Effects of Artemisia absinthium on broiler chicken coccidiosis: a systematic review and meta-analysis.

Coccidiosis is a recurring disease in broiler flocks that causes significant economic losses. This study aims to evaluate the effect of Artemisia absinthium on coccidiosis in broilers through a systematic review and meta-analysis. The article selection process included a search from the year 2000 to February 2021, with no restrictions on country or geographical region. Our objective was met by only six (06) studies, which underwent systematic review. The meta-analysis was conducted using the metafor package in R via RStudio (version 1.1.383; RStudio, Inc.).The systematic review indicates that in vivo studies have shown the effectiveness of various plant extracts (essential oil and methanolic extract) when administered in food or drinking water on the considered parameters (oocyst shedding, bloody diarrhea, mortality rate, weight gain, conversion index, lesion score). Furthermore, in vitro studies demonstrated a positive impact on oocyst count, LC50 (lethal concentration), sporulation rate (%), and sporulation inhibition rate (%).The meta-analysis of the four studies included in this analysis revealed that the inclusion of Artemisia absinthium extract resulted in a significant reduction in oocyst shedding (SMD = -1.64, 95% CI: -2.72 to -0.55; P < 0.0001). However, the effectiveness of Artemisia absinthium extract was not as significant as that of antibiotics (SMD = 0.57, 95% CI: -0.19 to 0.95; P = 0.0032). Various forms of administration and extracts of Artemisia absinthium have demonstrated antiparasitic activity against Eimeria spp, making them suitable as natural anticoccidial agents.

A Survey on Trypanosoma evansi (Kinetoplastida, Trypanosomatidae) Infection in Domestic Animals in a Surra Endemic Area of Southern Algeria.

Background: Trypanosoma (T.) evansi infection is endemic in dromedary camels (Camelus dromedaries) of southern Algeria. Materials and Methods: In order to assess the presence of T. evansi in other domestic animals living together with dromedary camels, a study was conducted in the wilayate of Béchar, El Bayadh, Ouargla and Tamanrasset, between 2015 and 2017. Authorisation to conduct the survey was obtained from the Direction des Services Vétérinaires (DSV, Ministry of Agriculture, Rural Development and Fisheries). A total of 190 animals were sampled, including 42 cattle (Bos taurus), 11 dogs (Canis familiaris), 44 horses (Equus caballus), 3 donkeys (Equus asinus) and 1 mule, 49 goats (Capra hircus) and 40 sheep (Ovis aries). These animals were examined by parasitological (Giemsa stained thin smear, GST), serological (card agglutination test for trypanosomosis (CATT/T. evansi), enzyme-linked immunosorbent assay/Variant Surface Glycoprotein/Rode Trypanozoon antigen type 1.2 [ELISA/VSG RoTat 1.2], immune trypanolysis [TL]) and molecular tests (T. evansi type A specific RoTat 1.2 PCR). Results and Conclusions: The CATT/T. evansi was positive in 10/42 cattle, 0/11 dogs, 2/48 equids, 27/49 goats and 15/40 sheep. On the other hand, 20/38 cattle, 1/9 dogs, 21/42 equids, 17/44 goats and 31/39 sheep were positive in ELISA/VSG RoTat 1.2. However, no single animal was positive in TL. In addition, the T. evansi parasite could not be demonstrated by either GST or RoTat 1.2 PCR in any of the examined animals. This may suggest cross-reactions of CATT/T. evansi and ELISA/VSG RoTat 1.2 with other pathogenic or commensal trypanosome species such as T. vivax or other parasites. Based on these data, in particular taking into account the high specificity of the TL for T. evansi type A, this study does not support the hypothesis that T. evansi circulates in the studied domestic animal species and that they would act as reservoirs for the parasite that causes trypanosomosis in dromedary camels.

Epidemiological investigations on Trypanosoma evansi infection in dromedary camels in the South of Algeria.

An epidemiological study of Trypanosoma evansi (T. evansi) infection in dromedaries was conducted in four wilayate (localities) of Southern Algeria: Béchar, El Bayadh, Ouargla, Tamanrasset. Between February 2014 and April 2016, 1056 camels of different ages and both sexes from 84 herds were sampled. The prevalence was determined through parasitological examination (Giemsa stained thin smear, GST), serological tests (CATT/T. evansi, ELISA/VSG RoTat 1.2, immune trypanolysis), and molecular tests (T. evansi type A specific RoTat 1.2 PCR and T. evansi type B specific EVAB PCR). The overall prevalence was 2.4 % with GST, 32.4% with CATT/T. evansi, 23.1% with ELISA/VSG RoTat 1.2, 21.0% with immune trypanolysis (TL), 11.2 % with RoTat 1.2 PCR and 0% with EVAB PCR. El Bayadh was the most affected wilaya with 11.8% positives in GST, 74.9% in CATT/T. evansi, 70.1% in ELISA/VSG RoTat 1.2 and 62.2% in immune trypanolysis. Only in Béchar, a non-significantly higher prevalence (13.6%) was observed with RoTat1.2 PCR than in El Bayadh (13.0%). We didn't find any evidence of the presence of T. evansi type B in the study area.

Evaluation of Immunofluorescence Antibody Test Used for the Diagnosis of Canine Leishmaniasis in the Mediterranean Basin: A Systematic Review and Meta-Analysis.

With an expected sensitivity (Se) of 96% and specificity (Sp) of 98%, the immunofluorescence antibody test (IFAT) is frequently used as a reference test to validate new diagnostic methods and estimate the canine leihmaniasis (CanL) true prevalence in the Mediterranean basin. To review the diagnostic accuracy of IFAT to diagnose CanL in this area with reference to its Se and Sp and elucidate the potential causes of their variations, a systematic review was conducted (31 studies for the 26-year period). Three IFAT validation methods stood out: the classical contingency table method, methods based on statistical models and those based on experimental studies. A variation in the IFAT Se and Sp values and cut-off values was observed. For the classical validation method based on a meta-analysis, the Se of IFAT was estimated in this area as 89.86% and 31.25% in symptomatic and asymptomatic dogs, respectively. The Sp of IFAT was estimated in non-endemic and endemic areas as 98.12% and 96.57%, respectively. IFAT can be considered as a good standard test in non-endemic areas for CanL, but its accuracy declines in endemic areas due to the complexity of the disease. Indeed, the accuracy of IFAT is due to the negative results obtained in non-infected dogs from non-endemic areas and to the positive results obtained in sera of symptomatic dogs living in endemic areas. But IFAT results are not unequivocal when it comes to determining CanL infection on asymptomatic dogs living in endemic areas. Statistical methods might be a solution to overcome the lack of gold standard, to better categorize groups of animals investigated, to assess optimal cut-off values and to allow a better estimate of the true prevalence aiming information on preventive/control measures for CanL.

Estimation of canine Leishmania infection prevalence in six cities of the Algerian littoral zone using a Bayesian approach.

A large-scale study on canine Leishmania infection (CanL) was conducted in six localities along a west-east transect in the Algerian littoral zone (Tlemcen, Mostaganem, Tipaza, Boumerdes, Bejaia, Jijel) and covering two sampling periods. In total 2,184 dogs were tested with an indirect fluorescent antibody test (IFAT) and a direct agglutination test (DAT). Combined multiple-testing and several statistical methods were compared to estimate the CanL true prevalence and tests characteristics (sensitivity and specificity). The Bayesian full model showed the best fit and yielded prevalence estimates between 11% (Mostaganem, first period) and 38% (Bejaia, second period). Sensitivity of IFAT varied (in function of locality) between 86% and 88% while its specificity varied between 65% and 87%. DAT was less sensitive than IFAT but showed a higher specificity (between 80% and 95% in function of locality or/and season). A general increasing trend of the CanL prevalence was noted from west to east. A concordance between the present results and the incidence of human cases of visceral leishmaniasis was observed, where also a maximum was recorded for Bejaia. The results of the present study highlight the dangers when using IFAT as a gold standard.

Epidemiology of visceral leishmaniasis in Algeria: an update.

Visceral leishmaniasis (VL), a zoonotic disease caused by Leishmania infantum, is endemic in Algeria. This report describes a retrospective epidemiological study conducted on human VL to document the epidemiological profile at national level. All human VL cases notified by the National Institute of Public Health between 1998 and 2008 were investigated. In parallel all VL cases admitted to the university hospitals of Algiers were surveyed to estimate the underreporting ratio. Fifteen hundred and sixty-two human VL cases were reported in Algeria between 1998-2008 with an average annual reported incidence rate of 0.45 cases per 100,000 inhabitants, of which 81.42% were in the age range of 0-4 years. Cases were detected year-round, with a peak notification in May and June. One hundred and seventy patients were admitted to the university hospitals in Algiers in the same period, of which less than one in ten had been officially notified. Splenomegaly, fever, pallor and pancytopenia were the main clinical and laboratory features. Meglumine antimoniate was the first-line therapy for paediatric VL whereas the conventional amphotericin B was used for adult patients. Visceral leishmaniasis in Algeria shows the epidemiological profile of a paediatric disease with a decrease of the annual reported incidence rate. However, vigilance is required because of huge underreporting and an apparent propagation towards the south.

Canine leishmaniasis in Algeria: true prevalence and diagnostic test characteristics in groups of dogs of different functional type.

A Bayesian approach was used to assess the prevalence of Canine leishmaniasis and evaluate three serological diagnostic tests: indirect fluorescent antibody test (IFAT), direct agglutination test, and particle gel immuno-assay (PaGIA) for Canine leishmaniasis (CL) in Algiers. Four hundred and sixty-two dogs were involved in this study and divided in four groups according to their functional type: stray dogs, farm dogs, national guard dogs and pet dogs. The stray dog group showed the highest prevalence of leishmaniasis (11.7%), followed by the national guard dogs (9.7%) and the farm dogs (5.9%). IFAT was shown to be the most sensitive test in all groups. However, IFAT specificity was considerably lowered in the farm dog group: 65.2% versus 94.5% for the stray dogs. A considerable drop in PaGIA specificity was noted in the stray dogs group. The results of the current study demonstrate the variability of test characteristics in different situations and underline the danger of using standard values, without verifying their appropriateness for the specific purposes.

Estimating disease prevalence in a Bayesian framework using probabilistic constraints.

Studies sometimes estimate the prevalence of a disease from the results of one or more diagnostic tests that are applied to individuals of unknown disease status. This approach invariably means that, in the absence of a gold standard and without external constraints, more parameters must be estimated than the data permit. Two assumptions are regularly made in the literature, namely that the test characteristics (sensitivity and specificity) are constant over populations and the tests are conditionally independent given the true disease status. These assumptions have been criticized recently as being unrealistic. Nevertheless, to estimate the prevalence, some restrictions on the parameter estimates need to be imposed. We consider 2 types of restrictions: deterministic and probabilistic restrictions, the latter arising in a Bayesian framework when expert knowledge is available. Furthermore, we consider 2 possible parameterizations allowing incorporation of these restrictions. The first is an extension of the approach of Gardner et al and Dendukuri and Joseph to more than 2 diagnostic tests and assuming conditional dependence. We argue that this system of equations is difficult to combine with expert opinions. The second approach, based on conditional probabilities, looks more promising, and we develop this approach in a Bayesian context. To evaluate the combination of data with the (deterministic and probabilistic) constraints, we apply the recently developed Deviance Information Criterion and effective number of parameters estimated (pD) together with an appropriate Bayesian P value. We illustrate our approach using data collected in a study on the prevalence of porcine cysticercosis with verification from external data.