Diagnostic challenges for Aelurostrongylus abstrusus infection in cats from endemic areas in Italy

Abstract

Background The lungworm Aelurostrongylus abstrusus infects wild and domestic feline species worldwide and is considered a primary respiratory parasite of cats. Definitive diagnosis is based on the identification of first-stage larvae (L1s) released in faeces approximately 5 to 6 weeks after infection. More recently, serology has been shown to be a diagnostic alternative for A. abstrusus infection in cats. The present study aimed at evaluating the diagnostic performance of serological antibody detection compared to faecal examination for A. abstrusus infection in a population of cats with known infection status from endemic areas in Italy and to identify factors (larval scores, age, co-infections with other helminths) that may influence test sensitivity and specificity of serology. Methods All cats resulting positive using the Baermann technique (n = 78) were tested with the A. abstrusus ELISA. An additional 90 serum samples from cats living in three geographical areas with infection prevalence > 10%, but that resulted negative on Baermann, were also tested. Results Among 78 cats copromicroscopically positive for L1s of A. abstrusus (Group 1), 29 (37.2%) were seropositive in ELISA. Of the 90 cats from Group 2 (cats living in three geographical areas in Italy with A. abstrusus prevalence > than 10%, but negative on Baermann examination), 11 (12.2%) were positive on ELISA. The overall seroprevalence was 23.8%. There was no statistical difference either between average optical density (OD) values of cats excreting > 100 L1s vs. cats excreting < 100 L1s (0.84 vs. 0.66; P value = 0.3247) or comparing the OD values with age of infected cats. Few Baermann-negative cats positive for Toxocara cati or hookworms were seropositive, supporting lack of cross-reactivity to these nematodes. Conclusions Results from the present study suggest that relying solely on faecal examination may underestimate prevalence of A. abstrusus infection in cats and that field surveys based on antibody detection are useful for establishing true prevalence of infected and/or exposed animals. Graphical Abstract

Comparative analysis of diagnostic methods and risk factors for Aelurostrongylus abstrusus infection in brazilian cats

“…Prevalence rates reported in the literature vary depending on factors such as lifestyle, geographic origin, and diagnostic methods employed, ranging from 0.21% in The high prevalence observed in the present study could be attributed to the study design, as the enrolled cats exhibited respiratory signs or pulmonary radiographic changes, thus constituting a selected sample of the population. Moreover, it is important to note that the use of fecal diagnosis alone may not reflect the true prevalence among exposed populations (Morelli et al 2020), and therefore, the use of serological detection methods such as ELISA has been proposed as a useful tool for detecting infection in endemic areas (Vismarra et al 2023). The prevalence of A. abstrusus in felines varies widely among countries and regions worldwide, with the disease considered endemic in the European continent (Knaus et al 2011;Echeverry et al 2012;Barutzki and Schaper 2013;Olsen et al 2015).…”

“…The high prevalence observed in the present study could be attributed to the study design, as the enrolled cats exhibited respiratory signs or pulmonary radiographic changes, thus constituting a selected sample of the population. Moreover, it is important to note that the use of fecal diagnosis alone may not reflect the true prevalence among exposed populations (Morelli et al 2020), and therefore, the use of serological detection methods such as ELISA has been proposed as a useful tool for detecting infection in endemic areas (Vismarra et al 2023).…”