Vector borne and zoonotic diseases最新文献

Background: Coxiella burnetii, an obligate intracellular bacterium, is the etiological agent of Q fever in humans and one of the causes of abortion in small ruminants. Although coxiellosis is considered an exotic disease, there are a few reports in Mexico. Methods: The objective of this work was to determine the presence of C. burnetii DNA in vaginal samples from sheep that presented abortion and ram semen. A total of 180 vaginal exudate samples and 20 semen samples were obtained from five Central and Southern States of Mexico. Total DNA was extracted from vaginal swabs and C. burnetii was identified by PCR amplification and sequencing of the IS1111 insertion sequence. Results and Conclusion: In total, 110 (110/180) vaginal samples and 12 (12/20) semen samples were positive for C. burnetii. This is the first report of C. burnetii in sheep that aborted and in ram semen in Mexico.

Crimean-Congo hemorrhagic fever (CCHF) is a zoonotic tick-borne disease, caused by an arbovirus of the genus Orthonairovirus and the family Nairoviridae. Crimean-Congo hemorrhagic fever virus (CCHFV) is widespread in several regions of the world. While the virus is not pathogenic to all susceptible livestock and wild mammals, it can lead to severe hemorrhagic fever in humans. In this review, we compiled published data on CCHFV infections in humans, animals, and ticks in Tunisia. Based on that, we discussed the epidemiology and the distribution patterns of CCHFV infections highlighting the risk factors for this virus in the country. CCHF infection prevalence in humans was estimated to 2.76% (5/181) and 5% (2/38) in Tunisian febrile patients and Tunisian slaughterhouse workers, respectively. Concurrently, seroprevalence in domestic ungulates (sheep, goats, cattle, and dromedaries) ranged from zero to 89.7%, and only one Hyalomma impeltatum tick specimen collected from dromedaries in southern Tunisian was positive for CCHFV by reverse transcriptase-polymerase chain reaction (0.6%; 1/165). As Tunisian studies on CCHFV are geographically scattered and limited due to very small sample sizes, further studies are needed to improve the knowledge on the epidemiology of CCHF in Tunisia.

Introduction: Brucellosis, which is among the endemic regions of Turkey, is a common zoonotic disease. The gold standard in diagnosing brucellosis is culture. We aimed to compare demographic characteristics, risk factors, and clinical and laboratory variables between cases with culture positivity and undetected in culture. Materials and Methods: This single-center study was conducted between January 2007 and April 2022. Clinical and laboratory data of patients with brucella growth in blood culture and patients without growth were compared. Results: A total of 150 patients were included in the study. The median age was 10 (1-18 years). Of the patients, 66 (44%) were female and 84 (56%) were male. Forty (26.7%) of the patients were bacteremic and 110 (73.3%) were nonbacteremic. In the bacteremic group, white blood cell count, platelet, and hemoglobin counts were lower, and aspartate aminotransferase (AST) and alanine aminotransferase (ALT) values were higher. In clinical evaluation, fever, hepatomegaly, splenomegaly, and abdominal pain were more common in the bacteremic group. Conclusion: The distinction between bacteremic and nonbacteremic brucellosis can be predicted using laboratory values such as white blood cells, hemoglobin counts, platelet, ALT, and AST, and clinical findings such as fever, abdominal pain, hepatomegaly, and splenomegaly.

Retrospective serological and case diagnostic data of endemic bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV) provide evidence of viral transmission among livestock and wildlife from 2016 in Kansas and Nebraska. Serological testing of mature cattle in nine distinct regional zones of Kansas revealed 76% to 100% had detectable antibodies to BTV and/or EHDV. Specimens tested in the Kansas Veterinary Diagnostic Laboratory (55 submissions) were 51% test positive for antibodies to BTV and/or EHDV. Specimens tested in the Nebraska Veterinary Diagnostic Center (283 submissions) were 25% test positive for antibodies to BTV and/or EHDV. Low disease incidence in white-tailed deer and other susceptible wild ungulates was observed during 2016. However, there were no confirmed reports of disease in livestock in either state. The reasons for emergence of significant clinical disease in livestock and wildlife populations remain undefined.

Background: Ehrlichia canis has been the main hemopathogen affecting domestic dogs in Brazil. Even though tick-infested dogs may lead to household infestation and predispose human exposure and public health concern, no comprehensive study has surveyed humans, dogs, and environmental ticks altogether. Materials and Methods: Accordingly, the present study aimed to assess tick-infested households, identify tick species, perform serological (immunofluorescence assay) and molecular (PCR and q-PCR) detection of Ehrlichia in ticks, in the eighth biggest metropolitan area of Brazil. Results: Between 2007 and 2020, 233/5973 (3.9%) out of all complaints were from tick-infested households of 200 different addresses. Overall, 370/552 (67.0%) ticks were collected and identified as adult and 182/552 (33.0%) as immature forms of Rhipicephalus sanguineus s.l. complex; a single tick from one owner, a female tick of Amblyomma sculptum; and 395 ticks from dogs, 319/395 (80.8%) adult and 72/395 (18.2%) immature forms of Rhipicephalus spp., and 4/395 (1.01%) female Amblyomma aureolatum. Overall, 2/135 (1.5%) owners and 13/136 (9.6%) dogs were seropositive for E. canis. The DNA of Anaplasmataceae family was molecularly detected in 16/50 (32.0%) R. sanguineus s.l. As expected, the number of monthly tick infestation complaints were directly associated, and mean (p = 0.01), maximum (p = 0.011), and minimum (p = 0.008) temperature were statistically significant and had a low positive correlation (0.24, 0.23, and 0.24, respectively). In addition, complaints were highly associated to all socioeconomic variables (p < 0.001), with the exception of the presence of vacant lots. Conclusions: Despite low samplings and human negative results, areas with low-income with adequate temperature and urban agglomerations have been shown to be associated risks for tick infestations, predisposing tick-borne diseases. In conclusion, monitoring should always be conducted in such areas, including One Health approach with serosurvey of owners and dogs, along with identification and molecular screening of ticks.

Background: The potential molluscicidal extracts, obtained from indigenous plants Cannabis sativa, Acacia nilotica, and Tinospora cordifolia, were tested for toxicity against freshwater pulmonate snail Lymnaea acuminata, an intermediate host of Fasciola hepatica. The organic extracts had a significant effect on young snails. Materials and Methods: All organic extracts and column-purified fractions gave median lethal concentrations (19-100.05 mg/L; 24 h) that fell well within the threshold level of 100 mg/L, set for a potential molluscicide by the World Health Organization. Results: The toxicity of T. cordifolia stem acetone extract (96 h LC₅₀: 16.08 mg/L) was more pronounced compared with C. sativa leaf ethanol extract (96 h LC₅₀: 16.32 mg/L) and A. nilotica leaf ethanol extract (96 h LC₅₀: 24.78 mg/L). β-caryophyllene, gallic acid, and berberine were characterized and identified as active molluscicidal components. Co-migration of β-caryophyllene (retardation factor [Rf] 0.95), gallic acid (Rf 0.30), and berberine (Rf 0.23) with column-purified parts of Cannabis sativa, Acacia nilotica, and Tinospora cordifolia on thin-layer chromatography demonstrates same Rf value, that is, 0.95, 0.30, and 0.23, respectively. Conclusion: This study indicates that these extracts thus represent potential plant-derived molluscicides that are worthy of further investigations.

Background: Mosquito-borne orthobunyaviruses in Canada are a growing public health concern. Orthobunyaviral diseases are commonly underdiagnosed and in Canada, likely underreported as surveillance is passive. No vaccines or specific treatments exist for these disease agents. Further, climate change is facilitating habitat expansion for relevant reservoirs and vectors, and it is likely that the majority of the Canadian population is susceptible to these viruses. Methods: A scoping review was conducted to describe the current state of knowledge on orthobunyavirus epidemiology in Canada. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews guideline was used. Literature searches were conducted in six databases and in gray literature. The epidemiology of orthobunyaviruses was characterized for studies focusing on host species, including spatiotemporal patterns, risk factors, and climate change impact. Results: A total of 172 relevant studies were identified from 1734 citations from which 95 addressed host species, including humans, wildlife, and domestic animals including livestock. The orthobunyaviruses-Cache Valley virus (CVV), Jamestown Canyon virus (JCV), Snowshoe Hare virus (SHV), and La Crosse virus (LACV)-were identified, and prevalence was widespread across vertebrate species. CVV, JCV, and SHV were detected across Canada and the United States. LACV was reported only in the United States, predominantly the Mid-Atlantic and Appalachian regions. Disease varied by orthobunyavirus and was associated with age, environment, preexisting compromised immune systems, or livestock breeding schedule. Conclusion: Knowledge gaps included seroprevalence data in Canada, risk factor analyses, particularly for livestock, and disease projections in the context of climate change. Additional surveillance and mitigation strategies, especially accounting for climate change, are needed to guide future public health efforts to prevent orthobunyavirus exposure and disease.

Background: Fleas are ectoparasitic insects with holometabolous development. It has a hematophagous habit with mouthparts adapted to sting and suck its hosts. There are about 3000 species in the world, ∼61 in Brazil, and 19 in Rio Grande do Sul state. The objective of the research is to catalog the diversity of fleas recorded in the state, their respective hosts, and endosymbionts. Materials and Methods: To this end, a search was carried out in the scientific literature, from articles, books, to abstracts submitted to congresses. Results: The 19 species of fleas occurring in Rio Grande do Sul are divided into 7 families and 10 genera. These ectoparasites, in addition to being found in the environment, were associated with 10 different families of hosts in Rio Grande do Sul, and on the endosymbiont, agents found associated with fleas, there were 7 different species. The main agents researched in the state are Rickettsia spp. and Bartonella spp. The relationships between parasites, hosts, environment, and etiological agents present different scenarios, whether anthropized or conserved, but unknown. Sometimes, this overlap, a factor that aggravates the possibility of spillovers, either from cosmopolitan fleas in these conserved areas, or from their endosymbionts. Conclusion: Thus, it is important to characterize the environment so that the complexities of each location are known for the adoption of environmental and public health policies in each case. The challenges are extensive, but necessary in view of the One Health perspective.

Background: Q fever has significant consequences for patients with persistent localized infection. A combination of doxycycline with hydroxychloroquine, for at least 18-24 months, is the first-line therapy. The use of serology as a prognostic marker during therapy is controversial. Methods: A retrospective, observational cohort study in two outpatient clinics in northern Israel. All adults with persistent Q fever (2015-2021) were included in the study. Clinical failure was defined as relapse or death related to Q fever after end of treatment (EOT). Serological cure was defined as phase 1 IgG ≤800 or a four-fold decrease at EOT. Results: Twenty-two patients were included in the study, with a median follow up of 40 months (IQR = 28.5-63.5), and median treatment duration of 28.5 months (IQR = 21.8-50.5). Clinical cure occurred in 18 patients (82%), serological cure in 10 (45%). Phase 1 IgG at presentation was significantly higher in the clinical failure group (median 9600 vs. 3200 in the clinical cure group, p = 0.019), and at 6-12 months after EOT (median 6400 vs. 800 respectively, p = 0.03). Phase 1 IgG levels at 1 year and EOT were similar in both groups. Positive phase 2 IgM after one year of therapy correlated with clinical failure (p = 0.038), but not at EOT or after EOT. Conclusion: Phase 1 IgG levels at presentation, phase 2 IgM at 1 year, and Phase 1 IgG 6-12 months after EOT were associated with clinical failure in patients with persistent Q fever.

This retrospective study was conducted in 2017 during the dual dengue and chikungunya outbreak in Bangladesh. Febrile participants underwent blood tests for chikungunya, dengue, and ABO groups and rhesus (Rh) factors. Blood grouping information was gathered from healthy donors. Males and those aged between 18 and 49 years had a higher risk of contracting dengue and chikungunya. Blood group O exhibited the highest infection rates at ∼50%, whereas group AB had the lowest at ∼9% among the participants in the study. Yet, when considering the general population's blood group distribution, the combined odds of infection were 2.0, 3.5, and 1.4 times higher in groups B, O, and AB, respectively, than in group A. Infection rates were greater in Rh-negative people. Blood groups B, O, and AB showed higher susceptibility than blood group A according to adjusted odds ratios. Blood groups ABO and Rh factor hold significance in disease susceptibility and vaccine effectiveness. Keeping these implications in mind, further investigations are necessary to understand the mechanisms underlying these connections and their effects on the efficacy of dengue and chikungunya vaccines.