Bartonella clarridgeiae, B. henselae and Rickettsia felis in fleas from Morocco

Geographical distribution of Bartonella spp in the countries of the WHO Eastern Mediterranean Region (WHO-EMRO)

Bartonellosis is a vector-borne and zoonotic diseases in humans, especially in immunocompromised individuals. However, there is no complete data about the geographical distribution of different species of Bartonella, as well as the status of its reservoirs, vectors, and human cases in most parts of the world. In this study, published reports related to Bartonella species from WHO-EMRO region countries were searched in different databases until October 2023. The eighteens different species of Bartonella were reported in WHO-EMRO countries including Bartonella henselae, Bartonella quintana, Bartonella elizabethae, Bartonella bovis, Bartonella clarridgeiae, Bartonella vinsonii, Bartonella doshiae, Bartonella taylorii, Bartonella rochalimae, Bartonella tribocorum, Bartonella rattimassiliensis, candidatus Bartonella merieuxii, candidatus Bartonella dromedarii, Bartonella acomydis, Bartonella jaculi, Bartonella coopersplainsensis and Bartonella koehlerae. Also, only human cases of B. henselae and B. quintana infections were reported from WHO-EMRO countries. The infections of Bartonella are important in the WHO-EMRO region, but they have been neglected by clinicians and healthcare systems.

An overview of fleas (Siphonaptera) in wild and domestic mammals from Algeria with new data from the central north and south of the country

Fleas (Siphonaptera) are medically and veterinary important ectoparasites known to infest a wide range of host species. This study presents a systematic review complemented by new data on the diversity of flea species and host associations in Algeria. 198 mammals were examined, including previously understudied hosts such as sheep, red foxes, fennec foxes, and golden African wolves. Of these animals, 108 (54.55%) were infested with fleas. Overall, 1.906 fleas belonging to seven species (Archaeopsylla erinacei s.l., Ctenocephalides felis, C. canis, Nosopsyllus fasciatus, Pariodontis riggenbachi, Pulex irritans, Xenopsylla cheopis) were identified, originating from seven provinces across Algeria. Statistical analysis techniques were employed to process the data, including descriptive statistics, statistical tests, and principal component analysis (PCA). This study reveals the diverse flea fauna in Algeria and their association with various host species, including wild and domestic animals. This comprehensive survey aimed to combine literature reviews, fieldwork, and statistical analysis to understand fleas' diversity and host associations. The findings contribute to the growing knowledge of flea ecology and host-parasite interactions, with implications for public health and veterinary practices in Algeria and potentially other regions with similar ecological characteristics.

Prevalence of Bartonella spp., haemotropic Mycoplasma spp. and others vector-borne pathogens in private-owned dogs and cats, Egypt

Vector-borne pathogens have been increasingly investigated for their impact on dog and cat health and their zoonotic potential. The aim of this study was to investigate the prevalence estimates of selected vector-borne pathogens in client-owned pets from the Giza and Cairo governorates, Egypt.  Out of 200 dogs and 100 cats, 94 (47%) and 23 (23%) were positive for at least one of the tested pathogens (P<0.0001). In particular, 84 (42%) dogs and 3 (3%) cats tested PCR-positive for Bartonella spp. (P<0.0001). A significantly higher prevalence of Bartonella spp. was detected in dogs from the rural areas of the Giza governorate (60/77, 79.2%, P<0.0001) compared to those from Cairo governorate. Bartonella henselae was the dominant species infecting dogs (81/200, 40.5%) followed by Candidatus Bartonella merieuxii (3/200, 1.5%), while B. henselae (2/100, 2%) and B. clarridgeiae were rare in cats. Haemoplasma DNA was detected in 17% (34/200) of dogs and 20% (20/100) of cats with increased risk in dogs from Giza rural areas (21/77, 27.27%, P=0.002) and from both dogs (16/63, 25.40%, P=0.03) and cats (7/14, 50%, P<0.002) with anemia. Candidatus Mycoplasma haematoparvum (30/200, 15%) and Mycoplasma haemocanis (4/200, 2%) in dogs and Candidatus Mycoplasma haemominutum (18/100, 18%) and M. haemofelis (2/100, 2%) in cats were detected. Additionally, 2 dogs were positive for C. burnetii DNA. Coinfections were detected in dogs, with the majority (23/200, 11.5%) including B. henselae and C.M. haematoparvum, followed by Mycoplasma haemocanis and C.M. haematoparvum (2/200, 1%) and B. henselae, CMhp and C. burnetii (2/200, 1%). Haemoplasma infection was high in Egyptian dogs and cats with a high prevalence for zoonotic Bartonella spp. in dogs with anemia, highlighting the need to investigate these agents in the diagnostic algorithm of anemia and to adopt preventive measures to protect both animal and human health.

Fleas (Siphonaptera) of domestic and wild animals in extreme northeastern Algeria: first inventory, hosts, and medical and veterinary importance

Fleas are an important member of the North African entomofauna. An understanding of the risks of flea-borne diseases to public and veterinary health can be gained with surveys of their abundance, distribution, and hosts. The aims of this study were to make an initial assessment of flea (Siphonaptera) species collected from a selected number of mammalian hosts in Algeria and debate their medical and veterinary importance. To do so, an entomological survey was conducted on several animal species (goats, dogs, cats, rabbits, hedgehogs, and mongooses) in six localities of El Tarf region located in extreme northeastern Algeria. During the survey, flea specimens were collected from hosts, stored in alcohol, and identified using a taxonomic key. More than 1,200 specimens were collected and identified; including four species: Ctenocephalides felis, Ctenocephalides canis, Pulex irritans, and Archaeopsylla erinacei (s.l.). Goats and dogs were the most infested animals, followed by cats and hedgehogs. Ctenocephalides felis was the most prevalent flea among all infested animals, with 631 collected specimens, followed by Pulex irritans with 433 samples. Overall, this study is an initial assessment of flea species recovered from selected common mammals in northeastern Algeria.

Molecular Evidence of a Broad Range of Pathogenic Bacteria in Ctenocephalides spp.: Should We Re-Examine the Role of Fleas in the Transmission of Pathogens?

The internal microbiome of common cat and dog fleas was studied for DNA evidence of pathogenic bacteria. Fleas were grouped in pools by parasitized animal. DNA was extracted and investigated with 16S metagenomics for medically relevant (MR) bacteria, based on the definitions of the International Statistical Classification of Diseases and Related Health Problems (WHO). The MR bacterial species totaled 40, were found in 60% of flea-pools (N = 100), and included Acinetobacterbaumannii, Bacteroidesfragilis, Clostridiumperfringens, Enterococcusfaecalis, E. mundtii, Fusobacteriumnucleatum, Haemophilusaegyptius, Kingellakingae, Klebsiellapneumoniae, Leptotrichiabuccalis, L. hofstadii, Moraxellalacunata, Pasteurellamultocida, Propionibacteriumacnes, P. propionicum, Proteusmirabilis, Pseudomonasaeruginosa, Rickettsiaaustralis, R. hoogstraalii, Salmonellaenterica, and various Bartonella, Staphylococcus, and Streptococcus species. B. henselae (p = 0.004) and B. clarridgeiae (p = 0.006) occurred more frequently in fleas from cats, whereas Rickettsiahoogstraalii (p = 0.031) and Propionibacteriumacnes (p = 0.029) had a preference in fleas from stray animals. Most of the discovered MR species can form biofilm, and human exposure may theoretically occur through the flea-host interface. The fitness of these pathogenic bacteria to cause infection and the potential role of fleas in the transmission of a broad range of diseases should be further investigated.

Investigation of Ctenocephalides felis on domestic dogs and Rickettsia felis infection in the Democratic Republic of Sao Tome and Principe

Rickettsia felis is an obligate intracellular Gram-negative bacterium which causes flea-borne spotted fever in humans. In the past decades, R. felis has been detected worldwide in Ctenocephalides felis fleas and various other arthropods. However, due to its shared symptoms with other common vector-borne diseases, human infection is prone to be underestimated or misdiagnosed, especially in the malaria-endemic areas including sub-Saharan Africa, where confirmatory laboratory diagnoses are not usually available. In this study, a 'One Health' approach was adopted to explore potential vector-borne and zoonotic pathogens in the Democratic Republic of Sao Tome and Principe (DRSTP), an island nation in the Gulf of Guinea. By collaborating with local veterinarians, 1,187 fleas were collected from 95 domestic dogs across the country and later identified as Ct. felis using taxonomic keys. A cytochrome oxidase gene-based phylogenetic analysis revealed that all collected fleas belonged to a single haplotype and were identical to isolates from Ivory Coast and Brazil that clustered into a clade of tropical distribution. Additional samples of 14 chigoe fleas (Tunga penetrans) were collected from the surrounding environment of the dogs' resting spots. Rickettsia felis infection in fleas was examined by molecular methods targeting the citrate synthase (gltA)- and outer membrane protein A (ompA)-coding genes as well as the R. felis-specific pRF plasmid. The bacterial DNA was detected in 21.01% (146/695) of cat fleas but none of the chigoe fleas. Microimmunofluorescence assay was then performed to assess pathogen exposure of the residents. Of 240 dried blood spots from participants with dog contacts, 8 (3.33%) exhibited R. felis antibodies. Our findings demonstrated the presence of R. felis in DRSTP. Further extensive epidemiological studies regarding its prevalence and its role in causing febrile illness while the nation is entering pre-elimination stage of malaria will be carried out.

Fleas and flea-borne diseases of North Africa

North Africa has an interesting and rich wildlife including hematophagous arthropods, and specifically fleas, which constitute a large part of the North African fauna, and are recognised vectors of several zoonotic bacteria. Flea-borne organisms are widely distributed throughout the world in endemic disease foci, where components of the enzootic cycle are present. Furthermore, flea-borne diseases could re-emerge in epidemic form because of changes in the vector-host ecology due to environmental and human behaviour modifications. We need to know the real incidences of flea-borne diseases in the world due to this incidence could be much greater than are generally recognized by physicians and health authorities. As a result, diagnosis and treatment are often delayed by health care professionals who are unaware of the presence of these infections and thus do not take them into consideration when attempting to determine the cause of a patient's illness. In this context, this bibliographic review aims to summarise the main species of fleas present in North Africa, their geographical distribution, flea-borne diseases, and their possible re-emergence.

Feline-Human Zoonosis Transmission in North Africa: A Systematic Review

Throughout human history, domestic animal species have represented a unique zoonotic disease risk for the transmission of pathogens ranging from viral, bacterial, parasitic, and fungal. In North Africa, cats have a particularly long record and occupy a specialized niche within many communities. This systematic review was conducted to analyze the current and historical literature documenting the breadth and variety of zoonoses in North Africa, specifically relating to the domesticated feline. Multiple electronic databases were searched on January 16, 2019, for published reports on feline zoonoses in North Africa. A total of 76 studies met the inclusion criteria for a full assessment. Articles selected for the review ranged in publication dates from 1939 to 2019 and included a case study, cross-sectional surveys, genomic analyses, and a book chapter. The most commonly studied pathogen was Toxoplasma gondii (n = 17) followed by a variety of helminths (n = 10). Of the countries in the target region, most publications were of studies conducted in Egypt (n = 53) followed by Tunisia (n = 12), Algeria (n = 11), Morocco (n = 5), and Libya (n = 3). The results of this review identify a variety of viral, bacterial, fungal, and parasitic zoonotic diseases associated with cats in North Africa, ranging from historically endemic diseases in both human and animal populations in the region, to emerging infections with recent confirmatory diagnoses. This review describes reported feline zoonoses in North Africa and provides recommendations for their prevention and control. In addition to vaccination campaigns for domesticated felines and postexposure prophylaxis for humans, prompt veterinary and medical care of exposure risks and subsequent infections are essential in limiting the zoonotic disease burden in North African communities of humans and cats.

Pathogens in fleas collected from cats and dogs: distribution and prevalence in the UK

Background

Fleas (Siphonaptera) are the most clinically important ectoparasites of dogs and cats worldwide. Rising levels of pet ownership, climate change and globalisation are increasing the importance of a detailed understanding of the endemicity and prevalence of flea-borne pathogens. This requires continued surveillance to detect change. This study reports a large-scale survey of pathogens in fleas collected from client-owned cats and dogs in the UK.

Methods

Recruited veterinary practices were asked to follow a standardised flea inspection protocol on a randomised selection of cats and dogs brought into the practice in April and June 2018. A total of 326 practices participated and 812 cats and 662 dogs were examined. Fleas were collected, identified to species and pooled flea samples from each host were analysed for the presence of pathogens using PCR and sequence analysis.

Results

Overall, 28.1% of cats and 14.4% of dogs were flea infested. More than 90% of the fleas on both cats and dogs were cat fleas, Ctenocephalides felis felis. Fleas of the same species from each infested host were pooled. DNA was amplified from 470 of the pooled flea samples using conventional PCR, 66 of which (14% ± 95% CI 3.14%) were positive for at least one pathogen. Fifty-three (11.3% ± 95% CI 2.85%) of the pooled flea DNA samples were positive for Bartonella spp., 35 were from cats and 4 from dogs, the remainder had no host record. Seventeen of the Bartonella spp. samples were found to be Bartonella henselae, 27 were Bartonella clarridgeiae (of two different strains), 4 samples were Bartonella alsatica and one was Bartonella grahamii; 4 samples could not be identified. Fourteen (3% ± 95% CI 1.53%) of the flea DNA samples were found to be positive for Dipylidium caninum, 10 of the D. caninum-infected samples were collected from cats and one from a dog, the other 3 positive flea samples had no host species record. Only 3 flea samples were positive for Mycoplasma haemofelis or Mycoplasma haemocanis; 2 were collected from cats and one had no host species record. Three fleas were positive for both D. caninum and Bartonella spp. One flea was positive for both Bartonella spp. and M. haemofelis or M. haemocanis.

Conclusions

This study highlights the need for ongoing flea control, particularly given the relatively high prevalence of Bartonella spp., which is of concern for both animal welfare and human health. The study demonstrates the ongoing need to educate pet owners about the effects of both flea infestation and also the pathogen risks these fleas present.

Seek and Find! PCR analyses of skin infections in West-European travelers returning from abroad with an eschar

BACKGROUND

Skin infections are among the leading causes of diseases in travelers. Diagnosing pathogens could be difficult.

METHOD

We applied molecular assays for the diagnostic of a large collection of skin biopsies and swabs from travelers with suspected skin infections. All samples were tested by qPCR for Coxiella burnetti, Bartonella sp., Rickettsia sp., Borrelia sp., Ehrlichia sp., Tropheryma whipplei, Francisella tularensis, Mycobacteria sp., Staphylococcus aureus, Streptococcus pyogenes, Leishmania spp., Ortho poxvirus and Para poxvirus and then screened for the presence of bacteria by PCR amplification and sequencing, targeting the 16S rRNA gene.

RESULTS

From January 2009 to January 2017, 100 international travelers presenting with a suspected skin infection were enrolled. We detected 51 patients with an identified pathogen on skin samples. Travelers presenting with eschars were more likely to have a positive PCR sample (n = 44/76, 57.9%) compared to other patients (n = 7/24, 29.2%). Spotted fever group Rickettsia (n = 28) was the most frequently detected pathogens (19 R. africae, 6 R. conorii, 3 R. mongolitimonae); S. aureus were detected in 11 patients; S. pyogenes in 3; Leishmania sp.; M. leprae and B. henselae in 1 patient, respectively.

CONCLUSION

By targeting the most commonly encountered causative agents of travel-related skin infections, our strategy provides a sensitive and rapid diagnostic method.

First molecular detection and characterization of zoonotic Bartonella species in fleas infesting domestic animals in Tunisia

Background

Bartonellosis is an emerging vector-borne disease caused by different intracellular bacteria of the genus Bartonella (Rhizobiales: Bartonellaceae) that is transmitted primarily by blood-sucking arthropods such as sandflies, ticks and fleas. In Tunisia, there are no data available identifying the vectors of Bartonella spp. In our research, we used molecular methods to detect and characterize Bartonella species circulating in fleas collected from domestic animals in several of the country’s bioclimatic areas.

Results

A total of 2178 fleas were collected from 5 cats, 27 dogs, 34 sheep, and 41 goats at 22 sites located in Tunisia’s five bioclimatic zones. The fleas were identified as: 1803 Ctenocephalides felis (83%) (Siphonaptera: Pulicidae), 266 C. canis (12%) and 109 Pulex irritans (5%) (Siphonaptera: Pulicidae). Using conventional PCR, we screened the fleas for the presence of Bartonella spp., targeting the citrate synthase gene (gltA). Bartonella DNA was detected in 14% (121/866) of the tested flea pools [estimated infection rate (EIR) per 2 specimens: 0.072, 95% confidence interval (CI): 0.060–0.086]. The Bartonella infection rate per pool was broken down as follows: 55% (65/118; EIR per 2 specimens: 0.329, 95% CI: 0.262–0.402) in C. canis; 23.5% (8/34; EIR per 2 specimens: 0.125, 95% CI: 0.055–0.233) in P. irritans and 6.7% (48/714; EIR per 2 specimens: 0.032, 95% CI: 0.025–0.045) in C. felis. Infection rates, which varied significantly by bioclimatic zone (P < 0.0001), were highest in the humid areas. By sequencing, targeting the gltA gene and the 16S–23S rRNA Intergenic Spacer Regions (ITS), we identified three Bartonella zoonotic species: B. elizabethae, B. henselae, B. clarridgeiae, as well as uncharacterized Bartonella genotypes.

Conclusions

To the best of our knowledge, this is the first time that fleas in Tunisia have been shown to carry zoonotic species of Bartonella. The dog flea, Ctenocephalides canis, should be considered the main potential vector of Bartonella. Our study not only provides new information about this vector, but also offers a public health update: medical practitioners and farmers in Tunisia should be apprised of the presence of Bartonella in fleas and implement preventive measures.

Electronic supplementary material

The online version of this article (10.1186/s13071-017-2372-5) contains supplementary material, which is available to authorized users.

Bacterial arthropod-borne diseases in West Africa

Arthropods such as ticks, lice, fleas and mites are excellent vectors for many pathogenic agents including bacteria, protozoa and viruses to animals. Moreover, many of these pathogens can also be accidentally transmitted to humans throughout the world. Bacterial vector-borne diseases seem to be numerous and very important in human pathology, however, they are often ignored and are not well known. Yet they are in a phase of geographic expansion and play an important role in the etiology of febrile episodes in regions of Africa. Since the introduction of molecular techniques, the presence of these pathogens has been confirmed in various samples from arthropods and animals, and more rarely from human samples in West Africa. In this review, the aim is to summarize the latest information about vector-borne bacteria, focusing on West Africa from 2000 until today in order to better understand the epidemiological risks associated with these arthropods. This will allow health and veterinary authorities to develop a strategy for surveillance of arthropods and bacterial disease in order to protect people and animals.

Rickettsia felis, an Emerging Flea-Borne Rickettsiosis

Rickettsia felis is an emerging insect-borne rickettsial pathogen and the causative agent of flea-borne spotted fever. First described as a human pathogen from the USA in 1991, R. felis is now identified throughout the world and considered a common cause of fever in Africa. The cosmopolitan distribution of this pathogen is credited to the equally widespread occurrence of cat fleas (Ctenocephalides felis), the primary vector and reservoir of R. felis. Although R. felis is a relatively new member of the pathogenic Rickettsia, limited knowledge of basic R. felis biology continues to hinder research progression of this unique bacterium. This is a comprehensive review examining what is known and unknown relative to R. felis transmission biology, epidemiology of the disease, and genetics, with an insight into areas of needed investigation.

Fleas and Flea-Associated Bartonella Species in Dogs and Cats from Peru

In the present study, we investigated 238 fleas collected from cats and dogs in three regions of Peru (Ancash, Cajamarca, and Lima) for the presence of Bartonella DNA. Bartonella spp. were detected by amplification of the citrate synthase gene (16.4%) and the 16S-23S intergenic spacer region (20.6%). Bartonella rochalimae was the most common species detected followed by Bartonella clarridgeiae and Bartonella henselae. Our results demonstrate that dogs and cats in Peru are infested with fleas harboring zoonotic Bartonella spp. and these infected fleas could pose a disease risk for humans.

Prevalence and diversity of small mammal-associated Bartonella species in rural and urban Kenya

Several rodent-associated Bartonella species are human pathogens but little is known about their epidemiology. We trapped rodents and shrews around human habitations at two sites in Kenya (rural Asembo and urban Kibera) to determine the prevalence of Bartonella infection. Bartonella were detected by culture in five of seven host species. In Kibera, 60% of Rattus rattus were positive, as compared to 13% in Asembo. Bartonella were also detected in C. olivieri (7%), Lemniscomys striatus (50%), Mastomys natalensis (43%) and R. norvegicus (50%). Partial sequencing of the citrate synthase (gltA) gene of isolates showed that Kibera strains were similar to reference isolates from Rattus trapped in Asia, America, and Europe, but that most strains from Asembo were less similar. Host species and trapping location were associated with differences in infection status but there was no evidence of associations between host age or sex and infection status. Acute febrile illness occurs at high incidence in both Asembo and Kibera but the etiology of many of these illnesses is unknown. Bartonella similar to known human pathogens were detected in small mammals at both sites and investigation of the ecological determinants of host infection status and of the public health significance of Bartonella infections at these locations is warranted.

Bartonella are bacteria that infect many different mammal species and can cause illness in people. Several Bartonella species carried by rodents cause disease in humans but little is known about their distribution or the importance of bartonellosis as a cause of human illness. Data from Africa are particularly scarce. This study involved trapping of rodents and other small mammals at two sites in Kenya: Asembo, a rural area in Western Kenya, and Kibera, an informal urban settlement in Nairobi. Blood samples were collected from trapped animals to detect and characterize the types of Bartonella carried. At the Kibera site over half of the trapped rats were infected with Bartonella very similar to human pathogenic strains isolated from rats from other global regions. In Asembo, Bartonella were detected in four of the five animal species trapped and these Bartonella were less similar to previously identified isolates. All of the small mammals included in this study were trapped in or around human habitations. The data from this study show that Bartonella that can cause human illness are carried by the small mammals at these two sites and indicate that the public health impacts of human bartonellosis should be investigated.

Bartonella clarridgeiae bacteremia detected in an asymptomatic blood donor

Human exposure to Bartonella clarridgeiae has been reported only on the basis of antibody detection. We report for the first time an asymptomatic human blood donor infected with B. clarridgeiae, as documented by enrichment blood culture, PCR, and DNA sequencing.

Molecular detection of Rickettsia felis and Bartonella henselae in dog and cat fleas in Central Oromia, Ethiopia

Fleas are important vectors of several Rickettsia and Bartonella spp. that cause emerging zoonotic diseases worldwide. In this study, 303 fleas collected from domestic dogs and cats in Ethiopia and identified morphologically as Ctenocephalides felis felis, C. canis, Pulex irritans, and Echidnophaga gallinacea were tested for Rickettsia and Bartonella DNA by using molecular methods. Rickettsia felis was detected in 21% of fleas, primarily C. felis, with a similar prevalence in fleas from dogs and cats. A larger proportion of flea-infested dogs (69%) than cats (37%) harbored at least one C. felis infected with R. felis. Rickettsia typhi was not detected. Bartonella henselae DNA was detected in 6% (2 of 34) of C. felis collected from cats. Our study highlights the likelihood of human exposure to R. felis, an emerging agent of spotted fever, and B. henselae, the agent of cat-scratch disease, in urban areas in Ethiopia.

Detection of Rickettsia in Rhipicephalus sanguineus ticks and Ctenocephalides felis fleas from southeastern Tunisia by reverse line blot assay

Ticks (n = 663) and fleas (n = 470) collected from domestic animals from southeastern Tunisia were screened for Rickettsia infection using reverse line blot assay. Evidence of spotted fever group Rickettsia was obtained. We detected Rickettsia felis in fleas, Rickettsia massiliae Bar 29 and the Rickettsia conorii Israeli spotted fever strain in ticks, and Rickettsia conorii subsp. conorii and Rickettsia spp. in both arthropods. The sensitivity of the adopted technique allowed the identification of a new association between fleas and R. conorii subsp. conorii species. The presence of these vector-borne Rickettsia infections should be considered when diagnosing this disease in humans in Tunisia.

Rickettsia species in African Anopheles mosquitoes

BACKGROUND

There is higher rate of R. felis infection among febrile patients than in healthy people in Sub-Saharan Africa, predominantly in the rainy season. Mosquitoes possess a high vectorial capacity and, because of their abundance and aggressiveness, likely play a role in rickettsial epidemiology.

METHODOLOGY/PRINCIPAL FINDINGS

Quantitative and traditional PCR assays specific for Rickettsia genes detected rickettsial DNA in 13 of 848 (1.5%) Anopheles mosquitoes collected from Côte d'Ivoire, Gabon, and Senegal. R. felis was detected in one An. gambiae molecular form S mosquito collected from Kahin, Côte d'Ivoire (1/77, 1.3%). Additionally, a new Rickettsia genotype was detected in five An. gambiae molecular form S mosquitoes collected from Côte d'Ivoire (5/77, 6.5%) and one mosquito from Libreville, Gabon (1/88, 1.1%), as well as six An. melas (6/67, 9%) mosquitoes collected from Port Gentil, Gabon. A sequence analysis of the gltA, ompB, ompA and sca4 genes indicated that this new Rickettsia sp. is closely related to R. felis. No rickettsial DNA was detected from An. funestus, An. arabiensis, or An. gambiae molecular form M mosquitoes. Additionally, a BLAST analysis of the gltA sequence from the new Rickettsia sp. resulted in a 99.71% sequence similarity to a species (JQ674485) previously detected in a blood sample of a Senegalese patient with a fever from the Bandafassi village, Kedougou region.

CONCLUSION

R. felis was detected for the first time in An. gambiae molecular form S, which represents the major African malaria vector. The discovery of R. felis, as well as a new Rickettsia species, in mosquitoes raises new issues with respect to African rickettsial epidemiology that need to be investigated, such as bacterial isolation, the degree of the vectorial capacity of mosquitoes, the animal reservoirs, and human pathogenicity.

An update on the detection and treatment of Rickettsia felis

Rickettsia felis was described as a human pathogen almost two decades ago, and human infection is currently reported in 18 countries in all continents. The distribution of this species is worldwide, determined by the presence of the main arthropod vector, Ctenocephalides felis (Bouché). The list of symptoms, which includes fever, headache, myalgia, and rash, keeps increasing as new cases with unexpected symptoms are described. Moreover, the clinical presentation of R. felis infection can be easily confused with many tropical and nontropical diseases, as well as other rickettsial infections. Although specific laboratory diagnosis and treatment for this flea-borne rickettsiosis are detailed in the scientific literature, it is possible that most human cases are not being diagnosed properly. Furthermore, since the cat flea infests different common domestic animals, contact with humans may be more frequent than reported. In this review, we provide an update on methods for specific detection of human infection by R. felis described in the literature, as well as the treatment prescribed to the patients. Considering advances in molecular detection tools, as well as options for as-yet-unreported isolation of R. felis from patients in cell culture, increased diagnosis and characterization of this emerging pathogen is warranted.