The seroprevalence of Bartonella henselae in healthy adults in Korea

Risk Factors for Bartonella Seroreactivity Among Veterinary Workers in the Pacific Northwest

Background: Exposure to zoonotic diseases is a significant occupational risk in veterinary medicine. In this study, we characterized personal protective equipment use, injury frequency, and Bartonella seroreactivity in Washington State veterinary workers. Methods: Using a risk matrix developed to reflect occupational risk factors for exposure to Bartonella and multiple logistic regression, we explored determinants of risk for Bartonella seroreactivity. Results: Depending on the titer cutoff used, Bartonella seroreactivity was between 24.0% and 55.2%. No significant predictors of seroreactivity were found, although the relationship between high-risk status and increased seroreactivity for some Bartonella species approached significance. Serology for other zoonotic and vector borne pathogens did not identify consistent cross reactivity with Bartonella antibodies. Conclusion: The predictive power of the model was likely limited by the small sample size and high level of exposure to risk factors for most participants. Given the high proportion of veterinarians seroreactive to one or more of the three Bartonella spp. known to infect dogs and cats in the United States, as well as seroreactivity to other zoonoses, and the unclear relationship between occupational risk factors, seroreactivity, and disease expression, more research is needed in this area.

Bartonella spp. in households with cats: Risk factors for infection in cats and human exposure

The aim of this study was to estimate the occurrence of Bartonella spp. per household in cats and the risk factors for Bartonella spp. positivity in cats and their owners from Valdivia, Chile. A total of 464 cats (distributed within 324 households) and 326 humans (control group [n = 112] and cat owner [n = 214]) distributed in 262 households were sampled. From the cat owners (n = 214), 128 humans were in households where the cat was also sampled, totaling 84 households with dual sampling. Real-time PCR (qPCR) was used for Bartonella spp. detection in blood from cats and humans, and immunofluorescent immunoassay (IFA) anti-Bartonella henselae was performed in human serum samples. Out of the total of 324 households, 20.43% presented at least one Bartonella positive cat. From the households with dual sampling, 29.7% (25/84) presented at least one qPCR-Bartonella spp. positive cat. However, Bartonella DNA was not amplified in humans, and in 7.3% (6/82) of the households was found at least one of the cat's owners exposed to B. henselae. Cats younger than one year (Odds Ratio (OR) = 5.3), non-neutered (OR 3.46), sampled at home (OR 5.82), and with improper application of tick/flea control products (OR 3.13) showed a higher risk for Bartonella spp. presence. Humans with occupational exposure involving animal contact, were more likely to exhibit B. henselae seropositivity (OR 7.5). Bartonella spp. was present in the cats a moderate number of households, but Bartonella DNA was not detected in owners' blood, inferring that there is a low risk of recent human infection in the studied population.

Comparison of molecular methods for Bartonella henselae detection in blood donors

The Bartonella genus consists of neglected pathogens associated with potentially transfusional-transmitted and fatal human diseases. We aimed to evaluate Bartonella sp. prevalence in 500 blood donors and compare the results with the data already published about these samples. We used molecular diagnostic methods to detect Bartonella sp.-DNA from blood and liquid culture samples: (A) conventional PCR for two gene regions, the ITS targeting the genus Bartonella and the specific gltA Bartonella henselae; (B) nested PCR for the ftsZ gene and (C) qualitative real-time PCR for the gltA gene, both B. henselae specific. We obtained 30/500 (6%) DNA detections from the blood samples; 77/500 (15.4%) DNA detections from liquid culture samples and five (1%) samples had DNA detection from both. In total, we detected B. henselae DNA from 102/500 (20.4%) donors. The samples used in this study had already been submitted for Bartonella sp.-DNA detection using only a conventional PCR in liquid culture. Sixteen samples (3.2%) were positive previously, and from these 16 samples, 13 were negative in the new investigation. We concluded that the use of liquid culture combined with different molecular tests increases the possibility of detecting Bartonella sp.-DNA, but the tests do not avoid false-negative results. More than a fifth of blood donors had at least one PCR that detected Bartonella sp.-DNA among the eight molecular reactions performed now (four reactions in whole blood and four in liquid culture). Seven percent had B. henselae-DNA detection for two or more distinct regions. Considering the results obtained previously, the DNA of Bartonella spp. was detected or the agent isolated in 23% of analyzed blood donors. The results establish that the low bacteremia and the fastidious characteristics of the bacterium are challenges to laboratory diagnosis and can make it difficult to confirm the infection in patients with bartonelloses.

Bartonella Species in Cambodia, Ghana, Laos, and Peru: Results from Vector and Serosurveys

Background: Bartonella species are fastidious gram-negative vector-borne bacteria with a wide range of mammalian reservoirs. While it is understood that some species of Bartonella are human pathogens, the extent of human exposure to Bartonella species (both pathogenic and nonpathogenic) is yet to be fully understood. Materials and Methods: To this end, residual sera from participants enrolled in undifferentiated fever studies in Cambodia, Ghana, Laos, and Peru were screened for the presence of IgG antibodies against Bartonella quintana and Bartonella henselae, using the FOCUS diagnostics Dual Spot- Bartonella IgG Immunofluorescence assay. Forty-eight patients with suspected or confirmed Bartonella bacilliformis exposure or infection in Peru were screened to assess cross-reactivity of the FOCUS assay for IgG against other Bartonella species. Results: Ten of 13 patients with confirmed B. bacilliformis infection were Bartonella-specific IgG positive, and overall, 36/48 of the samples were positive. In addition, 79/206, 44/200, 101/180, and 57/100 of the samples from Peru, Laos, Cambodia, and Ghana, respectively, were Bartonella-specific IgG positive. Furthermore, ectoparasite pools from Cambodia, Laos, and Peru were tested using quantitative real-time PCR (qPCR) for the presence of Bartonella DNA. Of the sand fly pools collected in Peru, 0/196 were qPCR positive; 15/140 flea pools collected in Cambodia were qPCR positive; while 0/105 ticks, 0/22 fleas, and 0/3 louse pools collected in Laos tested positive for Bartonella DNA. Conclusion: Evidence of Bartonella in fleas from Cambodia supports the possibility that humans are exposed to Bartonella through this traditional vector. However, Bartonella species were not found in fleas, ticks, or lice from Laos, or sand flies from Peru. This could account for the lower positive serology among the population in Laos and the strictly localized nature of B. bacilliformis infections in Peru. Human exposure to the Bartonella species and Bartonella as a human pathogen warrants further investigation.

Serological and Molecular Detection of Bartonella henselae in Cats and Humans From Egypt: Current Status and Zoonotic Implications

Bartonellosis is a vector-borne zoonotic disease caused by the intracellular bacterium of genus Bartonella. The disease has a worldwide distribution and cats represent the major reservoir of this disease. Despite its global distribution, very limited previous studies have investigated the occurrence of bartonellosis in cats and their owners in Egypt. In an endeavor to explore this topic, we investigated the occurrence of Bartonella henselae (B. henselae) infection in 225 samples (blood, saliva, and claw) obtained from 75 healthy cats in Upper Egypt. These samples were routinely obtained during veterinary clinic visits. This study also involved an examination of 100 humans, including cat owners and people with a history of contact with cats. Attempted isolation and identification of B. henselae in cats were also performed. Furthermore, PCR was performed for molecular identification of B. henselae in blood samples from cats. Meanwhile, an immunofluorescent assay was performed to study the seroprevalence of B. henselae infection in humans. In this study, B. henselae could not be isolated from any of the examined blood, saliva, or claw samples from cats. Interestingly, B. henselae was identified molecularly in 8% (6/75) of blood samples from cats. The seroprevalence of B. henselae in humans was 46% and its occurrence was higher in females (46.6%) than in males (41.7%) (P = 0.748). B. henselae infection was higher among cat owners [51.4% (19/37)] than among people with a history of contact with cats [42.9% (27/63)] (P = 0.410). Infection was higher in rural regions [79.5% (31/39)] than in urban regions [24.6% (15/61)] (P < 0.001). Collectively, this data provide interesting baseline information about the occurrence of B. henselae in cats and humans in Upper Egypt, which reflects the potential zoonotic transmission of this bacterium. Future study is mandatory to explore the occurrence of B. henselae in major reservoirs in Egypt.

In silico analyses and design of chimeric proteins containing epitopes of Bartonella henselae antigens for the control of cat scratch disease

Bartonella henselae is a Gram-negative bacterium that causes cat scratch disease (CSD), as well as bacteremia, endocarditis, and other clinical presentations. CSD remains one of the most common infections caused by bacteria in the genus Bartonella, and it is transmitted to humans through a scratch or cat bite. Vaccination and more efficient diagnostic methods would represent a promising and sustainable alternative measure for CSD control in humans and animals. Here, we described the in silico analyses and design of three recombinant chimeric proteins (rC1, rC2, and rC3), for use in the control of CSD. The chimeras were constructed with epitopes identified from the sequences of the GroEL, 17 kDa, P26, BadA, Pap31, OMP 89, and OMP 43, previously described as the most important B. henselae antigens. The rC1, rC2, and rC3 were expressed and purified using a heterologous system based on Escherichia coli and reacted with antibodies present in the sera of humans naturally infected. The chimeric proteins were used to immunize mice using Freund adjuvant, and the humoral immune response was evaluated. Animals immunized with rC1 and rC3 showed a significant IgG antibodies response from the 28th day (P < 0.05), and the animals immunized with the rC2 from the 35th day (P < 0.05) remained until the 56th day of experimentation, with a titer of 1:3200 (P < 0.05), 1:1600 (P < 0.05) and 1:1600 (P < 0.05) from rC1, rC2, and rC3, respectively. Significant production of IgA and IgG1 isotype was detected in animals immunized with rC1 and rC2 proteins. Additionally, analysis using 13 serum samples from naturally infected patients showed that the proteins are recognized by antibodies present in sera, reinforcing the possibility of using these chimeras for CSD control. KEY POINTS: • The recombinant chimeras were expressed in Escherichia coli with 37 kDa (rC1), 35 kDa (rC2), and 38 kDa (rC3). • Animals immunized with rC1, rC2, and rC3 showed significant antibody response. • The chimeras were recognized by the sera of naturally infected patients.

Cat Scratch Disease: The First Case Report in Republic of North Macedonia

Cat scratch disease (CSD) is the main clinical manifestation caused by Bartonella henselae in immuno-competent patients. The bacterium is transmitted to humans from cats via scratches or bites. In this case report, we are presenting to our knowledge the first etiologically confirmed case of CSD in our country. Here we describe the case of a previously healthy adult female patient presenting with fever and axillar lymphadenopathy over 1-month period. She underwent numerous clinical and paraclinical investigations for potential etiologies associated with lymphadenopathy and fever. Finally, serological testing for B.henselae was performed with titers for IgG 1:1024 and 1:160 for IgM, which confirmed the diagnosis. Five-day treatment with azithromycin resulted with good clinical response and complete recovery. We proved that CSD is a reality in our country and this report should raise awareness in medical doctors, especially infectious disease specialist. Also, CSD should be included in differential diagnosis in patients with fever of unkown origin (FUO), who are presenting with regional lymphadenopathy, with or without history of cat contact.

Epidemiological of cat scratch disease among inpatients in the Spanish health system (1997-2015)

Cat scratch disease, whose causative agent is Bartonella henselae, is an anthropozoonosis with a worldwide distribution that causes significant public health problems. Although it is an endemic disease in Spain, the available data are very limited. The aim of our study was to describe cat scratch disease inpatients in the National Health System (NHS) of Spain. This was a retrospective descriptive study using the minimum basic data set (CMBD in Spanish) in patients admitted to hospitals of the NHS between 1997 and 2015 with a diagnosis of cat scratch disease (ICD-9: 078.3). We found 781 hospitalized patients diagnosed with cat scratch disease. The mean age (± SD) was 30.7 ± 25.3 years old. The male/female ratio was 1.1:1. The incidence rate over the study period was 0.93 (95% CI, 0.86-0.99) cases per million person-years. The incidence rate in men was 0.98 cases per million person-years and that in women was 0.88 cases per million person-years. The cases were more frequent from September to January. A total of 652 (83.5%) cases were urgent hospital admissions. The average hospital stay was 8.4 ± 8.9 days. The overall lethality rate of the cohort was 1.3%. We have demonstrated that CSD causes a substantial burden of disease in Spain, affecting both adult and pediatric patients with a stable incidence rate. Our data suggest that CSD is benign and self-limited, with low mortality, and its incidence is possibly underestimated. Finally, there is a need for a common national strategy for data collection, monitoring, and reporting, which would facilitate a more accurate picture and the design of more strategic control measures. Hospital discharge records (HDRs) could be a good database for the epidemiological analysis of the hospital management of CSD.

Serosurvey of IgG Antibodies against Bartonella henselae and Rickettsia typhi in the Population of Attica, Greece

Rickettsia typhi and Bartonella henselae are the causative agents of murine typhus and cat-scratch disease, respectively. A small-scale survey (N = 202) was conducted in the Attica region, Greece, for determining the prevalence rates of IgG antibodies against B. henselae and R. typhi by indirect fluorescence antibody test. IgG against B. henselae and R. typhi were present in 17.8% (36/202) and 4.5% (9/202) of the participants, respectively; co-occurring IgG against both B. henselae and R. typhi were detected in 3.5% (7/202), whereas only anti-B. henselae IgG in 14.3% (29/202), and only anti-R. typhi IgG in 1.0% (2/202). Titres 1/64, 1/128, 1/256, and 1/512, of anti-B. henselae IgG were identified in 6.4%, 4.5%, 4.5%, and 2.4%, whereas titres 1/40 and 1/80 of anti-R. typhi IgG were detected in 4.0%, and 0.5%, respectively. A positive association of anti-B. henselae IgG prevalence with a coastal area featuring a major seaport (p = 0.009) and with younger age (p = 0.046) was identified. The findings of this survey raise concern for exposure of the population of Attica to B. henselae and R. typhi, which should be considered in the differential diagnosis when compatible symptoms are present. Our results also suggest that seaports may represent high-risk areas for exposure to Bartonella spp.

The seroprevalence of Bartonella spp. in the blood of patients with musculoskeletal complaints and blood donors, Poland: a pilot study

BACKGROUND

Bartonella spp. can cause a variety of diseases, such as lymphadenopathies, cat scratch disease, and trench fever, but can also give rise to many non-specific symptoms. No data exists regarding the prevalence of Bartonella spp. in patients with musculoskeletal complaints, nor among blood donors in Poland.

METHODS

The presence of anti-Bartonella IgM and IgG in the serum of blood donors (n = 65) (Lodz, Poland) and in the patients of the Department of Rheumatology Clinic (n = 40) suffering from musculoskeletal symptoms was tested by immunofluorescence. Blood samples were cultured on enriched media. Epidemiological questionnaires were used to identify key potential risk factors, such as sex, age, contact with companion animals, and bites from insects or animals.

RESULTS

Altogether, 27 of the 105 tested subjects were seropositive for Bartonella henselae IgG (23%) and three for Bartonella quintana IgG (2.85%); IgMs against B. henselae were found in three individuals (2.85%), and IgMs against B. quintana were found in one (1.54%). No statistically significant difference was found between the prevalence of B. henselae in the blood of donors or patients and the presence of unexplained musculoskeletal complaints (23% vs 30%). Individuals who had kept or been scratched by cats were not more likely to be B. henselae seropositive (p > 0.01). Tick bites were more commonly reported in patients, but insignificantly (p > 0.01).

CONCLUSION

This is the first report of a high seroprevalence of anti-Bartonella IgG in patients with musculoskeletal symptoms and in blood donors in Poland. The obtained results indicate that such seroprevalence may have a possible significance in the development of musculoskeletal symptoms, although it should be confirmed on a larger group of patients. Asymptomatic bacteremia might occur and pose a threat to recipients of blood from infected donors. Hence, there is a need for more detailed research, including molecular biology methods, to clarify the potential risk of Bartonella spp. being spread to immunocompromised individuals.

KEY POINTS

• This is the first study presenting high seroprevalence of Bartonella spp. in Poland. • IgG and IgM antibodies against B. quintana were found in blood samples of blood donors.

Current Status of Tick-Borne Diseases in South Korea

BACKGROUND

Bites with tick-borne pathogens can cause various bacterial, viral, or parasitic diseases in humans. Tick-transmitted diseases are known as contributing factors to the increasing incidence and burden of diseases. The present article investigated the epidemiology of tick-borne diseases in South Korea.

METHODS

The incidence and distribution of common tick-borne diseases in Korea (Lyme disease, Q fever, and severe fever with thrombocytopenia syndrome [SFTS]) were investigated and analyzed, using data from the Korea Centers for Disease Control and Prevention (KCDC) infectious disease reporting system. A literature review was compiled on the current status of uncommon tick-borne diseases (Rickettsia, anaplasmosis, ehrlichiosis, bartonellosis, tularemia, tick-borne encephalitis, and babesiosis).

RESULTS AND CONCLUSIONS

In South Korea, SFTS is an emerging disease, showing a rapid increase in reports since 2012, with high mortality. Likewise, reports of Lyme disease and Q fever cases have also been rapidly increasing during 2012-2017, although caution should be taken when interpreting these results, considering the likely influence of increased physician awareness and reporting of these diseases. Other tick-borne diseases reported in South Korea included spotted fever group rickettsiae, anaplasmosis, ehrlichiosis, tularemia, Bartonella, and babesiosis. Evidences on human infection with tick-borne encephalitis virus and Crimean-Congo hemorrhagic fever were recently unavailable, but both need constant monitoring.

Serologic Study of Bartonella henselae in Patients with Acute Undifferentiated Febrile Illness in Korea

BACKGROUND

Bartonella infection is an emerging cause of acute febrile illness; however, its significance has not been thoroughly investigated. We studied the antibody specific to Bartonella henselae in patients with various febrile diseases in Korea.

MATERIALS AND METHODS

A total of 177 patients with acute febrile illness who were managed at the Inha University Hospital from February 2012 to January 2013 were evaluated with an in-house immunofluorescent antibody test to detect B. henselae immunoglobulin G (IgG) antibody. The clinical features of the patients included fever of undetermined origin (n = 88 patients), lymphadenopathy (n = 28), febrile rash (n = 17), respiratory infection (n = 12), aseptic meningitis (n = 7), intra-abdominal infection (n = 5), arthritis (n = 4), and other conditions (n = 16). We reviewed the medical records of these patients and collected demographic data, clinical features, and their histories of animal exposure.

RESULTS

Among the 177 patients with acute febrile illness, 23.7% (42/177) had elevated levels of IgG antibodies to B. henselae (≥1:160). Of these seropositive patients, 32.4% (12/37) had contact with animals and had developed arthralgia (29.5%), headache (25%), or lymphadenopathy (15.9%). Seven (16.7%) of the 42 patients had higher IgG titers (≥1:640). Among them, four patients presented fourfold increase/decrease of IgG in convalescent serum. According to the clinical diagnosis, the antibody positivity rates were as follows: 24/88 with undifferentiated fever, 8/28 with lymphadenopathy, 4/17 with febrile rash, 2/12 with respiratory infection, 2/7 with aseptic meningitis, and 2/16 with other illnesses.

CONCLUSIONS

There was high prevalence of B. henselae in patients with undifferentiated fever in Korea, for which further research is needed.