Q fever vaccines for animals

Schmeer, N.; Müller, Philipp; Langel, J.; Krauss, H; Frost, J. W.; Wieda, J.

doi:10.1016/s0176-6724(87)80191-8

Cited by 20 publications

(28 citation statements)

References 6 publications

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“…from fixing complement (32,54,55). The CFT is thus likely to result in many false-negative sample results, which make the test unsuitable for estimating prevalences and identifying exposed or infected ruminants.…”

Section: Figmentioning

confidence: 99%

Bayesian Validation of the Indirect Immunofluorescence Assay and Its Superiority to the Enzyme-Linked Immunosorbent Assay and the Complement Fixation Test for Detecting Antibodies against Coxiella burnetii in Goat Serum

Muleme

Stenos²,

Vincent³

et al. 2016

Clin Vaccine Immunol

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dAlthough many studies have reported the indirect immunofluorescence assay (IFA) to be more sensitive in detection of antibodies to Coxiella burnetii than the complement fixation test (CFT), the diagnostic sensitivity (DSe) and diagnostic specificity (DSp) of the assay have not been previously established for use in ruminants. This study aimed to validate the IFA by describing the optimization, selection of cutoff titers, repeatability, and reliability as well as the DSe and DSp of the assay. Bayesian latent class analysis was used to estimate diagnostic specifications in comparison with the CFT and the enzyme-linked immunosorbent assay (ELISA). The optimal cutoff dilution for screening for IgG and IgM antibodies in goat serum using the IFA was estimated to be 1:160. The IFA had good repeatability (>96.9% for IgG, >78. Coxiella burnetii causes Q fever in humans as well as abortions, stillbirths, and infertility in ruminants (1-5). The organism replicates in the placenta of infected ruminants, reaching a level of up to 10 9 bacteria per gram of placenta tissue (4-6). C. burnetii organisms are shed in an extremely high concentration in birth fluids, placental tissues, and membranes of aborted fetuses as well as in milk, urine, and feces of infected ruminant animals around the parturition period (4, 5). The high concentration of C. burnetii organisms shed in tissues, fluids, and excreta of infected ruminants is the primary source of human infections (7).Caprine and ovine infections have been reported to result in severe placentitis and consequently in shedding of higher numbers of C. burnetii organisms than infections of cattle (8). Studies have also revealed that goats and sheep shed higher quantities of C. burnetii in feces, vaginal mucus, and birth tissues than other livestock (9). Thus, the risk of human transmission is higher when infections occur in herds of small ruminants than when they occur with other livestock. Unsurprisingly, the majority of reported large outbreaks of Q fever have been associated with infected sheep and goat flocks, including a major outbreak of more than 4,000 human Q fever cases in the Netherlands that was linked to sheep and goat farms with over 50 animals (9)(10)(11)(12)(13)(14). Infection with C. burnetii can be asymptomatic in many animals and may be detected in ruminants only when infection causes abortions and reproductive abnormalities in pregnant animals (1). Delay in diagnosis in livestock slows the implementation of appropriate control strategies, thus increasing the risk of human infection.Coxiellosis in animals can be diagnosed through microscopic examination of stained tissues, culture, detection of C. burnetii DNA using PCR, and detection of antibodies to C. burnetii in blood and milk (15,16). The microscopic diagnosis of coxiellosis is mainly undertaken on placental tissues using Stamp-Macchiavello coloration or Giemsa stain. The organism can be cultured in cells, embryonated hen eggs, or cell-free media (15,17). However, microscopy and culture are expensive and requi...

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Section: Figmentioning

confidence: 99%

Bayesian Validation of the Indirect Immunofluorescence Assay and Its Superiority to the Enzyme-Linked Immunosorbent Assay and the Complement Fixation Test for Detecting Antibodies against Coxiella burnetii in Goat Serum

Muleme

Stenos²,

Vincent³

et al. 2016

Clin Vaccine Immunol

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“…Bacterial shedding in placentas and milk was strongly reduced in experimental infection or in natural Q fever infection of ewes and cows vaccinated by phase I vaccines [25,133,134]. However, for several authors, phase I vaccines failed to prevent shedding in milk in naturally infected cows prior to vaccination [21,140], underlining that a vaccine can only protect uninfected animals but is not able to treat an infected one. In contrast, a phase II vaccine failed to protect livestock against the C. burnetii infection and to prevent the shedding of bacteria by the vaginal route and in milk [39,41]: the vaccine was not able to prevent abortions nor bacterial shedding in milk, vaginal secretions nor in feces [147].…”

Section: Vaccinesmentioning

confidence: 99%

“…In contrast, a phase II vaccine failed to protect livestock against the C. burnetii infection and to prevent the shedding of bacteria by the vaginal route and in milk [39,41]: the vaccine was not able to prevent abortions nor bacterial shedding in milk, vaginal secretions nor in feces [147]. Phase II vaccination, antibiotherapy, or a combination of both reduced but did not stop the milk excretion of Coxiella by cows [39,140] or by goats [41]. Since contaminated aerosols are the main sources of animal and human contaminations, the control of fecal excretion and placental bacterial discharge is essential.…”

Section: Vaccinesmentioning

confidence: 99%

Is Q Fever an emerging or re-emerging zoonosis?

2005

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-Q fever is a zoonotic disease considered as emerging or re-emerging in many countries. It is caused by Coxiella burnetii, a bacterium developing spore-like forms that are highly resistant to the environment. The most common animal reservoirs are livestock and the main source of infection is by inhalation of contaminated aerosols. Although the culture process for Coxiella is laborious, advances on the knowledge of the life cycle of the bacterium have been made. New tools have been developed to (i) improve the diagnosis of Q fever in humans and animals, and especially animal shedders, (ii) perform epidemiological studies, and (iii) prevent the disease through the use of vaccines. This review summarizes the state of the knowledge on the bacteriology and clinical manifestations of Q fever as well as its diagnosis, epidemiology, treatment and prevention in order to understand what factors are responsible for its emergence or re-emergence. Coxiella burnetii / epidemiology / bacteriology / diagnostic / control

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“…It was partly for that reason that a recent WHO workshop on Q fever advocated the establishment of a centralised collection of C. burnetii isolates of defined origin and history (2). In general, the antigenic components of animal coxiella vaccines have been inactivated whole cells (WC), with more recent use of particulate residue of chloroform/ methanol extracts of whole cells (CMR) (27) or an enzymically liberated protein of that residue (PE) (17,25).…”

Section: Preventionmentioning

confidence: 99%

Clinical aspects and prevention of Q fever in animals

Aitken

1989

Eur J Epidemiol

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The natural reservoir of Coxiella burnetii encompasses many free-living vertebrates but the major risk of human infection arises through contact with infected ruminant livestock and their contaminated products. The organism has a remarkable affinity for the ruminant placenta and mammary gland but the great majority of naturally-occurring infections are asymptomatic. However, the potential of C. burnetii to cause abortion has been demonstrated experimentally and observed in the field while more recent evidence has implied a contributory role in bovine infertility. Empirical vaccines incorporating inactivated whole cells of C. burnetii or derivatives have induced varying degrees of protection of cattle and sheep against both natural and experimental challenge but, in some cases, severe reactions have occurred at inoculation sites. Modifications in processes of antigen preparation seem to overcome this problem. Discrimination between antibodies resulting from natural infection and those induced by vaccination is possible using ELISAs with specificity for individual immunoglobulin isotypes.

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Q fever vaccines for animals

Cited by 20 publications

References 6 publications

Bayesian Validation of the Indirect Immunofluorescence Assay and Its Superiority to the Enzyme-Linked Immunosorbent Assay and the Complement Fixation Test for Detecting Antibodies against Coxiella burnetii in Goat Serum

Bayesian Validation of the Indirect Immunofluorescence Assay and Its Superiority to the Enzyme-Linked Immunosorbent Assay and the Complement Fixation Test for Detecting Antibodies against Coxiella burnetii in Goat Serum

Is Q Fever an emerging or re-emerging zoonosis?

Clinical aspects and prevention of Q fever in animals

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