Clinical assessment of a point-of-care assay to determine protective vaccinal antibody titers to canine viral diseases.

Guidelines recommend that dogs are vaccinated for canine distemper virus (CDV), canine parvovirus (CPV), and canine adenovirus (CAV) every 3 years. Alternatively, their antibody titers are measured and vaccines given when titers fall below a protective threshold. In this study, a point-of-care (POC) assay was compared to hemagglutination inhibition (for CPV) and virus neutralization (for CAV and CDV) assays to predict the need for revaccination Ninety-two dogs presented for vaccination were enrolled. The POC assay indicated protective titers against CDV in 79/80, CPV in 89/90, and CAV in 91/91 dogs with reference standard antibody measurements that were over a protective threshold. The sensitivity of the POC assay for to detect protective concentrations of CDV antibodies was 99% (95% confidence interval [CI 95%], 93.3-99.9%). Ten dogs were falsely considered protected against CDV by the POC assay with a specificity of 17% (CI 95%, 3.0-44.8%). The sensitivity of the POC assay for protective concentrations of CPV titers was 99% (CI 95%, 93.9-99.9%). The sensitivity of the POC assay to detect protective concentrations of CAV antibodies was 100% (CI 95%, 95.9-100%). Only classifying high-positive CDV and CPV titers on the POC assay as protective improved assay specificity to 100%, but sensitivity decreased to 51% and 76% respectively. This POC assay had a high sensitivity for the detection of protective antibody titers; however, some dogs were falsely categorized as protected, especially for CDV.

A comparison of the Sepsis-2 and Sepsis-3 definitions for assessment of mortality risk in dogs with parvovirus.

OBJECTIVE: To evaluate the use of a modified Sepsis-3 (mSepsis-3) definition compared to the currently used modified Sepsis-2 (mSepsis-2) definition to determine whether the mSepsis-2 or mSepsis-3 stratifications were able to identify populations of dogs ultimately more likely to die from canine parvovirus (CPV) infection. DESIGN: Retrospective, January 2009 to March 2020. SETTING: A private, small animal, urban, referral emergency and specialty hospital. ANIMALS: Fifty-nine client-owned dogs hospitalized for treatment of CPV. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Dogs were divided into mSepsis-2 and mSepsis-3 categories based on the highest level of illness severity reached during hospitalization. Greater illness severity based on mSepsis-2 criteria (ie, sepsis, severe sepsis, septic shock) was associated with an increase in average length of stay (P < 0.001), increase in average cost of stay (P < 0.01), and presence of leukopenia (P < 0.05). An increase in illness severity within the mSepsis-2 criteria was not associated with hyperlactatemia (P = 0.29), presence of neutropenia (P = 0.12), or mortality (P = 0.35). Greater illness severity based on mSepsis-3 criteria (ie, infection only, sepsis, septic shock) was associated with an increase in mortality (P < 0.05), increase in average length of stay (P < 0.001), increase in average cost of stay (P < 0.01), presence of leukopenia (P < 0.01), and presence of neutropenia (P < 0.05). The mSepsis-3 criteria were not associated with the presence of hyperlactatemia (P = 0.68). There was no significant difference between survivors and nonsurvivors in the presence of leukopenia (P = 0.19), neutropenia (P = 0.67), or hyperlactatemia (P = 0.58). CONCLUSIONS: The mSepsis-3 diagnostic criteria appear to better identify dogs with CPV at higher risk for mortality compared to the mSepsis-2 criteria.

The role of the sequential organ failure assessment score in evaluating the outcome in dogs with parvoviral enteritis.

SCIENTIFIC BACKGROUND: The aim of this prospective study was to assess whether the Sequential Organ Failure Assessment (SOFA) score could be indicative of outcome (survival to discharge) in dogs with parvoviral enteritis. METHODS: In 35 naturally infected dogs, the SOFA score and clinical score were calculated and the presence of systemic inflammatory response syndrome was verified on admission and during the first four days of hospitalization. RESULTS: 26 dogs survived, and out of the 9 non-survivors, 6 dogs had positive blood cultures. Mean SOFA scores and clinical scores between survivors and non-survivors and between septic and non-septic dogs on admission and on each hospitalization day were significantly different. Trends in SOFA score indicated that in non-survivors and septic dogs there was an increase in SOFA score during the first four days of hospitalization and a decrease occurred in survivors and non-septic dogs. The area under the curve (ROC curve analysis) for SOFA score predicting the outcome was 0.797 and predicting sepsis was 0.834. The best cut-off point of SOFA score for predicting the final outcome was 3.5 and the best cut-off of SOFA score for predicting sepsis was also 3.5. CONCLUSIONS: Either single values or trends in SOFA score can assist in suspecting sepsis and reaching prognosis in parvoviral enteritis.

Molecular phylogenetic assessment of the canine parvovirus 2 worldwide and analysis of the genetic diversity and temporal spreading in Brazil.

Canine parvovirus type 2 (CPV-2) is a relevant pathogen for dogs and causes a severe disease in carnivore species. CPV-2 reached pandemic proportions after the 1970s with the worldwide dissemination, generating antigenic and genetic variants (CPV-2a, CPV-2b, and CPV-2c) with different pathobiology in comparison with the original type CPV-2. The present study aimed to assess the current global CPV-2 molecular phylogeny and to analyze genetic diversity and temporal spreading of variants from Brazil. A total of 284 CPV-2 whole-genome sequences (WGS) and 684 VP2 complete genes (including 23 obtained in the present study) were compared to analyze phylogenetic relationships. Bayesian coalescent analysis estimated the time to the most recent common ancestor (tMRCA) and the population dynamics of the different CPV-2 lineages in the last decades. The WGS phylogenetic tree demonstrated two main clades disseminated worldwide today. The VP2 gene tree showed a total of four well-defined clades distributed in different geographic regions, including one with CPV-2 sequences exclusive from Brazil. These clades do not have a relationship with the previous classification into CPV-2a, CPV-2b, and CPV-2c, despite some having a predominance of one or more antigenic types. Temporal analysis demonstrated that the main CPV-2 clades evolved within a few years (from the 1980s to 1990s) in North America and they spread worldwide afterwards. Population dynamics analysis demonstrated that CPV-2 presented a major dissemination increase at the end of the 1980s / beginning of the 1990s followed by a period of stability and a second minor increase from 2000 to 2004.

Why serology just is not enough: Strategic parvovirus risk assessment using a novel qPCR assay.

Health monitoring of laboratory rodents not only improves animal health but also enhances the validity of animal experiments. In particular, infections of laboratory animals with murine parvoviruses influence biomedical research data. Despite strict barrier housing, prevalence remains high in animal facilities, leading to increased risk of parvovirus introduction after the import of contaminated mice. Unfortunately, hygienic rederivation can be challenging, since gametes often contain residual virus material. Consequently, the process has to be closely monitored with highly sensitive diagnostic methods to verify parvovirus decontamination of the rederived progeny. However, diagnostic sensitivity of traditional methods is often low and requires testing of large animal cohorts. Therefore, we aimed to develop a powerful quantitative real-time polymerase chain reaction (qPCR) assay for the fast and reliable detection of murine parvoviruses in different sample materials. We validated the assay within an infection experiment and systematically analysed various animal-derived and environmental sample materials. We further developed a strategic risk assessment procedure for parvovirus monitoring after embryo transfer. Our novel qPCR assay reliably detected parvovirus DNA in a broad variety of sample materials, with environmental samples dominating in the acute phase of infection, whereas animal-derived samples were more suitable to detect low virus loads in the chronic phase. Here, the assay served as a highly sensitive screening method for parvovirus contamination in mouse colonies, requiring significantly lower sample sizes than traditional methods like conventional PCR and serology. Thus, the use of our novel qPCR assay substantially improves parvovirus diagnostics, enhancing research validity according to the 6Rs.

Development of cost-effective quantitative PCR method for parallel detection of porcine circovirus2 and porcine parvovirus in perspective of North-eastern India.

Pig farming performs as an intricate part in the socio-economic situation in the north-eastern region of India. This region contributes 38% (3.95 million) of total pigs in India. In spite of this, the region unables to flourish as an enterprise as per the expectation due to a low productivity rate. Porcine infectious pathogens like porcine cirovirus2 (PCV2) and porcine parvovirus (PPV) have a direct economic impact on pig farming through slow growth rate, abortion, and mortality and ultimately maximize the production cost by increasing the usage of antibiotic or antiviral drugs. The veterinary diagnostic infrastructure is a fundamental aspect of the development of livestock status by rapid and effective detection of pathogens. Quantitative PCR (qPCR) is a precise and fast-track technique used for the routine diagnostic method. Hence, we developed a highly precise and comparatively cost-effective SYBR Green reporter dye-based qPCR assay for parallel identification of PCV2 and PPV. In the present assay, the correlation coefficient (R2) value was 0.99, and 10 copies of the gene/µl were the least limit of detection (LOD) concerning both viruses. Melt curve analysis of this study represented PCV2-specific melt curve (Tm) at 81.2 °C and PPV-specific melt curve (Tm) at 73.5 °C. Therefore, the assay easily differentiates the true positive amplicons of PCV2 and PPV through specific Tm values. Among the 50 field samples, 26 (52%) samples were PCV2 positive, 18 (36%) samples PPV positive, and 11 (22%) samples were co-infected of both the viruses. This method is cost-effective, precise, and sensitive to diagnose the concurrent or individual infection of the PCV2 and PPV in the pig. Hence, considering the impact of pig farming in the north-eastern part of the country, the present assay gives an unprecedented achievement in disease diagnosis.

Assessment of certain biomarkers for predicting survival in response to treatment in dogs naturally infected with canine parvovirus.

Canine parvovirus (CPV) enteritis is an important cause of morbidity and mortality in puppies despite aggressive treatment. Identification of reliable biomarkers for CPV enteritis is essential to determine the severity, duration of hospitalization, and predict the clinical outcome. Meanwhile, the biomarkers will assist in decision-making with clients about the further course of treatment or euthanasia. The present study was conducted to evaluate the changes of total leukocyte count (TLC), neutrophil count, and serum concentrations of creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), intestinal fatty acid binding protein-2 (IFABP-2), albumin, ceruloplasmin (Cp), cortisol, free triiodothyronine (FT3) and free thyroxine (FT4) in survivors and non-survivors as a predictor of the clinical outcome. Marked leukopenia, neutropenia, hypoalbuminemia, elevated levels of CK-MB, IFABP-2, Cp, and cortisol were noticed in CPV-infected dogs than healthy dogs but, LDH, FT3 and FT4 concentrations did not differ significantly. The CPV-infected non-survivors had persistent leukopenia, neutropenia and elevated CK-MB, IFABP-2, Cp and cortisol concentrations at 72 h of commencement of treatment. In CPV-infected survivors, TLC and neutrophil count were significantly increased, and CK-MB, IFABP-2, Cp and cortisol concentrations were significantly decreased at 72 h of commencement of treatment. The positive predictive values (PPVs) for survival using cut-off value of TLC (>3.2 × 103/µL), neutrophil count (>1.65 × 103/µL), CK-MB (≤234.50 U/L), IFABP-2 (≤7.61 ng/mL), Cp (≤0.605 g/L) and cortisol (≤16.90 ng/mL) were determined as 89.47%, 88.88%, 94.73%, 93.33%, 94.44% and 89.47%, respectively with better area under receiver operating characteristic (ROC) curve as well as sensitivity. The magnitude of decrease in TLC, neutrophil count, and increase in CK-MB, IFABP-2, Cp and cortisol concentrations at 72 h of initiation of treatment in dogs with parvoviral enteritis could be useful indicators for the prognosis of the disease. Based on sensitivity (%) and specificity (%) from ROC curve analysis and PPV (%), it is concluded that serum CK-MB concentration will serve as the most useful biomarker followed by Cp and absolute neutrophil count.

Assessment of intestinal and cardiac-related biomarkers in dogs with parvoviral enteritis.

The aim of this study was to evaluate the intestinal and cardiac biomarkers in the determination of intestinal and cardiac damage in dogs with parvoviral enteritis. The material of this study consisted of 10 healthy dogs (control group) and 30 dogs with parvoviral enteritis (experimental group) admitted to the Department of Internal Medicine, Faculty of Veterinary Medicine, Selcuk University.Serum samples were extracted from the collected blood samples taken from vena cephalicavenipuncture for analysis of blood gases, haemogram and to measure the levels of intestinal-fatty acid-binding protein (I-FABP), trefoil factor 3 (TFF-3), claudin-3 (CLDN-3), heart-type fatty acid-binding protein (H-FABP), cardiac troponin I (cTnI), and creatine kinase-myocardial band (CK-MB) by enzyme linked immunosorbent assay (ELISA) test kits. Statistically significant decreases in the blood gas hydrogen ion concentration (pH), partial pressure of oxygen (pO2), sodium (Na), bicarbonate (HCO3), and oxygen saturation (SatO2) levels and significant increase in the levels of I-FABP, TFF-3, CK-MB, cTnI and also in the haemogram, a decrease in leukocyte (WBC) level and an increase in platelet (THR) level were detected in parvoviral dogs compared to the control group (p⟨0.05). Also ROC analysis revealed on 0th hour for the utility of I-FABP and on 48th hour for TFF-3 in differentiating in the experimental group between the survivor and non-survivor dogs. Other intestinal-related biomarker (CLDN-3) and none of the cardiac-related biomarkers (H-FABP, CK-MB and cTnI) are not high enough for prediction of mortality.In conclusion, it was determined that I-FABP and TFF-3 for the intestinal injury and morta-lity prediction, and CK-MB and cTnI for the cardiac injury were useful and reliable biomarkers to determine the damage caused by parvovirus in dogs.

Canine parvovirus prevention-What influence do socioeconomics, remoteness, caseload and demographics have on veterinarians' perceptions and behaviors?

Canine parvovirus (CPV) is a cause of severe disease in dogs globally, yet is preventable by vaccination. A range of vaccination protocols are used by veterinary practitioners with evidence suggesting some protocols provide better protection than others in high infection-risk situations. This study investigated associations between veterinarians' vaccination recommendations and hospital remoteness, socioeconomic disadvantage, CPV caseload, and veterinarian perceptions and demographics. A national Australian veterinary survey in 2017 received 569 practitioner responses from 534 unique hospitals (23.6 % response rate). Respondents from major city hospitals had the lowest perceptions of the national CPV caseload (p < 0.0001). Those from hospitals with mild to moderate caseloads (6-40 cases per annum) recommended more frequent puppy revaccination - which is considered more protective - than those with the highest caseload (p = 0.0098), which might increase vaccination failure risk. Respondents from the most socioeconomically disadvantaged regions were over-represented in recommending annual revaccination of adult dogs; those from the least disadvantaged regions were over-represented in recommending triennial revaccination (p < 0.0001). Hospitals with higher CPV caseloads, greater socioeconomic disadvantage or increased remoteness did not favor two puppy vaccination protocols that are considered more protective (younger first vaccination age or older final vaccination age), despite these regions presenting higher CPV caseload risk. Titer testing to determine whether to revaccinate was more likely to be used in major city hospitals (p = 0.0052) and less disadvantaged areas (p = 0.0550). University of graduation was associated with CPV caseload, remoteness and level of socioeconomic disadvantage of the region where the graduate worked. University of graduation was significantly associated with age for final puppy vaccination and titer-testing recommendations. Graduates from one university were over-represented in recommending an earlier (10-week) finish protocol and titer testing, compared to all other universities. Year and university of graduation, and respondent's age were associated with a number of vaccination protocol recommendations suggesting that inherent biases might affect veterinarians' decisions. Emphasis on currently recommended vaccination protocols in undergraduate curricula and more protective vaccination protocol use in higher-risk regions could reduce immunization failure and CPV caseload.

Assessment of Immunological Response and Impacts on Fertility Following Intrauterine Vaccination Delivered to Swine in an Artificial Insemination Dose.

To protect the health of sows and gilts, significant investments are directed toward the development of vaccines against infectious agents that impact reproduction. We developed an intrauterine vaccine that can be delivered with semen during artificial insemination to induce mucosal immunity in the reproductive tract. An in vitro culture of uterine epithelial cells was used to select an adjuvant combination capable of recruiting antigen-presenting cells into the uterus. Adjuvant polyinosinic:polycytidylic acid (poly I:C), alone or in combination, induced expression of interferon gamma, tumor necrosis factor alpha, and select chemokines. A combination adjuvant consisting of poly I:C, host defense peptide and polyphosphazene (Triple Adjuvant; TriAdj), which previously was shown to induce robust mucosal and systemic humoral immunity when administered to the uterus in rabbits, was combined with boar semen to evaluate changes in localized gene expression and cellular recruitment, in vivo. Sows bred with semen plus TriAdj had decreased γδ T cells and monocytes in blood, however, no corresponding increase in the number of monocytes and macrophages was detected in the endometrium. Compared to sows bred with semen alone, sows bred with semen plus TriAdj showed increased CCL2 gene expression in the epithelial layer. These data suggest that the adjuvants may further augment a local immune response and, therefore, may be suitable for use in an intrauterine vaccine. When inactivated porcine parvovirus (PPV) formulated with the TriAdj was administered to the pig uterus during estrus along with semen, we observed induction of PPV antibodies in serum but only when the pigs were already primed with parenteral PPV vaccines. Recombinant protein vaccines and inactivated PPV vaccines administered to the pig uterus during breeding as a primary vaccine alone failed to induce significant humoral immunity. More trials need to be performed to clarify whether repeated intrauterine vaccination can trigger strong humoral immunity or whether the primary vaccine needs to be administered via a systemic route to promote a mucosal and systemic immune response.

Retrospective evaluation of outpatient canine parvovirus treatment in a shelter-based low-cost urban clinic.

OBJECTIVE: To evaluate survival and associated risk factors when utilizing an outpatient treatment protocol for treatment of canine parvovirus (CPV) performed in a shelter-based low-cost urban clinic. DESIGN: Retrospective study. SETTING: Pennsylvania Society for the Prevention of Cruelty to Animals. ANIMALS: Ninety-five CPV positive dogs presented between June 1 and July 31, 2016. Owners elected for outpatient care when inpatient care was not financially feasible and the dog was considered medically stable for outpatient care. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of the 95 CPV positive dogs, 79 (83%) survived treatment. Logistic regression indicated that an increasing number of days with clinical signs prior to treatment and an increase in percent body weight during treatment were significantly associated with survival (odds ratio [OR], 3.15, P = 0.020; and OR, 1.29, P = 0.027, respectively). Hypothermia upon presentation (T < 37℃) was negatively associated with survival (OR, 0.002; P = 0.002). CONCLUSIONS AND CLINICAL RELEVANCE: The survival rate of this clinic suggests that an outpatient program may be a potential alternative treatment to inpatient care. Longer duration of clinical signs prior to treatment and an increase in percent body weight during treatment appear to be associated with increased survival outcomes, while hypothermia on presentation appears to be associated with decreased survival outcomes.

An assessment of the risk, cost-effectiveness, and perceived benefits of anti-parvovirus B19 tested blood products.

BACKGROUND: Parvovirus B19 (B19V) can cause severe anemia, hydrops foetalis, and even death in vulnerable patients. To prevent transfusion-transmitted B19V infection of at-risk patients, B19V antibody screening of blood donors was implemented. The cost-effectiveness of this intervention is unclear, as the likelihood of transmission through blood and subsequent complications for recipients are unknown. This study estimates the cost-effectiveness of anti-B19V donor screening in the Netherlands. STUDY DESIGN AND METHODS: The estimates needed for the cost-effectiveness model were: the occurrence of B19V in Dutch blood donors, the number of anti-B19V tested products required by hospitals, the likelihood of morbidity and mortality given B19V infection, treatment costs, and screening costs. These estimates were obtained from literature and observational data. When data were unavailable, structured expert judgment elicitation and statistical modeling were applied. RESULTS: The costs of preventing one transfusion transmitted B19V infection are estimated at €68,942 (€42,045 - €102,080). On average, 1.25 cases of morbidity and 0.12 cases of mortality are prevented annually. Although the perceived risk of transfusion transmitted B19V infection was low, half of the treating physicians favored anti-B19V screening. CONCLUSION: The estimated mortality and morbidity caused by B19V infection was low in the risk groups. The cost-effectiveness ratio is similar to other blood safety screening measures. No guidance exists to evaluate the acceptability of this ratio. The explicit overview of costs and effects may further guide the discussion of the desirability of B19V safe blood products.

The geographic distribution and financial impact of canine parvovirus in Australia.

Canine parvovirus (CPV) is an important cause of serious and often fatal disease in dogs worldwide, however, a national survey of CPV cases in Australia has not been conducted since 1982. For this study we surveyed the entire Australian veterinary clinic population and achieved a response rate of 23.5% (534 unique veterinary clinics). Respondents reported 4,451 CPV cases in 2015 and 4,219 cases in 2016; the estimated total CPV case load across Australia was 20,661 in 2015 and 20,110 in 2016. The overall reported euthanasia rate was 41%. Geospatial analysis revealed large numbers of CPV cases in rural and remote areas of Australia. Where cases occurred in capital city areas, these were found in peri-urban areas, away from the inner city. The median cost to treat CPV cases was $A1,500 per patient. A significant difference in the cost of treating cases was found between Australian states; Western Australia (median $A2,500) was the most expensive state. There was a strong correlation between cost of treatment and rate of euthanasia without treatment reflecting the important role of affordability in disease-related euthanasia. These findings highlight the considerable impact of the evolving CPV situation in Australia, particularly in regional and rural areas. This survey is the most comprehensive epidemiological investigation of canine parvoviral-related disease, to date, globally and provides a process for national disease surveillance.

Assessment of acute kidney injury in canine parvovirus infection: Comparison of kidney injury biomarkers with routine renal functional parameters.

Dogs with naturally occurring canine parvovirus (CPV) infection are at risk of developing acute kidney injury (AKI) due to several factors, including severe dehydration, hypotension and sepsis. Serum creatinine (sCr) and serum urea are insensitive markers for the assessment of early kidney injury. Therefore, the aim of this study was to investigate potential kidney injury in dogs with CPV infection using both routine renal functional parameters and several kidney injury biomarkers. Twenty-two dogs with CPV infection were prospectively enrolled and compared with eight clinically healthy control dogs. Urinary immunoglobulin G (uIgG) and C-reactive protein (uCRP) were measured to document glomerular injury, whereas urinary retinol-binding protein (uRBP) and neutrophil gelatinase-associated lipocalin (uNGAL) served as markers for tubular injury. These biomarkers were compared to routine renal functional parameters, including sCr, serum urea, urinary protein:creatinine ratio (UPC) and urine specific gravity (USG). Dogs with CPV infection had significantly higher concentrations of uIgG, uCRP, uRBP and uNGAL compared to healthy dogs. In contrast, sCr was significantly lower in dogs with CPV infection compared to controls, while serum urea was not significantly different. UPC and USG were both significantly higher in CPV-infected dogs. This study demonstrated that dogs with CPV infection had evidence of AKI, which remained undetected by the routine functional markers sCr and serum urea, but was revealed by UPC, uIgG, uCRP, uRBP and uNGAL. These results emphasize the added value of novel urinary kidney injury biomarkers to detect canine patients at risk of developing AKI.

Simultaneous detection of 4 prototypic rat parvoviruses using the luminex xTAG assay in laboratory animal health monitoring.

There are currently four rat parvoviruses including Kilham rat virus (KRV), Toolans H-1 parvovirus (H-1virus), rat parvovirus type 1a (RPV-1a) and rat minute virus (RMV). Virus detection methods are commonly based on conventional PCR - agarose gel electrophoresis or serological assay methods These methods are both time-consuming and lack specificity. In this study, we developed a bead array xTAG assay for the simultaneous detection and discrimination of four rat parvoviruses. The detection limits ranged from 100 to 1000 copies/µL of input purified plasmid DNA. We examined 50 clinical specimens and 15 facal samples by xTAG assay and conventional PCR. The results showed a high consistency except for several weak positive infections. It demonstrated that the xTAG-multiplex PCR method is specific, sensitive and suitable for high throughput platforms for rat parvovirus screening of clinical samples and contaminated biological materials.

Assessment of NS1 gene-specific real time quantitative TaqMan PCR for the detection of Human Bocavirus in respiratory samples.

Human Bocaviruses (HBoV) were associated with respiratory diseases. Here, we assessed a TaqMan®-based PCR for the detection of all four HBoV subtype infections with a sensitivity up to 15 copies/reaction. To evaluate this assay on clinical samples, 178 nasopharyngeal aspirate specimens from pediatric cases were analyzed and HBoV genome was detected in 13 out of 178 patients with a viral load range between 1.6 × 103 and 9.4 × 107 copies/ml. These results indicated that this method could be used as an alternative technique for the diagnosis of HBoV infection.

Case-Control Assessment of the Roles of Noroviruses, Human Bocaviruses 2, 3, and 4, and Novel Polyomaviruses and Astroviruses in Acute Childhood Diarrhea.

BACKGROUND: The etiology of acute childhood diarrhea often eludes identification. We used a case-control study-stool archive to determine if nucleic acid tests for established and newly identified viruses diminish our previously published 32% rate of microbiologically unexplained episodes. METHODS: Using polymerase chain reaction, we sought to detect noroviruses GI and GII, classic and novel astroviruses, and human bocaviruses (HBoVs) 2, 3, and 4 among 178 case and 178 matched control stool samples and St. Louis and Malawi polyomaviruses among a subset of 98 case and control stool samples. We calculated adjusted odds ratios and 95% confidence intervals using conditional logistic regression. RESULTS: Noroviruses were more common in cases (GI, 2.2%; GII, 16.9%) than in controls (GI, 0%; GII, 4.5%) (adjusted odds ratio, 5.2 [95% confidence interval, 2.5-11.3]). Astroviruses and HBoVs 2, 3, and 4 were overrepresented among the cases, although this difference was not statistically significant. Malawi polyomavirus was not associated with case status, and St. Louis polyomavirus was identified in only 1 subject (a control). When identified in cases, HBoVs 2, 3, and 4 were frequently (77%) found in conjunction with a bona fide diarrheagenic pathogen. Thirty-five (20%) case and 3 (2%) control stool samples contained more than 1 organism of interest. Overall, a bona fide or plausible pathogen was identified in 79% of the case stool samples. Preceding antibiotic use was more common among cases (adjusted odds ratio, 4.5 [95% confidence interval, 2.3-8.5]). CONCLUSION: Noroviruses were found to cause one-third of the diarrhea cases that previously had no identified etiology. Future work should attempt to ascertain etiologic agents in the approximately one-fifth of cases without a plausible microbial cause, understand the significance of multiple agents in stools, and guide interpretation of nonculture diagnostics.

Molecular and serological assessment of parvovirus B-19 infection in Egyptian children with sickle cell disease.

BACKGROUND/PURPOSE: Human parvovirus B-19 (PB-19) is a cause of hemolysis, red blood cell aplasia, and severe conditions in patients with sickle cell anemia, but the molecular mechanisms of the infection are still insufficiently understood. This study aimed to detect PB-19 DNA together with its antibodies in the sera of Egyptian children with sickle cell disease and to assess the contribution of this infection, which causes transient cessation of erythropoiesis, in precipitating severe anemia in some cases. METHODS: One hundred children with sickle cell disease seeking medical advice in the pediatric-hematology clinic were recruited. Sera of the patients were compared with those of 60 healthy children regarding the presence of PB-19 immunoglobulin (Ig)G and IgM as well as detection of its DNA by nested-polymerase chain reaction technique. RESULTS: There were statistically significant differences in the prevalence of PB-19 IgM, IgG, and DNA among patients when compared with controls (p < 0.001, p = 0.001, and p < 0.001 respectively). Acute PB-19 infection detected by positive IgM and DNA was found in 30% of the patients, while chronic PB-19 infection detected by positive IgG and DNA was detected in 24% of the patients. Anemia was worse in children with acute PB-19 infection than in those with chronic infection, while anemia was mild in children with old infection. CONCLUSION: PB-19 infection is detected at high rates among Egyptian children with sickle cell disease and it may result in severe anemia. So, PB-19 must be suspected and screened for in such group of patients.