Scalp eschar and neck lymphadenopathy after tick bite: an emerging syndrome with multiple causes.

The clinical and epidemiological features of 56 patients with scalp eschar associated with neck lymphadenopathy after a tick bite (SENLAT) syndrome were evaluated at the National French Rickettsial Center. Eschar swabs, crusts, and biopsies as well as ticks and blood samples were acquired for molecular and serological assays. SENLAT predominantly affects children (p < 0.05), followed by 40- to 70-year-olds, and it is found mostly in women (p < 0.05). The seasonal distribution has two peaks: one in the spring (55%) and one in the autumn (30%). The etiological agent was identified in 18 cases, which include Rickettsia slovaca in 13 cases with incidences of two co-infections with Rickettsia raoultii and one case caused by Rickettsia sibirica mongolitimonae. Other possible agents that were found in attached ticks were Candidatus R. rioja, Coxiella burnetii, and Borrelia burgdorferi. The tick vector was Dermacentor marginatus in almost all cases, with the exception of one case, in which Ixodes ricinus was identified as the vector. Our findings show that SENLAT is a clinical entity characterized as a local infection controlled by the immune system and is neither pathogen- nor vector-specific.

Update on rickettsioses in Slovakia.

The reported incidence of vector-borne diseases including various cases of Rickettsioses in humans is increasing due to a combination of climatic and social factors, escalating the opportunities for contact between people and ticks, fleas or lice. Many of the emerging infectious diseases currently challenging human health in Europe are transmitted by ticks which normally feed on domestic or wild animals. Each Rickettsia spp. has one or several tick vectors, and their geographical distribution varies according to geographical conditions; e.g.; altitude or temperature, which is gradually changing due to a global warming. Evidence of Rickettsia spp. particularly of a newly discovered species is a strong indication that a great number of diseases may be caused by so far undetected or unrecognized organisms. Their diagnosis relies mostly on rare "spot like" cooperation of clinicians with scientists, the members of the working groups that are devoted to the scientific studies of the corresponding research areas. The clinical picture of the disease caused by rickettsiae varies significantly from flu like symptoms to severe fatal outcomes, reflecting the various factors, e.g. a variability of virulence of rickettsial species due to cell invasion, dissemination of rickettsiae, genomics, immune response of an infected organism, or a tricky impact of a treatment. Several major reviews on rickettsioses have been previously published, e.g. in 1997 (Raoult and Roux, 1997a), in 2005 (Parola et al., 2005), and in 2011 (Botelho-Nevers and Raoult, 2011). In this work we intend to present a short historical overview and to describe new trends in research studies of rickettsiology. The main focus will be on rickettsioses affecting Europe΄s population.

[Lymphangitis-associated rickettsiosis caused by Rickettsia sibirica mongolitimonae]. / "Lymphangitis-associated rickettsiosis" due à Rickettsia sibirica mongolitimonae.

Rickettsia sibirica mongolitimonae was first isolated 20 years ago in Asia but has now been identified on three continents. Hyalomma spp. and Rhipicephalus pusillus ticks are vectors but only a small number of cases have been reported to date, mainly on the Mediterranean coast. This bacterium induces the lymphangitis-associated rickettsiosis, a still unfamiliar rickettsiosis that is mainly characterized by fever with a rope-like lymphangitis and/or lymphadenopathy and skin eschar occurring after tick bites. These features are especially evocative if they occur in spring. Sequellae are very rare and treatment with doxycycline is recommended.

[Update on SENLAT syndrome: scalp eschar and neck lymph adenopathy after a tick bite]. / Les nouveautés sur le syndrome SENLAT : Scalp Eschar and Neck LymphAdenopathy after Tick bite.

SENLAT syndrome, also known as TIBOLA/DEBONEL, is an emerging disease in France. The major symptoms are necrotic eschar on the scalp associated with painful cervical lymphadenopathy. It occurs mainly in women and children during the cold seasons after a bite by a Dermacentor tick, responsible for transmitting Rickettsia slovaca or Rickettsia raoultii. Cutaneous swabs are safe, easy and reliable tools that should be used routinely by physicians to confirm diagnosis. In this particular disease, they should be preferred to serology, which is less sensitive. Doxycycline is the antibiotic of choice for this syndrome.

Diplorickettsia massiliensis as a human pathogen.

Diplorickettsia massiliensis has been recently isolated from Ixodes ricinus ticks. We screened 13,872 serum samples from patients in France with suspected tick-borne diseases and found three cases that had serological evidence of D. massiliensis infection; for one of these three cases, we obtained molecular evidence of an infection as well.

[Rickettsial diseases in Switzerland, update for the general practitioner]. / Rickettsioses d'importation.

Rickettsial diseases are arthropod-borne zoonosis. They are still misdiagnosed in Switzerland. Since development in molecular genetics, number of pathogenic species increased dramatically. In recent years, the incidence rise worldwide. Climatic conditions and development of tropical travels could explain it. In a near future, the Swiss general practitioner may face an increase of cases. Clinical presentation is unspecified. The eschar is the key diagnostic element but can be easily overlooked. Serology, the indirect immunofluorescence assay is the reference method. PCR can give the diagnosis in acute phase. However empirical treatment should be prescribed as soon as diagnosis is suspected. No vaccine is currently available and use of repellent is still the best way of prevention.

Update on tick-borne bacterial diseases in Europe.

In recent years, the prevalence of tick-borne bacterial diseases has significantly increased in European countries. The emergence and reemergence of these illnesses are attributed to changes in the environment and human behavior. Several diseases are caused by bacteria initially isolated from ticks and subsequently considered pathogenic. It is necessary to consider the bacteria found in arthropods capable of biting humans as potential human pathogens. Here we review the clinical and epidemiological data on bacterial tick-borne diseases in European countries. We focus on the epidemiological and clinical aspects of tick-borne rickettsioses and give an overview of other tick-borne illnesses as well as the emergence and re-emergence of these diseases.

[Ticks and human tick-borne diseases in Africa]. / Tiques et maladies transmises à l'homme en Afrique.

Ticks are obligate hematophagous arthropod parasites that feed on the blood of every class of vertebrates in almost every region of the world. Tick bites can transmit bacterial, viral and parasitic diseases to humans. In this review we describe ticks and human tick-borne diseases in Africa. The first part of this article presents elements linking the morphology and biology of these acarians as well as various aspects of their taxonomy and phylogeny. The next part of the article describes the main human tick borne diseases in Africa with particular focus on spotted fever group rickettsioses, relapsing fever borrelioses, and Crimean-Congo fever. Information is also provided on Q fever and other tick-borne diseases as ehrlichioses, anaplasmoses, Lyme disease, and babesiosis that can and do occur in Africa. Finally this article describes methods used for the collection and identification of ticks and for control and prevention of tick bites as well as essential points for early diagnosis and management of patients who have been bitten by ticks.