- Molecular Confirmation of Rocky Mountain Spotted Fever Epidemic Agent in Mexicali, Mexico. [Journal Article]
- EIEmerg Infect Dis 2018; 24(9):1723-1725
- Since 2008, a large epidemic of Rocky Mountain spotted fever has been emerging among humans and dogs in Mexicali, adjacent to the United States in Baja California, Mexico. We molecularly confirmed th...
Since 2008, a large epidemic of Rocky Mountain spotted fever has been emerging among humans and dogs in Mexicali, adjacent to the United States in Baja California, Mexico. We molecularly confirmed the causative agent; this information can be used to study the origin and dynamics of the epidemic.
- Distinguishing Japanese Spotted Fever and Scrub Typhus, Central Japan, 2004- 2015. [Journal Article]
- EIEmerg Infect Dis 2018; 24(9):1633-1641
- Japanese spotted fever (JSF) and scrub typhus (ST) are endemic to Japan and share similar clinical features. To document the clinical and epidemiologic characteristics that distinguish these 2 ricket...
Japanese spotted fever (JSF) and scrub typhus (ST) are endemic to Japan and share similar clinical features. To document the clinical and epidemiologic characteristics that distinguish these 2 rickettsial diseases, during 2004-2015 we recruited 31 JSF patients, 188 ST patients, and 97 nonrickettsial disease patients from the southern Boso Peninsula of Japan. JSF occurred during April-October and ST during November-December. Patients with JSF and ST were significantly older and more likely to reside in wooded areas than were patients with nonrickettsial diseases. Spatial analyses revealed that JSF and ST clusters rarely overlapped. Clinical findings more frequently observed in JSF than in ST patients were purpura, palmar/plantar rash, hyponatremia, organ damage, and delayed defervescence after treatment. Although their clinical features are similar, JSF and ST differ in seasonality, geographic distribution, physical signs, and severity. Because a considerable percentage of patients did not notice rash and eschar, many rickettsial diseases might be underdiagnosed in Japan.
- First molecular detection of Anaplasma phagocytophilum in the hard tick Rhipicephalus haemaphysaloides in Taiwan. [Journal Article]
- EAExp Appl Acarol 2018 Aug 16
- Anaplasma phagocytophilum is transmitted mainly by hard ticks and can cause potentially fatal granulocytic anaplasmosis in humans, but its occurrence in ticks in Taiwan has never been investigated al...
Anaplasma phagocytophilum is transmitted mainly by hard ticks and can cause potentially fatal granulocytic anaplasmosis in humans, but its occurrence in ticks in Taiwan has never been investigated although this pathogen has been detected in Taiwanese rodents before. Ticks collected from small mammals in Hualien, eastern Taiwan, were assayed for Anaplasma infections; infections of Rickettsia and Apicomplexa protozoans were also studied. Of the 270 individually assayed Rhipicephalus haemaphysaloides ticks, A. phagocytophilum was identified in a nymphal tick. Parasites most similar to Anaplasma bovis, Rickettsia rickettsii, Rickettsia sp. TwKM01, and at least seven apicomplexan species (including genera Cryptosporidium, Hepatozoon, and Theileria) were also identified. This study shows that A. phagocytophilum does occur in the hard tick in Taiwan, although whether R. haemaphysaloides can vector this pathogen remains to be determined. This work also reveals a high diversity of tick-borne bacteria and protozoans circulating in a small region and calls for further research on their potential risks for human health.
- Laboratory-acquired scrub typhus and murine typhus infections: The argument for risk-based approach to biosafety requirements for Orientia tsutsugamushi and Rickettsia typhi laboratory activities. [Journal Article]
- CIClin Infect Dis 2018 Aug 10
- This study examined the literature on laboratory-acquired infections (LAIs) associated with scrub typhus (Orientia tsutsugamushi) and murine typhus (Rickettsia typhi) research to provide an evidence ...
This study examined the literature on laboratory-acquired infections (LAIs) associated with scrub typhus (Orientia tsutsugamushi) and murine typhus (Rickettsia typhi) research to provide an evidence base for biosafety and biocontainment. Scrub typhus LAIs were documented in 25 individuals, from 1931-2000 with 8 (32%) deaths during the pre-antibiotic era. There were 35 murine typhus LAI reports and no deaths. Results indicated that highest risk activities were working with infectious laboratory animals involving significant aerosol exposures, accidental self-inoculation or bite related infections. A risk-based biosafety approach for in vitro and in vivo culture of O. tsutsugamushi and R. typhi would require only high-risk activities (animal work or large culture volumes) be performed in high containment BSL3 laboratories. We argue that relatively low risk activities including inoculation of cell cultures or the early stages of in vitro growth using low volumes/low concentrations of infectious materials can be performed safely in BSL2 laboratories within a biological safety cabinet.
- The tick endosymbiont Candidatus Midichloria mitochondrii and selenoproteins are essential for the growth of Rickettsia parkeri in the Gulf Coast tick vector. [Journal Article]
- MMicrobiome 2018 Aug 13; 6(1):141
- CONCLUSIONS: This study illustrates the potential of this new research model for augmenting our understanding of the pathogen interactions occurring within tick hosts and the important roles that symbionts and various tick factors play in regulating pathogen growth.
- 'One Health' solutions for ticks and tick-borne diseases, and rickettsial pathogens of humans, domestic animals and wildlife. [Editorial]
- TTTicks Tick Borne Dis 2018 Aug 08
- Molecular characterization of Haemaphysalis longicornis-borne rickettsiae, Republic of Korea and China. [Journal Article]
- TTTicks Tick Borne Dis 2018 Jul 29
- Haemaphysalis longicornis, the cattle tick or bush tick, has an extended distribution throughout Asia and the Pacific region, including China, Russia, the Republic of Korea (ROK), Japan, Australia, N...
Haemaphysalis longicornis, the cattle tick or bush tick, has an extended distribution throughout Asia and the Pacific region, including China, Russia, the Republic of Korea (ROK), Japan, Australia, New Zealand, and the South Pacific islands. It is an obligate ectoparasite found commonly on medium to large sized wild and domestic animals, with humans as an accidental host. Haemaphysalis longicornis transmits a number of pathogens, including severe fever with thrombocytopenia syndrome and tick-borne encephalitis viruses, bacteria, helminths, and protozoans, that impact on veterinary (wild and domestic animals) and human health. Surveys of rickettsial pathogens associated with H. longicornis from China, the ROK, and Japan have resulted in the discovery of more than 35 incompletely characterized molecular isolates of Rickettsia. In response to the increased global threat of tick-borne rickettsial diseases, H. longicornis collected in the ROK and China were assessed in our laboratory and two additional Rickettsia spp. isolates (ROK-HL727 and XinXian HL9) were identified. These agents were fully characterized by multilocus sequence typing using partial gene fragment sequences of rrs, gltA, ompA, ompB, and sca4. Phylogenetic comparisons of these Rickettsia isolates with known Rickettsia species and other molecular isolates identified from H. longicornis were performed to better understand their interrelationships. Phylogenetic analysis of the sequences from these 5 gene fragments showed that ROK-HL727 was closely related to rickettsial isolates of H. longicornis previously reported from China, the ROK and Japan, but distinct from any currently recognized Rickettsia species. It therefore qualifies genetically as a new species, introduced herein as Candidatus Rickettsia longicornii. The XinXian-HL9 isolate detected from China was determined to be genetically similar to the human pathogen Rickettsia heilongjiangensis. People living and working in areas where H. longicornis is endemic should be aware of the potential for rickettsial diseases.
- First molecular detection of the human pathogen Rickettsia raoultii and other spotted fever group rickettsiae in Ixodid ticks from wild and domestic mammals. [Journal Article]
- PRParasitol Res 2018 Aug 04
- Tick-borne rickettsioses are recognized as emerging vector-borne infections capable of infecting both human and animal hosts worldwide. This study focuses on the detection and molecular identificatio...
Tick-borne rickettsioses are recognized as emerging vector-borne infections capable of infecting both human and animal hosts worldwide. This study focuses on the detection and molecular identification of species belonging to the genus Rickettsia in ticks sampled from human, vegetation, and domestic and wild vertebrates in Sardinia. Ticks were tested by PCR targeting gltA, ompA, and ompB genes, followed by sequencing analysis. The results provide evidences of a great variety of Rickettsia species of the Spotted fever group in Ixodid ticks and allow establishing for the first time the presence of R. raoultii in Rhipicephalus sanguineus s.l. and Dermacentor marginatus ticks in Sardinia island. Rickettsia massiliae was detected on R. sanguineus s.l. and R. aeschlimannii in Hyalomma marginatum and Hy. lusitanicum ticks. In addition, eight D. marginatus ticks were positive for R. slovaca. This study provides further evidence that different Rickettsia species are widespread in Sardinian ticks and that detailed investigations are required to understand the role these tick species play on spotted fever group rickettsiae circulation. More studies will provide new background on molecular epidemiology of zoonotic rickettsiae, the geographical distribution of tick-transmitted rickettsial pathogens, and the involvement of vertebrate hosts in propagation and maintenance of these bacteria in nature.
- Exploring the diversity, infectivity and metabolomic landscape of Rickettsial infections for developing novel therapeutic intervention strategies. [Journal Article]
- CCytokine 2018 Jul 30
- Rickettsioses are zoonotic infections caused by obligate intracellular bacteria of the genera Rickettsia that affect human health; sometimes humans being considered as accidental hosts. At a molecula...
Rickettsioses are zoonotic infections caused by obligate intracellular bacteria of the genera Rickettsia that affect human health; sometimes humans being considered as accidental hosts. At a molecular level, the rickettsiae infection triggers molecular signaling leading to the secretion of proinflammatory cytokines. These cytokines direct the immune response to the host cell damage and pathogen removal. In this review, we present metabolic aspects of the host cell in the presence of rickettsiae and how this presence triggers an inflammatory response to cope with the pathogen. We also reviewed the secretion of cytokines that modulates host cell response at immune and metabolic levels.
New Search Next
- A Headache of a Diagnosis. [Case Reports]
- NEJMN Engl J Med 2018 Aug 02; 379(5):475-479