Mini Review: Q Fever (Coxiellosis): Epidemiology, Pathogenesis and Current Laboratory Diagnosis

Q fever is zooantroponozis with global distribution caused by the strictly intracellular bacterium Coxiella burnetii. Causative agent of Q fever is an obligate intracellular parasite, classified in the genus Coxiella, family Coxiellaceae, class Gammaproteobacteria. The importance of the disease was assessed both in terms of human health and the serious economic damage they cause on livestock. Clinical manifestation of Q fever in humans is characterized by a wide variety - from asymptomatic infection to a chronic disease that can be fatal. Several basic methods have been developed to detection of C. burnetii. PCR and C. burnetii genomic sequences in whole blood are a sensitive and safe method of detection, with >90% sensitivity. A four-fold or greater rise of (CF) antibody (phase 2) between the paired sera is also diagnostic approach. Sensitivity of a four-fold rise in titre has been estimated as 73% ÷78% and specificity has been estimated as 90%, respectively. EIA is method with highly sensitive and specific. EIA detect IgM and then IgG antibodies which develop to phase II antigens in 10 to 14 days from symptom onset. IFA tests are of particular value for confirmation of acute infection and for diagnosis of chronic infection with high sensitivity. The technique detected IgG, IgM and IgA immunoglobulin classes. Suitable specimens for C. burnetii detection are blood samples. Although scientific interest in Q fever has always existed, a number of facts concerning the unforeseen nature of the epidemic, various clinical manifestations both in humans and in animals, the opportunities for chronic and other features of infection remain unclear. For this reason, timely and highly sensitive laboratory diagnosis is crucial for the outcome of the disease and subsequent treatment and monitoring

Serological and Molecular Detection of Coxiella Burnetii in Clinical Samples from Veterinarians and Cattle Farm Workers from Gabrovo Region, Bulgaria

Coxiella burnetii, which causes Q fever, is a highly infectious agent that is widespread around the world.  During the last decades, the number of cases reported in Bulgaria varied from year to year. The present study aimed to determine the frequency of C. burnetii infection using ELISA and conventional PCR among freelance veterinarians and cattle farm workers in Gabrovo province, Bulgaria. In the period April 2020 to June, 2021 a total of 154 blood samples of target group was tested in the National Reference Laboratory of Cell cultures, rickettsia and oncogenic viruses (NRL CCROV) at NCIPD - Sofia. Diagnosis of C. burnetii was performed by indirect enzyme-linked immunosorbent assay ELISA (anti-Coxiella burnetii ph. II IgG/IgM) and by end-point PCR technique (to detect the sodB gene region of C. burnetii). By indirect ELISA assay of the tested 154 clinical samples, anti-C. burnetii positive ph. II IgM antibodies were registered in 37% of samples. A relatively high percentage are affected in the active age between 50-60 years old. Anti-C. burnetii positive ph. II IgG antibodies were proven at 50% of tested samples. A positive PCR signal for C. burnetii DNA was obtained at 37/154 (20% of samples) and follows the above reported trend of acute infection of active age patients. Around 10% of tested samples were positive for three C. burnetii laboratory markers. We conclude that Q fever is endemic in Bulgaria. More research is necessary in different Bulgarian regions to set the human risk groups, to diagnose acute and chronic Q fever and to determine the economic impact of Q fever in the cattle industry. In the NRL CCROV was developed diagnostic scheme including complex methods to improve early laboratory diagnosis of C. burnetii, allowing taking proper treatment of suspected with Q fever patients

HEALTHCARE WORKERS IN BULGARIA - ARE THEY PROTECTED FROM VACCINE-PREVENTABLE INFECTIONS?

Background: Healthcare workers (HCWs) are at increased risk of exposure to many viral infections, including vaccine preventable diseases (VPDs) such as measles, mumps and rubella (MMR) as compared to non-HCWs. Immunity of HCWs against these viruses is mandatory in a healthcare setting due to possible exposure from patients or colleagues. Aim: To provide an assessment of anti-measles, mumps and rubella IgG seropositivity among Bulgarian HCWs employed in hospitals and regional health inspectorates (RHI), as an indicator of protective immunity against MMR in this risk group.  Materials and Methods: In the current study, 181 HCWs from Infectious Units in regional hospitals in the country, and HCWs from the RHI, involved in the monitoring and surveillance of MMR cases in Bulgaria were screened. Serum specimens from all participants were tested by a commercial indirect enzyme-linked immunosorbent assay (Anti-Measles, Anti-Mumps, Anti-Rubella IgG EIA-Euroimmun®, Germany) for presence of IgG antibodies against measles, mumps and rubella, as an indicator of protective immunity.  Results: The study included 181 HCWs, 25 male and 156 female, aged 22 to 66 years. The average protective seroprevalence for measles, mumps and rubella was 82.9%, 76.2% and 92.3% percent, respectively. The highest share of negative results were obtained for mumps-specific IgG – 23.2% (42/181), followed by measles 16.6% (60/181) and rubella-specific IgG 7.7% (19/181). Regarding the age distribution, the highest number of HCWs non-immune to measles and mumps was found among the 31- 40-year olds, and against mumps – among the 41-50-year-olds. Conclusion: HCWs are at greater risk of contracting infections than the general population because of contact with sick patients or infectious material. Infected healthcare workers can spread nosocomial diseases to vulnerable patients with more severe illness, leading to complications and even death. Therefore, the vaccination status of HCWs must be strictly monitored

Assessment of the botanical origin of Bulgarian honey samples using melissopalynological, DNA barcoding and NMR analyses

Polyfloral honey samples from Bulgaria were subject to parallel analyses of their botanical origin and composition using traditional melissopalynology, DNAbarcoding based on the plastid rbcL gene and NMR analysis. The obtained datasets were compared with each other to evaluate the information capacity of the applied experimental methods. The results from the melissopalynological and DNA-barcoding studies demonstrated a significantly higher resolution of the latter, revealing the presence of pollen from a total of 17 plant families, 21 plant genera and 5 plant species in comparison to pollen from only 7 plant families, 3 plant genera and 4 plant species identified by melissopalynology. The higher resolution of DNA barcoding allows a more detailed characterisation of the diet and foraging preferences of honey bees, including foraging on plant species growing in lower abundance in the area. The comparison of the quantitative data on floral honey composition for several plant genera and species reveals significant differences between the relative abundance of the pollen grains estimated by melissopalynological analysis and the relative abundance of rbcL clones in rbcL libraries determined after DNA barcoding. All three applied methods confirm the polyfloral botanical origin of the analysed samples and support routine NMR use for the assessment of the floral origin of honey

The patient as an active subject of the learning process

The development of human civilization is inextricably linked to education. Every great achievement of mankind finds expression through and in education. Medical education has a unique character. There is no other area of human activity that affects the most valuable – human life and health. The training of highly qualified health professionals is vital for the needs of society. A specific feature of the educational process in the higher medical school is its implementation in real hospital conditions and the active participation of the patient in it. As a part of the complex „teacher-student-patient“ interaction and as a user of health services, the patient communicates daily with future medical professionals, which in itself is important not only for the individual patient but also for the relationship between teachers and students. The modern understanding of the learning process is based on the understanding of building and implementing active interaction between teacher and student, as the main subjects in it, but without the emergence of the third subject – the patient, this would be unattainable. From this point of view, the role of the patient as an active subject of the educational process can be defined as key

Immunity to mumps virus in children population in Bulgaria

AbstractMumps is an acute, contagious, viral vaccine-preventable disease caused by mumps virus (MuV). The measles, mumps, rubella (MMR) vaccine that is used in many countries is considered highly effective with decreased MuV incidence, but suboptimal MuV long-term immunity. This study assessed the MuV seropositivity and antibody titre among vaccinated children in Bulgaria to provide evidence for a better understanding of MuV circulation and immunity in Bulgaria. The samples from 734 immunized children (369 females and 365 males) aged 1 to 16, divided into four age groups (≥1, 2–6, 7–11, and 12–16) were tested. Qualitative and quantitative indirect enzyme-linked immunosorbent assay (Anti-Mumps IgG ELISA, Euroimmun, Germany) was performed to determine the mumps IgG antibody levels in sera. Among all participants, protective MuV immunity was identified in 93%. MuV IgG antibody positivity ranged between 87% in the age group between 1 and 2 years and 96% in the age group 12–16 years, but no statistically significant difference was found among age groups. At the same time, there was a statistically significant difference (p = 0.01) between seropositivity in male and female participants, with male participants having an overall seropositivity of 90% and female 95%. Among the antibody-positive samples, the quantitative measurements of median anti-MuV IgG concentrations showed that titres decreased with increasing age. A slightly waning immunity following vaccination was observed, but positivity remained high among vaccinated children over the years. Similar studies show that maintaining high immunity is crucial to prevent mumps outbreaks

Primate Erythroparvovirus 1 Infection in Patients with Hematological Disorders

Primate erythroparvovirus 1, commonly referred to as Parvovirus B19 (B19V), is a DNA virus that normally results in a mild childhood infection called “erythema infectiosum”. Besides respiratory spread, B19V can also be transmitted through transfusions, which may result in persistent anemia in immunodeficient hosts. Dialysis patients often face acute or chronic anemia after infection with B19V. Here, we describe the laboratory investigation of 21 patients with hematological disorders for B19V infections. B19V DNA was detected in 13 (62%) of them, with specific IgM antibodies in three of the DNA positives. All 13 patients received treatment and were laboratory-monitored over a period of one year. In only two patients (a 14-year-old child with a kidney transplantation and a 39-year-old patient with aplastic anemia), markers of recent B19V infection were still detectable in follow-up samples. For four B19V DNA positive samples, short sequences could be obtained, which clustered with genotype 1a reference strains. Our findings suggest that all cases of hematological disorders should be examined for specific B19V antibodies and DNA for accurate diagnosis and appropriate patient management