The elevated serum urea:creatinine ratio in canine babesiosis in South Africa is not of renal origin

The Diverse Pathogenicity of Various Babesia Parasite Species That Infect Dogs

Babesia species infect a very wide range of mammal hosts across the globe, and zoonotic infections are of growing concern. Several species of the Babesia genus infect dogs, and some of these cause significant morbidity and mortality. The Apicomplexan parasite resides within the red cell and infections result in direct damage to the host through intra- and extravascular hemolysis. An exuberant inflammatory response by the host to some species of Babesia parasites also results in significant collateral damage to the host. Canine infections have been the subject of many studies as the well-being of these companion animals is increasingly threatened by the spread of tick vectors and an increasingly mobile dog population. There are currently no widely available and effective vaccines, and effective treatment can be challenging. Understanding disease pathogenesis underlies the development of new treatments. The varying pathogenicity of the various Babesia parasite species that infect dogs offers an opportunity to explore the molecular basis for the wide range of diseases caused by infection with this parasite genus. In this review, we focus on what has been reported about the clinical presentation of Babesia-infected dogs in an attempt to compare the severity of disease caused by different Babesia species.

Association between Increased the De Ritis Quotient and Renal Azotaemia in Canine Babesiosis

Simple Summary

This study investigated the association between increased serum aspartate aminotransferase (AST) activity and renal indices such as renal failure index, sodium fractional excretion, and urinary creatinine to serum creatinine ratio in dogs with renal azotaemia infected with Babesia canis. This research revealed that increased serum AST activity in azotaemic dogs may be of renal origin, and the de Ritis quotient may be a convenient and useful tool in the recognition of renal azotaemia in canine babesiosis.

Abstract

Previous studies of azotaemia in canine babesiosis revealed pre-renal and renal azotaemia in infected dogs, and an association between an increased de Ritis quotient (aspartate aminotransferase to alanine aminotransferase activity; AST/ALT ratio) and azotaemia in affected animals. Serum activities of AST and ALT, and AST/ALT ratio were compared between azotaemic and non-azotaemic dogs infected with Babesia canis, and between affected dogs with pre-renal and renal azotaemia. Statistical analyses revealed higher AST activity and an increased AST/ALT ratio in azotaemic dogs, and an increase of these two parameters in infected dogs with renal azotaemia in comparison to dogs with pre-renal azotaemia. Moreover, AST activity and AST/ALT ratio were correlated with renal indices such as renal failure index, sodium fractional excretion, and urinary creatinine to serum creatinine ratio. The study also revealed a lack of correlation between AST and ALT activities in azotaemic dogs, although a correlation was observed when including all dogs in this study (azotaemic and non-azotaemic dogs treated as one group). The results of this study indicate that increased serum AST activity in azotaemic dogs infected with B. canis may have a renal origin, and the AST/ALT ratio could be considered as a simple and convenient renal index that is useful in the recognition of renal azotaemia in canine babesiosis.

Laboratory Predictors of COVID-19 Pneumonia in Patients with Mild to Moderate Symptoms

OBJECTIVE

This research aims to develop a laboratory model that can accurately distinguish pneumonia from nonpneumonia in patients with COVID-19 and to identify potential protective factors against lung infection.

METHODS

We recruited 50 patients diagnosed with COVID-19 infection with or without pneumonia. We selected candidate predictors through group comparison and punitive least absolute shrinkage and selection operator (LASSO) analysis. A stepwise logistic regression model was used to distinguish patients with and without pneumonia. Finally, we used a decision-tree method and randomly selected 50% of the patients 1000 times from the same specimen to verify the effectiveness of the model.

RESULTS

We found that the percentage of eosinophils, a high-fluorescence-reticulocyte ratio, and creatinine had better discriminatory power than other factors. Age and underlying diseases were not significant for discrimination. The model correctly discriminated 77.1% of patients. In the final validation step, we observed that the model had an overall predictive rate of 81.3%.

CONCLUSION

We developed a laboratory model for COVID-19 pneumonia in patients with mild to moderate symptoms. In the clinical setting, the model will be able to predict and differentiate pneumonia vs nonpneumonia before any lung computed tomography findings. In addition, the percentage of eosinophils, a high-fluorescence-reticulocyte ratio, and creatinine were considered protective factors against lung infection in patients without pneumonia.

Prognostic markers and their discriminant score in predicting the outcome of Babesia gibsoni infection

BACKGROUND

We aimed to identify prognostic markers and their discriminant score in predicting the lethal outcome of canine Babesia gibsoni.

METHODS

Blood samples were collected from 108 client-owned dogs with clinical signs commensurate with babesiosis to analyze haematological, biochemical, haemostatic, antioxidant profile and thiobarbituric acid reactive substance levels. Samples were screened for Babesia infection (microscopic and molecular techniques). Babesiosis-affected dogs were classified into survivors and non-survivors, and 30 healthy dogs were used in the control group.

RESULTS

Haemoglobin, thrombocytes, catalase, urea, creatinine, alanine aminotransferase (ALT), alkaline phosphatase, lactate and reticulocytes were highly correlated to survival. Receiver operating characteristics analysis revealed urea, ALT and lactate as specific prognostic markers for the disease. The formula for calculation of discriminant scores (Di) for lethal outcome of the disease was generated with cut-off score 0.141. The scoring system was 79% sensitive and 83% specific in predicting the lethal outcome of the disease.

CONCLUSIONS

A scoring system developed from the prognosticating markers may aid in predicting the outcome of Babesia gibsoni infection on the day of presentation itself enabling intensive care for those animals with a cut-off score more than 0.141.

A clinical and pathological description of 320 cases of naturally acquired Babesia rossi infection in dogs

Babesia rossi causes the most severe clinical disease in dogs of all the babesia parasites. We included 320 naturally-infected dogs that presented for care at the Onderstepoort Veterinary Academic Hospital between 2006 and 2016. All dogs had mono-infections confirmed by multiplex PCR. The data allowed more accurate clinical classification of the disease and identified parameters that were associated with disease severity and death. Odds ratios for dying were significant (P < 0.05) for increased band neutrophil count, collapse at presentation; presence of cerebral signs; hypoglycaemia; hyperlactatemia; high urea, high creatinine; hyperbilirubinaemia; hypercortisolaemia; and hypothyroxinaemia. Joint component analysis confirmed that the variables with significant odds ratios grouped together with death. Yet, multivariate logistic regression was unable to identify a group of significant independent predictors of death. Receiver Operator Characteristic curves indicated that low total thyroid hormone, high bilirubin, high serum urea and high cortisol concentrations were the variables with the highest sensitivity and specificity for death. These data provide both the clinician and researcher with a set of easily-measured laboratory and clinical assessments to classify cases into those that are uncomplicated and those that are complicated. The disease is complex and multisystemic and probably involves mechanisms more proximal in the pathogenesis than those that have been evaluated.

Canine babesiosis in a male Boerboel: Hematobiochemical and anatomic pathological changes in the cardiorespiratory and reproductive organs

A 9-month old male Boerboel was presented at the University of Abuja Small Animal Clinic with a primary complaint of inappetence and micturition with brownish-yellow urine. Physical examination revealed pale mucous membranes, enlarged pre-scapular lymph nodes, bilateral ocular discharges, pyrexia (41.2 °C), depression and the presence of ticks of the genus Rhipicephalus sanguineus on the body of the animal. History revealed that the dog was recently vaccinated against canine distemper, hepatitis, leptospirosis, parainfluenza, parvovirus (DHLPP) and rabies six days prior to the onset of clinical signs, and had been anorexic. Following clinical examination, blood and faecal samples were collected for biochemical and parasitological analyses, and the results revealed the presence of intraerythrocytic Babesia parasites, normocytic and normochromic anaemia with extensive cellular damage. However, during the course of the investigation, the dog died. With appropriate consent, a post-mortem examination was carried out. Diffuse oedema with interstitial pneumonia in the lung, focal haemorrhage with cellular infiltration in the heart and progressive necrosis of epithelial cells within the seminiferous tubules of the testicles were observed. Many of the observed clinicopathological alterations were consistent with complicated babesiosis. However, in the current case, some unique systemic complications such as testicular degeneration, which has not been previously observed in the Boerboel are discussed.

Cystatin C: a new renal marker and its potential use in small animal medicine

The occurrence of chronic kidney disease is underestimated in both human and veterinary medicine. Glomerular filtration rate (GFR) is considered the gold standard for evaluating kidney function. However, GFR assessment is time-consuming and labor-intensive and therefore not routinely used in practice. The commonly used indirect GFR markers, serum creatinine (sCr) and urea, are not sufficiently sensitive or specific to detect early renal dysfunction. Serum cystatin C (sCysC), a proteinase inhibitor, has most of the properties required for an endogenous GFR marker. In human medicine, numerous studies have evaluated its potential use as a GFR marker in several populations. In veterinary medicine, this marker is gaining interest. The measurement is easy, which makes it an interesting parameter for clinical use. This review summarizes current knowledge about cystatin C (CysC) in humans, dogs, and cats, including its history, assays, relationship with GFR, and biological and clinical variations in both human and veterinary medicine.

An overview of glomerular filtration rate testing in dogs and cats

Determination of glomerular filtration rate (GFR) is a valuable, yet underused, diagnostic tool for evaluating renal function in dogs and cats. This article first reviews the hormonal and hemodynamic factors which contribute to GFR, followed by a description of considerations when selecting a pharmacokinetic model and methods of animal-to-animal standardization. The best-characterized existing GFR markers, including creatinine, radiolabeled markers, and iohexol, are reviewed in depth, as well as alternative but lesser used techniques. A weighted means analysis of reported GFR measurements in healthy dogs and cats and a review of selected studies that have examined GFR alterations in animals with naturally occurring and experimental diseases provide the reader with preliminary guidelines on expected GFR results in these species and disease conditions.

Changes in the serum urea: creatinine ratio in dogs with babesiosis, haemolytic anaemia, and experimental haemoglobinaemia

The purpose of this study was to determine serum urea and creatinine concentrations, the derived urea : creatinine (UC) ratios, haemoglobin concentrations and glomerular filtration rates (GFR) in dogs with haemolytic anaemia and those with experimentally induced anaemia and/or haemoglobinaemia. There were 25 dogs with babesiosis (group 1), 13 control animals (group 2), six dogs with induced haemoglobinaemia and anaemia (group 3), six with induced haemoglobinaemia (group 4), and 14 with immune-mediated haemolytic anaemia (IMHA) (group 5). The median serum urea concentration was 11.18 mmol/L (group 1), 4.3 mmol/L (group 2), 4.3 mmol/L (group 3), 4.35 mmol/L (group 4), and 8.5 mmol/L (group 5). Median serum creatinine was 67 μmol/L (group 1), 75 μmol/L (group 2), 78.5 μmol/L (group 3), 84 μmol/L (group 4), and 82 μmol/L (group 5). Median serum haemoglobin was 1.3g/L (group 1), 0.8 g/L (group 2), 9 g/L (group 3), 3g/L (group 4), and 1.3g/L (group 5). The median UC ratio was 41.35 (group 1), 15.36 (group 2), 14.18 (group 3), 13.6 (group 4), and 14.15 (group 5). GFR was normal in all five groups. Serum urea concentration and the UC ratio were significantly greater in dogs with babesiosis than in those with IMHA, experimentally induced anaemia and/or haemoglobinaemia.

Clinical management of canine babesiosis

OBJECTIVE

To review and summarize current information regarding epidemiology, pathogenesis, and pathophysiology leading to the various clinical syndromes associated with canine babesiosis. Diagnosis, treatment, preventative strategies, and zoonotic implications are discussed.

ETIOLOGY

Babesiosis is caused by hemoprotozoa of the genus Babesia. Numerous species of Babesia exist worldwide. An increased incidence of babesiosis is described, especially in North America. The babesial organism spends the majority of its life cycle within the erythrocyte of the definitive host, resulting in hemolysis, with or without systemic complications.

DIAGNOSIS

Definitive diagnosis depends on direct visualization of the organism on blood smear or polymerase chain reaction. A positive serologic antibody test indicates exposure with or without active infection.

THERAPY

Antiprotozoal drugs, antimicrobials, and supportive care are the mainstays of babesiosis therapy.

PROGNOSIS

Prognosis depends on the severity of disease, which in turn depends on both organism and host factors. Clinical syndromes associated with a poorer prognosis include red biliary syndrome, acute renal failure, acute respiratory distress syndrome, neurologic dysfunction, acute pancreatitis, cardiac dysfunction, and hypoglycemia.