Epidemiology of Coxiella burnetii Infection in Africa: A OneHealth Systematic Review

Abstract

BackgroundQ fever is a common cause of febrile illness and community-acquired pneumonia in resource-limited settings. Coxiella burnetii, the causative pathogen, is transmitted among varied host species, but the epidemiology of the organism in Africa is poorly understood. We conducted a systematic review of C. burnetii epidemiology in Africa from a “One Health” perspective to synthesize the published data and identify knowledge gaps.Methods/Principal FindingsWe searched nine databases to identify articles relevant to four key aspects of C. burnetii epidemiology in human and animal populations in Africa: infection prevalence; disease incidence; transmission risk factors; and infection control efforts. We identified 929 unique articles, 100 of which remained after full-text review. Of these, 41 articles describing 51 studies qualified for data extraction. Animal seroprevalence studies revealed infection by C. burnetii (≤13%) among cattle except for studies in Western and Middle Africa (18–55%). Small ruminant seroprevalence ranged from 11–33%. Human seroprevalence was <8% with the exception of studies among children and in Egypt (10–32%). Close contact with camels and rural residence were associated with increased seropositivity among humans. C. burnetii infection has been associated with livestock abortion. In human cohort studies, Q fever accounted for 2–9% of febrile illness hospitalizations and 1–3% of infective endocarditis cases. We found no studies of disease incidence estimates or disease control efforts.Conclusions/Significance C. burnetii infection is detected in humans and in a wide range of animal species across Africa, but seroprevalence varies widely by species and location. Risk factors underlying this variability are poorly understood as is the role of C. burnetii in livestock abortion. Q fever consistently accounts for a notable proportion of undifferentiated human febrile illness and infective endocarditis in cohort studies, but incidence estimates are lacking. C. burnetii presents a real yet underappreciated threat to human and animal health throughout Africa.

Investigação sorológica de Rickettsia rickettsii e Coxiella burnetii em caprinos e ovinos no entorno do Parque Nacional da Serra das Confusões, Piauí

“…Pesquisas sobre a prevalência da infecção em caprinos e ovinos no Brasil são escassos. Estudos soroepidemiológicos realizados em outros países (Espanha, Alemanha, Irã) e no continente africano relataram prevalência da infecção por C. burnetii variando entre 11 a 74% (Ruiz-Fons et al 2010, Hilbert et al 2012, Esmaeli et al 2013, Vanderburg et al 2014 Apenas um ovino sororreativo foi encontrado parasitado por R. microplus, não permitindo estabelecer uma correlação segura entre a ocorrência do vetor e a presença de anticorpos nas amostras soropositivas, ainda que a presença do carrapato R. microplus em outros animais do mesmo rebanho sugira uma possível transmissão de C. burnetii. Mesmo não sendo verificada a presença de anticorpos anti--C. burnetii em caprinos, não se descarta a possível infecção nestes animais como parte do ciclo doméstico da C. burnetii.…”

“…Estes artrópodes são os reservatórios naturais mais amplamente conhecidos, sendo os vetores primários na transmissão da bactéria às espécies animais (Stoker & Marmion 1955, Parreira 2008. Os ruminantes (caprinos, ovinos e bovinos) são considerados os principais reservatórios no ambiente doméstico (Vanderburg et al 2014). A infecção nos animais (Coxielose) é geralmente assintomática, porém pode causar desordens reprodutivas em ruminantes domésticos (caprinos, ovinos e bovinos), tais como aborto, morte fetal, metrite, endometrite e infertilidade (Palmer et al 1983, Gürtler et al 2014.…”

Occurrence and Genotyping of Coxiella burnetii in Ixodid Ticks in Oromia, Ethiopia

“…16 Included in the few studies from African countries are reports of antibodies against C. burnetii in the sera of 1-24% of humans in 7 west African countries: 17 30.9% of humans, 28.3% of cattle, 18.2% of sheep and 32% of goats in Kenya, 18 24.2% of goats and 18.5% of sheep in Gambia, 19 C. burnetii DNA in the blood of 7.8% of cattle and 7.5% of goats in Tanzania, 20 and 0.3% of febrile patients in Algeria and 0.4% in Senegal 21 . A previous study performed nearly half a century ago in Ethiopia reported the detection of C. burnetii in 5.3% of Amblyomma variegatum and 10.8% of Hyalomma truncatum ticks.…”

Examining the reservoir potential of animal species for $$\varvec{\textit{Leishmania infantum}}$$ Leishmania infantum infection

“…Second, not necessarily directly surveying these characteristics through entomologic investigations, but also one could examine genetic or molecular characteristics of Leishmania spp. For instance, one could implement phylogenetic analysis to accurately capture the route of transmission and evolution, thereby permitting us to track the inter-specific transmission in an explicit manner [18][19][20][21][22][23][24][36][37][38]. Such analysis could also shed light on our assumption of SIS model (e.g.…”