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Sirvi Autor "Tummeleht, Lea (advisor)" järgi

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  • Pisipilt
    Kirje
    Approaches for detecting Dirofilaria immitis (heartworm) infections in dogs: A systematic literature review
    (Eesti Maaülikool, 2026) Abasli, Javidan Abasli; Tagel, Maarja (advisor); Tummeleht, Lea (advisor); Veterinaarse biomeditsiini ja toiduhügieeni õppetool
    Canine heartworm disease, caused by Dirofilaria immitis (D. immitis), is a vector-borne parasitic disease with zoonotic potential. Its geographic range is expanding due to climate change and mosquito vectors moving from south to north. Emerging dirofilariosis cases are reported from previously nonendemic regions of Northern and Central Europe. Even though early and accurate diagnosis of canine heartworm disease is essential to prevent irreversible cardiopulmonary changes in the host, it remains a significant challenge in daily veterinary practice. The aim of this systematic literature review was to compare different diagnostic methods for the detection of D. immitis, including the Modified Knott’s test (MK), antigen tests, and polymerase chain reaction (PCR) techniques. The MK test showed the lowest and most inconsistent detection rates. Sensitivity was approximately 52% in necropsy-confirmed studies, as it depends entirely on the presence of circulating microfilariae and fails in occult infections. Antigen-based detection, particularly laboratory enzyme-linked immunosorbent assay (ELISA) formats using heat-treated serum to dissociate immune complexes, demonstrated the strongest overall performance, with sensitivity ranging from 87.9–99%. Heat treatment consistently increased positive case detection across multiple independent studies. Nevertheless, antigen tests are limited in male-only infections and cases of low worm burden. Molecular methods showed variable field performance, with sensitivity ranging from 65 to 100% depending on the method and study setting. While real-time qPCR achieved 100% sensitivity and 99.3% specificity under controlled laboratory conditions, it did not consistently outperform antigen testing in field studies and remains constrained by cost and accessibility. Based on the study findings, no single diagnostic method provided sufficient reliability across all infection stages and clinical presentations. The most effective strategy combines antigen testing with heat-treated serum and microfilariae detection. Use of PCR is reserved for species confirmation or when test results conflict with clinical signs. Given the ongoing northward expansion of D. immitis, adoption of multimodal testing protocols is increasingly important for practitioners in previously non-endemic regions.
  • Pisipilt
    Kirje
    Changes in acute-phase proteins’ concentrations of neonatal ruminants in relation to colostrum and weight gain
    (Estonian University of Life Sciences, 2022) Peetsalu, Kristel; Orro, Toomas (advisor); Tummeleht, Lea (advisor); Institute of Veterinary Medicine and Animal Sciences; Sauerwein, Helga (opponent)
    Intensive farming has often led to increased spreading of pathogens in herds. After birth, neonatal ruminants are vulnerable to potential pathogens, as the syndesmochorial type of placentation prevents the transfer of antibodies from mother to foetus. Therefore, the vital immune protection will be obtained by passive immune transfer from colostrum. Colostrum contains various bioactive components, e.g. pro-inflammatory cytokines and acute-phase proteins, the effect of which on offspring is the focus of this research. A major role in protection against pathogens is played by the newborn ruminant's innate immune system, part of which is acute-phase reaction, during which the acute phase proteins are synthesised, mainly in the liver. Acute-phase proteins are used as quantitative sensitive inflammatory markers in medicine. In this thesis, the acute phase reaction during the neonatal period of reindeer calves, lambs and dairy calves was investigated by evaluating the acute phase proteins (serum amyloid A, haptoglobin, albumin, fibrinogen). Additionally, the influence of colostrum acute-phase proteins on the neonatal ruminants' acute phase reaction was evaluated. To identify the possible long-term effect of acute phase reaction in the neonatal period, the average daily weight gain in the 3, 4 and in 9 months was measured. During the neonatal period, there is a fluctuation in acute-phase proteins concentration, which is the lowest on the day of birth. The acute phase reaction on the first living week is influenced by colostrum acute phase proteins and pro-inflammatory cytokines. The acute phase reaction on the second and third week of life has a long-term influence on the animal’s growth. Knowledge of the early immunological development of a newborn ruminant allow providing a better growth environment, which means better welfare and preventing the spread of pathogens in intensive farming systems.
  • Pisipilt
    Kirje
    Mosquito (Diptera: Culicidae) diversity in the urban environment and countryside of Estonia
    (Estonian University of Life Sciences, 2022) Kirik, Heli; Kurina, Olavi (advisor); Tummeleht, Lea (advisor); Institute of Agricultural and Environmental Sciences; Robert, Vincent (opponent); Veromann, Eve (reviewer)
    Mosquitoes are globally distributed insects that are familiar to most people. Thus far, 3 591 mosquito species have been described, but only a small number of these are medically important. Mosquitoes of both genders mainly feed on nectar and plant liquids, only the females of some species require a blood meal to reproduce. Mosquito bites are extremely uncomfortable for the victims and can contribute to the spread of various pathogens. Mosquitoes have been manly seen as a problem in tropical and subtropical regions, with countries like Estonia receiving little attention since the mid-20th century. This thesis is based on research concerning the genetic variation of the species Aedes communis, relationships between urban mosquitoes and weather factors as well as a summary of Estonian mosquito fauna. Specimens were collected from numerous sites in the country, with sweep nets as well as various insect traps. For the most part, individuals were identified based on morphological traits, but genetic methods were also used when needed. The analysis of three genetic markers of Aedes communis specimens lead to the discovery of an additional mitochondrial DNA lineage within the species. In fact, the newly discovered lineage was found to be more similar to the genetic sequences of some North-American species than to other Aedes communis. Although the reason for this genetic variation is not known, it shows that species identifications should not be based on only mitochondrial markers. It is well known that cities are warmer and somewhat drier than the surrounding areas. Higher temperatures are usually favourable for mosquitoes, but they are in danger of drying out in low humidity. Research in the town of Tartu indicated, that as air temperature rises, the number of active mosquitoes lowers along with the relative humidity. Mosquitoes were also less active when it was windy and insect abundance was influenced by springtime floods. The updated Estonian mosquito checklist came to include 34 species, which is four more species than was on the first list published in 1957. Seven additional species are suspected to be present, but require more research.