Reproductive activity of Synosternus cleopatrae (Siphonaptera: Pulicidae) in relation to host factors.

Reproductive activity of Synosternus cleopatrae (Rothschild) infesting Gerbillus andersoni allenbyi Thomas was studied in a natural setting in Israel. Rodents were trapped and measured (weight and length), their sex was identified, and their reproductive status estimated. Their ectoparasites were removed, and fleas were dissected and their oocytes measured. Two indices of flea reproductive activity were analyzed: "reproductive status," which distinguished between gravid and nongravid females, and "reproductive intensity," which was estimated as the sum over the two largest oocytes of the products of oocyte length multiplied by oocyte width. Both indices showed that no reproduction took place between November and January, but reproduction was relatively stable during the rest of the year. Although flea reproductive activity differed significantly among individual hosts, only a small fraction of gerbils (10-15%) carried a significantly different proportion of reproductive fleas than their monthly sample proportion (based on all fleas regardless of hosts). All these hosts carried a lower proportion of reproductive fleas than their monthly sample proportion. The host's sex, but not reproductive status or age, had a significant effect on flea reproduction, expressed as a higher reproductive activity on male gerbils. Infestation burden expressed as ectoparasite counts was included in the statistical analysis. Only lice, Polyplax gerbilli Ferris, but not S. cleopatrae, Stenoponia tripectinata (Tiraboschi), and a total of five mesostigmatid Acari had a significantly negative association with S. cleopatrae reproductive activity. These relationships between S. cleopatrae reproductive activity and the host infestation burden do not support the hypothesis of modulation of S. cleopatrae reproduction by the infestation burden. However, differences in the reproductive activity of ectoparasites between their hosts may play a major role to generate the parasite clumped distribution. Thus, gerbil males probably carry more fleas than gerbil females because of the higher reproductive activity of S. cleopatrae on gerbil males.     

Evaluation of squirrels (Rodentia: Sciuridae) as ecologically significant hosts for Anaplasma phagocytophilum in California

Granulocytic anaplasmosis (GA), caused by Anaplasma phagocytophilum, is a potentially fatal, emerging rickettsial disease of humans, domestic animals, and wildlife. The purpose of this study was to determine whether sciurids from multiple areas of northern California were infested with ticks or exposed to or infected with A. phagocytophilum using polymerase chain reaction (PCR) and indirect-fluorescent antibody (IFA) serology. Sciurids of nine different tree- and ground-dwelling species were assessed: arboreal squirrels (western and eastern gray squirrels, Sciurus griseus and S. carolinensis, and Douglas squirrels, Tamiasciurus douglasii) but not northern flying squirrels (Glaucomys sabrinus) had greater evidence of exposure and current infection than did semiarboreal or ground dwelling sciurids (California ground squirrels, Spermophilus beecheyi, and chipmunks, Tamias spp.). Western gray squirrels had the most extensive exposure (70.7% seroprevalence and 12.1% PCR prevalence). Positive squirrels were identified in all regions where squirrels were collected. A logistic regression identified being a western gray squirrel (OR = 20.5, P = 2.95 X 10(-8)) and from the north coastal region of California (OR = 9.052, P = 1.41 X 10(-6)) as having the highest risk of exposure to A. phagocytophilum. Five of nine sciurid species had evidence of infestation with Ixodes pacificus or I. spinipalpis that could vector A. phagocytophilum. Extensive exposure from multiple areas suggests sciurids may be important in the maintenance of GA in California and indicates that studies of reservoir competence of these species are warranted.     

Ectoparasite infestation patterns of domestic dogs in suburban and rural areas in Borneo

Domestic dogs, Canis lupus, have been one of the longest companions of humans and have introduced their own menagerie of parasites and pathogens into this relationship. Here, we investigate the parasitic load of 212 domestic dogs with fleas (Siphonaptera) chewing lice (Phthiraptera), and ticks (Acarina) along a gradient from rural areas with near-natural forest cover to suburban areas in Northern Borneo (Sabah, Malaysia). We used a spatially-explicit hierarchical Bayesian model that allowed us to impute missing data and to consider spatial structure in modelling dog infestation probability and parasite density. We collected a total of 1,968 fleas of two species, Ctenocephalides orientis and Ctenocephalides felis felis, from 195 dogs (prevalence, 92 %). Flea density was higher on dogs residing in houses made of bamboo or corrugated metal (increase of 40 % from the average) compared to timber or stone/compound houses. Host-dependent and landscape-level environmental variables and spatial structure only had a weak explanatory power. We found adults of the invasive chewing louse Heterodoxus spiniger on 42 dogs (20 %). The effect of housing conditions was opposite to those for fleas; lice were only found on dogs residing in stone or timber houses. We found ticks of the species Rhipicephalus sanguineus as well as Haemaphysalis bispinosa gp., Haemaphysalis cornigera, Haemaphysalis koenigsbergi, and Haemaphysalis semermis on 36 dogs (17 %). The most common tick species was R. sanguineus, recorded from 23 dogs. Tick infestations were highest on dogs using both plantation and forest areas (282 % increase in overall tick density of dogs using all habitat types). The infestation probability of dogs with lice and ticks decreased with elevation, most infestations occurred below 800 m above sea level. However, the density of lice and ticks revealed no spatial structure; infestation probability of dogs with these two groups revealed considerable autocorrelation. Our study shows that environmental conditions on the house level appeared to be more influential on flea and lice density whereas tick density was also influenced by habitat use. Infestation of dogs with Haemaphysalis ticks identified an important link between dogs and forest wildlife for potential pathogen transmission.     

Macroparasite community of the Eurasian red squirrel (Sciurus vulgaris): poor species richness and diversity

The Eurasian red squirrel (Sciurus vulgaris) is the only naturally occurring tree squirrel throughout its range. We aim at improving current knowledge on its macroparasite fauna, expecting that it will have a poor parasite diversity because in species that have no sympatric congeners parasite richness should be lower than in hosts sharing their range with several closely related species, where host-switching events and lateral transmission are promoted. We examined gastro-intestinal helminth and ectoparasite communities (excluding mites) of, respectively, 147 and 311 red squirrel roadkills collected in four biogeographic regions in Italy and France. As expected, the macroparasite fauna was poor: we found five species of nematodes and some unidentified cestodes, three fleas, two sucking lice and two hard ticks. The helminth community was dominated by a single species, the oxyurid Trypanoxyuris (Rodentoxyuris) sciuri (prevalence, 87 %; mean abundance, 373?±?65 worms/host). Its abundance varied among seasons and biogeographic regions and increased with body mass in male hosts while decreased in females. The most prevalent ectoparasites were the flea Ceratophyllus (Monopsyllus) sciurorum (28 %), whose presence was affected by season, and the generalist tick Ixodes (Ixodes) ricinus that was found only in France (34 %). All the other helminths and arthropod species were rare, with prevalence below 10 %. However, the first record of Strongyloides robustus, a common nematode of North American Eastern grey squirrels (S. carolinensis), in two red squirrels living in areas where this alien species co-inhabits, deserves further attention, since low parasite richness could result in native red squirrels being particularly vulnerable to parasite spillover.     

Immune responses to fleas in two rodent species differing in natural prevalence of infestation and diversity of flea assemblages

We studied in vitro immune response to fleas in two gerbils, Gerbillus dasyurus and Gerbillus andersoni allenbyi, which differed in their natural species richness of flea assemblages and prevalence of infestation. G. dasyurus is parasitized naturally by several flea species, but the prevalence of infestation is low, whereas G. a. allenbyi is parasitized by a single flea species, with high prevalence of infestation. We hypothesized that immunological parameters and the cell-mediated specific immune response to an antigen from an unfamiliar flea species differ between the two gerbil species. Parasitized and control gerbils of both species demonstrated similar, relatively low levels of spontaneous glucose consumption. The same was true for the phytohemagglutinin treatment. Responses to antigen from unfamiliar flea species were higher than both spontaneous glucose consumption and response to phytohemagglutinin in parasitized and control G. a. allenbyi and parasitized G. dasyurus. However, no significant difference in the spontaneous blast transformation index and responses to both phytohemagglutinin and flea antigen was found in control G. dasyurus. The number of white blood cells was significantly lower in control than in parasitized G. dasyurus, whereas no difference in the number of white blood cells was found between control and parasitized G. a. allenbyi. The levels of circulating immune complexes and concentrations of immunoglobulins did not differ between parasitized and control individuals in both species. Phagocytic activity was significantly higher in males than in females of G. a. allenbyi but not of G. dasyurus. In addition, phagocytes of G. dasyurus appeared to be significantly more active than those of G. a. allenbyi.     

Seasonal occurrence of Ctenocephalides felis felis and Ctenocephalides canis (Siphonaptera: Pulicidae) infesting dogs and cats in an urban area in Cuernavaca, Mexico

The seasonal occurrence of Ctenocephalides felis felis (Bouché and Ctenocephalides canis (Curtis) infestation on dogs and cats in Cuernavaca City in Mexico, was determined by examining 1,803 dogs and 517 cats at two veterinary clinics during 1995-1997. The overall flea infestation was 30.3 and 30.1% for dogs and cats, respectively. There were no significant differences (P > 0.05) in percentage of infestation among years for both hosts. The infestation was somewhat higher in spring, summer, and autumn than in winter, but no statistical differences was found among seasons (P > 0.05) for both pets. No relationship existed between percentage of flea infestation and temperature or rainfall among seasons. On dogs, 81.1% were infested with only C. felis felis, 16.8% with C. canis, and 2% had both flea species; whereas 92.3% of the cats were infested with C. felis felis and 7.7% with C. felis felis and C. canis. The cat flea was the most prevalent flea species found other than C. canis; no other species were found on the dogs and cats. It appeared that flea life cycle development continued throughout the year.     

Prevalence of Pediculus humanus capitis infestation among kindergarten children in Bahía Blanca city, Argentina

The human head louse, Pediculus humanus capitis De Geer (Anoplura: Pediculidae), is a worldwide public health concern. This human obligate ectoparasite usually infests school age children. The aim of this work was to investigate the prevalence of head lice in kindergarten children from Bahia Blanca. In addition, the influence of risk factors for pediculosis infestation, such as gender, hair characteristics, and socioeconomic class, was studied in relation to the prevalence of this ectoparasite. From a total of 220 pupils examined (125 girls and 95 boys), 94 showed pediculosis. The overall prevalence of head lice infestation was 42.7 %. Pediculosis was more frequent in girls (53.6 %) than in boys (28.4 %) and in medium, long, and very long hairs. No differences were found between socioeconomic classes. This indicated that head lice are relatively common in kindergarten children from Bahía Blanca.     

The identity of <Emphasis Type="Italic">Menacanthus eisenachensis</Emphasis> Balát (Insecta,Phthiraptera, Amblycera,Menoponidae) from the Reed Warbler (Passeriformes,Sylviidae)

Three hundred and thirty-one Reed Warblers Acrocephalus scirpaceus (Hermann) were examined for chewing lice (Phthiraptera). Twenty-eight (8.5%) were parasitized with Menacanthus curuccae (Schrank, 1776). Mean intensity of infestation was 4.3 lice. Hence, the name Menacanthus eisenachensis Balát, 1981, currently applied to Menacanthus lice parasitizing Reed Warblers, is placed as a junior synonym of M. curuccae, with Reed Warbler as a new host for the latter species.     

Head louse infestations in Gaza governorates

In total, 2,408 primary school girls (6-14 yr old) in two districts within the Gaza Governorate were examined for the presence of head lice, Pediculus humanus capitis De Geer. The localities chosen for the study were the Old Gaza city and the rural village Jabalia. The rate of infestation with lice was 14.1%, and an additional 35% of girls had nits (eggs) only. The prevalence of louse infestation was high among the 6-12-yr-old girls. A sharp decline in infestation was observed after 12 yr of age. No lice were found on the 13 to 14-yr-old girls examined. Approximately 67.1% of infested girls had one to 10 lice and 49.8% had one to 10 nits on their hair. Significant difference in louse and nit only infestations was found between girls with short and long hair.     

Chewing lice (Insecta, Phthiraptera) and feather mites (Acari, Astigmata) associated with birds of the Cerrado in Central Brazil

The association of chewing lice and feather mites with wild birds of riparian forest was investigated in the Cerrado biome, Tocantins State, Brazil. The birds were captured with mist nets between July 2008 and March 2009. Ectoparasites were collected by the dust-ruffling technique. Infestation rates were determined by the sampling prevalence, abundance, and mean intensity of ectoparasites. A total of 1,479 chewing lice were collected that were distributed in 3 families and 18 genera, of which 15 taxa were identified to the species level. Sixteen genera of feather mites were found, and 10 species were identified. A high prevalence rate of chewing lice and feather mites was found in non-Passeriformes (66.7 and 50.0?%) and Passeriformes (57.8 and 75.6?%) birds. New host-parasite associations were registered for two species of chewing lice and for four species of feather mites, thus expanding the geographical distribution in Brazil of six chewing lice species. This is the first study of the ectoparasites of wild birds to be conducted in this region of Brazil.     

First molecular evidence of Bartonella quintana in Pediculus humanus capitis (Phthiraptera: Pediculidae), collected from Nepalese children

Trench fever is a body louse-borne disease caused by Bartonella quintana Brenner. The recent status of louse infestation in Nepalese children is not well known. We collected head and body lice, Pediculus humanus capitis De Geer and Pediculus humanus humanus L., respectively, from 30 children, including 11 cases of double infestation with both head and body lice. Detection of B. quintana in both louse species identified was carried out by polymerase chain reaction (PCR). PCR products with B. quintana DNA sequences were detected in both head and body lice from two children as well as in body lice derived from two other children. These results demonstrate that head lice may also play a role in the transmission of trench fever.     

Prevalence of pediculosis capitis among Korean children

Pediculus humanus capitis is an ectoparasite, which causes scalp pruritus particularly among children. A total of 15,373 children including 8,018 boys and 7,355 girls from 26 primary schools and 15 kindergartens attached to the primary schools and a total of 33 children from an orphanage were examined for head lice infestation (HLI). The overall prevalence of HLI in this study was 4.1% including 3.7% of the urban areas and 4.7% of the rural areas. Head lice were found more frequently in girls than in boys with prevalence of 6.5% and 1.9%, respectively. The infestation rate by school grade was 3.2%, 4.7%, 4.2%, 5.0%, 4.9%, 3.8%, and 2.1% for kindergarten, first, second, third, fourth, fifth, and sixth grades, respectively. The infestation rate of the children in an orphanage was 66.7%. The prevalence of HLI has decreased especially in the rural areas. However, HLI is a still health problem of kindergarteners and primary schoolchildren in Korea.     

Incidence of Upupicola upupae in the crest of the hoopoe

Hopoes belonging to waves of migrants through the Balearic Islands in August and September showed high rates of infestation by Upupicola upupae (77--85 p. c.). The parasite species was almost exclusively confined to the long and mobile feathers of the bird's crown. And at this time of the year the Mallophaga had put their egg cases on the crest feathers, too. A mean of 7 feather-lice was found at this localisation in 8 positive cases sampled. As some of the birds were moulting just these parts of their plumage, a relative high loss of the lice egg masses had to be expected. Evidently, in these cases, the lice didn't adaptively synchronise laying with the period during which moulting occurs. The wings of hopoes are conspiciously barred glossy-black and white. Here the relative dark coloured lice were sitting predominantly in a dark feather area. In these places they were much less visble than on a neighbouring white area. Thus the parasites hide themselves according to their colour.     

On the occurrence of hare lice,haemodipsus spp. (anoplura,hoplopleuridae) on hares,lepus europaeus,in The Netherlands

Summary In 1957 Haemodipsus setoni has been collected for the first time on Lepus europaeus in the Netherlands. Earlier H. lyriocephalus was the only known louse on the European hare.During a three years' survey, the occurrence of both lice species was studied. On diseased hares an increasing infestation rate of H. setoni was found, while the infestation rate of H. lyriocephalus remained stable. The infestation of H. setoni on healthy hares was on a much lower level than in the case of the diseased hares. H. lyriocephalus seemed very rare on healthy hares.No difference in infestation rate between the host sexes could be determined. Both sexes and juveniles of H. setoni and H. lyriocephalus seemed to be present during the whole year, but the infestation proved to be more severe in spring and summer.Great numbers of lice occurred only on hares in a bad state of health. Mostly, infestation by lice was combined with other parasitic infestations with a more prolonged character. The relationship between the state of health, the time spent in cleaning the skin and infestation by lice is discussed.     

Selection of La Crosse virus variants by sentinel squirrels (Sciuris carolinensis) and chipmunks (Tamius striatus).

Comparisons of La Crosse (LAC) virus strains, obtained from sentinel squirrels and chipmunks, were made using three viral markers: plaque size on Vero cells, virulence in 8 days old laboratory mice, and antigenic characteristics as measured by the plaque reduction neutralization test. All strains were in their first suckling mouse brain passage. The mean plaque size of viruses isolated from squirrels was slightly larger than the mean plaque size of viruses isolated from chipmunks. There were no differences in virulence and antigenic characteristics of LAC strains isolated from chipmunks compared to those from squirrels. However, significant differences in these characteristics between individual virus strains did occur, irrespective of the vertebrate species from which the strain was isolated. First suckling mouse brain passage of viremic blood apparently selected for a smaller mean plaque size than was present in the blood. These results indicate that the squirrel and chipmunk were not rapidly selecting for greatly divergent subpopulations of the three measured markers in nature. There were some indications, however, that even one suckling mouse brain passage of field LAC virus apparently decreased mean plaque size.     

Ectoparasite diversity and exposure to vector-borne disease agents in wild rodents in central coastal California

A survey of wild rodents was performed in the Morro Bay area of central coastal California to determine serological and polymerase chain reaction (PCR) prevalence of Anaplasma phagocytophilum Dumler, Barbet, Bekker, Dasch, Palmer, Ray, Rikihisa, and Rurangirwa, Borrelia burgdorferi Johnson, Schmidt, Hyde, Steigerwalt, and Brenner, Francisella tularensis McCoy, and Yersinia pestis Yersin; to describe the ectoparasitic fauna on important vector-borne disease hosts; and to determine whether pathogen exposure was associated with infestation by ectoparasites. We trapped 411 rodents from 10 species in 2004 and 2005. Anaplasma phagocytophilum exposure was detected in 11% of all wild rodents tested, with seropositive animals in eight species. Anaplasma phagocytophilum DNA was detected by PCR amplification in Neotoma fuscipes Baird and Reithrodontomys megalotis Baird (0.6% of all rodents). Yersinia spp. exposure was identified in 3.2% of all rodents tested, with highest detected exposure in peridomestic rodents, Mus musculus L. (20%), and Rattus rattus L. (50%). No individuals tested positive for the Y. pestis pla gene by PCR. In total, 338 fleas were identified from each of 10 rodent species examined. The most abundant flea was Malareus telchinus Rothschild. Relative density of flea infestation was highest on Spermophilus beecheyi Richardson and Microtus californicus Peale. Ticks recovered from trapped animals included Ixodes angustus Neumann, Ixodes pacificus Cooley & Kohls, Ixodes spinipalpis Hadwen & Nuttall, and Dermacentor occidentalis Marx. Given the moderate climate and diversity of rodents and arthropods in the Morro Bay area, ongoing investigation of this region will be helpful in understanding disease maintenance cycles.     

云南洱海周边地带社鼠体表寄生虫的群落组成（英文）

目的社鼠是东洋界种,不仅一直被认为是农林业有害动物,而且被怀疑为滇西北鼠疫疫源地的鼠疫、恙虫病和流行性出血热（汉坦病毒）等病原体的储存宿主。为了了解洱海周边地带社鼠体表寄生虫的多样性,我们研究了89只社鼠体表寄生虫的群落组成。方法选取云南洱海周边的不同地理方位作为野外抽样调查地点,用鼠笼加食饵诱捕小兽并检获其体表寄生虫。体表寄生虫在显微镜下鉴定寄生虫的种类。用染虫率和虫指数反映体表寄生虫的流行和密度状况,用统计分析中的非参数检验（Non-parametric Mann-Whitney U）分析雌雄小兽宿主间寄生虫数量差异,用Spearman相关分析（Spearman correlation analysis）体表寄生虫数量与宿主身体参数的关系。结果捕获89只社鼠,其中70只社鼠侵染体表寄生虫,总侵染率为79%。采集到体表寄生虫51种,包括31种恙螨、13种革螨、4种蚤及3种吸虱。攸氏无前恙螨为优势恙螨种,占恙螨总数的66.23%;土尔克厉螨为优势革螨种,占革螨总数的38.48%;绒鼠怪蚤为优势蚤种,占蚤总数的42.86%;太平洋甲胁虱为优势吸虱种,占吸虱总数的80.07%。这51种体表寄生虫中,有11种被证明是人类疾病的主要媒介。U检验表明,体表寄生虫、恙螨、吸虱、蚤类和革螨的个体数量和物种数在雌雄宿主体表间的差异无统计学意义。Spearman相关分析表明,体表寄生虫、恙螨、吸虱、蚤类和革螨的个体数量与宿主身体参数（体重）之间无相关性。结论社鼠的体表寄生虫群落结构复杂,物种多样性高,其中有11种曾经报道与人类疾病有关。社鼠主要的体表寄生虫为吸虱、蚤类、革螨和恙螨,社鼠很可能成为鼠疫、流行性出血热和灌丛斑疹伤寒等病原体的贮存宿主。     

Observations and larval descriptions of fleas (Siphonaptera: Ceratophyllidae, Ctenophthalmidae, Ishnopsyllidae) of the southern flying squirrel, little brown bat, and Brazilian free-tailed bat (Mammalia: Rodentia, Chiroptera)

Larvae of the four fleas infesting nests of the southern flying squirrel, Glaucomys volans colans (L.) [Conorhinopsylla stanfordi Stewart, Epitedia faceta (Rothschild), Opisodasys pseudarctomys (Baker), and Orchopeas howardi (Baker)], and of the bat fleas Myodopsylla insignis (Rothschild) and Sternopsylla distincta texana (C. Fox), associated with the bats Myotis lcifuigus (Le Conte) and Tadarida brasiliensis (I. Geof. St. Hilaire), respectively, are described. C. stanfordi has the second posterior-row seta on abdominal segments 1-5 at most one fourth the length of the first and third setae, but it is unique among the Leptopsyllini with five short setae in abdominal segment 9 anterior row. E. faceta has the straight line of anterior-row setae 2-5 on abdominal segment 1, which is diagnostic for Phalacropsyllini. O. howardi and O. pseudarctomys have three anterior-row setae on the anal comb, three ventrolateral setae on the anal segment (abdominal segment 10), and a narrow mandible with five or more teeth as other Ceratopyllinae, but O. pseudarctomys is distinguishable from O. howardi because the first setae on the posterior row of the head is long (greater than one half the length of the third posterior-row setae), the ventral setae on abdominal segment 7 are different sizes, and the third anterior-row setae on abdominal segment 8 does not extend past the spiracle posterior to it. Bat flea larvae have six posterior-row setae on abdominal segments 1-9 with the anal comb anterior row with two or more setae; M. insignis has eight mandible teeth and S. distincta texana three to four.     

Potential role of head lice,<Emphasis Type="Italic"> Pediculus humanus capitis</Emphasis>, as vectors of<Emphasis Type="Italic"> Rickettsia prowazekii</Emphasis>

Since the pioneering work of Charles Nicolle in 1909 [see Gross (1996) Proc Natl Acad Sci USA 93:10539-10540] most medical officers and scientists have assumed that body lice are the sole vectors of Rickettsia prowazekii, the aetiological agent of louse-borne epidemic typhus (LBET). Here we review the evidence for the axiom that head lice are not involved in epidemics of LBET. Laboratory experiments demonstrate the ability of head lice to transmit R. prowazekii, but evidence for this in the field has not been reported. However, the assumption that head lice do not transmit R. prowazekii has meant that head lice have not been examined for R. prowazekii during epidemics of LBET. The strong association between obvious (high) infestations of body lice and LBET has contributed to this perception, but this association does not preclude head lice as vectors of R. prowazekii. Indeed, where the prevalence and intensity of body louse infections may be high (e.g. during epidemics of LBET), the prevalence and intensity of head louse infestations is generally high as well. This review of the epidemiology of head louse and body louse infestations, and of LBET, indicates that head lice are potential vectors of R. prowazekii in the field. Simple observations in the field would reveal whether or not head lice are natural vectors of this major human pathogen.