Societal Factors Constraining the Control of COVID-19 and Mosquito and Tick-Borne Diseases (preprint)

Advances in biological sciences have been applied in medicine, agriculture and industry with great benefit. Some recent trends in society, governance structures and communications, however, appear to be hampering the use of new scientific findings for controlling infectious diseases. These limitations are illustrated with examples related to (i) the adaptation of fresh water mosquito vectors of major arboviral diseases to salinity in coastal areas with consequences for disease transmission, (ii) understanding the implications of reduced dengue transmission during the COVID-19 lockdown for dengue control, (iii) causes underlying the rapid spread of the malaria vector Anopheles stephensi in South Asia and Africa, (iv) the application of serodiagnostic techniques for Lyme disease and tick-borne relapsing fever caused by tick-borne bacteria of the genus Borrelia, and (v) COVID-19 prevention.

A parainfluenza virus 5 (PIV5)-vectored intranasal vaccine for Lyme disease provides long-lasting protection against tick transmitted Borrelia burgdorferi in mice (preprint)

Lyme disease (LD) is the most prevalent vector borne disease in North America and Europe and its geographic range continues to expand. Strategies for disease control are necessary to effectively reduce incidence of LD including development of safe vaccines for human use. Parainfluenza virus 5 (PIV5) vector has an excellent safety record in animals and PIV5- vectored COVID-19 and RSV vaccines are currently under clinical development. We constructed PIV5-vectored LD vaccine candidates expressing OspA from B. burgdorferi sensu stricto (OspAB31) and a chimeric protein containing sequences from B. burgdorferi and B. afzelii (OspABPBPk). Immunogenicity and vaccine efficacy were analyzed in C3H-HeN mice after prime-boost intranasal (IN) vaccination with PIV5-OspAB31 and PIV5-OspABPBPk, subcutaneous (SC) vaccination with rOspAB31+Alum as well as the respective controls. Mice vaccinated with either PIV5-AB31 or PIV5-ABPBPk intranasally had high endpoint titers of serum antibody against OspA antigen beyond 1 year post vaccination, similar to levels detected in mice vaccinated SC with rOspAB31. Flowcytometric analysis of spleen cells at 9-months post-immunization demonstrated that immunization with the intranasal PIV5 vaccine candidates led to an overall increase in the number of memory B cells, cytotoxic T and cytotoxic effector T cells compared to SC groups. Borreliacidal activity measured by neutralization assay was maintained up to 18 months post-immunization, with the response greater in intranasal PIV5-delivered OspA vaccines, than that induced by SC rOspAB31. Challenge with infected ticks (10-19 strains of B. burgdorferi) performed at 4-, 9- or 15-months post-immunization showed increased breakthrough infections in mice vaccinated with SC rOspAB31 compared to IN PIV5-AB31 or IN PIV5-ABPBPk at 9- and 15-months, as determined by qPCR of B. burgdorferi in tissues, culture of B. burgdorferi from tissues, and antibodies against B. burgdorferi protein VIsE. These data demonstrate that intranasal PIV5-based immunization is superior to parenteral immunization with the same recombinant protein and provides long-lasting protection (> 1 year) against Lyme disease.

Redox Imbalance and Its Metabolic Consequences in Tick-Borne Diseases.

One of the growing global health problems are vector-borne diseases, including tick-borne diseases. The most common tick-borne diseases include Lyme disease, tick-borne encephalitis, human granulocytic anaplasmosis, and babesiosis. Taking into account the metabolic effects in the patient's body, tick-borne diseases are a significant problem from an epidemiological and clinical point of view. Inflammation and oxidative stress are key elements in the pathogenesis of infectious diseases, including tick-borne diseases. In consequence, this leads to oxidative modifications of the structure and function of phospholipids and proteins and results in qualitative and quantitative changes at the level of lipid mediators arising in both reactive oxygen species (ROS) and ROS enzyme-dependent reactions. These types of metabolic modifications affect the functioning of the cells and the host organism. Therefore, links between the severity of the disease state and redox imbalance and the level of phospholipid metabolites are being searched, hoping to find unambiguous diagnostic biomarkers. Assessment of molecular effects of oxidative stress may also enable the monitoring of the disease process and treatment efficacy.

The Tick-Borne Pathogens: An Overview of China's Situation.

BACKGROUND: Ticks are important medical arthropods that can transmit hundreds of pathogens, such as parasites, bacteria, and viruses, leading to serious public health burdens worldwide. Unexplained fever is the most common clinical manifestation of tick-borne diseases. Since the emergence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the surge of coronavirus disease 2019 (COVID-19) cases led to the hospital overload and fewer laboratory tests for tick-borne diseases. Therefore, it is essential to review the tick-borne pathogens and further understand tick-borne diseases. PURPOSE: The geographic distribution and population of ticks in the Northern hemisphere have expanded while emerging tick-borne pathogens have been introduced to China continuously. This paper focused on the tick-borne pathogens that are threatening public health in the world. Their medical significant tick vectors, as well as the epidemiology, clinical manifestations, diagnosis, treatment, prevention, and control measures, are emphasized in this document. METHODS: In this study, all required data were collected from articles indexed in English databases, including Scopus, PubMed, Web of Science, Science Direct, and Google Scholar. RESULTS: Ticks presented a great threat to the economy and public health. Although both infections by tick-borne pathogens and SARS-CoV-2 have fever symptoms, the history of tick bite and its associated symptoms such as encephalitis or eschar could be helpful for the differential diagnosis. Additionally, as a carrier of vector ticks, migratory birds may play a potential role in the geographical expansion of ticks and tick-borne pathogens during seasonal migration. CONCLUSION: China should assess the risk score of vector ticks and clarify the potential role of migratory birds in transmitting ticks. Additionally, the individual and collective protection, vector control, comprehensive surveillance, accurate diagnosis, and symptomatic treatment should be carried out, to meet the challenge.

Old zoonotic agents and novel variants of tick-borne microorganisms from Benguela (Angola), July 2017.

BACKGROUND: Ticks and tick-borne diseases constitute a real threat for the livestock industry, which is increasing in Angola. In addition, ticks are vectors of zoonoses of public health concern, and scarce information is available from this country. In an effort to contribute to the prevention of zoonotic infectious diseases affecting humans and animals, the molecular screening of certain tick-related microorganisms collected on cattle in Angola was performed under a 'One Health' scope. METHODS: Ticks collected from cattle in Cubal (Benguela Province, Angola) in July 2017 were analysed in pools using specific PCR assays for bacteria (Rickettsia, Anaplasmataceae, Borrelia, Coxiella and Spiroplasma) and protozoa (Theileria and Babesia) detection. RESULTS: A total of 124 tick specimens were grouped in 25 pools (two Amblyomma variegatum, three Hyalomma truncatum, 16 Rhipicephalus decoloratus, two Rhipicephalus duttoni, one Rhipicephalus evertsi mimeticus and one Rhipicephalus sp.). The amplified microorganisms were (pools): Rickettsia africae (two A. variegatum and one R. decoloratus), Rickettsia aeschlimannii (three H. truncatum), Ehrlichia spp. (six R. decoloratus), Coxiella spp. (all but H. truncatum), Francisella sp. (one H. truncatum), Spiroplasma sp. closely related to Spiroplasma ixodetis (three R. decoloratus), Babesia bigemina (two R. decoloratus) and Babesia spp. (two A. variegatum). The obtained nucleotide sequences from Ehrlichia spp., two Coxiella genotypes (from R. duttoni and Rhipicephalus sp.), Francisella sp. and Babesia spp. (from A. variegatum) reached low identities with known genetically characterized species. CONCLUSIONS: This study demonstrates the circulation in Angola of the pathogen R. aeschlimannii and potential novel tick-related microorganisms belonging to Ehrlichia, Coxiella, Francisella, Spiroplasma and Babesia spp. and corroborates the presence of R. africae and B. bigemina. Our results should be considered in developing protocols for the management of fever of unknown origin and for veterinary practices. Further studies are required to evaluate the risk of tick-borne diseases in Angola.

Clinical and diagnostic manifestations of tickborne mixed infection in combination with COVID-19.

The coexistence of various pathogens inside the patient's body is one of the poorly studied and current issues. The aim of the study is to identify the relationship between the indicators of complex laboratory diagnostics and the clinical manifestations of a mixed disease during subsequent infection with the SARS-CoV-2 virus using the example of a case of chronic encephalitis-borreliosis infection. Seven blood serum samples were collected from the patient over the course of a year. For the etiological verification of the causative agents of TBE, Lyme disease and COVID-19, the methods of ELISA and PCR diagnostics were used. The patient was diagnosed with Lyme disease on the basis of the detection of IgG antibodies to Borrelia 5 months after the onset of the disease, since she denied the tick bite. In the clinical picture, there was an articular syndrome and erythema migrans. Later, IgG antibodies to the TBEV were found in the blood. Throughout the study, IgM antibodies to Borrelia were not detected. The exacerbation of Lyme disease could be judged by the clinical manifestations of this disease and by the growth of specific IgG antibodies. A feature of this case was that during an exacerbation of the Lyme disease, an infection with the SARS-CoV-2 virus occurred. Treatment (umifenovir, hydroxychloroquine, azithromycin, ceftriaxone) was prescribed, which improved the condition of the underlying disease, decreased joint pain, decreased IgG levels to borrelia. However, during this period, serological markers of TBEV appear: antigen, IgM antibodies, and the titer of IgG antibodies increases. Most likely, this was facilitated by the switching of the immune system to the SARS-CoV-2 virus, with the simultaneous suppression of borrelia with antibiotics and the appointment of hydroxychloroquine, which has an immunosuppressive effect. Despite the activation of the virus, clinical manifestations of TBE were not observed in the patient, which is most likely associated with infection with a weakly virulent TBEV strain. The further course of tick-borne infections revealed the dominant influence of B. burgdorferi in relation to TBEV. Laboratory studies have shown that suppression of the activity of the borreliosis process by etiotropic treatment subsequently led to the activation of the persistent TBEV.

Highlights of Medical Entomology, 2020.

Medical Entomology as a field is inherently global - thriving on international and interdisciplinary collaborations and affected dramatically by arthropod and pathogen invasions and introductions. This past year also will be remembered as the year in which the SARS-CoV-2 COVID-19 pandemic affected every part of our lives and professional activities and impacted (or changed, sometimes in good ways) our ability to collaborate and detect or respond to invasions. This incredible year is the backdrop for the 2020 Highlights in Medical Entomology. This article highlights the broad scope of approaches and disciplines represented in the 2020 published literature, ranging from sensory and chemical ecology, population genetics, impacts of human-mediated environmental change on vector ecology, life history and the evolution of vector behaviors, to the latest developments in vector surveillance and control.

COVID-19 vaccination rates among health care workers by immigrant background. A nation-wide registry study from Norway. (preprint)

BackgroundStudies have suggested that some minority groups tend to have lower vaccination rates than the overall population. This study aims to examine COVID-19 vaccination rates among health care workers (HCWs) in Norway, according to immigrant background. MethodsWe used individual-level, nation-wide registry data from Norway to identify all HCWs employed full-time at 1 December 2020. We examined the relationship between country of birth and COVID-19 vaccination from December 2020 to August 2021, both crude and adjusted for e.g. age, sex, municipality of residence, and detailed occupation codes in logistic regression models. ResultsAmong all HCWs in Norway, immigrants had a 9 percentage point lower vaccination rate (85%) than HCWs without an immigrant background (94%) at 31 August 2021. The overall vaccination rate varied by country of birth, with immigrants born in Russia (71%), Serbia (72%), Lithuania (72%), Romania (75%), Poland (76%), Eritrea (77%), and Somalia (78%) having the lowest crude vaccination rates. When we adjusted for demographics and detailed occupational codes, immigrant groups that more often worked as health care assistants, such as immigrants from Eritrea and Somalia, increased their vaccination rates. ConclusionSubstantial differences in vaccination rates among immigrant groups employed in the health care sector in Norway indicate that measures to improve vaccine uptake should focus specific immigrant groups rather than all immigrants together. Lower vaccination rates in some immigrant groups appears to be largely driven by the occupational composition, suggesting that some of the differences in vaccine rates can be attributed to variation in vaccine access.

Crimean-Congo Hemorrhagic Fever Virus: Current Advances and Future Prospects of Antiviral Strategies.

Crimean-Congo hemorrhagic fever virus (CCHFV) is a widespread, tick-borne pathogen that causes Crimean-Congo hemorrhagic fever (CCHF) with high morbidity and mortality. CCHFV is transmitted to humans through tick bites or direct contact with patients or infected animals with viremia. Currently, climate change and globalization have increased the transmission risk of this biosafety level (BSL)-4 virus. The treatment options of CCHFV infection remain limited and there is no FDA-approved vaccine or specific antivirals, which urges the identification of potential therapeutic targets and the design of CCHF therapies with greater effort. In this article, we discuss the current progress and some future directions in the development of antiviral strategies against CCHFV.

Has COVID-19 influenced on tick-borne epidemiology?

no abstract available.

Negative impact of the COVID-19 pandemic on the timely diagnosis of tick-borne infections.

We describe 3 adult patients who did not have COVID-19 but instead had a treatable tick-borne infection. In each case, however, the duration of time until diagnosis was delayed due to issues that have arisen because of the COVID-19 pandemic. These issues need to be addressed to preserve patient well-being.