Immune humoral response of young lambs naturally infested by Oestrus ovis (Diptera: Oestridae)

An Enzyme-Linked Immunosorbent Assay for the Detection of Antibodies to Linguatula serrata in Experimentally Infected Dogs

Background:

Linguatula serrata is a causative agent of visceral and nasopharyngeal linguatulosis in humans and animals. The aim of the present study was to investigate the immune response of dogs experimentally infected by L. serrata with ELISA.

Methods:

Five puppies were infected by inserting the L. serrata nymphs in their nasal cavities (infected group) in the Department of Parasitology of Shahid Chamran University of Ahvaz, during 2018–2019. Three animals were kept as the non-infected control group. Blood samples were collected from the animals for seven months at approximately monthly intervals for serum preparation. Nasal samples were taken weekly from the fourth month. ELISA was designed and performed on 64 sera (24 negatives, and 40 positives) using somatic (S), and excretory-secretory (ES) antigens.

Results:

Overall, 100% of the animals were infected with the parasite. Based on the results of ELISA, the ES antigen (sensitivity 95% and specificity 92%) was more preferred than the S antigen (sensitivity 95% and specificity 85%). Female parasites had significant effects on the immune response. There was a significant correlation between the clinical symptoms and the presence of female parasites (P<0.05).

Conclusion:

The results showed a practical method for dogs’ experimental infection. ELISA method is suitable for the detection of infection at different stages of development, especially before the maturation stage of the parasite. In this regard, the ES antigen of the parasite was more immunogenic. Therefore, ELISA can be used as a serological method in the early detection and epidemiological studies of infection with L. serrata in dogs.

The global and regional prevalence of oestrosis in sheep and goats: a systematic review of articles and meta-analysis

Background

Oestrosis, caused by the larvae of Oestrus ovis, commonly known as sheep nose bot, is an obligatory cavitary myiasis of sheep and goats. Oestrus ovis is a widespread parasite, but little is known about the prevalence of oestrosis at the global and broad geographical levels. The present study aimed to explore the epidemiology of oestrosis at the global and regional level to estimate prevalences and their associated factors using a systematic approach. This is, to the author’s knowledge, the first meta-analysis of oestrosis in sheep and goats.

Methods

Published articles were obtained from nine electronic databases (PubMed, CAB Abstracts, Web of Science, Scopus, UCB library, Medline, Biosis Citation Index, Indian journals and Google Scholar) reporting the prevalence of O. ovis in sheep and goats from 1970 to 2018. Pooled prevalences were estimated using a random effect meta-analysis model.

Results

Sixty-six studies were eligible, and data from 40,870 sheep and 18,216 goats were used for quantitative analysis. The random effect estimated prevalence of oestrosis at the global level in sheep was 51.15% (95% CI: 42.80–59.51%) and in goats was 42.19% (95% CI: 33.43–50.95%). The pooled prevalence estimates for Africa, Asia, Europe and the Americas were 47.85% (95% CI: 36.04–59.66%), 44.48% (95% CI: 33.09–55.87%), 56.83% (95% CI: 48.92–64.74%) and 34.46% (95% CI: 19.90–49.01%), respectively. Heterogeneity (I² > 80%) was detected in most pooled estimates.

Conclusions

Oestrosis is highly prevalent in many geographical regions of the world, especially in Europe and Africa. Factors that contribute to the pooled prevalence estimate of oestrosis need to be emphasised in any survey to estimate the true prevalence of oestrosis. Furthermore, there is a need for immunisation or implementation of other preventive measures to reduce the burden of oestrosis in sheep and goats and to improve the health and welfare status.

Electronic supplementary material

The online version of this article (10.1186/s13071-019-3597-2) contains supplementary material, which is available to authorized users.