Cytauxzoon felis in salivary glands of Amblyomma americanum

Cytauxzoon felis is a tick-borne piroplasmid hemoparasite that causes life-threatening disease in cats. Despite the critical role that ticks play in pathogen transmission, our knowledge regarding the C. felis life cycle remains limited to the feline hosts. Specific life stages of C. felis within the tick host have never been visualized microscopically and previous investigations have been limited to molecular detection by polymerase chain reaction (PCR). Sporozoites are the infectious stage of piroplasmids that are transmitted by ticks. In other tick-borne piroplasmids, sporozoite-based vaccines play a key role in disease prevention and management. We believe sporozoites have similar potential for cytauxzoonosis. Therefore, the objective of this study was to use different molecular and microscopic techniques to detect and evaluate C. felis sporozoites in tick salivary glands (SG). A total of 140 Amblyomma americanum adults that were fed on C. felis-infected cats as nymphs were included for this study. Specifically, dissected SGs were quartered and subjected to C. felis RT-PCR, RNAscope® in situ hybridization (ISH), histology, direct azure staining, and transmission electron microscopy (TEM). Cytauxzoon felis RT-PCR was also performed on half tick (HT) carcasses after SG dissection. Cytauxzoon felis RNA was detected in SGs of 17/140 ticks. Of these, 7/17 ticks had microscopic visualization via ISH and/or TEM. The remaining 10/17 ticks had only molecular detection of C. felis in SGs via RT-PCR without visualization. Cytauxzoon felis RNA was detected solely in HT carcasses via RT-PCR in 9/140 ticks. In ISH-positive tick SGs, hybridization signals were present in cytoplasms of SG acinar cells. TEM captured rare C. felis organisms with characteristic ultrastructural features of sporozoites. This study describes the first direct visualization of any developing stage of C. felis in ticks. Forthcoming studies should employ a combination of molecular and microscopic techniques to investigate the C. felis life cycle in A. americanum.     

Spotted fever group rickettsiae in ticks and fleas from the Democratic Republic of the Congo

Little is known about the prevalence of spotted fever group (SFG) rickettsiae in ticks and fleas in the Democratic Republic of the Congo. In 2008, 12 Amblyomma compressum ticks were collected from 3 pangolins (Manis gigantea). Two Haemaphysalis punctaleachi ticks were collected from 2 African civets (Civettictis civetta congica), and one was collected from an antelope (Onotragus leche). A total of 111 Rhipicephalus sanguineus ticks, 23 Ctenocephalides canis fleas, 39 C. felis fleas, and 5 Trichodectes canis lice were sampled from 19 dogs. One C. canis flea was collected from a human. Six of the 12 A. compressum ticks were positive for rickettsial DNA, as determined by genus-specific qPCR. The ompA gene sequences amplified from positive samples showed 100% homology with Rickettsia africae (GenBank accession number CP001612). The detection of Ri. africae in A. compressum ticks, which are highly specialized parasites of pangolins, is consistent with our previous data showing the presence of Ri. africae in A. compressum ticks from Liberia. No other ticks contained rickettsial DNA. A total of 9 C. canis fleas (39%, 9/23) and 37 C. felis fleas (95%, 37/39) that was collected from dogs and one C. canis flea collected from a human harbored Ri. felis.     

Common Epidemiology of Rickettsia felis Infection and Malaria,Africa

This study aimed to compare the epidemiology of Rickettsia felis infection and malaria in France, North Africa, and sub-Saharan Africa and to identify a common vector. Blood specimens from 3,122 febrile patients and from 500 nonfebrile persons were analyzed for R. felis and Plasmodium spp. We observed a significant linear trend (p<0.0001) of increasing risk for R. felis infection. The risks were lowest in France, Tunisia, and Algeria (1%), and highest in rural Senegal (15%). Co-infections with R. felis and Plasmodium spp. and occurrences of R. felis relapses or reinfections were identified. This study demonstrates a correlation between malaria and R. felis infection regarding geographic distribution, seasonality, asymptomatic infections, and a potential vector. R. felis infection should be suspected in these geographical areas where malaria is endemic. Doxycycline chemoprophylaxis against malaria in travelers to sub-Saharan Africa also protects against rickettsioses; thus, empirical treatment strategies for febrile illness for travelers and residents in sub-Saharan Africa may require reevaluation.     

Human rickettsioses in the Batna area,eastern Algeria

In order to investigate the prevalence of rickettsioses in febrile exanthemas in eastern Algeria, we conducted a prospective serological analysis of all patients presenting with this clinical picture at the Infectious Diseases Department in the Batna Hospital from January 2000 to September 2006. One hundred and eight adult patients were included in the study, 46% of whom younger than 25 years, and 72.5% were admitted from May to September. Patients were tested for antibodies to Rickettsia conorii conorii, R. conorii israelensis, R. aeschlimannii, R. felis, R. sibirica mongolitimonae, R. africae, R. massiliae, R. typhi, and R. prowazekii using microimmunofluorescence and Western blot as confirmation procedure. Both methods confirmed the diagnosis of Mediterranean spotted fever in 5 patients (4.6%), flea spotted fever in 2 patients (1.9%), and R. aeschlimannii infection in 2 patients (1.9%). In addition, 4 patients were diagnosed as having murine typhus (3.7%) and one with epidemic typhus (0.9%). To the best of our knowledge, this is the first report of R. felis infection and R. aeschlimannii infection in Algeria. In conclusion, at least 5 different kinds of rickettsiosis coexist in eastern Algeria and, being responsible for 13% of cases of febrile exanthemas, should be considered among major causes of this clinical picture in this area. In addition, we emphasize the high incidence of typhus group rickettioses, including epidemic typhus, in this area.     

Survey of bacterial and protozoan agents in ticks and fleas found on wild animals in the state of Rio de Janeiro,Brazil

This study evaluates the presence of bacterial and protozoan agents in ticks and fleas found on wild animals in the state of Rio de Janeiro, Brazil. These ectoparasites were collected on mammal species Hydrochoerus hydrochaeris, Tapirus terrestris, Dicotyles tajacu, Didelphis aurita, Cuniculus paca, Cerdocyon thous, and Coendou prehensilis, and on the terrestrial bird Dromaius novaehollandiae. Ticks and fleas were identified morphologically using specific taxonomic keys. A total of 396 ticks and 54 fleas were tested via polymerase chain reaction (PCR) for the presence of Rickettsia spp., Borrelia spp., microorganisms of the order Piroplasmida and Anaplasmataceae family. This total is distributed among nine tick species of the genus Amblyomma and one flea species. Rickettsia bellii was detected in Amblyomma dubitatum and Amblyomma pacae; Rickettsia sp. strain AL was found in Amblyomma longirostre; Rickettsia parkeri strain Atlantic rainforest was found in Amblyomma ovale; and “Candidatus Rickettsia senegalensis” and Rickettsia felis were detected in Ctenocephalides felis felis. Wolbachia sp. was detected in C. f. felis, and Borrelia sp. was detected in Amblyomma calcaratum (here named Borrelia sp. strain Acalc110). All tested samples were negative for Ehrlichia spp. and microorganisms of the Piroplasmida order. This study detected a new bacterial strain, Borrelia sp. strain Acalc 110 (which is genetically close to B. miyamotoi and B. venezuelensis) and the Rickettsia sp. strain 19P, which is 100% similar to “Ca. R. senegalensis”, a bacterium recently discovered and now being reported for the first time in Brazil.     

Zoonotic Pathogens in Wildlife Traded in Markets for Human Consumption,Laos

We tested animals from wildlife trade sites in Laos for the presence of zoonotic pathogens. Leptospira spp. were the most frequently detected infectious agents, found in 20.1% of animals. Rickettsia typhi and R. felis were also detected. These findings suggest a substantial risk for exposure through handling and consumption of wild animal meat.     

Tick-borne pathogens in dogs,wild small mammals and their ectoparasites in the semi-arid Caatinga biome,northeastern Brazil

Caatinga is a biome exclusive to the semiarid zone of Brazil, where studies on ticks and tick-borne diseases are scarce. Herein, we investigated the occurrence of Rickettsia, Ehrlichia, and Coxiella in wild mammals, domestic dogs and their ectoparasites using molecular and serological techniques. During 2014–2016, blood samples and ectoparasites were collected from 70 small mammals (51 rodents, 18 marsupials, 1 wild canid) and 147 domestic dogs in three areas of the Caatinga. Through serological analyses of domestic dogs of the three areas, 8 to 11 % were seropositive for Rickettsia rickettsii, 9 to 37 % for Rickettsia amblyommatis, 61 to 75 % for Ehrlichia canis, and 0–5% for Coxiella burnetii. All wild mammals were seronegative for Rickettsia spp. and C. burnetii, except for one rodent (Wiedomys pyrrhorhinos) and one marsupial (Didelphis albiventris) that were seroreactive to C. burnetii, one wild canid (Cerdocyon thous) for R. amblyommatis, and two Rattus rattus for Rickettsia spp. Through PCR targeting DNA of Rickettsia, Ehrlichia or Coxiella, all blood samples were negative, except for the presence of Ehrlichia canis DNA in 8.8 % of the domestic dogs, and a recently reported novel agent, Ehrlichia sp. strain Natal, in one marsupial (Gracilinanus agilis). A total of 222 ticks, 84 fleas, and six lice were collected. Ticks were mostly Rhipicephalus sanguineus sensu lato, some Ixodes loricatus, Ornithodoros rietcorreai, Haemaphysalis sp., and Amblyomma spp.; fleas were Ctenocephalides felis felis, Pulex sp. and Polygenis (Polygenis) bohlsi jordani; and lice were Polyplax sp. and Gyropus sp. Through molecular detection of microorganisms, 9% of C. felis felis contained Rickettsia felis, 20 % of A. auricularium contained R. amblyommatis and 13 % of A. parvum contained ‘Candidatus Rickettsia andeanae’, whereas Ehrlichia canis DNA was detected in at least 6% of the R. sanguineus s.l. from one area. We report a variety of ectoparasites infesting small mammals and domestic dogs in the Caatinga biome, where these ectoparasites probably act as vectors of rickettsiae, ehrlichial agents (E. canis and Ehrlichia sp. strain Natal) and C. burnetii. Our results highlight to the potential risks of human infection by these tick-borne agents in the Caatinga biome.     

Hepatozoon species infecting domestic cats from countries of the Mediterranean basin

Tick-borne diseases (TBDs) are caused by pathogens of human and veterinary concern representing a major public health issue worldwide. Although feline medicine has progressed much in the recent decades, data on feline TBDs (FeTBDs) remain scant. Therefore, this study aimed to assess the prevalence of apicomplexan parasite infections, associated risk factors and clinical-hematological abnormalities in domestic feline populations from countries of the Mediterranean basin. Blood and serum samples from cats (n = 600) living in France, Greece, Israel, Italy, Portugal and Spain were collected along with animal data (i.e., age, sex, breed, housing conditions and geographical origin), clinical signs and laboratory blood test parameters. Cats were grouped according to their age as kitten (up to one year), young (between one and six years), mature (between seven and ten years) and senior (older than ten years). Blood samples were tested for Hepatozoon spp. and piroplasmids by conventional PCR targeting 18S rRNA gene. The overall prevalence of Hepatozoon spp. infection was 14.5%, being significantly higher in cats from Greece (30%) and Portugal (23%), followed by Spain (15%), Israel (15%) and France (4%). Cats from Italy scored negative. Hepatozoon felis was identified in 86 animals, with three different sequence types and H. silvestris was detected in one shelter cat from Portugal. No piroplasmid DNA was amplified. The risk of Hepatozoon spp. infection was related to feline geographical provenience, housing condition and age. No statistical correlation was reported with any clinical signs, while increased alanine aminotransferase (ALT) activity was the only laboratory abnormality significantly associated (p = 0.03) with the infection. Data suggest a high circulation of H. felis, and only occasionally of H. silvestris, within domestic feline populations in the Mediterranean basin, mainly in shelter or free roaming and young cats with asymptomatic or subclinical infection.     

The effect of flea control on Yersinia (Pasteurella) pestis antibody rates in the California vole, Microtus californicus, and its epizootiological implications

The effects of flea control on the prevalence of (Pasteurella) pestis antibody rates in the California vole, Microtus californicus, were studied in San Mateo County, California, USA. In this area, which had shown antibody prevalence rates of 50% or more during epizootics in previous years, continuous flea control measures reduced the antibody rate to virtually zero and held it at that level for 12 months, although a nearby area showed an incidence of 40-80% seropositive voles for 5 months during the same period. The striking correlation between the reduction of the flea population and the decline of Y. pestis antibody rates suggests that in the area studied there is no evidence that soil, or any factor other than the flea vector, was the agent of transmission of the infective agent in wild rodents.     

Techniques for rearing and handling body lice,Oriental rat fleas,and cat fleas

The authors describe techniques for handling and rearing large numbers of body lice (Pediculus humanus humanus L.), oriental rat fleas (Xenopsylla cheopis (Rothschild)), and cat fleas (Ctenocephalides felis felis (Bouché)).     

Macquarie Island: the introduction of the European rabbit flea Spilopsyllus cuniculi (Dale) as a possible vector for myxomatosis

The European rabbit flea Spilopsyllus cuniculi (Dale) was first released on Macquarie Island in December 1968. The flea has survived and bred on the island and about 30% of the rabbits sampled from the original release area in January 1972 were flea-infested.     

Tick and flea infestations in captive Tapirus terrestris and Tapirus kabomani (Perissodactyla: Tapiridae) in the Brazilian Amazon

The present study aimed to identify tick and flea species infesting captive tapirs (Tapirus terrestris and Tapirus kabomani) in the Brazilian Amazon. Ectoparasites were collected from tapirs chemically restrained in Zoo-botanical Parks, breeding facilities, conservationists and, environmental compensation areas in the states of Amapá, Amazonas, and Pará. After collection, the tick and flea specimens were placed in plastic pots containing isopropanol and identified according to dichotomous keys. Ectoparasite infestations were observed in 55% (18/33) tapirs, of which 61% (11/18) were single infestations with ticks or fleas, and 39% (7/18) were mixed infestations with different species of ticks and/or fleas. In total, 227 ticks (15 larvae, 107 nymphs, 38 females and 67 males) and 14 fleas (eight females and six males) were collected, identifying four tick species (Amblyomma cajennense sensu stricto , Amblyomma naponense, Amblyomma oblongoguttatum, and Amblyomma pacae) and three flea species and/or subspecies (Ctenocephalides felis felis, Rhopalopsyllus australis australis, and Tunga penetrans). In conclusion, infestations with Ixodidae ticks and Rhopalopsyllidae, Pulicidae and Tungidae fleas were found in captive tapirs in the Brazilian Amazon, and A. cajennense s.s. was the most frequent species. Additionally, the present study reports new associations between A. pacae and R. a. australis with T. terrestris and between A. cajennense s.s. with T. kabomani.     

The first outbreak of human plague in Lushoto district,north-east Tanzania

A one-week investigation was performed at Mkunki and Mavumo (ward of Shume, Lushoto district, Tanzania) at the time of outbreak (June, 1980). Rodents, people, domestic dogs and fleas were examined. 36 rats, mostly Rattus rattus, were caught and used in serological and bacteriological analysis for plague. 48 fleas, mostly Xenopsylla brasiliensis, were collected from the captured rodents. 413 people and 11 dogs were examined. All rodent, carnivorous and human sera were tested for plague antibodies, using the Passive Haemagglutination (PHA) test. Similarly protein extracts from rodent organs were tested for Yersinia pestis fraction I. Impression smears prepared from these organs were stained with methylene blue and examined for presence of bipolar bacteria. Bacteriological isolation of Y. pestis was performed on bubo aspirates and/or blood samples of ten patients.Over-all total and infested flea indices of rodents were 1.3 and 3.7, respectively. Bipolar organisms were demonstrated in 13.3% of the rodent smears while specific agglutinating plague antibodies were detected in 3.3% of the tested rodent sera. Y. pestis fraction I antigen was detected in 8.3% of the rodents. Of all the human sera tested, 1.4% contained specific plague antibodies. Y. pestis was bacteriologically isolated and biochemically confirmed in 16.7% of the cultured specimens. All the dog sera were negative for plague.It was generally concluded that the causative agent of the outbreak was Yersinia pestis and that the disease probably spread from Rongai (Rombo district).     

猫立克次体病1例报道

猫立克次体(Rickettsia felis)是一种新出现的立克次体病原体,与普氏立克次体、莫氏立克次体等同,属于立克次体属。本文分析1例老年患者感染猫立克次体的临床病历资料,并结合国内外文献对猫立克次体现有的检测技术及方法进行进一步总结,目的在于提升临床医务工作者对猫立克次体感染早期诊断的水平。     

Cryptosporidium species from human immunodeficiency–infected patients with chronic diarrhea in Jakarta,Indonesia

PurposeCryptosporidium is an opportunistic parasite that manifests as chronic and severe diarrhea in the immune-compromised subject. We investigated the species of Cryptosporidium to understand the epidemiology, mode of transmission, response to treatment, and prevention.MethodsPolymerase chain reaction/restriction fragment length polymorphism of the 18 S rRNA gene and sequencing were performed on 41 Cryptosporidium-positive stools from 36 patients with HIV AIDS, which comprised 36 pretreatment stools and 5 stools after treatment with Paromomycin.ResultsC. hominis, C. meleagridis, C. felis, and C. parvum were detected; 28 of 36 (77.7%) patients were infected with C. hominis and two (5.5%) patients with multiple species of Cryptosporidium. Treatment with Paromomycin resulted in different outcomes, perhaps because patients harbored other intestinal parasitic infections.ConclusionsMultiple infection with various Cryptosporidium species in the presence of other intestinal parasites occurs in patients with HIV AIDS suffering from chronic diarrhea who are severely immune-compromised. Common transmission of Cryptosporidium is anthroponotic.     

Pathogens in ticks collected in Israel: II. Bacteria and protozoa found in Rhipicephalus sanguineus sensu lato and Rhipicephalus turanicus

Rhipicephalus sanguineus sensu lato and Rhipicephalus turanicus are very prevalent in Israel and are known to be vectors of human and animal diseases. The aim of this study was to identify the pathogens found in questing ticks and such parasitizing domestic and wild animals. Ticks were collected from 16 localities in Israel with the flagging technique and by examining dogs, hedgehogs, a badger and a tortoise. Bacterial and protozoal pathogens were analyzed by PCR and sequencing. Overall, 374 R. sanguineus s.l. specimens were collected, out of which 142 by flagging and 132 from six dogs. Rickettsia africae, Rickettsia massiliae, Rickettsia conorii subsp. israelensis, and Anaplasma sp. were identified in ticks collected by flagging, Rickettsia aeschlimannii was found only in specimens collected from dogs, while Ehrlichia sp., Coxiella burnetii, Hepatozoon canis and Leishmania infantum were recorded in ticks collected by flagging and from dogs. Out of 226 specimens of R. turanicus, 124 were collected by flagging, while additional 33 from eight dogs, 64 from seven southern white-breasted hedgehogs (Erinaceus concolor), two from a European badger (Meles meles) and one from a Greek tortoise (Testudo graeca). Out of 65 R. sanguineus s.l. pools 17 (26.2%) had pathogens, while seven of them were positive for one pathogen, and 10 for two pathogens. In 43 R. turanicus pools, R. aeschlimannii R. africae, Rickettsia barbariae, R. massiliae, Anaplasma sp., Ehrlichia sp. and C. burnetii, as well as Babesia microti, B. vogeli, Hepatozoon felis, and L. infantum was detected, while Listeria monocytogenes, Bartonella sp. and Toxoplasma gondii were negative in all R. sanguineus s.l. and R. turanicus pools examined. In conclusion, Babesia microti is reported for the first time in Israel, R. africae, R. aeschlimannii, C. burnetii and L. infantum are reported for the first time in R. sanguineus s.l. and R. turanicus, while H. felis is reported for the first time from R. turanicus in the country.     

The prevalence of public health significance of Toxoplasma gondii in domestic cats in the Niger Delta

The prevalence of Toxoplasma gondii in domestic cats in the Niger Delta was assessedby both serological examination for antibody using the Sabin-Feldman dye-test and faecal examination for the presence of oocyst. Of the cats, 94·2% had dye-test antibody. No significant sex or age-linked variation was observed in the prevalence of the antibody. Of the faecal samples, 22·0% contained oocysts of Isospora felis, 12·4% Isospora rivolta and 32·0% Toxoplasma gondii. These observations are discussed in relation to public health.     

The Pathogenesis of Rheumatic Fever in its Climatological Relationship to a Possible Insect Carrier

A short while ago a special sub-committee of the British Medical Association [1] sat to inquire into the problem of rheumatic heart disease in children, and suggested, among other conclusions, that the material for any accurate world map of the incidence of rheumatism was probably not available. My objects in presenting this paper are:—(1) To provide data for this map.(2) To show that the geographical distribution of rheumatic fever coincides with that of the common rat flea, Ceratophyllus fasciatus, and(3) To suggest that this disease is caused by a protozoön, spirochæte or allied organism, which is carried by that flea.