Human West Nile virus (WNV) infection is usually asymptomatic. Less than 1% of patients develop neuroinvasive disease (WNND) which may result in permanent neurological impairment. The aim of this study was to assess the functional and cognitive status of patients with WNND approximately one year after the onset of symptoms. This prospective observational cohort study involved patients with WNND. Patients’ functional and cognitive abilities one year post-infection were assessed by telephone interviews using the Modified Rankin Scale (mRS), Barthel Index, and Telephone Interview for Cognitive Status. Sixty-two participants were analyzed. All patients had encephalitis, and 7 (11.3%) also had acute flaccid paresis/paralysis (AFP). At discharge, 40 (64.5%) patients had no or minimal neurological deficit (mRS 0–1), and 14 (22.6%) were functionally dependent (mRS 3–5). One year later, 52 (83.9%) patients were functionally independent (mRS 0–2), none was severely dependent (Barthel index 0–60), and 50 (90.9%) had a Barthel index score of 91–100. Among 14 functionally dependent patients at discharge, 3 (21.4%) remained functionally dependent one year later. During the follow-up, 7 (11.3%) patients died. No significant difference was observed in the fatality rate between patients with and without AFP, mRS 3–5 at discharge, or age over 65. The most common persistent symptoms were muscle weakness, walking instability, and issues with focus and memory. Using TICS, it was found that 33/55 patients (60%) had unimpaired and 2 (3.6%) had moderately or severely impaired cognitive status. The long-term prognosis after WNV encephalitis is satisfying. The majority of patients reached functional independence and 60% had unimpaired cognitive status.

Introduction: The region of Serbia is characterised by a high prevalence and diversity of Borrelia species, with Borrelia lusitaniae dominating, followed by Borrelia afzelii. Before this report, there were no data on Borrelia species causing Lyme borreliosis (LB) in Serbia. Case presentation: We report the case of a 10-year-old boy with a clinical presentation of disseminated erythema migrans (EM). His results showed IgM antibodies at 6.27 (negative ˂ 0.20; positive ˃ 0.32) against Borrelia burgdorferi sensu lato, which was confirmed via ELFA. Except for skin lesions, the patient did not show any other clinical signs of systemic infection. His blood was taken to isolate and cultivate spirochetes and for molecular analysis. Antimicrobial therapy was prescribed according to the recommended treatment for patients with LB. A follow-up examination was conducted after nine days. The EMs on the skin had disappeared, and antibiotic therapy was continued for 14 days. A second follow-up was conducted one month after the end of therapy. The boy's health condition was normal. After 16 days of incubation in BSK-H medium, viable, motile, and spiral-shaped spirochetes were observed in the culture tube, and cultivation was prolonged for 29 days. PCR and sequencing were successful in both the blood sample and the culture and confirmed the presence of B. lusitaniae. Conclusions: The results presented here is the first Borrelia isolate from the blood of a patient with the clinical manifestation of LB-disseminated EM. The presented results confirm the potential of B. lusitaniae for dissemination via the hematogenous route.

Introduction: In addition to known systemic manifestations, coronavirus disease (COVID-19) can cause serious neurological manifestations as a result of damage to the central and peripheral nervous system. Case report: A 62-year-old male with medical history of arterial hypertension and type 2 diabetes mellitus was admitted to the hospital, complaining of high fever, fatigue, cough, and disturbed mental state. He was diagnosed with COVID-19, had fever of up to 38 °C 7 days before admission, dry cough, and became disoriented and psychotic after 5 days. The chest X-ray and computed tomography (CT) of the head were normal. Following a lumbar puncture, the patient was diagnosed with encephalitis based on clinical and laboratory findings (pleocytosis and hyperproteinorachia in cerebrospinal fluid (CSF)). CSF was checked with the polymerase chain reaction meningitis-encephalitis panel which excludes the more common viral or bacterial causes of encephalitis. Anti-edematous, anti-inflammatory, anticoagulant, gastroprotective, and other symptomatic medications were administered. Ataxic gait was the only focal neurological abnormality identified during neurological assessment. The chest CT did not reveal COVID-19 pneumonia and brain magnetic resonance imaging revealed only cortical reductive brain alterations. The COVID-19 swab test after 10 days was negative. The patient was recovered and released from hospital treatment with normal physical findings and without neurological abnormalities. Conclusions: The diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) encephalitis can be challenging, and it is usually based on the exclusion of other etiological agents of brain infections.

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.

Mosquitoes are ubiquitous arthropods from the order Diptera and are related to flies. They can be found worldwide except at high latitudes and elevations, as well as during the colder seasons in moderate climates. They can be ectoparasites of practically all vertebrates including humans. Culex pipiens (most common), Culex modestus, Aedes albopictus, Aedes japonicum, Aedes vexans, Aedes cinnereus, Anopheles plumbeus and Anopheles maculipennis complex have all been detected in Serbia. These mosquitoes are vectors for numerous infections including West Nile fever, dirofilariasis, Eastern equine encephalitis, Japanese encephalitis, Rift Valley fever, malaria, dengue, yellow fever, chikungunya, zika and usutuviral, Bataviral, Tahynaviral and Sindbis viral infections. The most common mosquito-borne infection in our country is West Nile fever. This infection can be complicated by the development of encephalitis with a lethality as high as 14% and relatively common neurologic deficits. All patients with an infection of the central nervous system, a rash and arthralgia/arthritis (especially during the summer months) should be evaluated for mosquitoborne pathogens. Patients with chronic conditions and the elderly should take precautions to prevent mosquito-borne diseases. Remaining vigilant for the establishment of autochthonous transmission of deadly mosquito-borne pathogens (e.g. malaria) is of vital importance.

Ticks are arthropods from the class Arachnida, related to spiders and mites. They can be found in a wide range of terrestrial ecosystems and are obligate hematophagous ectoparasites of all vertebrates except fish. They cannot reproduce at high altitudes and latitudes, and they are inactive during the winter. Ticks often live in symbiosis with bacteria such as Francisella spp. and Coxiella spp. They go through four developmental stages, with nymphs and adults being the most significant in the context of vectors for human pathogens. In Serbia, several species of ticks have been detected, including Ixodes ricinus, Ixodes hexagonus, Dermacentor reticulatus, Dermacentor marginatus, Rhipicephalus sanguineus, Haemaphysalis punctata, Haemaphysalis concinna, and Hyalomma marginatum. The most medically significant species is the common tick (I. ricinus), which can transmit Lyme disease, anaplasmosis, relapsing fever, babesiosis, tick-borne encephalitis, and orbivirus infections. Lyme disease, the most common vector-borne illness in the Northern Hemisphere, affects hundreds of thousands of people annually. Other significant diseases transmitted by ticks include tularemia, TIBOLA (Tick-borne Lymphadenopathy), Mediterranean spotted fever and Mediterranean spotted fever-like illnesses, Crimean-Congo hemorrhagic fever, and Neoehrlichia mikurensis infection. The highest risk of complications is seen in patients who are hypoor asplenic, as well as immunosuppressed individuals. It is important to maintain a high index of suspicion for tick-borne diseases in all patients presenting with a rash, hepatosplenomegaly, neurological deficits, headache, and/or a reduced peripheral blood cell count.