Diagnosis and prevalence of canine leishmaniasis in the Atlas shepherd dog

The aim of this study was to determine the prevalence of canine leishmaniasis in the Atlas shepherd dogs from the Tiaret region of Algeria. A total of 161 dogs were included in this study and four diagnostic techniques were used, namely lymph node cytology, PCR, IFAT and ELISA. 110 out of 161 dogs were positive by at least one diagnostic technique, a percentage of 68.32% of the total number, which represent very high prevalence of canine leishmaniasis in this canine breed. 152 dogs underwent the two serological tests namely IFAT and ELISA among which 137 dogs underwent in addition the molecular examination by PCR. IFAT was positive in 9.86% of the dogs, ELISA was positive in 12.5% while 68% of the dogs proved positive by PCR. 47 dogs with lymph node enlargement underwent lymph node cytology, of which 26 dogs showed forms of amastigotes in their smears after microscopic examination, confirming the usefulness of this approach for the diagnosis of canine leishmaniasis. The clinical signs of the disease in this breed are similar to those of other canine breeds The dominant clinical signs in these dogs were onychogryphosis, poor general condition and lymph node hypertrophy. The autopsy was carried out on 7 dogs that died of canine leishmaniasis, all of which showed splenomegaly, while 5 dogs also showed hepatomegaly. Renal damage was found in 1 dog with frank jaundice. The splenic cytology was positive in all 7 dogs with the presence of amastigote forms in the smears after microscopic examination.

Human cystic echinococcosis: Serological diagnosis by indirect hemagglutination test, enzyme-linked immunosorbent assay, immunoelectrophoresis, and immunoblotting in surgically confirmed patients versus cases diagnosed by imaging techniques

INTRODUCTION

Human cystic echinococcosis (CE) diagnosis is based on imaging findings and serology. Serology is the first-line test followed by imaging tests.

MATERIALS AND METHODS

A total of 268 serum samples from CE patients were included in this study. The serodiagnosis was made simultaneously by indirect hemagglutination assay (IHA), enzyme-linked immunosorbent assay (ELISA), immunoblotting test (IB), and immunoelectrophoresis (IEP).

RESULTS

In serum samples belonging to surgically confirmed CE patients, we observed a percentage of positivity of 83.7% [77.2%-89.0%] and 80.7% [73.9%-86.4%] for IHA and IgG-ELISA, respectively. IgG-IB was associated with a higher positivity rate than IEP with 81.3% [74.6%-86.9%] and 62.0% [54.2%-69.5%], respectively. IHA and ELISA results were analyzed using cut-off generated by receiver operating curves. The best diagnostic performances were achieved by IHA (cut-off ≥1/128) and ELISA (>1.16 index). Sensitivities reported in patients with suggestive imaging findings and positive Echinococcus IB were 86.2% [78.0%-92.2%], 72.5% [62.8%-80.9%], 49.0% [39.0%-59.1%] for IHA, IgG-ELISA, and IEP, respectively. All tests gave false negative results in the confirmed CE group. Overall, 18.6% of negative results were obtained by IgG-IB test. Cross-reactivities with non-hydatid serum samples were observed in all tests. Only one patient carrying Taenia saginata serum cross-reacted with 8/12 kDa band by IB. We observed specificity at 73% [63.2%-81.4%], 87% [78.8%-92.9%], 99% [94.6%-100.0%], and 99% [94.6%-100.0%] with IHA, IgG-ELISA, IEP, and IgG-IB, respectively. Serology was less sensitive (74%) in lung cysts. Sensitivity was better in liver cysts, especially by IgG-IB (96%).

A post-mortem study of bovine fasciolosis in the Mitidja (north center of Algeria): prevalence, risk factors, and comparison of diagnostic methods

The present study was conducted to determine the prevalence of fasciolosis and investigate the associated risk factors (sex, age, and season) in slaughtered cattle of the Mitidja area. This survey also aimed to compare three diagnostic methods: liver inspection, microscopic bile examination, and ELISA test. Liver and bile of 1400 cattle were examined for the presence of adult and eggs of Fasciola hepatica, respectively. Based on the results obtained by liver and bile examination, a subset of 206 cattle from the 1400 was selected for antibodies detection using the ELISA test. Liver inspection and microscopic bile examination showed prevalences of 2.86% and 5.50%, respectively. The difference between the two methods was highly significant (p < 0.001). The overall prevalence of bovine fasciolosis found by both methods was 6.07%. The disease was more prevalent in females (11.96%) than in males (2.43%), and in older cattle (12.30%) than in younger ones (2.36%). The ELISA test showed some conflicting results: 23.61% of cattle previously diagnosed positive with liver inspection and bile examination were found seronegative, and 3.73% of cattle previously diagnosed negative were found to be seropositive. The sensitivity and specificity of microscopic bile examination were respectively 80% (CI 65.2-89.5%) and 96.7% (CI 95.6-97.5%) as compared with the liver inspection. Likewise, this same method has a sensitivity of 81.36% (CI 69.6-89.3%) and a specificity of 88.97% (CI 82.8-93.1%) as compared with the ELISA test. Our results show that microscopic bile examination is able to detect more infected cattle than liver inspection. In addition to being simple, fast, inexpensive, sensitive, and specific, it is an effective method for the diagnosis of fasciolosis.

Distinguishing Echinococcus granulosus sensu stricto genotypes G1 and G3 with confidence: A practical guide

Cystic echinococcosis (CE), a zoonotic disease caused by tapeworms of the species complex Echinococcus granulosus sensu lato, represents a substantial global health and economic burden. Within this complex, E. granulosus sensu stricto (genotypes G1 and G3) is the most frequent causative agent of human CE. Currently, there is no fully reliable method for assigning samples to genotypes G1 and G3, as the commonly used mitochondrial cox1 and nad1 genes are not sufficiently consistent for the identification and differentiation of these genotypes. Thus, a new genetic assay is required for the accurate assignment of G1 and G3. Here we use a large dataset of near-complete mtDNA sequences (n = 303) to reveal the extent of genetic variation of G1 and G3 on a broad geographical scale and to identify reliable informative positions for G1 and G3. Based on extensive sampling and sequencing data, we developed a new method, that is simple and cost-effective, to designate samples to genotypes G1 and G3. We found that the nad5 is the best gene in mtDNA to differentiate between G1 and G3, and developed new primers for the analysis. Our results also highlight problems related to the commonly used cox1 and nad1. To guarantee consistent identification of G1 and G3, we suggest using the sequencing of the nad5 gene region (680 bp). This region contains six informative positions within a relatively short fragment of the mtDNA, allowing the differentiation of G1 and G3 with confidence. Our method offers clear advantages over the previous ones, providing a significantly more consistent means to distinguish G1 and G3 than the commonly used cox1 and nad1.

Global phylogeography and genetic diversity of the zoonotic tapeworm Echinococcus granulosus sensu stricto genotype G1

Echinococcus granulosus sensu stricto (s.s.) is the major cause of human cystic echinococcosis worldwide and is listed among the most severe parasitic diseases of humans. To date, numerous studies have investigated the genetic diversity and population structure of E. granulosus s.s. in various geographic regions. However, there has been no global study. Recently, using mitochondrial DNA, it was shown that E. granulosus s.s. G1 and G3 are distinct genotypes, but a larger dataset is required to confirm the distinction of these genotypes. The objectives of this study were to: (i) investigate the distinction of genotypes G1 and G3 using a large global dataset; and (ii) analyse the genetic diversity and phylogeography of genotype G1 on a global scale using near-complete mitogenome sequences. For this study, 222 globally distributed E. granulosus s.s. samples were used, of which 212 belonged to genotype G1 and 10 to G3. Using a total sequence length of 11,682 bp, we inferred phylogenetic networks for three datasets: E. granulosus s.s. (n = 222), G1 (n = 212) and human G1 samples (n = 41). In addition, the Bayesian phylogenetic and phylogeographic analyses were performed. The latter yielded several strongly supported diffusion routes of genotype G1 originating from Turkey, Tunisia and Argentina. We conclude that: (i) using a considerably larger dataset than employed previously, E. granulosus s.s. G1 and G3 are indeed distinct mitochondrial genotypes; (ii) the genetic diversity of E. granulosus s.s. G1 is high globally, with lower values in South America; and (iii) the complex phylogeographic patterns emerging from the phylogenetic and geographic analyses suggest that the current distribution of genotype G1 has been shaped by intensive animal trade.

Large-scale evaluation of a rapid diagnostic test for human cystic echinococcosis

Cystic echinococcosis (CE) is a neglected zoonotic disease, diagnosed through clinical findings, imaging techniques, and serology, for which many serological tests are available. Here we report a rapid unit assay, the immunochromatographic VIRapid® HYDATIDOSIS test (Vircell, Granada, Spain), potentially suitable for laboratories in low-prevalence or poorly equipped areas. This test was evaluated with a large retrospective cohort (224 sera), including patients suffering from CE or from other parasitic or liver diseases. The test was also assessed in routine conditions with a prospective cohort (115 sera) in areas where both cystic and alveolar echinococcoses have been diagnosed. Its performance (in terms of sensitivity, specificity, and both positive and negative likelihood ratios) was similar to an ELISA based on a crude antigen. Our study shows that this test performs adequately in the diagnostic process, when used with caution, especially regarding cross-reactivity with other parasitic diseases.

Molecular characterization of Echinococcus granulosus sensu stricto and Echinococcus canadensis in humans and livestock from Algeria

In Algeria, previous studies investigated genotypes of Echinococcus granulosus sensu lato in animals and identified E. granulosus sensu stricto (s.s.) genotypes G1 and G3 whereas Echinococcus canadensis genotype G6 was only reported from dromedary cysts. Molecular data on human cystic echinococcosis (CE) were limited. We implemented a large genotyping study of hydatid cysts from humans and livestock animals to specify CE's molecular epidemiology and the genetic diversity in Algeria. Fifty-four human CE cysts from patients predominantly admitted in surgical units from Mustapha Hospital, Algiers, and 16 cysts from livestock animals gathered in two geographically distinct slaughterhouses, Tiaret and Tamanrasset, were collected. Molecular characterization was performed using sequencing of two mitochondrial genes, cytochrome c oxidase subunit I (COI) and NADH dehydrogenase subunit I (NDI). In humans, G1 of E. granulosus s.s. was the main genotype (90.7 %); four samples (7.4 %) were characterized as E. granulosus s.s. G3 and one cyst as E. canadensis G6 (1.8 %). This molecular confirmation of E. canadensis G6 human infection in Algeria was observed in a Tuareg female living in a desertic area in Tamanrasset. All cysts from sheep, cattle, and goat were identified as E. granulosus s.s. G1 and the two cysts originating from dromedary as E. canadensis G6. Twenty concatenated haplotypes (COI + NDI) were characterized. Among E. granulosus s.s., one haplotype (HL1) was highly predominant in both humans and animals cysts (71.6 %). This study revealed main occurrence of E. granulosus s.s. in humans and livestock animals, with description of a predominant shared haplotype corresponding to the main worldwide observed haplotype E.granulosus s.s. G1. E. canadensis G6 was limited to South Algeria, in dromedary as well as in human.

[Parasitological study of 78 cases of human cystic echinococcosis collected between 2005 to 2012 in Mustapha hospital center of Algiers]

AIM

The aim of this work is to know the fertility rate of the metacestodes resulting from patients suffering from hydatidosis, the one of protoscoleces's viability and by comparing the results obtained with those found elsewhere. It reports, also, the epidemiological, clinical and diagnostically aspects of the studied patients.

MATERIALS AND METHODS

This study has carried on 78 hydatics samples resulting from 78 patients collected between 2005 and 2012 at the laboratory of parasitology of the Mustapha hospital center of Algiers. A questionnaire on the epidemiological context (contact with an animal-host of the cycle, place of residence, presence of family cases reached of hydatidosis and knowledge on the hydatic disease) concerned 69 patients. For each sample, a direct microscopic examination is made with or without vital staining. The presence of protoscoleces made qualified the fertile cyst. Those visualized moving or resistant to eosin at 0.2% are considered viables. Indirect diagnosis is based on the techniques: passive hemagglutination, electrophoresis, Elisa IgG Echinococcus granulosus and immunoblotting IgG "Echinococcus". Molecular analysis is based on PCR and sequencing the partials fragments of two mitochondrial genes with the primers COX1 and ND1.

RESULTS

The results obtained show that the surgical frequency of hydatidosis is significant at the young adult and at the child. The epidemiological context associated at the disease is the conjointly presence of a dog and herbivores. The fertility rate of human hydatid cysts is 88.4% and the ones of viability of the protoscoleces is 74.5%. In this series, the serology shows global positivity at 70%. The molecular characterization of five samples identify the species: E. granulosus ss.

CONCLUSION

Finally, the viability and fertility rates found here are raised. Sometimes viables protoscoleses are found after use of scolicidal solution. In front of these results, the parasitical treatment is more than necessary in order to minimize the risk of occurred of secondary echinococcosis or the relapses postoperatives.

[Epidemiological profile of 290 cases of human cystic echinococcosis diagnosed in the Mustapha University Hospital (Algiers) from 2006 to 2011]

THE AIM OF THE STUDY

This study reports a series of 290 cases of hydatidosis confirmed by the surgery and/or the imagery with a positive immuno-diagnosis collected between 1st January 2006 and 31 March 2011 at parasitology-mycology laboratory of hospital university center of Mustapha of Algiers. Our aim is to specify, through the listed cases, the epidemiological aspects of this affection and compared with those obtained in two previous Algerian epidemiological investigations carried out, between 1963-1964 and 1966-1975.

PATIENTS AND METHODS

It is a retrospective (2006-2008) and prospective (2008-2011) study. The parasitological diagnosis was carried out by the direct macroscopic and/or microscopic identification of the parasite and indirect diagnosis based on four techniques: passive hemagglutination, Elisa IgG "Echinococcus granulosus", Western Blot IgG "Echinococcus" and electrophoresis.

RESULTS

The study shows that this affection is still prerogative of the young adult. It bring out also in this study that the child of school age (ten years), in particular the boy, pays a heavy tribute. At the child, the preferential pulmonary seat of the hydatic disease is not devoid of risk. At adult, this parasitic disease mainly affect the active woman.

CONCLUSION

Generally, the epidemiological and clinical characteristics join the endemic countries data and confirmed the row of our country among them. The transmission seems as strong as in the past, in spite of a much better social educational level.

[Study of 71 cases of visceral leishmaniasis diagnosed at the Mustapha University Hospital (Algiers) from 1998 to 2009]

OBJECTIVE

The authors retrospectively studied the epidemiological, clinical, diagnostic and therapeutic aspects of 71 cases of visceral leishmaniasis from 1998 to 2009.

POPULATION AND METHODS

The diagnosis was made by finding Leishmania amastigotes in bone marrows smears and/or by serology.

RESULTS

Most cases occur in winter (35.2%) and in spring (36.6%). The source areas are endemic ones located in the north of Algeria (74.6%) and more rarely arid or semi-arid climate areas (8.4%). 88.7% of patients are children. The sex ratio is 1.53. The clinical characteristics are: fever (77.4%), paleness (43.6%); splenomegaly (83%), hepatomegaly (57.7%). The biological anomalies are: anemia (56.3%), thrombocytopenia (33.8%), and leucopenia (28.1%). N-methylglucamine (Glucantime(®)) was most often prescribed (70.4%). Four deaths (5.6%) were recorded.

CONCLUSION

Visceral leishmaniasis remains a pediatric affection but does not spare adults.