Seroprevalence of Coxiella burnetii (Q fever) Exposure in Humans on Reunion Island.
Ontology highlight
ABSTRACT:
SUBMITTER: Jaubert J
PROVIDER: S-EPMC6602885 | biostudies-literature | 2019 Jul
REPOSITORIES: biostudies-literature
Publications
Seroprevalence of <i>Coxiella burnetii</i> (Q fever) Exposure in Humans on Reunion Island.
Jaubert Julien J Naze Florence F Camuset Guillaume G Larrieu Sophie S Pascalis Hervé H Guernier Vanina V Naty Nadège N Bertolotti Antoine A Manaquin Rodolphe R Mboussou Yoan Y Atiana Laura L Picot Sandrine S Filleul Laurent L Tortosa Pablo P Cardinale Eric E Gérardin Patrick P
Open forum infectious diseases 20190515 7
After the documentation of sporadic cases of Q fever endocarditis, we conducted a serosurvey to assess <i>Coxiella burnetii</i> exposure on Reunion Island. Two hundred forty-one stored frozen human sera were analyzed using an immunofluorescence assay. The weighted seroprevalence of Q fever was of 6.81% (95% confidence interval, 4.02%-9.59%). Despite the absence of infection in youths <20 years of age, exposure was not driven by age or by gender. There was a spatial disparity in exposure across t ...[more]
Similar Datasets
Project description:Coxiella burnetii is the causative bacterium of the zoonotic disease Q fever, which is recognised as a public health concern globally. Macropods have been suggested as a potential source of C. burnetii infection for humans. The aim of this cross-sectional study was to determine the prevalence of C. burnetii exposure in a cohort of Australian wildlife rehabilitators (AWRs) and assess Q fever disease and vaccination status within this population. Blood samples were collected from adult participants attending the Australian Wildlife Rehabilitation Conference in Sydney in July 2018. Participants completed a questionnaire at the time of blood collection. Antibody titres (IgG, IgA and IgM) against phase I and phase II C. burnetii antigens as determined by immunofluorescence assay, revealed that of the unvaccinated participants, 6.1% (9/147) had evidence of exposure to C. burnetii. Of the total participants, 8.1% (13/160) had received Q fever vaccination, four of whom remained seropositive at the time of blood collection. Participants reporting occupational contact with ruminants, were eight times more likely to have been vaccinated against Q fever, than those reporting no occupational animal contact (OR 8.1; 95% CI 1.85-45.08). Three AWRs (2%) reported having had medically diagnosed Q fever, two of whom remained seropositive at the time of blood collection. Despite the lack of association between macropod contacts and C. burnetii seropositivity in this cohort, these findings suggest that AWRs are approximately twice as likely to be exposed to C. burnetii, compared with the general Australian population. This provides support for the recommendation of Q fever vaccination for this potentially 'at-risk' population. The role of macropods in human Q fever disease remains unclear, and further research into C. burnetii infection in macropods including: infection rate and transmission cycles between vectors, macropods as reservoirs, other animals and humans is required.
| S-EPMC7725937 | biostudies-literature
Project description:ObjectiveMurine typhus has been increasingly reported on Reunion island, Indian ocean, following documentation of eight autochthonous infections in 2012-2013. We conducted a serosurvey to assess the magnitude of the seroprevalence of rickettsioses in the population. Two hundred and forty-one stored frozen sera taken from the 2009 Copanflu-RUN cohort were analysed using an immunofluorescence assay allowing to distinguish typhus group (TGR) and spotted fever group Rickesttsiae (SFGR). Seropositivity was defined for a dilution titre of Rickettsia IgG antibodies ≥ 1:64. Seroprevalence was weighted to account for the discrepancy between the Copanflu-RUN subset and the general population, as to infer prevalence at community level. Prevalence proportion ratios (PPR) were measured using log-binomial models.ResultsThe weighted seroprevalences of typhus group rickettsioses and spotted fever group rickettsioses were of 12.71% (95% CI 8.84-16.58%) and 17.68% (95% CI 13.25-22.11%), respectively. Pooled together, data suggested that a fifth of the population had been exposed at least to one Rickettsia group. Youths (< 20 years) were less likely seropositive than adults (adjusted PPR 0.13, 95% CI 0.01-0.91). People living in the western dryer part of the island were more exposed (adjusted PPR 2.53, 95% CI 1.07-5.97). Rickettsioses are endemic on Reunion island and circulated before their first identification as murine typhus in year 2011. Surprisingly, since isolation of Rickettsia africae from Amblyomma variegatum in year 2004 or isolation of Rickettsia felis from Amblyomma loculosum, no autochthonous cases of African tick-bite fever or flea-borne spotted fever has yet been diagnosed.
| S-EPMC6617902 | biostudies-literature
Project description:BACKGROUND:Q fever (Coxiella burnetii infection) has been associated with adverse perinatal outcomes. After investigating the obstetrical importance of Q fever on Reunion island and demonstrating an association between incident Q fever and miscarriage, we conducted a cross-sectional serosurvey to assess the prevalence of Coxiella burnetii infection among parturient women. METHODS:Between January 9 and July 24, 2014, within the level-4 maternity of Saint Pierre hospital and the level-1 maternity of Le Tampon, we proposed to screen all parturient women for Coxiella burnetii serology. Seropositivity was defined using indirect immunofluorescence for a dilution of phase 2 IgG titre ≥1:64. Further dilutions were chosen to discriminate recent or active infections from past or prevalent infections (< 1:128) and classify these as either possible (1:128), or probable (≥1:256). Recurrent miscarriage, stillbirth, preterm birth, small-for-gestational as well as a composite outcome of these adverse pregnancy outcomes were compared according to seropositivity using bivariate analysis or propensity score matching of seropositive and seronegative women on confounding factors. RESULTS:Among 1112 parturient women screened for Q fever over this 7-month period, 203 (18.3%) were seropositive. Overall weighted seroprevalence was of 20.1% (95%CI, 17.7-22.5%). Weighted seroprevalence of probable infections was 4.7% (95%CI 3.4-5.9%), while > 90% of positive serologies corresponded to past infections or false positives. Seropositivity was associated with none of the abovementioned adverse perinatal outcomes, whether in unpaired or matched analyses on propensity score. CONCLUSION:The magnitude and the pattern of seroprevalence suggest that Q fever is endemic on Reunion island. In this context, we found no significant contribution of prevalent Coxiella burnetii infection to adverse pregnancy outcomes. Although reassuring, these data put in our endemic context, with a previously demonstrated increased risk of incident Q fever associated miscarriage, encourage us to protect pregnant women against the risk of new infection, periconceptional or early in pregnancy.
| S-EPMC7118902 | biostudies-literature
Project description:Objective:Hepatitis E virus (HEV) has been scarcely investigated in the Indian Ocean. Following a nationwide serosurvey among blood donors, we conducted a population-based serosurvey to assess the magnitude of HEV exposure on Reunion Island. Methods:Four hundred and sixty-six archived frozen human sera from the 2009 CoPanFlu-RUN cohort were analysed using the Wantai HEV IgG enzyme immunoassay. HEV seropositivity was defined as an IgG titre ?5 UI/ml. Raw and weighted seroprevalences were assessed to account for the discrepancy between the CoPanFlu-RUN subset and the general community. Prevalence proportion ratios (PPR) were measured using log-binomial models. Results:The raw and the weighted seroprevalences of HEV were 9.01% (95% CI 6.41-11.61) and 6.73% (95% CI 4.47-8.98), respectively. The presence of HEV IgG antibodies was associated with increasing age (P?<?0.001). In a survey-adjusted model minimizing the sampling bias and adjusting for age, males were more likely to be seropositive than females (adjusted PPR 2.59, 95% CI 1.07-6.25). Seropositivity was spatially heterogeneous across the island (P?<?0.01). Living in the neighbourhood of a pig farm within a low to intermediate slope area was associated with seropositivity in several models adjusting for age, gender, altitude of residency and interaction between slope and pig farms. Conclusion:Reunion Island is a low endemic area for HEV exposure. Despite limitations related to the retrospective study design, our findings confirm the roles of cumulative lifetime exposure and male gender in HEV exposure. The risk associated with neighbouring pig farms might also suggest environmental contamination in this setting.
| S-EPMC6831862 | biostudies-literature
Project description:Coxiella burnetii is a category B bioterrorism agent. We numerically evaluated the risks and benefits from postexposure prophylaxis (PEP) after an intentional release of C. burnetii to the general population, pregnant women, and other high-risk populations. For each group, we constructed a decision tree to estimate illness and deaths averted by use of PEP/100,000 population. We calculated the threshold points at which the number of PEP-related adverse events was equal to the cases averted. PEP was defined as doxycycline (100 mg 2x/day for 5 days), except for pregnant women, where we assumed a PEP of trimethoprim-sulfamethoxazole (160 mg/800 mg 2x/day) for the duration of the pregnancy. PEP would begin 8-12 days postexposure. On the basis of upper-bound probability estimates of PEP-related adverse events for doxycycline, we concluded that the risk for Q fever illness outweighs the risk for antimicrobial drug-related adverse events when the probability of C. burnetii exposure is >or=7% (pregnant women using trimethoprim-sulfamethoxazole = 16%).
| S-EPMC2609859 | biostudies-literature
Project description:Coxiella burnetii, the agent of Q fever, persists in humans despite specific immune responses: however, its reservoir remains unknown. We detected C. burnetii in adipose tissue from BALB/c and C57/BL6 mice 4 months after infection when no bacteria were found in other tissues. C. burnetii infected cultivated adipocytes, replicated within late phagosomes and induced a transcriptional program that was enriched for the expression of genes associated with inflammatory response, hormonal responses and cytoskeleton.
2014-05-25 | GSE46335 | GEO
Project description:Q fever is a neglected zoonosis in South Africa, causing significant losses in livestock and game animals through reproductive disorders. However, there are limited studies on the extent of Coxiella burnetii infections in livestock in South Africa. Further, there is also lack of knowledge about the types of C. burnetii strains that are currently circulating in the country. Therefore, a cross-sectional, abattoir-based study was conducted to determine the seroprevalence of C. burnetii and associated risk factors, and to characterize C. burnetii strains from slaughter livestock at red meat abattoirs in Gauteng, South Africa. Of the 507 animals tested, 6.9% (95% CI: 4.9-9.5%) were positive for antibodies against C. burnetii. The seroprevalence was 9.4% (31/331) in cattle, 4.3% (3/69) in sheep, and 0.9% (1/107) in pigs. Out of the 63 tissue samples from 35 seropositive animals including material from two sheep aborted fetuses from Mangaung district (Free State province), 12.7% (8/63) tested positive by IS1111 PCR. Genotyping of the eight PCR-positive tissues from eight animals by MLVA revealed two novel genotypes, not available in Coxiella MLVA databases. It is concluded that slaughter animals pose a risk of exposing abattoir and farm workers to C. burnetii in South Africa.
| S-EPMC7996333 | biostudies-literature
Project description:Cytokine responses of chronic Q fever patients to the intracellular bacterium Coxiella burnetii have mostly been studied using ex vivo stimulation of immune cells with heat-killed C. burnetii due to the extensive measures needed to work with viable biosafety level 3 agents. Whether research with heat-killed C. burnetii can be translated to immune responses to viable C. burnetii is imperative for the interpretation of previous and future studies with heat-killed C. burnetii Peripheral blood mononuclear cells (PBMCs) of chronic Q fever patients (n = 10) and healthy controls (n = 10) were stimulated with heat-killed or viable C. burnetii of two strains, Nine Mile and the Dutch outbreak strain 3262, for 24 h, 48 h, and 7 days in the absence or presence of serum containing anti-C. burnetii antibodies. When stimulated with viable C. burnetii, PBMCs of chronic Q fever patients and controls produced fewer proinflammatory cytokines (interleukin-6 [IL-6], tumor necrosis factor alpha, and IL-1β) after 24 h than after stimulation with heat-killed C. burnetii In the presence of Q fever seronegative serum, IL-10 production was higher after stimulation with viable rather than heat-killed C. burnetii; however, when incubating with anti-C. burnetii antibody serum, the effect on IL-10 production was reduced. Levels of adaptive, merely T-cell-derived cytokine (gamma interferon, IL-17, and IL-22) and CXCL9 production were not different between heat-killed and viable C. burnetii stimulatory conditions. Results from previous and future research with heat-killed C. burnetii should be interpreted with caution for innate cytokines, but heat-killed C. burnetii-induced adaptive cytokine production is representative of stimulation with viable bacteria.
| S-EPMC6204733 | biostudies-literature
Project description:The inability to propagate obligate intracellular pathogens under axenic (host cell-free) culture conditions imposes severe experimental constraints that have negatively impacted progress in understanding pathogen virulence and disease mechanisms. Coxiella burnetii, the causative agent of human Q (Query) fever, is an obligate intracellular bacterial pathogen that replicates exclusively in an acidified, lysosome-like vacuole. To define conditions that support C. burnetii growth, we systematically evaluated the organism’s metabolic requirements using expression microarrays, genomic reconstruction, and metabolite typing. This led to development of a complex nutrient medium that supported substantial growth (~ 3 log10) of C. burnetii in a 2.5% oxygen environment. Importantly, axenically grown C. burnetii were highly infectious for Vero cells and exhibited developmental forms characteristic of in vivo grown organisms. Axenic cultivation of C. burnetii will facilitate studies of the organism’s pathogenesis and genetics, and aid development of Q fever preventatives such as an effective subunit vaccine. Furthermore, the systematic approach used here may be broadly applicable to development of axenic media that support growth of other medically important obligate intracellular pathogens.
2009-10-21 | GSE13338 | GEO
Project description:BackgroundQ fever is a worldwide zoonotic disease caused by Coxiella burnetii. Epidemiologically, animals are considered reservoirs and humans incidental hosts.Methodology/principal findingsWe investigated Q fever in rural Senegal. Human samples (e.g., sera, saliva, breast milk, feces) were screened in the generally healthy population of two villages of the Sine-Saloum region. Ticks were collected in four regions. Seroprevalence was studied by immunofluorescence, and all other samples were tested by two qPCR systems for detection of C. burnetii. Positive samples were genotyped (multispacer typing) by amplification and sequencing of three spacers. Strains were isolated by cell culture. We found that the seroprevalence may be as high as 24.5% (59 of 238 studied) in Dielmo village. We identified spontaneous excretion of C. burnetii by humans through faeces and milk. Hard and soft ticks (8 species) were infected in 0-37.6%. We identified three genotypes of C. burnetii. The previously identified genotype 6 was the most common in ticks in all studied regions and the only one found in human samples. Three strains of genotype 6 of C. burnetii were also recovered from soft tick Ornithodoros sonrai. Two other genotypes found in ticks, 35 and 36, were identified for the first time.Conclusions/significanceQ fever should be considered a significant public health threat in Senegal. Humans, similar to other mammals, may continuously excrete C. burnetii.
| S-EPMC2850317 | biostudies-literature