Detection of Leishmania infantum in animals and their ectoparasites by conventional PCR and real time PCR

Visceral leishmaniosis (VL) is a parasitic disease caused by Leishmania infantum, which is primarily transmitted by phlebotomine sandflies. However, there has been much speculation on the role of other arthropods in the transmission of VL. Thus, the aim of this study was to assess the presence of L. infantum in cats, dogs and their ectoparasites in a VL-endemic area in northeastern Brazil. DNA was extracted from blood samples and ectoparasites, tested by conventional PCR (cPCR) and quantitative real time PCR (qPCR) targeting the L. infantum kinetoplast DNA. A total of 280 blood samples (from five cats and 275 dogs) and 117 ectoparasites from dogs were collected. Animals were apparently healthy and not previously tested by serological or molecular diagnostic methods. Overall, 213 (76.1 %) animals and 51 (43.6 %) ectoparasites were positive to L. infantum, with mean parasite loads of 795.2, 31.9 and 9.1 fg in dogs, cats and ectoparasites, respectively. Concerning the positivity between dogs and their ectoparasites, 32 (15.3 %) positive dogs were parasitized by positive ectoparasites. The overall concordance between the PCR protocols used was 59.2 %, with qPCR being more efficient than cPCR; 34.1 % of all positive samples were exclusively positive by qPCR. The high number of positive animals and ectoparasites also indicates that they could serve as sentinels or indicators of the circulation of L. infantum in risk areas.

Origin of clothing lice indicates early clothing use by anatomically modern humans in Africa

Clothing use is an important modern behavior that contributed to the successful expansion of humans into higher latitudes and cold climates. Previous research suggests that clothing use originated anywhere between 40,000 and 3 Ma, though there is little direct archaeological, fossil, or genetic evidence to support more specific estimates. Since clothing lice evolved from head louse ancestors once humans adopted clothing, dating the emergence of clothing lice may provide more specific estimates of the origin of clothing use. Here, we use a Bayesian coalescent modeling approach to estimate that clothing lice diverged from head louse ancestors at least by 83,000 and possibly as early as 170,000 years ago. Our analysis suggests that the use of clothing likely originated with anatomically modern humans in Africa and reinforces a broad trend of modern human developments in Africa during the Middle to Late Pleistocene.

New record of Afrimenopon waar (Eichler) (Phthiraptera: Menoponidae) from budgerigar Melopsittacus undulatus (Psittaciformes: Psittacidae) from Karachi, Pakistan

Chewing lice of the species Afrimenopon waar (Eichler) were collected from captive budgerigar Melopsittacus undulatus (Shaw) in Pakistan. This is the first record of amblyceran lice from this host. It is also the first record of the genus Afrimenopon from Pakistani region. The primary host species of Afrimenopon waar is the rosy-faced lovebird Agapornis roseicollis (Vieillot). The finding of A. waar on budgerigars is, most likely, a result of a contamination in captivity. Morphological variation and origin of these lice are discussed.

Blood-sucking lice may disseminate Trypanosoma cruzi infection in baboons

Trypanosoma cruzi (Schyzotrypanum, Chagas, 1909), and Chagas disease are endemic in captive-reared baboons at the Southwest Foundation for Biomedical Research, San Antonio, Texas. We obtained PCR amplification products from DNA extracted from sucking lice collected from the hair and skin of T. cruzi-infected baboons, with specific nested sets of primers for the protozoan kinetoplast DNA, and nuclear DNA. These products were hybridized to their complementary internal sequences. Selected sequences were cloned and sequencing established the presence of T. cruzi nuclear DNA, and minicircle kDNA. Competitive PCR with a kDNA set of primers determined the quantity of approximately 23.9 +/- 18.2 T. cruzi per louse. This finding suggests that the louse may be a vector incidentally contributing to the dissemination of T. cruzi infection in the baboon colony.

Comparative ultrastructural study of the cuticle of larvae and adults of Centrorhynchus milvus Ward, 1956 (Acanthocephala, Centrorhynchidae)

The cuticle of Centrorhynchus milvus acanthella and cystacanth larvae, obtained from the terrestrial crustacean Porcellionides pruinosus, is roughly 0.2 micron thick. The cuticle of juveniles encysted in toads, paratenic hosts, measures up to 0.5 micron whereas that of adults may exceed 2 microns in thickness. In all cases it is perforated by numerous pores that communicate with the hypoderm. During larval development, the numerous endocytotic vacuoles observed in acanthella 3, 4, and 5 and cystacanths became elongated canals in juveniles and adults. There is no significant ultrastructural modification in the cuticle. In the larvae, on the other hand, there was progressive thickening of the cyst wall.

Louse borne relapsing fever (LBRF): mortality and frequency of Jarisch-Herxheimer reaction

The charts of 132 louse-borne relapsing fever (LBRF) patients admitted to a teaching and provincial hospital in Northwestern Ethiopia covering the period 1970-1985 were analysed.

Of the 83 males (62.9%) and 49 (37.1%) females, there were 97 patients treated with varying doses of intramuscular procaine penicillin (100,000-600,000 u) as well as a group of 35 patients treated with single or multiple doses of tetracycline. The average age of tetracycline-treated and penicillin-treated groups was similar, but 65.7% of the former group were above 20 years of age while 51.6% of the latter group were above 20 years of age. The overall rate of the Jarisch-Herxheimer (J-HR) reaction was 21.2%. The corresponding rates in penicillin- and tetracycline-treated groups were 24.7% and 11.4% respectively. Although the frequency of the J-HR reaction is twice as large in the penicillin-treated group as compared with the tetracycline- treated group, the difference is not statistically significant (P>0.05). Similarly the overall death rate following antibiotic treatment was 3.8%. In terms of the J-HR reaction, there were more deaths in the penicillin-treated group (4.1 %), with 2.8% in the tetracycline group. In terms of the frequency as well as mortality from the J-HR reaction, it appeared that penicillin had no therapeutic advantage over tetracycline, and the latter was associated with less frequent J-HR reaction and death. These findings are in contrast to the preference for penicillin in the treatment of hospitalized LBRF patients in Ethiopia at present. As there is no concensus on the treatment of LBRF, a multicentre trial involving older and more recent antibiotics is recommended.

[Ectoparasites of small mammals, their nests and of the nests of birds in the floodplain of the Kamchatka River]

The paper presents data on the specific composition and abundance of bloodsucking arthropods parasitic on small mammals and birds in the valley of the Kamchatka river. One species of ixodids, I. lividus, 9 species of gamasids, P. crassipes, E. kraepelini, G. bispinosus, V. bujakova, H. casalis, H. mandschuricus, M. decoloratus, P. bujakovae, Macroheles sp., and one species of fleas, C. riparius, were first recorded from Kamchatka. 723 rodents were bacteriologically examined for tularemia with negative results.

[Ectoparasites of small mammals in the eastern portion of the Baikal-Amure mainline]

11.501 ectoparasites of 45 species were collected from small mammals (rodents, shrews and double-toothed rodents) in the north-eastern part of Priamurje. The parasitecoenoses are formed in general by gamasid mites (60.4%) and lice(24.7%) but faunistically fleas (19 species or 42.2%) are dominant. Among all ectoparasites the gamasid mites, Laelaps clethrionomydis and Hirstionyssus isabellinus, and the louse Hoplopleura acanthopus account for 64.9%. The impoverishment of the arthropod fauna in the northern part of Priamurje as compared to southern ones proceeds at the expence of chigger mites and more thermophilous species of gamasids and ixodids. With cultivation of forests the content of members of parasitecoenoses becomes more homogenous and their abundance falls.

[Case of the transmission of the rat trypanosome by lice]

Data are given on the laboratory spontaneous occurrence of trypanosomiasis in young rats. It was demonstrated that the louse Polyplax spinulosa is the main mechanical vector of Trypanosoma lewisi. Unlike the case of the real host, the flea, the trypanosomes do not undergo the whole developmental cycle in the louse.

A mallophaga, Trinoton anserinum, as a cyclodevelopmental vector for a heartworm parasite of waterfowl

The biting louse Trinoton anserinum serves as the intermediate host in the life cycle of the filarial heartworm, Sarconema eurycerca. Microfilariae, second-, and third-stage larvae were dissected from 39 of 89 lice infesting whistling swans, Cygnus columbianus columbianus, in North America and mute swans, Cygnus olor, in the Black Sea, U.S.S.R. Infective third-stage larvae obtained from lice collected from heartworm-parasitized whistling swans were injected subcutaneously into each of two hand-reared, nonparasitized mute swan cygnets. Both of these birds developed heartworm infections, one becoming microfilaremic at 14 weeks. The results of this study provide conclusive evidence that a mallophagan serves as a natural cyclodevelopmental vector of a filarial parasite.