No abstract

Following an intensive health education programme, 8651 finger-prick blood samples, 4122 from a predominantly adult group attending a primary care clinic and 4529 from schoolchildren, were collected in Tamra, northern Israel. An enzyme-linked immunosorbent assay (ELISA) for immunoglobulin G (IgG) was used to detect anti-Echinococcus granulosus antibodies, using both crude and purified antigens. The seroprevalence in the adult group was 0.48% (20/4122); optical density values were 0.1-0.14 in 10 subjects, 0.15-0.19 in 9, and > or = 0.2 in one; prevalences did not differ significantly between males and females or among age groups. Twenty-six of the schoolchildren (0.57%) were seropositive, 23 with optical densities of 0.1-0.14, one of 0.15-0.19, and 2 > or = 0.2. A high correlation was observed between ELISA positivity and both positivity in the arc 5 immunoelectrophoresis test and the presence of a high titre in the indirect immunofluorescence assay. Cross reactivity was observed with sera from schistosomiasis and ancylostomiasis patients, using both crude and purified echinococcal antigens. The results indicated that the IgG ELISA, using both crude and purified antigens, was very useful for seroepidemiological screening for echinococcosis, and that this condition is an emerging disease in northern Israel.

In a survey carried out during the period May 1995 to November 1996, in communities of various ethnic groups in northern Israel, 206 dogs were examined for Echinococcus granulosus and other intestinal helminth parasites by arecoline hydrobromide purges and the coproantigen-ELISA. The arecoline test was performed close to the owners' homes, using plastic sheets secured to the ground. From 56 dogs examined in the Muslim town of Tamra, six (10.7%) were found to be infected with E. granulosus. Four of them also had a mixed infection of Taenia hydatigena and Dipylidium caninum (two dogs), and the remaining two dogs were infected with either D. caninum or Taenia pisiformis. An additional 18 dogs were infected with either T. pisiformis (eight dogs), D. caninum (seven dogs), or T. hydatigena (three dogs). Two of these dogs harboured mixed infections whereas the remaining 32 dogs were free of helminths. In the Jewish villages, none of the 150 dogs examined were infected with E. granulosus, although 26 (17.3%) were infected with D. caninum, four (2.7%) with Ancylostoma spp. and one (0.7%) with Toxocara canis. Only one of the 22 stray dogs and none of the 15 jackals examined were infected with E. granulosus. However, 21 (95.4%) of the dogs and 12 (80%) of the jackals harboured helminth infections, including: D. caninum (16 dogs and seven jackals), Ancylostoma spp. (five jackals), T. hydatigena (three dogs), and T. canis (one dog). Approximately 18% of the dogs and 33% of the jackals showed mixed infections with two or more of the above helminths. In the abattoirs, 52 (5.9%) of the 874 sheep and 33 (5.3%) of the 616 goats from 17 herds slaughtered in the Muslim and Druze villages were found to be infected with E. granulosus, compared with a 0% infection rate observed in 93 sheep from two herds in Jewish villages. *Fax: 972 7 6277 453

No abstract

No abstract

Leishmaniasis is a vector-borne disease caused by flagellated protozoan parasites of the genus Leishmania, which affects both humans and other mammals. Most of the available drugs against the disease are toxic and parasite resistance to some of the drugs has already developed. In the present study, the leishmanicidal activities of methanolic extracts of some Israeli plants have been evaluated in vitro, against the free-living promastigotes and intracellular amastigotes of Leishmania major. Of the 41 extracts examined, those of two plants (Nuphar lutea>Withania somnifera) were highly effective (with a maximum inhibitory effect of >50%), those of three other species (Pteris vittata>Smyrnium olusatrum>Trifolium clypeatum) were moderately effective (25%-50%) and another four extracts (Erodium malacoides>Hyparrhenia hirta>Thymelaea hirsuta>Pulicaria crispa) showed a marginal effect (15%-22%) against the parasites. Extracts of nine plant species therefore showed antileishmanial activity but only the extract of N. lutea, used at 1.25 microg/ml, eliminated all the intracellular parasites within 3 days of treatment, with no detectable toxicity to the host macrophages. The mean (S.D.) values recorded for the median inhibitory concentrations of this extract (IC50) against the promastigotes [2.0 (0.12) microg/ml] and amastigotes [0.65 (0.023) microg/ml] and the median lethal concentration (LD50) against macrophages [2.1 (0.096) microg/ml] were encouraging, giving a therapeutic selectivity index [LD50/IC50 for amastigotes)] of 3.23. The extract of N. lutea was, in fact, generally as effective as the paromomycin that was used as the 'gold standard' drug. These results indicate that N. lutea and probably also Withania somnifera might be potential sources of clinically useful, antileishmanial compounds.

Only limited data are available on the early immunological events associated with human cutaneous leishmaniasis (CL). In this study, peripheral-blood mononuclear cells were obtained from 66 individuals (34 patients with cutaneous lesions and 32 apparently healthy controls) who had each spent no more than 3 months in the endemic region of Qetzioth, in southern Israel. These cells' responses to Leishmania major antigen were then explored, by the flow-cytometry-based evaluation of blast transformation (BT). The lymphocytes from 17 (50%) of the patients but only one (3%) of the controls displayed BT. When, in an ELISA, most (52) of the subjects were checked for anti-L. major antibodies, none of the 22 controls investigated but 19 (63%) of the 30 patients were found seropositive. Although 14 (47%) of the 30 patients who were checked for antibodies were BT-positive, the seropositive patients were not significantly more or less likely to be BT-positive than the seronegative patients (P<0.919). These data indicate that, in CL, the hosts' cellular and humoral responses develop independently within the first 3 months post-infection, but further investigation is required to confirm this hypothesis.