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A serological study was carried out in two Senegalese villages located in the Sine‐Saloum region in order to estimate the presence of anti‐leptospiral antibodies in humans and animals, and to identify the predominant serogroups. Seven hundred and forty‐nine serum samples were collected from humans (n = 545), dogs (n = 33), donkeys (n = 20), goats (n = 52), sheep (n = 43) and N'Dama cattle (n = 56), all originated from Dielmo and Ndiop villages. All samples were tested for different serovars of pathogenic Leptospira species by the microscopic agglutination test. Considering titres ≥ 1:100, 7.7% [CI 95:5.5 to 9.9] on the 545 human blood samples tested and 42.2% [CI95:35.4 to 48.9] on the 204 animal blood samples tested were found to be positive to one or more serovars. The results obtained indicate that the Australis serogroup is the most prevalent serogroup in human (67.3%) and cattle (27.3%). Serogroup Icterohaemorhagiae is the most frequent serogroup in goat (55.6%) and donkey (37.5%). Canicola (23.4%), Icterohaemorhagiae (21.1%) and Australis (12.5%) serogroups are the most prevalent serogroups in dogs. This study shows that diverse Leptospira serovars occur in a wide range of wild and domestic mammal species, as well as in humans in Senegal. However, further studies are needed to better understand the complexity of Leptospira epidemiology in Africa, identify the reservoirs of different serogroups and estimate its impact on livestock. Understanding the multi‐host epidemiology of leptospirosis is essential to control and prevent the disease. [ABSTRACT FROM AUTHOR]

Mediterranean spotted fever is the most important tick-borne disease occurring in Southern Europe and North Africa. The first case of this life-threatening zoonosis was reported in 1910. In the 1930s, the role of the brown dog tick, Rhipicephalus sanguineus, and the causative agent, Rickettsia conorii were described. However, basic questions regarding the relationships between the rickettsia and its tick vector are still unresolved, and the life cycle of R. conorii is incompletely known. There is a lack of knowledge associated with the role of Rh. sanguineus in the maintenance and transmission of R. conorii. The infectious rate of Rh. sanguineus ticks with R. conorii has been found low every time it has been tested; usually lower that 1%. The deleterious impact of R. conorii on ticks has been suggested in experimental models as a potential reason to explain a low prevalence in nature. The long-recognized phenomenon known as reactivation has been suggested as a cause of negative effects – that is, the change in temperature and physiology of the tick host induces the agent to emerge from dormancy and attain infectivity with bad effects on ticks. However, naturally infected colonies of ticks have been maintained in laboratory conditions over several generations. We discuss here several aspects that have been recently studied to better understand Rh. sanguineus– R. conorii relationships, including comparison between the fitness of infected and non-infected ticks in laboratory conditions and the role of external factors such as temperature and starvation. [ABSTRACT FROM AUTHOR]

This overview summarize the salient features of advances in the epidemiology, vectors, and clinical and laboratory diagnoses of rickettsiology. Presentations on veterinary rickettsiology highlight the importance of the rickettsiae in animal husbandry. [ABSTRACT FROM AUTHOR]

We recently reported the first documented cases of a new rickettsial disease caused by Rickettsia heilongjiangensis in the Russian Far East (Far Eastern tick-borne rickettsiosis). Here we report the amplification of DNA of R. heilongjiangensis from both the skin biopsy of an acutely ill patient and the tick removed from him prior to the disease development. The tick has been identified as Haemaphysalis spp. The clinical picture was that of a spotted fever group rickettsiosis and a seroconversion was noted with R. heilongjiangensis antigen . Screening testing of both species of Haemaphysalis ticks inhabiting Russian Far Eastern regions showed that up to 28.13% of H. concinnae and 4.48% of H. japonica douglasii ticks harbor R. heilongjiangensis. It has been concluded that H. concinnae may serve as the main vector for the transmission of R. heilongjiangensis. H. japonica douglasii ticks harbor several varieties of rickettsiae. DNA of “ Candidatus Rickettsia tarasevichiae,” previously found in Ixodes persulcatus ticks, was amplified from one male tick. Two sequenced complete gltA genes belong to the novel spotted fever group rickettsial species provisionally called here “ Candidatus ” variants Hjd54 and Hjd61. The rate of infection has been found to be not higher than 1.5%. [ABSTRACT FROM AUTHOR]

During our more than 20 years of monitoring, we have used epidemiological, field, and experimental methods for characterization of natural foci of tick-borne rickettsioses in Russia. The main results were obtained through genetic methods (PCR sequence) at the Université de la Mediterranée (Marseille, France). We describe considerable heterogeneity of tick-borne α1-proteobacteria: 16 microorganisms the of the order Rickettsiales were detected in Russia and Kazakhstan. R. sibirica–caused North Asiatic tick-borne rickettsiosis is the main tick-borne rickettsiosis in Russia, with wide distribution in Siberia and the Russian Far East and high epidemic activity of natural foci of different landscape types. Our results show circulation of different pathogenic rickettsiae in the same endemic territories. In the Far East region, R. sibirica R. sibirica, R. sibirica BJ-90, and R. heilongjiangensis were detected; in the Altay and Krasnojarsk regions, R. sibirica R. sibirica and R. heilongjiangensis; and in the Kurgan district of West Siberia, R. sibirica R. sibirica and R. slovaca. The roles of more than 15 new genotypes of α1-proteobacteria in infectious disease in Russia and Kazakhstan are in need of further study. [ABSTRACT FROM AUTHOR]

Atypical pneumonia is a term applied to lower respiratory tract infections that are not characterized by signs and symptoms of lobar consolidation. This article will discuss the epidemiology, clinical manifestations, and laboratory diagnoses of Mycoplasma pneumoniae, Chlamydia sp., Legionella sp., Francisella tularensis, and Coxiella burnetii, which are the agents most commonly associated with atypical pneumonia. Because many of these pathogens are intracellular, diagnosis depends upon serological confirmation. The current serological tests used to identify these agents in the etiologic diagnosis of atypical pneumonia are described. Recently, however, it has become possible to make a diagnosis directly in these cases using DNA or protein microarrays. Here, we describe the development of a new, automated technique for simultaneous testing and detection of several pathogens using a multiplexed serology test. This should prove to be a valuable tool for the rapid determination of patient status, allowing effective and efficient postexposure prophylaxis and treatment. [ABSTRACT FROM AUTHOR]