate the safety and immunogenicity of a Serbian-produced seasonal trivalent split, inactivated influenza vaccine in healthy adults. The vaccine was manufactured in eggs by the Torlak Institute of Virology, Vaccines and Sera, Belgrade, Serbia and contained A/H1N1, A/H3N2 and B viruses. The clinical trial took place at the Clinical Center of Serbia in Belgrade. Sixty healthy volunteers, aged 18-45 years, were enrolled in the trial. On the day of immunization, volunteers were randomly assigned to receive either a single dose of the trivalent seasonal influenza vaccine (15 µg of hemagglutinin per strain) or placebo (phosphate-buffered saline). Subjects were monitored for adverse events through a clinical history and physical examination, and blood was taken for testing at screening and on day 8 to assess vaccine safety. Serum samples obtained before and 21 days after immunization were tested for influenza antibody titers using hemagglutination-inhibition (HAI) and microneutralization (MN) tests. No serious adverse events were reported. Pain and tenderness at the injection site were the most commonly reported symptoms in both vaccine and placebo groups. Overall, serum HAI responses of fourfold or greater magnitude were observed to H1, H3, and B antigen in 80%, 75%, and 70% of subjects, respectively. Seroprotection rates as measured by HAI were also high (100%, 100% and 86.67%, respectively, for H1, H3 and B). Thus, Torlak's seasonal trivalent influenza vaccine was not associated with adverse events, was well-tolerated and immunogenic. It should be further evaluated in clinical trials to provide sufficient safety and immunogenicity data for licensing in Serbia.

Clinical characteristics of imported malaria: An 11-year experience in a Serbian referral center.

INTRODUCTION: Due to intercontinental traffic, population migration trends, natural disasters, and climate change, imported malaria remains important to consider in a febrile returning traveler. This study aims to raise awareness about malaria and help European clinicians maintain a working knowledge of this disease by reviewing the most important clinical characteristics in a non-endemic setting. METHODOLOGY: Using medical records, a retrospective study was performed on clinical and laboratory data in order to analyze 103 malaria cases managed at the Clinic for Infectious and Tropical Diseases in Belgrade, from 2000 to 2010. Descriptive statistics, Chi-squared test, Spearman's rank correlation, and analysis of variance were used. RESULTS: Patients were predominantly male (89.3%) with a mean age of 46.66 ± 12.45 years, and most (98.06%) returned from Africa without having taken chemoprophylaxis (72.88%). Fever, arthralgia, myalgia, headache, vomiting, dark urine, and cough were common at presentation. Hepatosplenomegaly, jaundice, neurological and pulmonary findings, and thrombocytopenia were dominant findings on physical and laboratory examinations. Most (73.48%) were infected with P. falciparum. Few patients (17.55%) who were hyperparasitemic had significantly higher values of bilirubin and more frequent neurological complications. All patients were treated with artemisinin-based drug combinations regardless of Plasmodium species. Three (2.9%) patients succumbed to P. falciparum malaria. CONCLUSION: We suggest a high index of suspicion of malaria be maintained when evaluating febrile patients returning from endemic regions, especially if thrombocytopenia and hemolysis are present. Hyperparasitemia, high bilirubin levels, and neurological symptoms are associated with severe malaria. The importance of adequate malaria chemoprophylaxis cannot be overstated.

Retrospective PCR-based species identification of Leishmania in two patients with visceral leishmaniasis in Serbia.

INTRODUCTION: Retrospective molecular identification of Leishmania parasites in two patients with visceral leishmaniasis (VL) previously treated in Serbia was carried out. DNA was isolated from unstained bone marrow smears (BMSs) kept for 11 and 8 years. Genus-specific real-time PCR was combined with conventional PCR and sequencing for detection and species identification. CASE PRESENTATION: In 2003, a 40-year-old Serbian male was admitted to the Clinical Centre of Serbia (CCS) with fever, sweating, fatigue and splenomegaly, which developed over a period of 7 weeks. He had frequently travelled around Europe. VL was confirmed by microscopy of Giemsa-stained BMS. Treatment by pentavalent antimonials was successfully completed. Two years later, the patient developed post-kala-azar dermal leishmaniasis. Treatment resulted in symptom resolution. Later on, Leishmania infantum was identified as the causative agent of the VL by sequencing of the ITS (internal transcribed spacer) region; mixed Leishmania spp. infection could not be excluded. In 2006, a 33-year-old female from Vojvodina, Serbia, with pre-existing diabetes mellitus and chronic meningoencephalitis and a history of frequent visits to the Montenegrin seacoast, was admitted to the CCS with fever, pancytopenia and moderate hepatosplenomegaly. A stained BMS revealed abundant Leishmania amastigotes. Indirect haemagglutination analysis was positive with a titre of 1 : 2048, and a rapid dipstick rK39 test was also positive. Treatment by liposomal amphotericin B was successful; however, shortly after, the patient developed neural infection and pneumonia and died. The causative agent was identified as L. infantum. CONCLUSION: Molecular diagnosis of VL and species delineation using DNA from unstained BMSs stored for several years is possible.

Clinical significance of molecular methods in the diagnosis of imported malaria in returning travelers in Serbia.

OBJECTIVES: The goal of this study was to assess the clinical significance of conventional and PCR-based molecular diagnosis in patients with imported malaria in Serbia. METHODS: Giemsa microscopy, the rapid diagnostic test, and quantitative real-time PCR (qPCR) were used to detect Plasmodium species in 109 whole-blood samples from patients after their return from malaria endemic areas, including those clinically suspected for malaria (n=97) and healthy travelers (n=12) examined as part of epidemiological surveillance. RESULTS: A total of 45 patients were diagnosed with malaria: 42 (93.3%) by microscopy and three (6.7%) additional ones by qPCR. The agreement between the results of species-specific qPCR and microscopy was 73.3%; it was as high as 90.6% for Plasmodium falciparum infections. Follow-up analysis demonstrated persistence of Plasmodium sp DNA for a mean 6 days after the disappearance of parasitemia on microscopy. CONCLUSIONS: Due to its sensitivity and specificity, qPCR is a helpful method complementary to microscopy, particularly in cases of low parasitemia. In addition, it is superior to microscopy for species identification.

Clinical characteristics and functional outcome of patients with West Nile neuroinvasive disease in Serbia.

Neurologic manifestations are prominent characteristic of West Nile virus (WNV) infection. The aim of this article was to describe neurological manifestations in patients with WNV neuroinvasive disease and their functional outcome at discharge in the first human outbreak of WNV infection in Serbia. The study enrolled patients treated in the Clinic for Infectious and Tropical Diseases, Clinical Center Serbia in Belgrade, with serological evidence of acute WNV infection who presented with meningitis, encephalitis and/or acute flaccid paralyses (AFP). Functional outcome at discharge was assessed using modified Rankin Scale (mRS) and Barthel index. Fifty-two patients were analysed. Forty-four (84.6 %) patients had encephalitis, eight (15.4 %) had meningitis, and 13 (25 %) had AFP. Among patients with AFP, 12 resembled poliomyelitis and one had clinical and electrodiagnostic findings consistent with polyradiculoneuritis. Among patients with encephalitis, 17 (32.7 %) had clinical signs of rhombencephalitis, and eight (15.4 %) presented with cerebellitis. Respiratory failure with subsequent mechanical ventilation developed in 13 patients with WNE (29.5 %). Nine (17.3 %) patients died, five (9.6 %) were functionally dependent (mRS 3-5), and 38 (73.1 %) were functionally independent at discharge (mRS 0-2). In univariate analysis, the presence of AFP, respiratory failure and consciousness impairment were found to be predictors of fatal outcome in patients with WNV neuroinvasive disease (p < 0.001, p < 0.001, p = 0.018, respectively). The outbreak of human WNV infection in Serbia caused a notable case fatality ratio, especially in patients with AFP, respiratory failure and consciousness impairment. Rhombencephalitis and cerebellitis could be underestimated presentations of WNV neuroinvasive disease.

Non-specific inflammatory parameters in patients with pandemic H1N1 influenza.

The measurement of non-specific inflammation parameters, such as erythrocyte sedimentation rate (ESR), fibrinogen, C-reactive protein (CRP) and procalctinon (PCT) are very important tools for diagnosis of infections, as well as for monitoring of treatment response. The aim of this study was to determine the significance of non-specific inflammatory parameters in patients with influenza H1N1 infection. ESR, fibrinogen, CRP and PCT were analyzed in patients with influenza H1N1 infection. The diagnosis of influenza H1N1 was established from the nasopharyngeal swabs using Real Time Polymerase Chain Reaction - (RT PCR) method. Chest X-ray was performed to diagnose pneumonia Sixty-three out of 340 hospitalized patients with influenza had pandemic influenza. Their mean age was 34.60±13.82 years. They were referred to hospital 1 to 7 (4.06±2.0) days after onset of symptoms. Of these, 46 had pneumonia, while the majority (41 patients) had interstitial pneumonia, and only five had lobar or segmental pneumonia. Patients with pneumonia had significantly higher levels of CRP and PCT in comparison with those without pneumonia. Patients with lobar pneumonia had significantly higher CRP than those with interstitial pneumonia. However, mean values of PCT between interstitial and lobar pneumonia cases did not differ significantly. Interstitial pneumonia was the most common complication of H1N1 infection among our patients. Non-specific parameters of inflammation, especially CRP and PCT were increased in all pneumonia cases, regardless of the etiology. Monitoring of non-specific inflammatory parameters in patients with H1N1 infection allows recognition of patients with complications, their prompt hospitalization and early initiation of antimicrobial therapy.

A rare case of Candida parapsilosis endocarditis in a young healthy woman--case report.

UNLABELLED: Disseminated fungal infections are still rare conditions, mostly caused by Candida spp. during immunosuppression. Infection of immunocompetent individuals is uncommon. Endocarditis is a rare manifestation during candidaemia, mostly in patients with prosthetic valves. Affection of previously unaltered valves is uncommon. CASE PRESENTATION: We presented a case of a young, previously healthy female patient with endocarditis, caused by Candida parapsilosis. The initial symptom, fever, was present four months before hospital admittance. She was febrile without other symptoms and during observation in a local hospital. After her condition deteriorated, she was transferred to the Institute for infectious and tropical diseases, Belgrade. Clinical findings on admission include petechial skin rash and moderate hepatosplenomegaly. Newly developed systolic murmur was noted, and Candida parapsilosis was isolated in multiple blood cultures. Echocardiography revealed 15 × 14 mm vegetations on the right aortic vellum. She was treated with antifungal drugs (fluconasole, liposomal amphotericin B), and the affected valve was successfully replaced. The same strain of Candida parapsilosis was isolated from the intraoperative material of the valve. There were no markers of immunosuppression or other conditions which could affect the immune system. CONCLUSION: After a prolonged period of treatment she was successfully cured, and she received a long-term intermittent suppressive fluconasole therapy for the time being.

Imported malaria in Belgrade, Serbia, between 2001 and 2009.

Since 2000, travel of Serbian citizens to tropical areas has been slowly but steadily increasing. To determine the epidemiological and clinical characteristics of imported malaria in Serbia, we analyzed clinical history data of all travelers who presented at the Clinic for Infectious and Tropical Diseases in Belgrade after their return from tropical and subtropical areas between 2001 and 2009. The study series involved a total of 2981 travelers, and included both those with (847) and without (2134) health problems. Malaria was diagnosed in 102 cases (3.4% of all travelers; 12.0% of travelers with febrile episodes). Occurring at a rate of 6 to 16 cases per year, it was predominantly imported from Africa (92.2%), particularly from Equatorial Guinea (38.2%) and Nigeria (15.7%). The most frequent reason for travel was work/business. Patients were predominantly (87.3%) male, and the majority (66.7%) was between 40 and 59 years of age. A total of 15 (14.7%) patients took some form of anti-malarial chemoprophylaxis. The dominant causative species was Plasmodium falciparum (78), alone (70) or in mixed infection with P. vivax (5) and P. malariae (3). P. vivax, P. ovale and P. malariae as single agents were each identified in 11, 1 and 1 cases, respectively. Of the 11 cases in which the parasite was not detected, six appeared to be true submicroscopic cases. The clinical course of the disease was severe in 13 patients, all with falciparum malaria, of which three (2.9%) died. Rather than for all travelers, in Serbia screening for malaria should be mandatory in all travelers to endemic regions who present with fever irrespective of chemoprophylaxis history. Inadequate sensitivity of conventional diagnostic methods, illustrated by the cases of submicroscopic malaria, requires introduction of molecular diagnosis in routine practice.

[Disseminated BCG infection in patients with urinary bladder carcinoma].

INTRODUCTION: Bacillus Calmette-Guërin--a live, attenuated strain of Mycobacterium bovis has been used in immunotherapy of patients with superficial urinary bladder carcinoma. Some patients develop complications after intravesical instillation of BCG: high temperature followed by hematuria or granulomatous prostatits, epidydimoorchitis, urethral obstruction, and less than 1% have a systemic disease followed by dissemination of bacteria into other organs. CASE REPORT: A 50-year-old man underwent transurethral resection of a bladder tumor. One month after the operation BCG intravesical installations were administered for three weeks. After the fourth installation, our patient developed high fever, fatigue, vomiting, dark urine, light stools, and jaundice. On admission he was jaundiced with a high fever, enlarged liver and spleen and laboratory findings which included high erythrocyte sedimentation rate, pancytopenia, elevated liver enzymes, especially alkaline phosphatase and aminotranspherases. The bone-marrow biopsy showed granulomatous inflamation suggesting mycobacterial spread in the bone marrow, liver and spleen and sepsis. The patient was initially treated with antituberculous therapy, but his state did not improve until corticosteroids were added to the antituberculous treatment regimen. CONCLUSION: Although dissemination of BCG is a rare complication of intravesical BCG treatment of the bladder carcinoma, it may result in prolonged fever and granulomatous inflamation of the liver, spleen, lungs, bone marrow and BCG sepsis. Antituberclous agents in combination with corticosteroids comprise the treatment of choice for disseminated BCG infection.

High procalcitonin in a patient with drug hypersensitivity syndrome.

We present a patient who developed carbamazepine (CBZ)-induced Drug Rash with Eosinophilia and Systemic Symptoms (DRESS) syndrome associated with high serum procalcitonin (PCT). The presentation (high fever, hepatosplenomegaly, leukocytosis), high PCT and CRP initially suggested sepsis, and he was treated with antibiotics, while CBZ was continued. The rash and hepatitis worsened. After withdrawal of CBZ, corticosteroid therapy was administered and the patient recovered with normalization of PCT. This case demonstrates that PCT may be increased in patients with DRESS. This is the first report of CBZ-induced DRESS associated with high PCT, and the second case of increased PCT in DRESS.

[The frequency of pathological ultrasonographic findings of the gallbladder in patients with infectious diseases].

INTRODUCTION: The objective of our study was to establish, through retrospective analysis of sonographic findings obtained by portable ultrasound devices, the frequency of pathological findings of the gallbladder and common bile duct in a randomized group of patients with infectious diseases. MATERIAL AND METHODS: During five years (January 1, 2000 - December 31, 2004), gallbladder and common bile duct were examined by ultrasonography in 2691 adult patients (1440 males and 1251 females), mean age 48 +/- 17 years, ranging from 17 to 92 years at the Institute of Infectious and Tropical Diseases in Belgrade. The examination included the measurement of size and shape of the gallbladder, its wall and lumen, as well as measurement of caliber and content of the common bile duct. Conventional portable ultrasound devices, ALOKA SSD-500 and SSD-1000 (B-mod) with convex 3.5 and 5 MHz probes were used. RESULTS: The cholecyst was normal in size (<120 x 50 mm) in 2164 (80.4%), and enlarged in 65 (2.4%) patients. The gallbladder was surgically removed in 163 (6.1%) patients, it was pseudoseptal in 141 (5.2%) and invisible in 44 (1.6%) patients. The gallbladder wall was normal in 2031 (75.5%), thickened in 259 (9.6%) and edematous in 173 (6.4%). Gallbladder calculosis was present in 310 (11.5%), and choledocholithiasis in 13 (0.5%) patients. CONCLUSION: Development of morphological abnormalities of the gallbladder and common bile duct was frequent in non-selected patients with infectious diseases. The majority of them may be detected by portable ultrasound devices, which makes them rather applicable for large clinical-epidemiological studies.