Q fever case spike in Queensland, Australia drives renewed push for more accessible vaccine for "nasty" bacterial disease

Queensland, Australia health experts have been mystified by an unusual spike in cases of Q fever. There have been 89 reported infections across the state so far this year, an increase of almost 90 per cent on the same time in 2023. Townsville's Public Health Unit director Dr Steven Donohue said that the current case numbers were unusually high in light of the recent wet summer.

The surge in cases has sparked renewed calls for a more accessible and affordable vaccine. Q-Vax is the only vaccination for Q fever in the world and is only available in Australia. It is recommended for people aged 15 years and older whose work involves contact with high-risk animals such as abattoir employees, shearers, vets, and animal refuge workers. But Dr Donohue said he would like to see a wider take up of the vaccine.

Dr Steven Graves (Australian Rickettsial Reference Laboratory) said the current vaccine, while effective, was expensive and inaccessible. Dr Graves and his team were tasked with creating a new and improved vaccine in 2020. He hopes it will be available to the public, including children, in the next five years.

Adapted from www.abc.net.au (March, 14, 2024)

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Interdisciplinary studies on Coxiella burnetii: From molecular to cellular, to host, to one health research

Highlights 

• The Q-GAPS consortium investigated Q fever based on the One Health approach.

• Molecular, cellular, host, and One Health aspects were studied.

• The Web-based platform CoxBase was developed for genomic analysis of C. burnetii.

• Strategies for the treatment and monitoring of Q fever were developed

• All findings are freely accessible from an information database (www.q-gaps.de)

Fig. 1. Schematic representation of tasks, goals, and networking of the interdisciplinary Q-GAPS (Q fever GermAn interdisciplinary Program for reSearch) consortium. Q-GAPS is a multidisciplinary network of scientists dedicated to implementing the One Health approach. Q-GAPS aims to support the public health and veterinary communities in preventing and controlling Q fever.

Extracted from original publication: Interdisciplinary studies on Coxiella burnetii: From molecular to cellular, to host, to one health research, Bauer et al., International Journal of Medical Microbiology 313 (2023), doi:10.1016/j.ijmm.2023.151590.

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Flyer for Animal Owners and Veterinarians "Q Fever – A Risk for Humans and Animals. Information on Q Fever in Humans and Small Ruminants" available for download in English now

Q fever is a zoonosis caused by the bacterium Coxiella burnetii and particularly transferred by birth fluids and the afterbirth of infected sheep/goats posing a risk to human and animal health. This flyer intends to provide information to animal owners and vets on how to deal with infections in your herd/flock and to prevent further spreading of the disease.

New Q fever Flyers in French/Nouvelles brochures de la fièvre Q en français

 Background of the project

 In 2021, the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) called for the initiation of an international collaboration programme in the field of public health between scientists from sub-Saharan Africa and Germany.
The aim of the initiative is for participating researchers to identify joint interests in the area of public health and initiate new collaborative ventures.

Thus, the project "Detection of tick-borne bacterial and viral pathogens in ticks, livestock and wildlife in Benin: a chance to establish One Health concepts in veterinary and human medicine", initiated by Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institute (FLI), Jena, Germany, Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut (FLI), Greifswald-Insel Riems, Germany in cooperation with the Communicable Diseases Research Unit, Department of Production and Animal Health, University of Abomey-Calavi (UAC), Godomey, Benin, was initiated.

As the Q-GAPS consortium has already published Q fever flyers in German and English, the idea emerged to create an African-related flyer for Benin in French.

Download flyer "La Fièvre Q - Plus qu'un état grippal (population)"

Download flyer "Informations sur la fièvre Q chez les humains & les petits ruminants"

Download flyer "La Fièvre Q - Plus qu'un état grippal (médicins)"

Suspected Q fever in my flock or herd – which measures should I take as owner?

 Q fever is a notifiable animal disease in Germany and a zoonosis caused by the bacterium Coxiella (C.) burnetii. In particular, the pathogen is transferred by birth fluids and the afterbirth of infected sheep/goats and is a risk for human and animal health. If there is shedding of the bacterium by animals, it is important to prevent further spreading to other animals and humans in particular.

An infection with C. burnetii can be asymptomatic especially in sheep. Thus, an early detection of the pathogen in the flock/herd is often difficult for livestock owners.

Therefore, it is even more important to take the following Q fever symptoms in ruminants seriously:

Abortion and stillbirth 
 Birth of weak lambs/kids/calves
Retarded expulsion of the afterbirth

In the event of a suspected case your veterinarian can initiate diagnostics for Q fever. The most sensitive and meaningful test for verifying a C. burnetii infection is direct detection of gene material (DNA) of the pathogen by means molecular analysis of afterbirth material, dead lambs/kids/calves, vaginal swabs or preputial swabs.

At least the following measures should be taken when Q fever occurs in your flock/herd:

• Make sure births and shearing occur in closed premises.

• Store all after birth material immediately in a closed container until it is disposed of by animal by-products processing plants (rendering plants). The container should be cleaned and disinfected after having been emptied.

• Clean and disinfect your working clothes as well as your working material.

• Inform your colleagues and family members about necessary protective and hygiene measures.

• Post a sign near your stables: „Valuable livestock – Do Not Enter. Authorized Personnel Only."

• Prevent non-authorized people from getting access to your animals.

• Don't offer raw milk or raw milk products to consumers and stand down from drinking raw milk and eating raw milk products.

• Important: The process of pasteurisation results in inactivation of the pathogen.

• Store the dung for 9 months underneath foil as well as apart from any population, before you spread it on the fields.

• Have your herd/flock vaccinated against C. burnetii.

Tip (Germany): Please consult your Animal Diseases Fund (Tierseuchenkasse) for support for vaccination costs.

For further information please read our FAQs.

Q Fever was agreed on the list of 10 prioritised pathogens by EFSA:

 Prioritisation of zoonotic diseases for coordinated surveillance systems under the One Health approach for cross‐border pathogens that threaten the Union

In the context of the initiative ‘CP‐g‐22‐04.01 Direct grants to Member States’ authorities', EFSA was requested to develop and conduct a prioritisation of zoonotic diseases, in collaboration with Member States, to identify priorities for the establishment of a coordinated surveillance system under the One Health approach.

The methodology developed by EFSA's Working Group on One Health surveillance was based on a combination of multi‐criteria decision analysis and the Delphi method. It comprised the establishment of a list of zoonotic diseases, definition of pathogen‐ and surveillance‐related criteria, weighing of those criteria, scoring of zoonotic diseases by Member States, calculation of summary scores, and ranking of the list of zoonotic diseases according to those scores.

Results were presented at EU and country level. A prioritisation workshop was organised with the One Health subgroup of EFSA's Scientific Network for Risk Assessment in Animal Health and Welfare in November 2022 to discuss and agree on a final list of priorities for which specific surveillance strategies would be developed. Those 10 priorities were Crimean‐Congo haemorrhagic fever, echinococcosis (both E. granulosus and E. multilocularis), hepatitis E, influenza (avian), influenza (swine), Lyme borreliosis, Q‐fever, Rift Valley fever, tick‐borne encephalitis and West Nile fever. ‘Disease X' was not assessed in the same way as other zoonotic diseases on the list, but it was added to the final list of priorities due to its relevance and importance in the One Health context.
© European Food Safety Authority

Source: EFSA Journal 2023;21(3)

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Impact of Coxiella burnetii vaccination on humoral immune response, vaginal shedding, and lamb mortality in naturally pre-infected sheep

Introduction: Sheep are considered to be one of the main reservoirs for Coxiella burnetii, a gram-negative bacterium with high zoonotic potential. Infected sheep shed tremendous amounts of the pathogen through birth products which caused human Q fever epidemics in several countries. Information about the impact of an inactivated C. burnetii Phase I vaccine on humoral immune response, vaginal shedding, and lamb mortality in naturally pre-infected sheep is scarce.

Methods: Two identically managed and naturally C. burnetii-infected sheep flocks were examined for two lambing seasons (2019 and 2020). One flock (VAC) received a primary vaccination against Q fever before mating and the second flock served as control (CTR). In each flock, one cohort of 100 ewes was included in follow-up investigations. Serum samples at eight different sampling dates were analyzed by C. burnetii phase-specific ELISAs to differentiate between the IgG Phase I and II responses. Vaginal swabs were collected within three days after parturition and examined by a C. burnetii real-time PCR (IS1111). Lamb losses were recorded to calculate lamb mortality parameters.

Results: After primary vaccination, almost all animals from cohort VAC showed a high IgG Phase I response up until the end of the study period. In cohort CTR, the seropositivity rate varied from 35.1% to 66.3%, and the Phase I and Phase II pattern showed an undulating trend with higher IgG Phase II activityduring both lambing seasons. The number of vaginal shedders was significantly reduced in cohort VAC compared to cohort CTR during the lambing season in 2019 (p < 0.0167). There was no significant difference of vaginal shedders in 2020. The total lamb losses were low in both cohorts during the two investigated lambing seasons (VAC 2019: 6.8%, 2020: 3.2%; CTR 2019: 1.4%,2020: 2.7%).

Discussion: Neither the C. burnetii vaccine nor the C. burnetii infection seem to have an impact on lamb mortality. Taken together, the inactivated C. burnetii Phase I vaccine induced a strong IgG Phase I antibody response in naturally pre-infected sheep. It might also reduce vaginal shedding in the short term but seems to have little beneficial impact on lamb mortality.

Source: Bauer et al., Frontiers in Veterinary Science 01 frontiersin.org, 10.3389/fvets.2022.1064763

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TGF-β/IFN-γ Antagonism in Subversion and Self-Defense of Phase II Coxiella burnetii-Infected Dendritic Cells

 Dendritic cells (DCs) belong to the first line of innate defense and come into early contact with invading pathogens, including the zoonotic bacterium Coxiella burnetii, the causative agent of Q fever. However, the pathogen-host cell interactions in C. burnetii-infected DCs, particularly the role of mechanisms of immune subversion beyond virulent phase I lipopolysaccharide (LPS), as well as the contribution of cellular self-defense strategies, are not understood. Using phase II Coxiella-infected DCs, we show that impairment of DC maturation and MHC I downregulation is caused by autocrine release and action of immunosuppressive transforming growth factor-β (TGF-β). Our study demonstrates that IFN-γ reverses TGF-β impairment of maturation/MHC I presentation in infected DCs and activates bacterial elimination, predominantly by inducing iNOS/NO. Induced NO synthesis strongly affects bacterial growth and infectivity. Moreover, our studies hint that Coxiella-infected DCs might be able to protect themselves from mitotoxic NO by switching from oxidative phosphorylation to glycolysis, thus ensuring survival in self-defense against C. burnetii. Our results provide new insights into DC subversion by Coxiella and the IFN-γ-mediated targeting of C. burnetii during early steps in the innate immune response.

Source: Matthiesen S, Christiansen B, Jahnke R, Zaeck LM, Karger A, Finke S, Franzke K, Knittler MR. Infect Immun. 2023 Jan 23:e0032322. doi: 10.1128/iai.00323-22. Online ahead of print. PMID: 36688662

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Surveillance of Coxiella burnetii Shedding in Three Naturally Infected Dairy Goat Herds after Vaccination, Focusing on Bulk Tank Milk and Dust Swabs

Q fever outbreaks on three dairy goat farms (A–C) were monitored after the animals had been vaccinated with an inactivated Coxiella burnetii phase I vaccine. The antibody response was measured before vaccination by serum samples with two C. burnetii phase-specific ELISAs to characterize the disease status. Shedding was determined by vaginal swabs during three kidding seasons and monthly bulk tank milk (BTM) samples. Dust swabs from one windowsill of each barn and from the milking parlors were collected monthly to evaluate the indoor exposure.

These samples were analyzed by qPCR. The phase-specific serology revealed an acute Q fever infection in herd A, whereas herds B and C had an ongoing and past infection, respectively. In all three herds, vaginal shedders were present during three kidding seasons. In total, 50%, 69%, and 15% of all collected BTM samples were C. burnetii positive in herds A, B, and C, respectively. Barn dust contained C. burnetii DNA in 71%, 45%, and 50% of examined swabs collected from farms A, B, and C, respectively. The largest number of C. burnetii positive samples was obtained from the milking parlor (A: 91%, B: 72%, C: 73%), indicating a high risk for humans to acquire Q fever during milking activity.

Abstract taken from: Benjamin U Bauer, Clara Schoneberg, T Louise Herms, Martin Runge, Martin Ganter, Surveillance of Coxiella burnetii Shedding in Three Naturally Infected Dairy Goat Herds after Vaccination, Focusing on Bulk Tank Milk and Dust Swabs, Vet Sci. 2022 Feb 24;9(3):102. doi: 10.3390/vetsci9030102.

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Q fever expertise among human and veterinary health professionals in Germany – A stakeholder analysis of knowledge gaps

Q fever is a zoonosis caused by Coxiella burnetii. In Germany, the common sources of human infections include small ruminants that excrete the pathogen. Q fever in humans can be asymptomatic or nonspecific. However, severe disease progression is also possible, which can lead to death. Q fever in small ruminants is usually asymptomatic, although reproductive disorders may occur. To protect humans from Q fever, it is important that human and veterinary health professionals (practitioners/health authority employees) have comprehensive knowledge of the diagnosis, control and prevention of Q fever, and its zoonotic potential. To ensure and enhance this understanding, this stakeholder analysis assessed Q fever expertise in human and veterinary health professionals in Germany and investigated how these knowledge gaps can best be resolved.

For this purpose, an online survey and two focus group discussions were conducted with 836 and 18 participants, respectively. Knowledge gaps are due to a lack of awareness of Q fever, especially among human health practitioners. Moreover, colleagues who have heard about Q fever still lack the necessary cross-species knowledge to successfully diagnose, control and prevent this zoonosis. Additionally, differences exist between stakeholders regarding their work context and the region in which they work. In this study, stakeholders in southwestern Germany had slightly better Q fever knowledge than their colleagues in North-eastern Germany.

In addition, information sources aimed at resolving knowledge gaps involve direct conversations between the stakeholders, as well as reading materials and seminars. Each of these information sources should focus on interdisciplinary resources to strengthen the cooperation between human and veterinary health professionals and to raise awareness of the strengths of each stakeholder group. These results have already been implemented by the Q-GAPS project, with goals of raising awareness of Q fever and filling knowledge gaps.

Abstract taken from: Fenja Winter und Amely Campe, A stakeholder analysis of knowledge gaps, PLoS One, 2022 Mar 3;17(3):e0264629.

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