Procena potencijalnog i aktuelnog rizika transmisije uzročnika lajmske bolesti na teritoriji Beograda

In the territory of Belgrade, at 16 sites (15 of test and one control), which belong to different enviromental categories such as: parks (Topcider, Hajd park, park Banovo brdo, Sumice, Usce), park-forests (Kosutnjak, Zvezdara, SP Jajinci, Banjica, Ada Ciganlija) and forests (Avala, Lipovica, Bojcinska forest, Manastirska forest, Makis), there were investigated potential and actual risk of transmission of Borrelia burgdorferi sensu lato. Suplja Stena was taken as a control site, where no chemical treatment was performed. Once of month, from March to October 2012, ticks were collected by flag-hours (drag-and-drop) method. Ticks were determined by the species and all Ixodes ricinus were observed by a dark-field microscope. A total of 3,158 individual ticks were collected, out of which 2,797 (88,6%) were Ixodes ricinus, 175 (5,5%) Dermacentor reticulatus and 186 (5,9%) Rhipicephalus sanguineus. At forest sites there were collected 1,102 Ixodes ricinus, in park-forest regions 730 and in the parks 569. Infection rate of ticks by B. burgdorferi sensu lato at the forest sites ranged between 23,8 and 36,3%, in the park-forests region 23,2- 32,6% and 23,8 to 40% in the parks. Twelve of the sites met the criteria for high potential risk and three of them for moderate risk. Except for Makis, at all the forest sites, the actual risk from March to April was certain, and in other months the risk varied. In the park-forest regions, the actual risk was registered 16 times, the possible risk 23 times, and the limited riosk once. At the sites belonging to the park areas, cetrain actual risk was established 3 times, possible risk 30 times and the limited 7 times At the control site Suplja Stena, the actual risk of transmission of B. burgdorferi sensu lato was registered during all the months of the reaserch. At the territory of Belgrade there are favorable conditions for maintaining vector Lyme disease and the potential and actual risk of transmission of Borrelia burgdorferi sensu lato.Na tertoriji Beograda na 16 lokaliteta (15 opitnih i jedan kontrolni) koji su pripadali različitim ekološkim kategorijama: parkovi (Topčider, Ušće, park Banovo brdo, Šumice, Hajd park), park-šume (Košutnjak, Zvezdara, SP Jajinci, Ada Ciganlija, Banjica) i šume (Avala, Lipovica, Bojčinska šuma, Manastirska šuma, Makiš) istraživan je potencijalni i aktuelni rizik transmisije Borrelia burgdorferi sensu lato. Za kontrolni lokalitet uzeta je Šuplja Stena na kojoj se ne izvode hemijski tretmani. Jednom mesečno, od marta do oktobra 2012. godine, metodom flag-časa sakupljani su krpelji. Krpelji su determinisani do vrste. Svi krpelji Ixodes ricinus pregledani su u tamnom polju mikroskopa. Ukupno je prikupljeno 3.158 jedinki krpelja od čega 2.797 (88,6%) I. ricinus, 175 (5,5%) Dermacentor reticulatus i 186 (5,9%) Rhipicephalus sanguineus. Na šumskim lokalitetima sakupljeno je 1.102 I. ricinus, na lokalitetima park-šuma 730 i na lokalitetima parkova 569. Inficiranost krpelja B. burgdorferi sensu lato na lokalitetima šuma kretala se između 23,8 i 36,3%, na lokalitetima park-šuma 23,2 - 32,6% i na lokalitetima parkova 23,8 - 40,0%. Dvanaest lokaliteta je ispunjavalo uslove visokog potencijalnog rizika, a 3 umerenog. Sem Makiša, na lokalitetima šuma, aktuelni rizik je marta i aprila bio siguran, a u ostalim mesecima je bio promenljiv. Na lokalitetima park-šuma, siguran aktuelni rizik je registrovan 16 puta, moguć rizik 23 i ograničen jednom. Na lokalitetima koji pripadaju parkovskim površinama, siguran aktuelni rizik je ustanovljen 3 puta, moguć 30 i ograničen 7 puta. Na kontrolnom lokalitetu Šuplja Stena, aktuelni rizik transmisije B. burgdorferi sensu lato je registrovan svih meseci istraživanja. Na teritoriji Beograda postoje povoljni uslovi za održavanje vektora lajmske bolesti i potencijalni i aktuelni rizik za transmisiju B. burgdorferi sensu lato

Statistical evaluation of the larvicidal effect of diflubenzuron on culex pipiens larval stages

Diflubezuron is increasingly used in areas where mosquito larvae developed resistance to other insecticides. In our community diflubenzuron is not used to control mosquito larvae. Two formulations of 1% diflubenzuron (on corn-cob EF-1, and zeolite EF-2) were tested on Culex pipiens L (larvae) on one canal in the Belgrade suburb area. The effect was followed for seven weeks after application of the formulations. Formulation EF1 achieved a reduction in mosquito L 1 L 2 larvae between 23.9% and 89.4%. The change was statistically significant the 21st and 28th day (p<0.001), 35th and 42nd day (p<0.01) and 49th day (p<0.05). The maximal reduction obtained by formulation EF2 was 69.1%. The accomplished reduction was significant on the 28th and 42nd day (p<0.001), 35th day (p<0.01) and 21st (p<0.05). Both formulations have maintained a good residual effect on the lower developmental larval stages. Maximum reduction achieved by EF1 on L-3 L-4 larvae was 97.4%. Reduction of larvae was high between the 7th and 42nd day (66.4 - 97%). Statistically significant values were recorded on the 21st, 28th and 35th day. Formulation EF2 achieved a reduction of 99.5%. A statistically significant reduction in the value of mosquito larvae was obtained on the 14th, 21st, 28th, 35th and 42nd day. Between the two used formulations there was no significant difference in the number reduction of lower larval stages, but for the higher larval stages EF1 proved to be more efficient

Ekologija komaraca roda Anopheles na području Beograda u proceni vektorskog potencijala za ponovno uspostavljanje transmisije malarije

Belgrade is situated in the area that is potentially at risk from malaria outbrakes. Until eradication, the main vector of malaria in this area was Anopheles maculipennis s. s. (previous name An. typicus) and secondary vectors were An. messeae and An. atroparvus. In this study we examined the distribution and ecology of Anopheles mosquitoes (Diptera, Culicidae) in Belgrade. Females of Anopheles mosquitoes were collected from animal shelters in Belgrade at eight locations during 2003. Egg morphology was used to identify the specimens. A total of 3704 females deposited eggs ready for identification. Three species of An. maculipennis complex were identified: An. messeae, An. atroparvus and An. maculipennis s. s.. The most abundant species were An. messeae (64%). The relative frequency of three species varied depending on the site of collection. Seasonal fluctuations of mosquitoes' species varied. Each develops in a distinct type of water, too. The three species of the An. maculipennis complex, particularly An. messeae and An. atroparvus, are considered as potential vectors of malaria in Belgrade. With the possible reintroduction of Plasmodium species due to climatic changes and increased travel to and from the countries where malaria is endemic, a more efficient vector control is necessary.Beograd je smešten u području koje je potencijalno rizično za ponovno uspostavljanje transmisije malarije. Do eradikacije malarije, glavni vektor malarije na području Beograda bio je An. maculipennis s. s. (raniji naziv An. typicus) a sekundarni vektori bili su An. messeae i An. atroparvus. Mi smo analizirali distribuciju i ekologiju komaraca roda Anopheles (Diptera, Culicidae) na području Beograda. Ženke komaraca roda Anopheles sakupljali smo tokom 2003. godine na 8 lokaliteta šireg područja Beograda. Identifikaciju vrsta vršili smo na osnovu morfologije položenih jaja. Od ukupnog broja izlovljenih ženki komaraca roda Anopheles, njih 3704 je položilo jaja, a njihovom identifikacijom nađene su tri vrste komaraca roda Anopheles, svi pripadnici Anopheles maculipennis kompleksa: An. messeae, An. atroparvus i An. maculipennis s. s.. U ukupnoj populaciji najzastupljeniji je bio An. messeae 64%, zatim An. atroparvus 21%, a najmanje Anopheles maculipennis s. s. 8%. Postojala je razlika u procentualnoj zastupljenosti ovih vrsta u ukupnoj Anopheles populaciji prema lokalitetima, po mesecima, prema izboru vodenih staništa. Prisutne vrste Anopheles komaraca, posebno An. messeae i An. atroparvus ukazuju da je Beograd receptivan za transmisiju malarije, a klimatski uslovi tokom leta pogodni su za kompletiranje sporogoničnog razvoja pripadnika roda Plasmodium

Some traits of Verotoxin-producing strains of Escherichia coli isolated from cattle

Verotoxin-producing Esherichia coli (VTEC) is one of six pathogenicity groups of Eschericha coli. The reservoir for VTEC is the intestinal tract of domestic animals, primarily ruminants. Investigations in our geographic region have also demonstrated that domestic animals are a significant VTEC reservoir. In spite of this, sporadic diseases in humans caused by these agents are rare, and no epidemics have been registered so far. The question is, therefore, what percentage of VTEC isolated in our region have the characteristics of enterohaemorrhagic E. coli (EHEC) which cause intestinal diseases in humans. The aim of this study was to test the isolated bovine strains for some phenotypic and genotypic traits and to determine the percent of strains that belong to EHEC. A total of 105 VTEC strains isolated from cattle were tested for the presence of verotoxin (vtx) genes by PCR (polymerase chain reaction) method. All of them possessed one or more vtx genes. In accordance with our investigations, only four (3.8%) strains, of a total of 105 VTEC strains belong to groups of EHEC. It may be concluded that the majority of strains isolated from cattle in this part of the world do not have phenotypic traits typical for EHEC. Therefore human VTEC associated diseases in Serbia are rare, despite the fact that domestic animals frequently harbor VTEC

Comparative phylogenetic analysis of Dobrava-Belgrade virus l and s genetic segments isolated from an animal reservoir in Serbia

The Dobrava-Belgrade virus (DOBV) is a member of the Bunyaviridae family, genus Hantavirus, possessing a single-stranded RNA genome consisting of three segments, designated L (large), M (medium) and S (small). In this study, we present phylogenetic analysis of a newly detected DOBV strain isolated from Apodemus agrarius. Analysis was based on partial L and S segment sequences, in comparison to previously published DOBV sequences from Serbia and elsewhere. A phylogenetic tree based on partial S segment revealed local geographical clustering of DOBV sequences from Serbia, unrelated to host (rodent or human). The topology of the phylogenetic tree was confirmed with a high percent of completely or partially resolved quartets in likelihood-mapping analysis, whereas no evidence of possible recombination in the examined S segment data set was found

Epidemiologija i dijagnostika fascioloze ljudi

Fasciolosis is a zoonotic infection caused by the trematoda Fasciola hepatica and Fasciola gigantica. Human fasciolosis is endemic in some parts of South America, Africa, Eastern Asia and Europe. High prevalence of human fasciolosis does not necessarily occur in areas where fasciolosis is a major veterinary problem. Infection with Fasciola hepatica has not been reported in humans in Serbia and former Yugoslavia, although a large variety of animals, such as sheep and cattle show infection rates that may reach significant proportions in some areas. Humans can become accidental hosts of this parasite by ingesting contaminated drinking water or plants in an endemic area. Infection with Fasciola hepatica has a variable clinical presentation depending on the stage of the disease. Typical symptoms that may be associated with fascioliasis can be divided by the phases of the disease including the acute or liver phase, the chronic or biliary phase, the obstructive phase, and ectopic or pharyngeal fascioliasis. The diagnosis of human fasciolosis may be problematical and delayed, especially in non-endemic areas, because physicians rarely encounter this disease and a long list of other diseases must be included in the differential diagnosis. The diagnosis of fasciolosis is complex and requires the application of direct an indirect methods of diagnostics: clinical diagnosis, haematological and biochemical findings, parasitological diagnosis, immuno-diagnosis, imaging procedures, liver biopsy. At the Clinic for Infectious and Tropical Diseases in 2005, we recorded the first case of human fasciolosis in a woman from Belgrade, a citizen of Serbia, who developed clinical symptoms of acute fasciolosis after several months of living in Bosnia-Herzegovina. This article reviews the epidemiology and diagnostics of human fasciolosis. .Fascioloza je zoonozna infekcija izazvana trematodama Fasciola hepatica i Fasciola gigantica. Fascioloza ljudi je endemska bolest u pojedinim delovima Južne Amerike, Afrike, istočne Azije i Evrope. Visoka prevalencija fascioloze ljudi nije uvek povezana sa visokom prevalencijom animalne fascioloze. Iako je fascioloza domaćih životinja, pre svega ovaca i goveda, značajno prisutna u pojedinim krajevima Srbije i bivše Jugoslavije, nema dokumentacije, odnosno objavljenih slučajeva fascioloze ljudi u Srbiji. Čovek postaje slučajan domaćin unošenjem infektivnih oblika parazita kontaminiranom vodom ili biljkama. Klinička slika ove bolesti je raznovrsna i zavisi od stadijuma infekcije: akutna ili hepatična, hronična ili bilijarna, obstruktivna, ređe ektopična ili faringealna. Dijagnostika fascioloze ljudi može da bude komplikovana i dugotrajna, naročito u krajevima gde se bolest retko javlja i gde se na nju retko pomišlja, kao i zbog brojnih bolesti slične kliničke manifestacije, koje treba isključiti. Dijagnostika fascioloze ljudi je kompleksna i podrazumeva primenu direktnih i indirektnih dijagnostičkih procedura. Dijagnoza se zasniva na kliničkoj slici, hematološkim i biohemijskim nalazima, parazitološkom nalazu, imunološkoj dijagnostici, tehnikama vizuelizacije patoloških promena i biopsiji jetre. Na Klinici za infektivne i tropske bolesti 2005. godine je dijagnostikovan prvi slučaj fascioloze ljudi u Srbiji. Pacijentkinja iz Beograda razvila je kliničku sliku akutne fascioloze nakon nekoliko meseci boravka u Hercegovini. Ovaj rad predstavlja osvrt na epidemiološki i dijagnostički aspekt fascioloze ljudi.

Risk for infection by Lyme disease cause in green surfaces maintenance workers in Belgrade

Background/Aim. Lyme disease (LD) is a cosmopolitan disease from the group of zoonoses that in humans can affect skins, joints, heart and/or nervous system. Research conducted in endemic areas, shows not only that the population, which lives or works in tick habitats, is in a high risk for getting infected by LD cause, but also that every enviroment itself is specific in regard to both vectors and B. burgdorferi species. In our enviroment, research of seropositivity to B. burgdorferi in persons exposed to vectors of LD have not been conducted. The aim of this study was to determine whether there was a higher risk for getting B. burgdorferi infection in the fieldworks of JKP "Zelenilo Beograd" than in other persons. Methods. Risk for getting LD in the fieldworkers of JKP "Zelenilo Beograd" (park-maintanance company) was determined according to seropositivity, the number and infection rate of LD vectors, and entomological risk index (ERI) value. Serum samples of 34 fieldworkers of JKP "Zelenilo Beograd", and 35 persons of the control group, were tested for the presence of specific IgM and IgG anti-B. burgdorferi antibodies by using ELISA test. In the research localities, the number of ticks was estimated by using the flag hours method, and tick infection rate was determined by dark field microscopy, with magnification rate of 400×. The data were analyzed statistically using χ2 test, and Pearson's correlation analysis. Results. Out of 34 fieldworkes serum samples, 8 (23.5%) were positive on anti-B. burgdorferi antibody presence, while in the control group only one (2.9%) sample was positive (p &lt; 0,05). Seropositivity rate varied from 0-66.6% among localities. Flag hours value among the localities ranged from 8.2-29.9, and tick infection rate ranged from 10.8- 22.3%. ERI value was 0.03-0.15. Correlation between flag hour rate and seropositivity, tick infection rate and seropositivity, and also ERI and seropositivity was established. Conclusion. Frequency of B. burgdorferi seropositivity was significantly higher in green-surface maintenance workers, than in the control group not exposed to these habitats. A significant correlation was found between anti-B. burgdorferi antibodies findings and the number of ticks, tick infection rate, and ERI. The results obtained in our study indicate that there was a significantly higher risk for getting LD cause in the fieldworkers than in the control group.

Insect repellents - transmissive disease vectors prevention

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Biocidi i globalne klimatske promene

Biocidi su hemijske supstance kojima je čovek kroz različite vremenske periode rešavao brojne probleme u zdravstvu, veterini, poljoprivredi, industriji i šumarstvu. Zahvaljujući njima spašeni su mnogi ljudski životi u vanrednim situacijama, obezbeđeno dovoljno hrane za postojeće stanovništvo, sačuvan stočni fond, poboljšana higijena u industriji i zaštićene šume od štetočina. Njihov broj je stalno rastao i usavršavao se, a proizvedene količine su se menjale svakim danom. Procenjuje se da je preko 60.000 hemijskih supstanci ispoljilo biocidno svojstvo i da se deo njih koriste za tu svrhu. Istovremeno je jedan broj biocida skinut sa liste upotrebe zbog štetnog uticaja. Dobrobit biocida se ni jednog trenutka ne umanjuje, ali ako se uzme njihovo poreklo, na«in proizvodnje, transporta, čuvanja i način primene koji je «esto puta bio nestru«an i nekontrolisan u pogledu doze, koncentracije i zaštite, a što je dovelo do kontaminiranja sredine i obolevanja kod ljudi i životinja, onda se to ne sme da zanemari. Prilikom ovakve primene biocida došlo je do uginuća jednog broja osetljivih biljnih i životinjskih vrsta, jedan broj je sveden na minimum, neke vrste ptica, ze«eva, šakala, lisica i p«ela, a jedan broj vrsta je odreagovao svojom rezistencijom, gde spadaju neke vrste mikroorganizama, vektorske i molestanske vrste artropoda (komarci, vaši, krpelji, buve, muve, bubašvabe, stenice), skladišne štetočine (insekti, grinje, glodari) i korovi. Godišnje kod ljudi su u velikom broju registrovana trovanja, oboljenja i letalni ishodi nastali usled njihove primene ili konzumiranja hrane koja je bila kontaminirana perzistentnim biocidima. Poslednjih godina, biocidima se pridaje zna«aj u globalnim klimatskim promenama zbog njihovog učešća u remećenju gasnog sastava staklene bašte, ovde se pre svega isti«e zna«aj herbicida, fumiganata, perzistentnih i lako isparljivih biocida. Imajući to u vidu, predlaže se redukcija njihove brojnosti i primene, alternativna zamena, dekarbonizacija velikog broja biocida i reaktivacija degradiranog tla.Zbornik radov

Prevalence of Borrelia burgdorferi sensu lato in Ixodes ricinus ticks and assessment of entomological risk index at localities in Belgrade

Background/Aim. The first case of human Lyme borreliosis (LB) in Serbia was recorded in 1987. The number of reported LB cases has increased in the past decade. The aim of this study was to estimate the density of Ixodes ricinus (I. ricinus) ticks, the prevalence of Borrelia burgdorferi sensu lato (B. burgdorferi) in them, and entomological risk index (ERI) at 19 Belgrade localities which were grouped into three categories (forests, parkforests, parks). The values of ERI were compared with the number of tick bites in humans. Methods. Ticks were collected monthly by using the flag hours method and the infection rate was determined by using dark field microscopy. The ERI value was calculated for each locality where the ticks were collected. The related data about tick bites was obtained from the patient protocol of the Institute of Epidemiology, Military Medical Academy, Belgrade. Results. The total number of collected ticks, the number of nymphs and the infection rates of the nymphs were significantly higher in forests (p < 0.05) than park-forests and parks. Statistically, the ERI value was significantly higher in forests than parks of Belgrade (χ2 = 7.78, p < 0.01). In March and July, the ERI value was also significantly higher in forests, than park-forests (p < 0.01) and parks (p < 0.01). May was the month with the highest ERI value in each ecological category (forests p < 0.05; park-forests p < 0.01; parks p < 0.001). However, the number of tick bites in humans did not correlate with ERI values. Conclusion. The obtained results indicate that the risk of tick bite and human exposure to B. burgdorferi sensu lato is present at all selected localities in Belgrade. For a more comprehensive Lyme disease risk assessment the method of entomological risk index assessment should be combined with other methods, taking into consideration all tick stages and the behaviour and habits of people who may get infected B. burgdorferi sensu lato