Human Q Fever on the Guiana Shield and Brazil: Recent Findings and Remaining Questions

Clinical and Epidemiological Aspects of Acute Q Fever in Reunion Island over Fourteen Years: A Retrospective Cohort Study

The clinical characteristics and epidemiology of Q fever in the Tropics are poorly described. We performed a retrospective cohort study of hospitalized cases between 2004 and 2017 in Reunion Island. Acute Q fever was defined in presence of a positive serology (phase II IgG ≥ 200 and phase II IgM ≥ 50), or a seroconversion (4-fold increase in phase II IgG between paired samples), or a positive PCR (blood or serum). Forty-two cases matched the diagnostic criteria. The most common clinical manifestations were fever (85.7%) and pulmonary symptoms (61.9%), including pneumonia (45.2%). Ninety percent of the patients were living in a farming area. Cumulative incidence was estimated at 9.3 per 100,000 inhabitants (95%CI: 6.4-12.1) with cases diagnosed yearly all throughout the study period except in 2006. Together with the seroprevalence figures, these data suggest that Q fever reaches low to moderate endemic levels on Reunion Island. As previously reported, pulmonary symptoms are in the foreground.

Coxiellosis in Livestock: Epidemiology, Public Health Significance, and Prevalence of Coxiella burnetii Infection in Ethiopia

Coxiellosis is a zoonotic disease that is prevalent globally and can pose significant challenges, especially in less developed countries like Ethiopia. Coxiella burnetii is responsible for causing an infection called Q fever in humans and coxiellosis in ruminants. Pneumonia and endocarditis are the only signs that characterize the acute and chronic forms of Q fever, respectively. Ruminants exhibit symptoms such as abortion during the later stages of pregnancy, impaired fertility, perinatal death, premature delivery, and reduced birth weight. C. burnetii infection typically spreads among healthy cattle via tick bites and exposure to infected cattle or their bodily secretions. The primary source of human infection is through the ingestion of contaminated milk and milk products, but transmission through aerosols and dust generated during livestock operations is also common. Cattle, sheep, camels and goats are the primary sources of human infection, and the bacterium can be found in various bodily fluids of infected animals. Several factors, including host characteristics, environmental conditions, and management practices, can potentially affect the occurrence of C. burnetii infection in livestock, such as cattle, camels, sheep, and goats. Coxiellosis is prevalent in Ethiopia's pastoral and mixed cattle management systems, as individuals frequently interact with cattle and are therefore more prone to exposure to the C. burnetii bacterium. Vaccination and biosecurity measures are effective techniques for managing C. burnetii infection. Therefore, it is crucial to implement appropriate mitigation strategies, raise awareness about the spread of C. burnetii infection, and conduct further studies on C. burnetii infection in high-risk groups.

Novel Species of Brucella Causing Human Brucellosis, French Guiana

Human brucellosis is a zoonoses caused by bacteria of the genus Brucella. Infection results in subacute or chronic debilitating disease with nonspecific clinical manifestations and is often associated with consuming unpasteurized dairy products. We report 2 cases of brucellosis in male patients who were hospitalized in distinct towns of French Guiana, an overseas territory of France located on the northeastern shore of South America. Both men were citizens of Brazil working as clandestine goldminers in the deep Amazonian rainforest. Characterization of the 2 bacterial isolates revealed that they represent a potential new species of Brucella. Medical practitioners working in contact with wildlife in this region of the world should be aware of the existence of these pathogens and the potential for human infection.

Zoonoses and gold mining: A cross-sectional study to assess yellow fever immunization, Q fever, leptospirosis and leishmaniasis among the population working on illegal mining camps in French Guiana

Background

Most emerging pathogens are zoonoses and have a wildlife origin. Anthropization and disruption of ecosystems favor the crossing of inter-species barriers. We hypothesize that the marginalized population of undocumented goldminers in the Amazon is at risk of acquiring zoonoses.

Method

A multicentric cross-sectional study included consenting gold-mining adult workers in 2019. A clinical examination recorded dermatological signs of leishmaniosis and past history of yellow fever vaccination. Biological tests were performed for yellow fever, Q fever and leptospirosis serologies. Additional blood samples from a previous study in 2015 were also tested for leptospirosis.

Results

In 2019, 380 individuals were included in the study, along with 407 samples from the 2015 biological collection. The seroprevalence of leptospirosis was 31.0% [95%CI = 26.4–35.5] in 2015 and 28.1% [23.5–32.7] in 2019. The seroprevalence of Q fever was 2.9% [1.2–4.6]. The majority of participants reported being vaccinated against yellow fever (93.6%) and 97.9% had seroneutralizing antibodies. The prevalence of suspected active mucocutaneous leishmaniasis was 2.4% [0.8–3.9].

Discussion

These unique data shed new light on the transmission cycles of zoonoses still poorly understood in the region. They support the existence of a wild cycle of leptospirosis but not of Q fever. Leishmaniasis prevalence was high because of life conditions and tree felling. High yellow fever vaccine coverage was reassuring in this endemic area. In the era of global health, special attention must be paid to these vulnerable populations in direct contact with the tropical ecosystem and away from the health care system.

Many pathogens are zoonotic in origin and human transmission can occur via vector, direct contact, inhalation, absorption, among other routes enabling human-reservoir interaction. In Amazonia, the cycle of these pathogens (the reservoir, the mode of transmission …) is not always well known. It is important to better understand these cycles in order to evaluate and anticipate the potential risk for human health, both on an individual and collective scale (risk of epidemic). In French Guiana, a French territory located in the Amazon, undocumented gold miners represent several thousand people mainly from Brazil who work in very remote areas in the middle of the rainforest. Documenting several zoonotic diseases among this population living in the middle of biodiversity is very valuable to better understand these cycles but also to assess the impact for their own health and to identify risks for public health. This article provides new data for four zoonoses: Q-fever, leptospirosis, leishmaniasis and yellow fever in this population and discusses the contributions to the understanding of cycles and public health issues.

High incidence of acute Q fever among incarcerated people in Cayenne, French Guiana

Q fever is a major public health problem in French Guiana. In recent years, a considerable number of cases has been reported in French Guiana's penitentiary center. The main objective of this study was to describe the epidemiology of these cases. A retrospective study was conducted at the prison to identify cases of acute Q fever in people incarcerated between 2010 and 2021. During the study period, 16 patients were diagnosed with acute Q fever. The positivity rate varied between 13 and 57%. The annual incidence rate in 2019, 2020 and 2021 was 269 (95% CI: 0-640) 1,120 (95% CI: 290-1950) and 1,931 (95% CI: 60-3810) per 100,000 person-years, respectively. While several vertebrate species have already been shown to play an important role in the transmission of Coxiella burnetii, the full epidemiology picture in the tropics is far from clear, and the prison context, with its controlled environment, could help provide answers.