L’ehrlichiose granulocytique humaine en Europe

Prevention of tick-borne diseases: challenge to recent medicine

Abstract

Ticks represent important vectors and reservoirs of pathogens, causing a number of diseases in humans and animals, and significant damage to livestock every year. Modern research into protection against ticks and tick-borne diseases focuses mainly on the feeding stage, i.e. the period when ticks take their blood meal from their hosts during which pathogens are transmitted. Physiological functions in ticks, such as food intake, saliva production, reproduction, development, and others are under control of neuropeptides and peptide hormones which may be involved in pathogen transmission that cause Lyme borreliosis or tick-borne encephalitis. According to current knowledge, ticks are not reservoirs or vectors for the spread of COVID-19 disease. The search for new vaccination methods to protect against ticks and their transmissible pathogens is a challenge for current science in view of global changes, including the increasing migration of the human population.

Highlights

• Tick-borne diseases have an increasing incidence due to climate change and increased human migration

• To date, there is no evidence of transmission of coronavirus COVID-19 by tick as a vector

• To date, there are only a few modern, effective, and actively- used vaccines against ticks or tick-borne diseases

• Neuropeptides and their receptors expressed in ticks may be potentially used for vaccine design

Epidemiological and Comparative Diagnostic Study of Anaplasma Spp. Infection in Goats from North-Eastern Algeria

Anaplasmosis is an infectious disease affecting goats and other ruminants. Our goal was to estimate the prevalence of Anaplasma spp. infections, and to identify different tick species in goa ts along with their associated risk factors. The epidemiology of Anaplasma spp. (A. ovis/A. marginale) was investigated from April to September 2016 in dairy goats from three different agro-ecological areas in the northeast region of Algeria (Guelma and El-Taref). We tested 182 goat sera using a MSP5 competitive ELISA (cELISA) test for IgG antibody screening, and by microscopic examination using the Giemsa (May-Greunwald-Giemsa) stain of 128 blood smears to detect intraerythrocytic inclusions bodies. The results demonstrated a total infection rate of 78.02 % and 42.18 % using cELISA and MGG, respectively. Only two species of ticks collected were identified, i. e. Rhipicephalus sanguineus (85.39 %) and Rhipicephalus bursa (14.60 %). Our study revealed that factors, such as the season, the type of farming, the hygienic status and the climatic conditions of the studied areas were found to be significantly associated with the tick infestation of goats (P < 0.05). The Anaplasma spp. infection prevalence was found to be highly dependent on the climatic conditions, the season (P < 0.05) and most closely related to the type of breeding and herd management (P = 0.000).

The evaluation of the Giemsa technique showed specificity and sensitivity of 60.71 % and 45.16 % respectively. Calculating the concordance between the two techniques revealed Cohen’s Kappa value of 0.038 in the range 0.21—0.40, which corresponded to a very low agreement. The McNemar test results showed that both tests gave significantly different results (P < 0.05). This work provides evidence for Anaplasma spp. in goats from north-eastern Algeria.

A clear and present danger: tick-borne diseases in Europe

Ticks can transmit a variety of viruses, bacteria or parasites that can cause serious infections or conditions in humans and animals. While tick-borne diseases are becoming an increasing and serious problem in Europe, tick-borne diseases are also responsible for major depressions in livestock production and mortality in sub-Saharan Africa, Latin America and Asia. This review will focus on the most important circulating tick-transmitted pathogens in Europe (Borrelia spp., Anaplasma phagocytophilum, Babesia spp., tick-borne encephalitis virus, Rickettsia spp. and Crimean-Congo hemorrhagic fever virus).

Efficacy of a long-term antibiotic treatment in patients with a chronic Tick Associated Poly-organic Syndrome (TAPOS)

SETTINGS

Despite a now codified antibiotic treatment for Lyme disease, a significant proportion of patients treated according to recommendations complain of persistent signs and symptoms. The pathophysiological mechanisms which underlie this syndrome of post-treatment chronic systemic illness remain unclear. For some physicians post-treatment symptoms indicate a persistent infection requiring prolonged antibiotic therapy. For others, there is no benefit from antimicrobial therapy. The difficulty of assessment encountered in studies is significant because many symptoms are subjective. We think that the term "chronic Lyme disease" is not appropriate and should be replaced by chronic "tick associated poly-organic syndrome" (TAPOS).

OBJECTIVE

This open-label prospective study was made on a group of 100 patients having followed a medical treatment for a chronic TAPOS and to evaluate their evolution under prolonged antibiotic treatment.

RESULTS

The medical management was found to be effective for symptoms, especially for patients with a high probability of chronic TAPOS (NEJM score). Patients with post tick-bite symptoms, which often worsens their quality of life, deserve particular attention.

CONCLUSION

This study had methodological limitations but could help in terms of feasibility, choice of inclusion criteria, and design of follow-up for a future randomized, double blind study to test for an optimal management of TAPOS.

Antibiothérapie de la phase primaire de la borréliose de Lyme

OBJECTIVE

The aim of this article is to provide clinicians with guidelines for the antibiotherapy of early-localized Lyme disease. The outcome measures are the clearance of erythema migrans and associated symptoms of early localized Lyme disease and the prevention rate of late complications, with a low risk of adverse effects. Design. The reviewed studies were selected by Medline with the keywords: "erythema migrans, treatment". Sixteen studies comparing treatment or duration of treatment were analyzed.

RESULTS

Amoxicillin, doxycycline, and cefuroxim axetil are equally efficacious for early-localized Lyme disease. Azithromycin is an alternative. Most patients respond completely and less than 10% fail to respond. All antibiotics are associated with a low frequency of adverse effects, with the exception of Jarisch Herxheimer reaction which occurs in about 15% of the patients.

CONCLUSIONS

We recommend treating adults with amoxicillin (50 mg/kg/day in 3 intakes) or doxycycline (100 mg bid) for 14 days (erythema migrans) to 21 days (early localized Lyme disease with associated symptoms). For children, we recommend amoxicillin (50 mg/kg/day in 3 intakes) or doxycycline (4 mg/kg/day in 2 intakes, maximum 100 mg/dose) above 8 years of age. Cefuroxim axetil (500 mg twice daily for adults or 30 mg/kg/day in 2 intakes, maximum 500 mg/dose, for children), and azithromycin (500 mg/day for adults and 20 mg/kg/day for children for 7-10 days) are second line treatment.