Clinico-laboratory profile of dengue patients returning from tropical areas to Poland during 2010-15.

BACKGROUND & OBJECTIVES: Dengue is a mosquito-borne viral disease, incidences of which have increased rapidly in the past decade. About 400 million new infections are recorded annually worldwide, and 40% of the human population lives in the areas at risk of dengue transmission. In this study, the clinical and laboratory profile of dengue diagnosed patients returning to Poland from tropical areas has been analyzed. METHODS: This is a retrospective study of 65 patients based on clinical symptoms and serological tests conducted in the Department of Tropical Parasitology of Institute of Maritime and Tropical Medicine (IMTM) in Gdynia, Poland during 2010-15. The diagnosis of dengue virus (DENV) infection was based on the detection of specific immunoglobulin M (IgM) and IgA antibodies performed by specific ELISA assays. The samples were considered as positive, if the absorbance was >10% above the cut-off value. RESULTS: Among 65 persons with dengue selected for the analysis, 59 patients were admitted to the hospital because of clinical symptoms of the disease; the six persons initially asymptomatic were hospitalized due to routine control treatment returning from tropical regions. Patients reported various destinations, purpose and duration of their travels. All of them had returned from dengue endemic regions and were positive for IgM antibodies against DENV. Common clinical symptoms observed were fever (ranging from 38 to 40°C in 43% of patients), weakness, headache and rash. Laboratory tests revealed elevated levels of transaminase activity, leukopenia and thrombocytopenia in 35.3, 24.6 and 20% of patients, respectively. INTERPRETATION & CONCLUSION: The number of Polish travelers to subtropics and tropics increases every year. As cases of fever and other symptoms appear to be increasingly in Polish people returning from tropical regions of Asia, America and Africa, their screening and management should be taken seriously. The study also suggests that the disease might be more widespread than it was known previously.

Serological and molecular evidence of human granulocytic ehrlichiosis focus in the Bialowieza Primeval Forest (Puszcza Bialowieska), northeastern Poland.

Human granulocytic ehrlichiosis (HGE) is an emerging tickborne zoonosis. First described in the USA, it is being increasingly reported from several European countries. This study was undertaken to provide serological and molecular evidence of the occurrence of the HGE focus in the Bialowieza Primeval Forest, located in northeastern Poland. To this end, the seroprevalence of HGE in this area, where Lyme borreliosis and tickborne encephalitis are highly endemic, was determined by means of an indirect immunofluorescence antibody assay. In addition, the frequency of granulocytic Ehrlichia spp. infection in Ixodes ricinus ticks from the same area was estimated using a polymerase chain reaction method with EHR 521 and EHR 747 primers, which amplified a fragment of 16S rDNA. The rate of seropositivity for HGE was 6.2% (8/130 subjects). Individuals seropositive for Lyme borreliosis were more likely to have anti-HGE antibodies than seronegative ones (P<0.05; OR=6.34, 95%CI=1.12-36.98). There was no association between self-reported frequency of tick bites or forestry employment and HGE seropositivity. Sixty of 376 (16%) Ixodes ricinus ticks tested were positive for the Ehrlichia phagocytophila genogroup by polymerase chain reaction. Ehrlichial DNA was present in 59 of 302 (19.5%) adult ticks and in 1 of 74 nymphs (1.4%). There was a significantly higher infection rate among female ticks (32.9%; 49/149) than among male ticks (6.5%; 10/153) (P<0.05). Dual infection with Ehrlichia spp. and Borrelia burgdorferi sensu lato was detected in 10 samples that were positive for ehrlichiae. The results obtained confirm the perpetuation of the HGE agent in the primeval forest ecosystem of northeastern Poland.

Detection of three genospecies of Borrelia burgdorferi sensu lato in Ixodes ricinus ticks collected in different regions of Poland.

Ixodes ricinus ticks, collected in 1996-1998 in different Polish woodlands, were examined to assess the frequency of the occurrence of Lyme borreliosis-associated genospecies. A total of 568 samples of individual adults and 162 samples of individual (n =48) and pooled (of 2 to 7) samples of nymphs were analysed by the polymerase chain reaction (PCR) for Borrelia burgdorferi sensu lato. Spirochetes were detected in 130 adult ticks (22.9%) and in a minimum of 32 (5.3%) nymphs. Further identification of 153 B. burgdorferi s.l.-positive samples by nested PCR using three species-specific primers revealed the occurrence of B. afzelii, B. burgdorferi sensu stricto and B. garinii. Both single-species and mixed infections were noted. Single-species infections were observed in the majority of samples (n = 83/153; 54.2%). Within this group B. afzelii was found in 38/153 samples (24.9%), followed by B. burgdorferi sensu stricto (n = 23/153; 15.0%) and B. garinii (n = 22/153; 14.4%). Dual infections with B. burgdorferi s.s. and B. afzelii were detected in 17/121 (14.0%) adults, while both B. burgdorferi s. s./B. garinii and B. afzelii/B. garinii coinfected 11/121 (9.1%) adult ticks. Triple infection with B. burgdorferi s.s., B. afzelii and B. garinii was noted twice (1.6%). In general, B. afzelii was found in 72/153 (47.1%) tick samples and was the predominant species. B. burgdorferi s. s. and B. garinii were detected in a total of 60/153 (39.2%) and 51/153 (33.3%) samples, respectively. Although, 21 (13.7%) samples were infected by B. burgdorferi s.l. genospecies undetectable by the primers used, results of our study confirm that Lyme borreliosis pathogenic genospecies are well established in tick populations throughout Poland.

Heart rate variability in exposure to high altitude hypoxia of short duration.

The objective of the presented studies is to attempt an evaluation of heart rate (HR) and heart rate variability (HRV) regulatory mechanisms in the presence of autonomous nervous system (ANS) components in transient exposure to high altitude hypoxia. During 24 hrs including a stay in hypobaria, the participants had their HR continuously recorded using the Holter method. The following parameters were calculated at rest and during the stay in a thermobarochamber: spectral power in low frequency bands (LF) 0.04-0. 15 Hz and high frequency bands (HF) 0.15-0.5 Hz, and the sympathetic-parasympathetic balance index LF/HF. Under hypobaric conditions, a decrease in mean spectral power of R-R intervals was noted within both frequency ranges, compared with the study performed in normobaria. The observed differences were larger at daytime.

Prevalence of Borrelia burgdorferi sensu lato in Ixodes ricinus ticks (Acari, Ixodidae) in different Polish woodlands.

In 1996-1998, a total of 2285 Ixodes ricinus ticks (1063 nymphs, 637 males, 585 females) were collected from vegetation from 25 different localities in the 8 Polish provinces throughout the country. Ticks inhabited all 25 collection sites. The average number of ticks per collection site was 91.4 +/- 13.7. All 2285 ticks were examined for Borrelia burgdorferi sensu lato (s.l.) presence, of which 1333 specimens from 3 provinces were tested by routine indirect immunofluorescence assay (IFA) using polyclonal antibody PAB 1B29. The remaining 952 specimens from 5 provinces were examined by polymerase chain reaction (PCR), using FL6 and FL7 primers. The overall infection rate in ticks estimated by these 2 methods was 10. 2%. Nymphs showed lower positivity rate (6.2%) as compared to adult ticks (14.9% in females and 12.4% in males). The highest percentage of infected I. ricinus ticks (37.5%) was noted in the Katowice province while the lowest (4.1%) in the Bia ystok province. In particular collection sites, infection rates varied from 0-37.5%. The obtained results confirmed that B. burgdorferi s.l. is present throughout the distributional areas of I. ricinus in Poland and that a prevalence of spirochete-infected ticks may be high in some locations.

The etiological agent of Lyme disease, Borrelia burgdorferi, in ticks (Acari:Ixodidae) from eastern Poland.

In 1994, 4204 out of 4656 Ixodes ricinus collected both from vegetation in three different areas and from hunter-killed deer and wild boar in the Bialystok province (eastern Poland) were examined individually for the presence of Borrelia burgdorferi s.I. Detection of spirochetes was carried out by the routine indirect immunofluorescence assay (IFA) using polyclonal antibody (anti-B. burgdorferi, strain 1 B 29). B. burgdorferi spirochetes were evident in 349 (8.8%) nymphal and adult I. ricinus collected from vegetation (n = 3958) and in 8 (3.2%) of those removed from hosts (n = 246). Among the ticks collected from vegetation, infection rates in nymphs (5.8-6.4%) in particular areas were about 2-4 times lower than in adults (8.1-24.6%). The calculated minimal and maximal infection rates of ticks collected from different sites were 1.6% and 15.4%, respectively. Prevalence of B. burgdorferi in I. ricinus was determined with respect to the abundance and seasonal activity of the ticks.

[The prevalence of Ixodes ricinus ticks (Acari, Ixodidae) in the forested areas of Gdansk, Sopot, and Gdynia and their infection rate with Borrelia burgdorferi spirochetes]. / Wystepowanie kleszczy Ixodes ricinus (Acari, Ixodidae) na zalesionych obszarach Trojmiasta i ich zakazenie kretkami Borrelia burgdorferi.

Data are presented on the variable patterns on the seasonal activity of Ixodes ricinus questing on vegetation in 6 study sites in the forested areas of Gdansk, Sopot and Gdynia in 1993-1995. A total of 8992 specimens collected there show that ticks frequently occupy habitats closely associated with man. Out of them 5775 (4328 nymphs, 713 females and 680 males) collected in 1994 and 1995 were examined individually for Borrelia burgdorferi sensu lato-the etiologic agent of Lyme borreliosis-using in-direct immunofluorescence assay (IFA). Spirochetes were detected in 577 (10.3%) of the ticks tested. The overall infection rate was 8.2% for nymphs (n = 353), 14.9% for females (n = 102) and 18.9% for males (n = 122). The infection rates in particular study sites varied between 1.4% and 16.4% in 1994 and between 3.6% and 26.9% in 1995. The highest prevalence of B. burgdorferi was observed in June (10%) and October (11.9%) in 1994 and in August (16.3%) and October (25%) in 1995. Detection of B. burgdorferi in ticks derived from the same area in the two following years shows that the infection of the I. ricinus population with this pathogen in the forested areas of Gdansk, Sopot and Gdynia is permanent.

Heart rate variability during centrifuge (+Gz) and lower body negative pressure (LBNP) in pilot candidates.

NASA: Electrocardiograms were recorded in healthy men undergoing centrifugation and lower body negative pressure. Heart rate variability was studied in conjunction with acceleration tolerance. Specific results allowed the authors to conclude that there was significantly lower sympathetic nervous system activity in individuals with high acceleration tolerance.^ieng

Occurrence of Borrelia spirochaetes in ticks (Acari, Ixodidae) collected in the forest areas in Olsztyn province (north central Poland).

In 1993, 2178 out of 3816 Ixodes ricinus and 45 out of 82 Dermacentor reticulatus collected from vegetation at 35 sites and removed from hunter-killed deer in Olsztyn province (N. C. Poland) were examined individually for the presence of Borrelia spirochaetes. Detection of spirochaetes was carried out by the routine indirect immunofluorescence assay (IFA) using polyclonal antibody anti-B. burgdorferi, strain 1 B 29. Borreliae, presumably B. burgdorferi, were evident in 192 (11.5%) I. ricinus (nymphs and adults) collected from vegetation (n = 1666) and in 6 (1.2%) of those removed from hosts (n = 512). Among the first ones, infection rate in nymphs (7.5%) was 2.5 times lower than in adults (18.8%) but was similar in females (18.7%) and males (18.9%). The calculated minimal and maximal infection rates of ticks collected from different locations were 2.9% and 35.7%, respectively. No spirochetes were observed in D. reticulatus tested.