摘要:

Abstract.Ectoparasite records are presented for four species of commensal murid rodents (Rattus rattus palelaeMiller&Hollister,R.argentiventer(Robinson&Kloss),R.exulans(Peale) andMus musculus castaneusWaterhouse) in Sulawesi Utara, with particular reference to the potential for these arthropods to bite and transmit pathogens to humans. The flea,Xenopsylla cheopis(Rothschild), was most common onR.r.palelaeand is capable of transmitting plague and other pathogens to humans although no current foci for these diseases are known in Sulawesi.Hoplopleura pacificaEwing andPolyplax spinulosa(Burmeister) sucking lice parasitized all threeRattusspecies althoughH.pacificawas mainly associated withR.exulansandP.spinulosawithR.r.palelae.These lice do not bite humans but may be intramurid vectors of murine typhus and other zoonoses. The mitesLaelaps echidninaBerlese andL.nuttalliHirst were both collected; the latter was recorded from all four murid species, mainlyR.exulans.The miteOrnithonyssus bacotiHirst was rare. Only one chigger mite,Walchiella oudemansi(Walch), was retrieved from murids (fromR.exulans)and a singleLeptotrombidium deliense(Walch) chigger was taken from a human subject. AlthoughL.delienseis a significant vector of scrub typhus, a disease known from Sulawesi, theL.deliense– R.argentiventerrelationship frequently noted in the ecology of this rickettsial disease, was not evident in this survey. Other ectoparasites collected from murids were the ticks,Ixodes granulatusSupino (first record for Sulawesi),Haemaphysalissp. andDermacentorsp., the mitesMyocoptes musculinus(Koch) andListrophoroides cucullatus(Trouessart), acarids and a uropodid. Additional ectoparasites noted on humans were the tickAmblyoma babirussae(Schulze), the scabies miteSarcoptes scabieiL. and the head lousePediculus humanus capitisDe Gee

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1991.tb00513.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract.Potential vectors ofLeishmania braziliensisVianna were assessed at four study sites in the mountainous Valle del Cauca, western Colombia, from March to June 1989.In an active focus of transmission at 1450 m altitude, a coffee plantation at Versalles, there were high densities of anthropophilic phlebotomines:Lutzomyia columbiana(Ritorcelli&Van Ty) andLu.townsendi(Ortiz), both in theverrucarumspecies group, and ofLu.pia(Fairchild&Hertig). At a comparable altitude in a forest reserve at Yotoco where leishmaniasis is unknown,Lu.piawas the prevalent species andLu.townsendiwas absent.In two localities at 1150 m altitude, there were plentifulLu. lichyi(Floch&Abonnenc) plus both species in theverrucarumgroup, butLu.piawas absent. One of these localities, a coffee plantation at Villa Hermosa where a leishmaniasis outbreak occurred in 1986, was compared with a leishmaniasis‐free, partly wooded nature reserve at Mateguadua.No natural infections ofLeishmaniawere found in a total of 1896 wild‐caught female phlebotomines belonging to at least seven species. It remains unclear why Leishmaniasis transmission is associated with coffee plantations in this part of Colombia.Laboratory‐bredLu. lichyifemales were invariably autogenous, and blood‐seeking females of this species were always parous. Parity rates in wild‐caught females of other species were 55%Lu.pia, 24%Lu.columbianaand 14%Lu.townsendi.FemaleLutzomyiainfected artificially withLe.braziliensispromas‐tigotes developed peripylarian infections. Higher proportions ofLu.townsendi(96%) andLu.columbiana(78%) became infected but these species developed lower rates of stomodaeal infections (P<0.1) thanLu.lichyi(37%) orLu.pia(44%). Only 33% of a Colombian strain ofLu.longipalpis(Lutz&Neiva) beca

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1991.tb00514.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract.Nine monoclonal antibodies (MAbs) developed againstPlasmodium vivax(Grassi&Feletti) salivary gland sporozoites were evaluated for use in an enzyme‐linked immunosorbent assay (ELISA), using sporozoites developed inAnopheles dimsPeyton&HarrisonAn.gambiaeGiles andAn.maculatusTheobald. Four of the antibodies were unsuitable due to the low sensitivity of the resulting assays or the requirement for high concentrations of capture antibody. An additional two MAbs were rejected because they resulted in assays with high background absorbance, attributed to self‐binding. Of the three remaining MAbs, the use of Navy vivax sporozoite (NVS) 3 resulted in an ELISA with the highest sensitivity and the lowest concentration requirement for capture antibody. Assay sensitivity varied with sporozoite strain indicating possible quantitative epitope heterogeneity. None of the MAbs cross‐reacted with the heterologous sporozoites tested by immunofluorescence antibody assay (IFA). The IFA activity was not an indicator of ELISA sensitivity. The use of MAb NVS 3 in a standardized ELISA method resulted in an assay 10 times more sensitive than reported previously forP. vivaxsporozoites, with a detection limit of fewer than 100 sporozoites per mos

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1991.tb00515.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract.The behaviour of tsetse (mainlyGlossina pallidipesAusten) around odour‐baited targets, with or without a coating of ox sebum, was recorded in the field using video. The addition of sebum increased the total time a fly was in contact with the target, as well as the time spent flying around and landing on it. When carbon dioxide was released as part of the attractant odour plume, the presence of sebum on the target increased the number of landings made by each fly, but did not significantly affect the duration of each contact. When carbon dioxide was absent from the odour plume, sebum did not affect the number of landings made by flies but the duration of each contact with the target did increase. Evidence for an interactive effect of sebum and carbon dioxide was obtained. In addition, the presence of sebum on the target increased the percentage of landed flies which walked on its surface; such behaviour may represent an ‘inspection’ of the artificial host. The potential tsetse control application of the current findings are disc

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1991.tb00516.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract.Acquired resistance to adults of the two‐host tickRhipicephalus evertsi evertsiNeumann has been demonstrated in guinea‐pigs and rabbits. Four infestations of both hosts withR.e.evertsiadults resulted in a significant reduction in the mean weight of the engorged females. A decline in the mean weight of the female ticks was also observed in ticks which fed on a rabbit previously injected with serum taken from a rabbit resistant toR.e.evertsi.This suggests that humoral immunity may have an important role in the acquired resistance to ticks. In both hosts an increase in the level of serum globulins was recorded. In rabbits the level of gamma globulin was affected, while in guinea‐pigs an increase was observed in the concentration of α and β globulins. The differences in host responses to theR.e.evertsiadults are di

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1991.tb00517.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract.Feeding behaviour ofGlossina palpalis gambiensisVanderplank infected withTrypanosoma vivaxZiemann was studied and compared with that of uninfected control tsetse. The parameters measured were: total number of probes into the ear‐skin of rabbits; rate of bloodmeal engorgement; weight of freshly ingested blood; survival; and mean weight of pupae. The results showed that the rosettes ofT. vivaxparasites in the labrum did not interfere with the feeding behaviour of the vectors. Furthermore, mean survival ofT.vivax‐infected males was significantly higher (82.2±4.2 days) compared with that of uninfected ones (70.5±3.1 days). However, with the female tsetse, mean survival of those infected was lower (98.8±4.0 days) compared to the uninfected controls (102.2±5.6days), but the difference was not significant. A few infected males and females lived a little longer than the uninfected ones. Fecundity of the female tsetse remained unaffected by the infection, and furthermore the mean weight of pupae from the infected females was not significantly different from that of pupae from the uninfected control group. Thus the physiology of pregnant female tsetse in terms of nourishment of intra‐uterine larva was unaffected byT. vivaxinfection.Two successive probes into the skin of two different goats followed by feeding on a third goat by each of four infected tsetse resulted in successful transmission of the infection to eleven out of twelve goats. Thus probing alone into the skin of this host can result in the transmission ofT. vivax

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1991.tb00518.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract.In the the early 1970s the Egbe area of Nigeria was known to be one of high trypanosomiasis risk, with fourGlossinaspeciesG.morsitans submorsitansNewstead,G.longipalpisWiedemann,G.palpalis palpalisRobineau‐Desvoidy andG.tachinoidesWestwood present. Grazing by Fulani pastoralists used to be short‐term and only in the dry season. In recent years these pastoralists have grazed their cattle in the area throughout the year and this has prompted a reappraisal of the tsetse situation.Tsetse populations were sampled for 3 years using hand‐net catches from man or an ox and biconical traps. Resident livestock, slaughter cattle and some of the flies were examined for trypanosome infection.Of the four tsetse species previously reported from the area, only the riverine species,G.p.palpalisandG.tachinoides, were encountered during the investigation. None of the 152G.p.palpalisand 52G.tachinoidesexamined was infected with trypanosomes. No infection was detected in 101 slaughtered cattle, 65 live Muturu, twelve goats and two pigs by wet film examination. However, a 14.3%Trypanosoma vivaxinfection rate was detected by Haematocrit Centrifugation Technique (HCT) examination in twenty‐one slaughtered cattle. Increased human activities over the years had destroyed much of the vegetation and depleted the wild‐life population to an extent that resulted in the disappearance ofG.m.submorsitansandG.longipalpis, resulting in turn in a greatly reduced trypanosomiasis risk. It is likely that a similar trend is occurring in other areas of the Derived Savanna and Forest zones of West Africa as the human population expands. As a result, more cattle are resident in these zones now than in the past and a reappraisal of cattle distribution in Nigeria is

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1991.tb00519.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract.Susceptibility to five insecticides was assessed on seven colonies of the oriental latrine fly,Chrysomya megacephala(Fabricius), originating from Japan, Hong Kong, Philippines, Indonesia and Papua New Guinea, and onC.saffranea(Bigot) from PNG.All the colonies we're susceptible to fenitrothion, diazinon, dichlorvos, permethrin and y‐HCH, although the Jakarta, Manila and Tokyo colonies ofC.megacephalawere least susceptible (most tolerant) to diazinon, dichlorvos and permethrin. Feral forms of bothChrysomyaspecies were 4–5‐fold more susceptible to permethrin at the LD50level than were all six colonies of the synanthropic form ofC.megace

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1991.tb00520.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract.Seasonal variations in mosquito larval head capsule width and adult female wing length were investigated in a field population ofAnopheles merusDonitz at Nceswana Lake, Ophansi, within the endemic malaria area of Natal, South Africa. An inverse relationship was detected between each of these morphological characters and seasonal fluctuations in air/water temperatures. Mean head capsule width in all larval instars decreased by 4.8‐7.9% in summer, while mean wing length decreased by 19.6%. These changes are discussed in relation to the annual range in mean air temperature in southern Africa and the distribution ofAn. merus.Implications for the use of such morphological characteristics in existing taxonomic keys are discusse

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1991.tb00521.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract.The number of malaria sporozoites in the salivary glands was determined microscopically for 1137 wild, naturally infectedAnophelesfrom western Kenya. InfectiveAnopheles gambiaeGilessensu lato(n=874) contained a geometric mean (GM) of 962 sporozoites andAn.funestusGiles (n=263) contained 812. No significant differences were detected in geometric mean numbers of sporozoites between species, collection techniques or sites.Of the infectiveAn.gambiae, 1.7% (15/874) contained more than 41,830 sporozoites, the maximum observed forAn.funestus.Microscopic techniques were found to be more sensitive than enzyme‐linked immunosorbent assays (ELISA) for detecting low‐grade sporo‐zoite infections in salivary glands. Salivary gland sporozoites from 83.6% of the 1137 gland infections were identified by ELISA as eitherPlasmodium falciparumWelch (n=910),P.ovaleStephens (n=7),P.malariaeGrassi&Feletti (n=3) or mixed (n=30). The 187 gland infections which could not be identified by ELISA contained significantly fewer sporozoites (GM=242) than those which could be identified (GM=

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1991.tb00522.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY