Detection and modeling of anti-Leptospira IgG prevalence in cats from Lisbon area and its correlation to retroviral infections, lifestyle, clinical and hematologic changes

Current knowledge on leptospirosis in cats: A systematic review with metanalysis on direct detection, serological response, and clinical data

Leptospirosis is a neglected bacterial zoonosis that affects a wide range of mammals, with important implications from a One Health perspective. Over the past years feline leptospirosis has gained increased attention in the scientific community. Here we describe a systematic review with meta-analysis that followed the PRISMA guidelines, with an additional PROSPERO registration. The study provides global seropositivity, urinary shedding rates, global serogroup distribution, descriptive data of leptospires that had been isolated from cats and clinical and laboratory features presented by symptomatic cats with acute disease. The search was carried out in six different databases, with the identification of 79 reports describing leptospiral infection in cats. The pooled frequency of seroreactive cats was 11% (95% CI: 9%-13%), with Javanica and Pomona as the most frequent serogroups found. Frequency for urinary shedding was 8% (95% CI: 5%-10%), with L. interrogans identified in most samples. A total of 16 isolates were isolated from cats, with Bataviae as the most frequent serogroup. Twenty symptomatic cats with confirmed leptospiral infection were identified. Anorexia, lethargy, polydipsia, and bleeding disorders were the clinical signs most frequently reported. The results suggest that cats from some locations are exposed to leptospires and may act as urinary shedders of this pathogen, thus indicating a possible role of this species in disease transmission. Clinical data indicates that acute infection is mostly atypical when compared to dogs, and due to difficulties to define an archetypal clinical presentation in cats, feline leptospirosis is likely to be underdiagnosed disease in this species.

Seroprevalence of pathogenic Leptospira serogroups in asymptomatic domestic dogs and cats: systematic review and meta-analysis

Leptospirosis is a neglected zoonotic disease transmitted by contact with the urine of animals infected with pathogenic species of the bacteria Leptospira or by contact with environments contaminated with the bacteria. Domestic dogs and cats may act as reservoirs or as sentinels of environmental contamination with leptospires, posing a public health concern. There is a great diversity of leptospires, and one common way to classify them is into serogroups that provide some information on the host species they are associated with. The aims of this study were: (1) to quantitatively summarize the overall prevalence and serogroup-specific prevalence of antibodies against pathogenic leptospires in asymptomatic dogs and cats and (2) to identify environmental and host characteristics that may affect the prevalence. Three electronic databases and the reference lists of eligible articles were screened, for epidemiological studies conducted between the years 2012-2022. We estimated overall and serogroup-specific prevalence using three-level meta-analysis models and assessed potential sources of heterogeneity by moderator analysis and meta-regression. Eighty-four studies met the inclusion criteria (dog studies 66.7%, cat studies 26.2%, and both species 7.1%). There were significant differences between dogs and cats in the overall prevalence model (P < 0.001), but not in the serogroup-specific model (P>0.05). In dogs, the prevalence of Leptospira interrogans serogroup Canicola was significantly higher than the other pathogenic serogroups (P < 0.001), while in cats there were no significant differences among serogroups (P = 0.373). Moderator analysis showed that the prevalence of L. kirschneri serogroup Grippotyphosa was significantly higher in stray/sheltered dogs than in domiciled dogs (P = 0.028). These results suggest that pathogenic serogroups associated with small mammals are circulating among asymptomatic pets and should be taken into account in the transmission cycle of leptospires, as well as in the standard MAT panel for diagnosis in dogs and cats. It also highlights the importance of including both dogs and cats as potential reservoirs when conducting eco-epidemiological studies in different geographical and ecological areas.

Feline leptospirosis prevalence worldwide: A systematic review and meta-analysis of diagnostic approaches

Background and Aim

Leptospirosis in felids (domestic and wild cats) presents an ongoing challenge in our understanding. Numerous studies have reported the detection of Leptospira spp. in these feline populations, highlighting their potential as zoonotic carriers. This systematic review and meta-analysis aimed to provide insight into the global prevalence of leptospirosis in domestic and wild cats.

Materials and Methods

We conducted extensive searches across five databases (PubMed, Scopus, Web of Science, Science Direct, and Google Scholar) following the Preferred Reporting Items for Systematic Reviews and Meta-analyses Protocols guidelines. Random-effect meta-analyses were performed using R software version 4.3.0 to estimate pooled prevalence rates. Subgroup meta-analyses were conducted based on continents, diagnostic methods, sample types, and wildcat genera.

Results

A total of 71 articles on leptospirosis in domestic cats and 23 articles on leptospirosis in wild cats met the eligibility criteria. Our findings indicated a significantly higher pooled seroprevalence of leptospirosis in domestic cats compared with infection prevalence (9.95% [95% confidence interval (CI), 7.60%-12.54%] vs. 4.62% [95% CI, 2.10%-7.83%], p = 0.01). In contrast, no significant difference was observed in pooled seroprevalence and infection prevalence among wild cats (13.38% [95% CI, 6.25%-21.93%] vs. 2.9% [95% CI, 0.00%-18.91%], p = 0.21). A subgroup meta-analysis of domestic cats revealed significant differences in seroprevalence across continents, sample types, and diagnostic methods. On the contrary, wild cats had no significant differences in any of the subgroups.

Conclusion

Leptospira spp. have evidently been exposed to both domestic and wild cats, highlighting their potential roles as reservoir hosts for leptospirosis. These findings highlight the importance of considering felids as a possible public health threat.

Population measles seroprevalence: Heterogeneity by birth-year cohort

Objective

This work sought to estimate population measles seroprevalence and heterogeneity in the antibody concentration distribution that could be explained by the birth-year cohort according to the opportunity of viral and vaccine exposure, applied to data from Medellín, Colombia.

Methods

Prevalence of IgG antibodies was analyzed for measles based on a population study with a random sample of 2098 individuals from 6 to 64 years of age. Finite mixture models were used to estimate global seroprevalence and that of three birth-year cohorts (I: born up to 1982; II: 1983-1994; III: born since 1995). Multiple linear regression permitted adjusting the concentration of antibodies by cohort, zone, and sex.

Results

Globally, seronegativity was 6.5% (95% CI 4.9- 8.6), seropositivity of 78.4% (95% CI 75.1-81.4), and equivocal of 15.1% (95% CI 12.5-18.1). Two components were found with skewed normal distribution, which reclassified those equivocal as seropositive. Differences were observed by cohort in the geometric mean of antibodies [Cohort I: 1704.6; II: 562.2; III: 802.1 milli-international units per milliliter (mIU/mL] and seronegativity (Cohort I: 4%; II:13.3%; III: 8.9%). Antibody concentration increased by 1.26 mIU/mL in residents in the rural area, while diminishing in individuals from cohort II (by 3.02 mIU/mL) and cohort III (by 2.14 mIU/mL).

Conclusion

The younger cohorts (II and III) had a lower antibody concentration (higher seronegativity), indicating the need to monitor periodically seroprevalence and an eventual reestablishment of the transmission in these groups with higher risk of infection.

A case-control study of agricultural and behavioral factors associated with leptospirosis in Vietnam

Introduction

Leptospirosis is a neglected disease in Vietnam. Until now, there has been limited knowledge about risk factors of this disease in Vietnam. The study was carried out to identify agricultural and behavioral factors associated with the transmission of leptospirosis in Vietnam.

Methods

This matched retrospective hospital-community-based case–control study was conducted from 1 October 2018 to 31 October 2019. We recruited cases from 11 selected government hospitals in three provinces of Vietnam, while controls were selected from the same communes of cases and matched by age (± 2 years) and sex. Microscopic agglutination test (MAT) and enzyme-linked immunosorbent assay (ELISA) were applied to determine confirmed cases, while only MAT was used to identify controls with a single high MAT titer < 1:100.

Results

504 participants (252 cases and 252 controls) were identified. Cultivating (OR 2.83, CI 1.38–5.79), animal farming (OR 8.26, CI 2.24–30.52), pig owners (OR 10.48, CI 5.05–21.73), cat owners (OR 2.62, CI 1.49–4.61) and drinking unboiled water (OR 1.72, CI 1.14 –2.59, p = 0.010) were significantly associated with human leptospirosis in Vietnam. Hand washing after farming/ gardening (OR 0.57, CI 0.38–0.86, p = 0.007) and bathing after farming, gardening, contact with cattle and poultry (OR 0.33, CI 0.19–0.58, p = 0.000) were determined as protective factors for this disease.

Conclusions

In short, the case–control study has revealed the risks in agricultural and animal practices and protective behavioral factors related to human leptospirosis in Vietnam. The findings suggested promotion of communication and health education programs targeting health behaviors in daily life and agricultural practices. Using personal protective equipment such as gowns, gloves, and boots during agricultural practices, especially cultivating and animal farming, is most recommended.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07561-6.

Herpesviruses Serology Distinguishes Different Subgroups of Patients From the United Kingdom Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Biobank

The evidence of an association between Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and chronic herpesviruses infections remains inconclusive. Two reasons for the lack of consistent evidence are the large heterogeneity of the patients' population with different disease triggers and the use of arbitrary cutoffs for defining seropositivity. In this work we re-analyzed previously published serological data related to 7 herpesvirus antigens. Patients with ME/CFS were subdivided into four subgroups related to the disease triggers: S0-42 patients who did not know their disease trigger; S1-43 patients who reported a non-infection trigger; S2-93 patients who reported an infection trigger, but that infection was not confirmed by a lab test; and S3-48 patients who reported an infection trigger and that infection was confirmed by a lab test. In accordance with a sensitivity analysis, the data were compared to those from 99 healthy controls allowing the seropositivity cutoffs to vary within a wide range of possible values. We found a negative association between S1 and seropositivity to Epstein-Barr virus (VCA and EBNA1 antigens) and Varicella-Zoster virus using specific seropositivity cutoff. However, this association was not significant when controlling for multiple testing. We also found that S3 had a lower seroprevalence to the human cytomegalovirus when compared to healthy controls for all cutoffs used for seropositivity and after adjusting for multiple testing using the Benjamini-Hochberg procedure. However, this association did not reach statistical significance when using Benjamini-Yekutieli procedure. In summary, herpesviruses serology could distinguish subgroups of ME/CFS patients according to their disease trigger, but this finding could be eventually affected by the problem of multiple testing.

Leptospira infection among human-close-contact animals in different geographical areas in Vietnam

Leptospirosis is a neglected disease in Vietnam. Only a few studies have evaluated the status of Leptospira infection in both humans and animals. To our knowledge, this is the first serological survey of Leptospira in both domestic and wild animals, which may act as reservoirs of this agent. This study aimed to evaluate the seroprevalence of Leptospira in animals that are in close contact with humans in different geographical areas in Vietnam. Sera were collected from 1205 individual animals of six species, including buffaloes, cattle, cats, dogs, swine, and rats. The microscopic agglutination test (MAT) against 25 serovars of Leptospira spp. has been employed to detect serovars of Leptospira among the studied population. Overall, 44.2% of buffaloes, 24.9% of cattle, 10.2% of swine, 32.9% of dogs, 12.2% of cats, and 16% of rats were seropositive. A total of 17 different serovars were detected, of which serovars Hebdomadis and Canicola circulated in all the studied animal species. Variability of the predominant serovars circulating in animal species and in different geographical areas of Vietnam has been noted. We conclude that this study showed a high prevalence of Leptospira circulating in animals that are in close contact with humans, raising an alert of the important sources of pathogenic leptospires transmission to humans in Vietnam. These findings prove an imperative need for effective measures for disease prevention.