A new nairo-like virus associated with human febrile illness in China.

ABSTRACTSeveral nairo-like viruses have been discovered in ticks in recent years, but their relevance to public health remains unknown. Here, we found a patient who had a history of tick bite and suffered from a febrile illness was infected with a previously discovered RNA virus, Beiji nairovirus (BJNV), in the nairo-like virus group of the order Bunyavirales. We isolated the virus by cell culture assay. BJNV could induce cytopathic effects in the baby hamster kidney and human hepatocellular carcinoma cells. Negative-stain electron microscopy revealed enveloped and spherical viral particles, morphologically similar to those of nairoviruses. We identified 67 patients as BJNV infection in 2017-2018. The median age of patients was 48 years (interquartile range 41-53 years); the median incubation period was 7 days (interquartile range 3-12 days). Most patients were men (70%), and a few (10%) had underlying diseases. Common symptoms of infected patients included fever (100%), headache (99%), depression (63%), coma (63%), and fatigue (54%), myalgia or arthralgia (45%); two (3%) patients became critically ill and one died. BJNV could cause growth retardation, viremia and histopathological changes in infected suckling mice. BJNV was also detected in sheep, cattle, and multiple tick species. These findings demonstrated that the newly discovered nairo-like virus may be associated with a febrile illness, with the potential vectors of ticks and reservoirs of sheep and cattle, highlighting its public health significance and necessity of further investigation in the tick-endemic areas worldwide.

Usability and Feasibility of a Smartphone App to Assess Human Behavioral Factors Associated with Tick Exposure (The Tick App): Quantitative and Qualitative Study.

BACKGROUND: Mobile health (mHealth) technology takes advantage of smartphone features to turn them into research tools, with the potential to reach a larger section of the population in a cost-effective manner, compared with traditional epidemiological methods. Although mHealth apps have been widely implemented in chronic diseases and psychology, their potential use in the research of vector-borne diseases has not yet been fully exploited. OBJECTIVE: This study aimed to assess the usability and feasibility of The Tick App, the first tick research-focused app in the United States. METHODS: The Tick App was designed as a survey tool to collect data on human behaviors and movements associated with tick exposure while engaging users in tick identification and reporting. It consists of an enrollment survey to identify general risk factors, daily surveys to collect data on human activities and tick encounters (Tick Diaries), a survey to enter the details of tick encounters coupled with tick identification services provided by the research team (Report a Tick), and educational material. Using quantitative and qualitative methods, we evaluated the enrollment strategy (passive vs active), the user profile, location, longitudinal use of its features, and users' feedback. RESULTS: Between May and September 2018, 1468 adult users enrolled in the app. The Tick App users were equally represented across genders and evenly distributed across age groups. Most users owned a pet (65.94%, 962/1459; P<.001), did frequent outdoor activities (recreational or peridomestic; 75.24%, 1094/1454; P<.001 and 64.58%, 941/1457; P<.001, respectively), and lived in the Midwest (56.55%, 824/1457) and Northeast (33.0%, 481/1457) regions in the United States, more specifically in Wisconsin, southern New York, and New Jersey. Users lived more frequently in high-incidence counties for Lyme disease (incidence rate ratio [IRR] 3.5, 95% CI 1.8-7.2; P<.001) and in counties with cases recently increasing (IRR 1.8, 95% CI 1.1-3.2; P=.03). Recurring users (49.25%, 723/1468) had a similar demographic profile to all users but participated in outdoor activities more frequently (80.5%, 575/714; P<.01). The number of Tick Diaries submitted per user (median 2, interquartile range [IQR] 1-11) was higher for older age groups (aged >55 years; IRR 3.4, 95% CI 1.5-7.6; P<.001) and lower in the Northeast (IRR[NE] 0.4, 95% CI 0.3-0.7; P<.001), whereas the number of tick reports (median 1, IQR 1-2) increased with the frequency of outdoor activities (IRR 1.5, 95% CI 1.3-1.8; P<.001). CONCLUSIONS: This assessment allowed us to identify what fraction of the population used The Tick App and how it was used during a pilot phase. This information will be used to improve future iterations of The Tick App and tailor potential tick prevention interventions to the users' characteristics.

A bite so sweet: the glycobiology interface of tick-host-pathogen interactions.

Vector-borne diseases constitute 17% of all infectious diseases in the world; among the blood-feeding arthropods, ticks transmit the highest number of pathogens. Understanding the interactions between the tick vector, the mammalian host and the pathogens circulating between them is the basis for the successful development of vaccines against ticks or the tick-transmitted pathogens as well as for the development of specific treatments against tick-borne infections. A lot of effort has been put into transcriptomic and proteomic analyses; however, the protein-carbohydrate interactions and the overall glycobiology of ticks and tick-borne pathogens has not been given the importance or priority deserved. Novel (bio)analytical techniques and their availability have immensely increased the possibilities in glycobiology research and thus novel information in the glycobiology of ticks and tick-borne pathogens is being generated at a faster pace each year. This review brings a comprehensive summary of the knowledge on both the glycosylated proteins and the glycan-binding proteins of the ticks as well as the tick-transmitted pathogens, with emphasis on the interactions allowing the infection of both the ticks and the hosts by various bacteria and tick-borne encephalitis virus.

Short communication: Tick-borne disease is associated with changes in feeding behavior in automatically fed weaned dairy calves.

Tick-borne disease is a hemolytic disease complex that causes extensive losses to the dairy industry in tropical regions. Its timely diagnosis is challenging and labor intensive. Our objective was to investigate whether tick-borne disease was associated with changes in ingestive behavior of weaned dairy calves. Weaned calves (n = 35) enrolled at 108 ± 8 d of age were group housed (n = 12, 12, and 11/group) for 4 wk in the experimental pen, which had 12 electronic feed bins and 2 electronic water bins. Data were automatically collected at each feed or water bin visit via radio frequency identification ear tags. Water and total mixed ration were provided ad libitum. Calves were examined weekly for tick-borne disease detection. A disease bout was confirmed if packed cell volume was ≤25% at any exam. Diseased calves received antimicrobial and antipyretic treatment. Data were summarized by day within bin type (feed or water) as intake (kg/d; as-fed basis), frequency of visits (visits/d), and total duration of visits (min/d). Day of detection was set as d 0; a 9-d behavioral screening period for evaluation of behavioral changes was set according to d 0 (d -4 to +4). A within-calf mean was calculated for the healthy period (HP; mean of all days between 2 consecutive negative exams) for each response variable. Data were analyzed as within-calf differences between HP and each day of the behavioral screening period. Tick-borne disease was detected in 12 calves; thus, only data referent to these animals were included in the analyses. Compared with HP, daily feed intake was reduced on d -1, 0, and +1, and daily frequency and total duration of feed bin visits were reduced from d -3 to d +4. Daily feed intake was reduced by 35% on d -1 (3.5 ± 0.4 vs. 5.4 ± 0.5 kg/d for HP), and daily frequency and duration of visits were reduced by 27% (56.3 ± 7.8 vs. 76.7 ± 8.1 visits/d for HP) and 24% (27.0 ± 3.8 vs. 35.4 ± 3.9 min/d for HP) on d -3, respectively. Daily water intake on d 0 (9.1 ± 1.4 kg/d) was lower than at HP (12.9 ± 1.6 kg/d), but other drinking behaviors were not different from healthy means during the screening period. Feeding behavior, but not drinking behavior, was different from HP means before detection at weekly exams. Therefore, feeding behavior could be further explored for the development of algorithms for tick-borne disease detection.

The Emergence of Severe Fever with Thrombocytopenia Syndrome Virus.

Severe fever with thrombocytopenia syndrome (SFTS) is a newly recognized hemorrhagic fever disease found throughout Asia with a case fatality rate between 12% and 30%. Since 2009, SFTS has been reported in China throughout 14 Chinese Provinces. In addition, SFTS has been recognized in South Korea and Japan with the first confirmed cases reported in 2012. A similar disease, caused by the closely related Heartland virus, was also reported in the United States in 2009. SFTS is caused by SFTS virus, a novel tick-borne virus in the family Bunyaviridae, genus Phlebovirus. Unlike other mosquito- and sandfly-borne bunyaviruses, SFTS virus has not been extensively studied due to its recent emergence and many unknowns regarding its pathogenesis, life cycle, transmission, and options for therapeutics remains. In this review, we report the most current findings in SFTS virus research.

Rickettsia australis and Queensland Tick Typhus: A Rickettsial Spotted Fever Group Infection in Australia.

Rickettsia australis, the etiologic agent of Queensland tick typhus (QTT), is increasingly being recognized as a cause of community-acquired acute febrile illness in eastern Australia. Changing human population demographics, climate change, and increased understanding of expanding vector distribution indicate QTT is an emerging public health threat. This review summarizes the epidemiology, pathogenesis, clinical features, treatment principles, and future directions of this disease. Increased recognition of QTT will enable consideration of and prompt treatment of R. australis infection by clinicians in Australia.

Kyasanur Forest Disease (KFD): Rare Disease of Zoonotic Origin.

Kyasanur forest disease (KFD) is a rare tick borne zoonotic disease that causes acute febrile hemorrhagic illness in humans and monkeys especially in southern part of India. The disease is caused by highly pathogenic KFD virus (KFDV) which belongs to member of the genus Flavivirus and family Flaviviridae. The disease is transmitted to monkeys and humans by infective tick Haemaphysalisspinigera. Seasonal outbreaks are expected to occur during the months of January to June. The aim of this paper is to briefly summarize the epidemiology, mode of transmission of KFD virus, clinical findings, diagnosis, treatment, control and prevention of the disease..

Arthropod-borne arthritides.

Infections with several types of viral and bacterial pathogens are able to cause arthritic disease. Arthropod vectors such as ticks and mosquitoes transmit a number of these arthritis-causing pathogens, and as these vectors increase their global distribution, so too do the diseases they spread. The typical clinical manifestations of infectious arthritis are often similar in presentation to rheumatoid arthritis. Hence, care needs to be taken in the diagnoses and management of these conditions. Additionally, clinical reports suggest that prolonged arthropathies may result from infection, highlighting the need for careful clinical management and further research into underlying disease mechanisms.

Perioperative temperature elevation: not all hyperthermia is malignant hyperthermia.

OBJECTIVES: The objective of this review is to assist the readers, anesthesiologists, intensivists, and emergency physicians in making a more accurate diagnosis of perioperative fever or hyperthermia and subsequently choose the proper course of treatment. AIM: To identify the many sources of perioperative fever and after a more accurate differential diagnosis, select appropriate treatment options. Most anesthesiologists, intensivists, and emergency physicians are not familiar with an expansive differential of perioperative fever. This article attempts to expose these physicians to that differential diagnosis. BACKGROUND: Much of the medical literature has anecdotal reports, small case series, or limited reviews of the possible sources of hyperthermia or fever. This is especially true of the anesthesia literature. RESULTS: A literature search was performed which identified many possible common and uncommon sources of fever. Some of these sources are quite relevant to the anesthesiologist. Other sources had potential relevance in obscure cases.

Preliminary analysis of an agent-based model for a tick-borne disease.

Ticks have a unique life history including a distinct set of life stages and a single blood meal per life stage. This makes tick-host interactions more complex from a mathematical perspective. In addition, any model of these interactions must involve a significant degree of stochasticity on the individual tick level. In an attempt to quantify these relationships, I have developed an individual-based model of the interactions between ticks and their hosts as well as the transmission of tick-borne disease between the two populations. The results from this model are compared with those from previously published differential equation based population models. The findings show that the agent-based model produces significantly lower prevalence of disease in both the ticks and their hosts than what is predicted by a similar differential equation model.

Tick bite fever and Q fever - a South African perspective.

Tick bite fever (TBF) and Q fever are zoonotic infections, highly prevalent in southern Africa, which are caused by different genera of obligate intracellular bacteria. While TBF was first described nearly 100 years ago, it has only recently been discovered that there are several rickettsial species transmitted in southern Africa, the most common of which is Rickettsia africae. This helps to explain the highly variable clinical presentation of TBF, ranging from mild to severe or even fatal, that has always been recognised. Q fever, caused by Coxiella burnetii, is a protean disease that is probably extensively under-diagnosed. Clinically, it also shows a wide spectrum of severity, with about 60% of cases being clinically inapparent. Unlike TBF, Q fever may cause chronic infection, and a post-Q fever chronic fatigue syndrome has been described. The molecular pathophysiology of these diseases provides insight into different strategies that intracellular parasites may use to survive and cause disease. While newer macrolide and quinolone antibiotics show activity against these pathogens and may be useful in young children and pregnant women, the treatment of choice for acute infection in both diseases is still tetracycline-group antibiotics. Chronic Q fever remains challenging to treat.

The clinical assessment, treatment, and prevention of lyme disease, human granulocytic anaplasmosis, and babesiosis: clinical practice guidelines by the Infectious Diseases Society of America.

Evidence-based guidelines for the management of patients with Lyme disease, human granulocytic anaplasmosis (formerly known as human granulocytic ehrlichiosis), and babesiosis were prepared by an expert panel of the Infectious Diseases Society of America. These updated guidelines replace the previous treatment guidelines published in 2000 (Clin Infect Dis 2000; 31[Suppl 1]:1-14). The guidelines are intended for use by health care providers who care for patients who either have these infections or may be at risk for them. For each of these Ixodes tickborne infections, information is provided about prevention, epidemiology, clinical manifestations, diagnosis, and treatment. Tables list the doses and durations of antimicrobial therapy recommended for treatment and prevention of Lyme disease and provide a partial list of therapies to be avoided. A definition of post-Lyme disease syndrome is proposed.

Coinfections acquired from ixodes ticks.

The pathogens that cause Lyme disease (LD), human anaplasmosis, and babesiosis can coexist in Ixodes ticks and cause human coinfections. Although the risk of human coinfection differs by geographic location, the true prevalence of coinfecting pathogens among Ixodes ticks remains largely unknown for the majority of geographic locations. The prevalence of dually infected Ixodes ticks appears highest among ticks from regions of North America and Europe where LD is endemic, with reported prevalences of < or =28%. In North America and Europe, the majority of tick-borne coinfections occur among humans with diagnosed LD. Humans coinfected with LD and babesiosis appear to have more intense, prolonged symptoms than those with LD alone. Coinfected persons can also manifest diverse, influenza-like symptoms, and abnormal laboratory test results are frequently observed. Coinfecting pathogens might alter the efficiency of transmission, cause cooperative or competitive pathogen interactions, and alter disease severity among hosts. No prospective studies to assess the immunologic effects of coinfection among humans have been conducted, but animal models demonstrate that certain coinfections can modulate the immune response. Clinicians should consider the likelihood of coinfection when pursuing laboratory testing or selecting therapy for patients with tick-borne illness.