We describe the first reported outbreak of West Nile virus (WNV) infection in humans in Serbia in August to October 2012 and examine the association of various variables with encephalitis and fatal outcome. Enzyme-linked immunosorbent assay (ELISA) was used for detection of WNV-specific IgM and IgG antibodies in sera and cerebrospinal fluid. A total of 58 patients (mean age: 61 years; standard deviation: 15) were analysed: 44 were from Belgrade and its suburbs; 52 had neuroinvasive disease, of whom 8 had meningitis, while 44 had encephalitis. Acute flaccid paralysis developed in 13 of the patients with encephalitis. Age over 60 years and immunosuppression (including diabetes) were independently associated with the development of encephalitis in a multivariate analysis: odds ratio (OR): 44.8 (95% confidence interval (CI): 4.93-408.59); p=0.001 (age over 60 years); OR: 10.76 (95% CI: 1.06-109.65); p=0.045 (immunosuppression including diabetes). Respiratory failure requiring mechanical ventilation developed in 13 patients with encephalitis. A total of 35 patients had completely recovered by the time they were discharged; nine patients died. The presence of acute flaccid paralysis, consciousness impairment, respiratory failure and immunosuppression (without diabetes) were found to be associated with death in hospital in a univariate analysis (p<0.001, p=0.007, p<0.001 and p=0.010, respectively).

A retrospective epidemiological and diagnostic study of visceral leishmaniasis (VL) was carried out during the period 2001-2007 and included patients suspected of VL who had been diagnosed at the Parasitological Laboratory at the Institute for Infectious and Tropical Diseases, Belgrade. Diagnosis of VL was confirmed by microscopic examination of Giemsa-stained bone marrow (BM) smears. BM smears from 134 patients were examined; 22 cases of VL were diagnosed, the majority of which involved individuals who had been on holiday at the Montenegrian sea coast. The sensitivity of the initial BM smears was inadequate; this required the application of a serological test, adapted for routine use, for the diagnosis of VL.

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.

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.

Summary:A retrospective study of the course and outcome of trichinellosis in a series of 50 patients hospitalized at the Institute for Infectious and Tropical Diseases in Belgrade between 2001 and 2008 was performed. Clinical diagnosis of trichinellosis was based upon the patients' clinical history, symptoms and signs, and eosinophilia. The occurrence of cases showed a strong seasonality (P < 0.0001). The incubation period ranged between one and 33 days. The mean time between onset of symptoms and admission was nine days. Family outbreaks were the most frequent. Smoked pork products were the dominant source of infection (76 %). Fever was the most frequent clinical manifestation (90 %), followed by myalgia (80 %) and periorbital edema (76 %). 43 patients were examined serologically and 72 % of them had anti-Trichinella antibodies. Eosinophilia and elevated levels of serum CK and LDH were detected in 94, 50 and 56 % of the patients, respectively. All patients responded favorably to treatment with mebendazole or albendazole, but eight developed transient complications. Trichinellosis remains a major public health issue in Serbia.

Introduction: In the Europe, the number of tick-borne encephalitis (TBE) has been increased in the last decade, and the number of endemic areas has been also increased and is still growing. In the present case series, we present clinical and socio-epidemiological data of patients with TBE hospitalized in the period of TBE virus epidemic in Serbia. Methodology: A case series was conducted in Serbia in 2017. Patients with confirmed TBE were included in the study. Biochemical and serological analysis of blood and CSF, as well as radiological imaging (CT and MRI) were done. Results: In total, 10 patients with TBE were included in the study. M:F ratio was 1.5:1, while average age was 45.1 years. Half of the patients had severe clinical picture. Endocranial CT scan and MRI did not reveal any abnormality, except in the patient with the most severe CNS infection (meningoencephalomyelitis). Mean value of sedimentation and CRP was slightly elevated (29.6 mm/1hours and 20.1 mg/L, respectively) in 80% of the patients, although elevation was almost negligible. The average number of leucocytes in the cerebrospinal fluid (CSF) was 171×106/L, the mean value of the CSF protein was 1.1g/L. There were no fatal outcomes. Conclusion: Since other CNS infections have similar clinical picture and CSF finding as TBE, serological analysis for TBE should be included in routine diagnostic practice.

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.

Cryptococcosis is an opportunistic fungal infection causes significant disease predominantly in immunocompromised patients. Here we present an excepcional case of disseminated cryptococcosis with pulmonary and cerebral involvement in an immunocompetent patient with no apparent predisposing factors at the time of hospital admission. We described a case of an apparently immunocompetent 66-years old man admitted to hospital with a one-month history of cough, fever and vertigo. During hospitalization, thorax imaging was suggestive of lung metastasis, therefore, he went through several investigations. During hospitalization, he developed neurological symptoms and subsequently underwent a lumbar puncture. Cerebrospinal fluid (CSF) culture was positive for Cryptococcus spp. isolated on Sabouraud's dextrose agar and bird seed agar. In addition, the direct microscopy examination was positive for the India ink test, as well as with the latex agglutination test for cryptococcal polysaccharide antigen (CrAg) in CSF, while serum CrAg was negative. Despite the absence of classic immunocompromising features, he was treated with amphotericin B and fluconazole due to suspected disseminated cryptococcal infection. Later, he was diagnosed with prostatic adenocarcinoma. Upon successful completion of treatment for disseminated cryptococcosis, the patient underwent radical prostate ablation surgery as a treatment forprostatic adenocarcinoma. This exceptional case emphasizes the high degree of suspicion of atypical infections, and in these cases, it is particularly important to consider fungal infections in hitherto healthy patients with no apparent predisposing factors. Although Cryptococcus spp. is predominantly reported in patients with hematological malignancies, cryptococcosis investigation should also be considered as part of the initial workup of patients with a new diagnosis of a solid tumour prior to chemotherapy or radiotherapy.