Effectiveness of primary vaccination against tick-borne encephalitis in employees of the armed forces.

OBJECTIVE: The aim of our study is to evaluate immune response after receiving the primary vaccination against tick-borne encephalitis (TBE), and to establish a link between seropositivity and selected factors in soldiers. METHODS: Blood samples, questionnaires and vaccination records were obtained. TBE antibodies were detected using both ELISA and a neutralization test (NT). We used logistic regression for statistical analysis. RESULTS: Overall, seropositivity (presence of IgG) was detected in 88% of participants. The proportion of seropositive subjects in relation to the number of doses of vaccine was 69% (2 doses) and 91% (3 doses). A statistically significant relationship was found between seropositivity and the number of vaccine doses. No statistical significance was identified in relation to age and sex. There was no statistical significance of seropositivity, depending on the time of the last dose of the vaccine. CONCLUSIONS: TBE immunisation should be targeted at individuals in the most affected locations and those at highest risk of exposure according to lifestyle and occupation.

West Nile virus - a new infection in the Slovak Republic?

OBJECTIVE: The aim of the study was to evaluate the seroprevalence of West Nile virus (WNV) among the variable population of Eastern Slovakia. METHODS: A serologic survey was conducted using 464 serum samples. The basic demographic, epidemiologic and clinical information was obtained for each serum sample at the time of specimen collection. The presence of antibodies against WNV was investigated using a commercial enzyme-linked immunosorbent assay (ELISA). All the ELISA positive samples were further analysed by a neutralization test with WNV and Usutu virus. RESULTS: Three serum samples (0.65%) from the participants (N = 464) were considered positive for antibodies to WNV. A 29-year-old female was repeatedly exposed to mosquito bites working as a shepherdess and participating in many outdoor activities. Two other females (61 and 76 years old) were treated at the Department of Neurology due to monoparesis of the upper extremity, vertigo; both had a significant epidemiological history with frequent tick and mosquito bites and stay in an endemic region. CONCLUSIONS: Although there was no evidence of WNV infection in the Slovak Republic, the epidemiological situation in the neighbouring countries warrants vigilance and appropriate measures, including the introduction of specific diagnostic tools into clinical practice. The constant monitoring of birds and mosquitoes also seems necessary.

Risk factors of preterm birth and low birth weight neonates among Roma and non-Roma mothers.

OBJECTIVE: This study analyses the differences in birth outcomes between Roma and non-Roma mothers and investigates the potential causes of such differences. METHODS: We conducted a retrospective cohort study of 1,989 non-Roma and 799 Roma mothers who gave birth in 2014 and 2015 at the Gynaecology and Obstetrics Clinic of Louis Pasteur University Hospital in Kosice. Data on mothers and new-born infants have been obtained from the birth book and from the reports on mothers at childbirth. For low birth weight we considered the weight of a new-born weighing less than 2,500 grams and as for premature birth we referred to childbirth before pregnancy week 37. The file was split by ethnicity and statistically processed in IBM SPSS Statistics 21.0. RESULTS: Our results confirmed a lower birth weight among Roma children (-365.4 grams, p < 0.001). The shorter gestation age and higher risk of premature birth were not statistically significant regarding Roma children. Based on the characteristics of Roma mothers, they are at higher risk of giving birth as minor (OR = 23.64; 95% CI = 15.29-36.54; p < 0.001), as single mothers (OR = 7.13; 95% CI = 5.80-8.76; p < 0.001), with basic education or lack of education (OR = 141.31; 95% CI = 100.47-198.76; p < 0.001). They also have a higher risk of smoking during pregnancy (OR = 23.84; 95% CI = 18.06-31.49; p < 0.001); drinking alcohol (OR = 11.71; 95% CI = 3.36-40.90; p < 0.001) and taking drugs (OR = 8.70; 95% CI = 1.81-42.02; p < 0.001). Roma women attended gynaecologists more rarely. CONCLUSION: It is therefore important to support the work of community health workers and stimulate collaboration between community health professionals, paediatricians and gynaecologists to overcome institutional barriers in maternity and child care for mothers living in Roma settlement.

Milk outbreaks of tick-borne encephalitis in Slovakia, 2012-2016.

OBJECTIVE: Tick-borne encephalitis virus (TBEV) is most commonly transmitted to humans via the bite of an infected tick. Alimentary infection through the consumption of TBEV-contaminated dairy products is also well-documented and is responsible for some diseases in endemic areas. The aim of the study was to emphasize the risk of contracting tick-borne encephalitis (TBE) by consuming raw milk and dairy products and to describe TBE epidemics in Slovakia for the period 2012-2016. METHODS: The data on epidemics were obtained from the Annual Reports for the period 2012-2016 available on the website of the Public Health Authority of the Slovak Republic. Medical records of patients hospitalized during epidemics were provided by the Department of Infectology and Travel Medicine, Faculty of Medicine, Pavol Jozef Safárik University in Kosice, and the Louis Pasteur University Hospital in Kosice. RESULTS: During the period 2012-2016, 13 smaller or larger TBE epidemic outbreaks were recorded in the Slovak Republic. The two outbreaks of TBE reported in 2012 were associated with the consumption of raw goat's milk and dairy products. The first case was an outbreak involving 12 infected people in the Lucenec District. The second case was a family outbreak in the Zilina District, where 3 persons out of 4 family members were infected. In 2013, one epidemic was reported involving 5 persons following the consumption of sheep's cheese from a farm in the Presov District. One outbreak with 11 cases was reported in 2014. The investigation confirmed its association with the consumption of sheep's cheese in a restaurant located in the Ruzomberok District. In 2015, 4 epidemics were described related to the consumption of goat's/sheep's milk and cheese (Zilina District, Krupina District, Kysucké Nové Mesto District, Trencín District). In 2016, there were 5 TBE epidemics related to the consumption of milk and dairy products. The largest TBE epidemic outbreak in the last 5 years occurred in the Kosice District. In this outbreak approximately 500 people were exposed, and 44 contracted the disease. Infected persons confirmed consumption of sheep's cheese from a farm. CONCLUSIONS: Consumption of milk and dairy products made only from pasteurized milk, as well as the immunization of humans and animals are the most effective preventive measures against TBE.

Association of seroprevalence and risk factors in Lyme disease.

OBJECTIVE: The aim of the presented cross-sectional seroepidemiological study was to determine the current presence of antibodies against B. burgdorferi s.l. in the groups of Slovak population, and to identify potential risk factors to Lyme borreliosis. METHODS: A group of 261 adults (patients from the Neurological Clinic with possible symptoms of LB and healthy persons with possible working exposure to tick bite: gardeners and soldiers working in afforested areas) were examined in order to assess the seroprevalence of anti-Borrelia antibodies. Sera were screened by commercial enzyme-linked immunosorbent assay (ELISA). The respondents completed questionnaires with general demographic, epidemiological and clinical data. RESULTS: We detected 17.2% presence of positive IgG and 5.7% presence of positive IgM antibodies in all investigated groups. Our results confirmed that the following risk factors such as age and gender are significantly associated with the presence of positive specific antibodies against investigated disease. CONCLUSION: The results of seroprevalence obtained in the present study confirm the possibility of infection with B. burgdorferi among respondents exposed to contact with ticks.

Seroprevalence of Lyme disease in Eastern Slovakia.

OBJECTIVE: Lyme disease (LD) is chronic, multi-system zoonosis transmitted by ticks, and LD aetiological agents are spirochetes of the Borrelia burgdorferi sensu lato complex. The aim of the cross-sectional study was to analyze the LD incidence on the basis of the presence of specific antibodies in the serum of patients in Eastern Slovakia, and to compare the results of serological ELISA and immunoblot assays. METHODS: Venous blood with questionnaires was obtained by field sampling of respondents from Eastern Slovakia. Overall, we examined 537 human sera by the ELISA and for confirmation we tested all positive IgG antibodies against the Borrelia immunoblot assay. RESULTS: Our results confirmed the high serum prevalence of anti-Borrelia antibodies (17.9% for IgG), while the immunoblot seropositive test was confirmed in 69.8% of responders from ELISA IgG positive sera. Positive antibodies of the IgM class were found in 7.6% of the population under study. Most commonly found were antibodies against VlsE (80.2%), p41 (66.7%), p18 (56.3%), p100 (41.7%), p58 (31.3%), and p39 (30.2%). CONCLUSION: It should be noted that detection of antibodies against B. burgdorferi s.l. is only an indirect evidence of the presence of this bacterium in the development of clinical signs of LD in humans. Laboratory LD tests should be performed in accordance with valid standards, positive and uncertain results must be confirmed by the Western Blot/Immunoblot assay.

Serostatus and risk factors of tick-borne encephalitis.

OBJECTIVE: The aim of this seroepidemiological study was to determine the current prevalence of antibodies against tick-borne encephalitis virus (TBEV) in the representative group of Slovak population with included potential risk factors for TBEV. METHODS: Representative group consisted of 428 persons (also with possible exposure to risk factors for tick bite or raw milk consumption). Serum samples were screened by commercial enzyme-linked immunosorbent assay (ELISA). The persons involved in the study completed questionnaires with general demographic, epidemiological and clinical data. During the analysis, we used linear regression to interpret the influence between selected variables. RESULTS: We detected 1.2% prevalence of positive IgG and 1.6% prevalence of positive IgM antibodies in all tested groups. Our results also confirmed that the following risk factors such as tourism, hunting, fishing, and consumption of raw milk are significantly associated with the prevalence of specific antibodies against TBEV. CONCLUSION: The results of seroprevalence obtained by this study confirm the possibility of infection with TBEV among respondents exposed to possible contact with ticks.