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PubMed1997

The intermediate hosts of Dracunculus medinensis in northern region, Ghana.

Cyclopoid copepods were collected over a period of 17 months from six man-made water reservoirs in an area of northern Ghana where dracunculiasis is endemic. The numbers and species of cyclopoid copepods as well as the species naturally infected with Dracunculus medinensis larvae were recorded at fortinightly intervals. The occurrence of copepods was compared with concurrent rainfall and with monthly incidences of dracunculiasis in the year after the reservoir survey. Seven species and two subspecies of copepods were found in the study area: Thermocyclops neglectus decipiens, T. crassu' consimilis, T. incisus, T. inopinus, T. emini, Mesocyclops major, M. ogunnus, M. kieferi and Cryptocyclops linjanticus. More than 60% of all the cyclopoids found were T. n. decipiens and only four species (T. incisus, T. inopinus, T. n. decipiens and M. kieferi) were found infected. Infection rates were very low (< or = 0.3%). The seasonal fluctuations of cyclopoid copepods showed different patterns in the six reservoirs, perhaps related to local circumstances not investigated in the present study. As the people in the study area are very mobile during the dracunculiasis transmission season, it seems likely that some of them become infected at water sources other than the ones investigated. It was therefore difficult to correlate occurrence of cyclopoid copepods in the local water sources with the prevalence of the human infection in the catchment area. No conclusion as to the most important intermediate host(s) in the area could be made.

Animals↗
PubMed2002

Dracunculus medinensis and Schistosoma mansoni contain opiate alkaloids.

The results of analysis, by high-performance liquid chromatography coupled with electrochemical detection and by nano-electrospray-ionization, double quadrupole/orthogonal-acceleration, time-of-flight mass spectrometry, indicate that adult Dracunculus medinensis and Schistosoma mansoni both contain the opiate alkaloid morphine and that D. medinesis also contains the active metabolite of morphine, morphine 6-glucuronide. From these and previous observations, it would appear that many helminths are probably using opiate alkaloids as potent immunosuppressive and antinociceptive signal molecules, to down-regulate immunosurveillance responsiveness and pain signalling in their hosts.

Animals↗
PubMed1976

Attempted experimental cross infections with mammalian guinea-worms, Dracunculus spp. (Nematoda: Dracunculoidea).

Dracunculus medinensis and D. insignis are morphologically indistinguishable. Experiments to test the susceptibility of various mammalian hosts to these two guinea worm species are described. Infective 3rd-stage larvae of D. medinensis were administered to each of four raccons (Procyon lotor): infective 3rd-stage larvae of D. insignis were administered to a rhesus monkey (Macaca mulatta), two dogs, two ferrets (Mustela putorius furo), and a marten (Martes americana). D. medinensis was not found in the raccoons when necropsies were performed on days 247, 283, 354, and 390 post-infection, respectively. Nine female D. insignis containing eggs, embryos, and motile 1st-stage larvae were found in the rhesus monkey 180 days post-infection. Lesions had not formed and the larvae were presumed to be immature and not yet infective as they were comparatively inactive and attempts to infect suitable copepods failed. D. insignis was not found in the dogs or the marten, although both ferrets were successfully infected. Variations in susceptibility of various mammalian species to the guinea worm are discussed together with comments on variations in migration routes and sites of emergence in hosts which may be partially refractory. D. insignis and D. medinensis may represent physiological strains of a single species, or they may in fact be two distinct species which have evolved in different geographical locations.

Animals↗
PubMed1989

Red Dracunculus medinensis.

Two instances of the emergence of a bright-red worm from humans in Pakistan are described. A 25-year-old man and a 26-year-old woman, unrelated and living in separate households, were observed in 1987 and 1988, respectively, to have emergent worms typical in size and location for Guinea worm disease, except for the color of the worms. The posterior end of 1 worm was recovered and appeared to be a female Dracunculus medinensis. Histologic sections provided insufficient information to determine the cause of the red color, although we could exclude blood as the cause.

Adult↗
PubMed1990

Specific and cross-reacting antibodies in human responses to Onchocerca volvulus and Dracunculus medinensis infections.

Immunoelectroblotting and enzyme-linked immunosorbent assay were used to identify non-cross-reacting antigenic components of Dracunculus medinensis and the filarial worms Onchocerca volvulus, Loa loa, Wuchereria bancrofti, Brugia malayi, and Mansonella ozzardi. Parasite specific serodiagnostic ELISA systems for onchocerciasis and dracunculiasis were devised based on these findings. Phosphate buffered saline extracts of adult worms were passed through a column of monoclonal antibodies to phosphorylcholine (PC). Crude and PC-depleted extracts were reacted on ELISA plates with individual sera from subjects infected with a range of nematodes. Binding of total antibody (Ig) or IgG class antibody and IgG4 subclass antibody was revealed using goat antihuman-Ig-phosphatase conjugate, or appropriate mouse monoclonal antihuman-Ig-type-specific reagents, followed by goat antimouse-Ig-phosphatase conjugate. Specificity of ELISA was improved by restricting reaction to the host's IgG4 antibody subclass, and/or by removing PC determinants from crude antigens. In parallel immunoelectroblots, crude and PC-depleted extracts probed with pooled sera showed potentially useful diagnostic antigens, including a 12 kDa protein from D. medinensis and 14, 18, and 27 kDa proteins from O. volvulus. Two Onchocerca specific ELISA systems non-reactive with antibodies to D. medinensis were devised.

Animals↗
PubMed1998

Immunoepidemiology of Dracunculus medinensis infections I. Antibody responses in relation to infection status.

The specific serum IgG1, IgG4, and IgE responses to Dracunculus medinensis and the level of total IgE of individuals living in a highly endemic area of northern Ghana were measured by ELISA. Sera were obtained in the high transmission season from individuals with prepatent, patent, or postpatent infection as well as from individuals from the same endemic area who claimed to have never had a patent infection (i.e., endemic normal individuals). Individuals with prepatent or postpatent infections responded with a significantly lower mean level of specific IgG1 and IgG4 compared with individuals with a patent infection, and with a significantly higher mean level of specific IgG1 and IgG4 compared with endemic normal individuals. For specific IgE, no differences were found in the mean antibody level between the infection status categories. Individuals with a patent infection had a significantly lower mean serum level of total IgE compared with prepatent, postpatent, and endemic normal individuals. Endemic normal individuals had the highest mean level of total IgE. Furthermore, in all clinical categories, high responders for specific IgG1 and IgG4 generally had low levels of total IgE, whereas low responders for specific IgG1 and IgG4 generally had high levels of total IgE. A similar dichotomy, although less distinct, was observed between specific IgG1 and IgG4 on the one hand and specific IgE on the other. Thus, similar to what has been suggested for schistosomiasis and lymphatic filariasis, the relationship between the IgG subclasses and IgE appears to play a role in, or at least to reflect, a mechanism for protective immunity in dracunculiasis.

Adolescent↗
PubMed1998

Immunoepidemiology of Dracunculus medinensis infections II. Variation in antibody responses in relation to transmission season and patency.

The serum antibody responses (specific IgG1, IgG4, and IgE, and total IgE) to Dracunculus medinensis infection in humans from a highly endemic area of northern Ghana were examined regularly by ELISA over a period of one year in cohorts of individuals who developed a patent D. medinensis infection during the study period (actively infected category), or who claimed to have never had a patent infection (endemic normal category). The results were analyzed in relation to seasonality and time of patency of infection. For individuals in the actively infected category, a clear seasonal variation in the mean levels of specific IgG1 and IgG4 was found, with the highest levels late in the dry season and early in the rainy season, when transmission is high, and the lowest levels late in the rainy season and early in the dry season. Endemic normal individuals responded with low and fluctuating levels of specific IgG1 and with low and nonfluctuating levels of specific IgG4. For specific and total IgE, no seasonal variation was observed in any of the two infection status categories. In relation to time of patency of infection (only involving the category of actively infected individuals), the mean levels of specific IgG1 and IgG4 increased from two months before patency of infection, peaked during patency, and then gradually decreased for four months until a constant level was reached. No significant fluctuations in the levels of specific and total IgE were observed in relation to time of patency. The present study thus showed extensive variation in levels of D. medinensis-specific IgG1 and IgG4 (but not IgE) over time. Seasonal variations in antibody responses may also occur in other helminth infections, especially those with seasonal transmission, and these should be taken into consideration when interpreting the results of immunologic studies.

Adult↗
PubMed1999

Massive Dracunculus insignis infection in a dog.

An 11-year-old 13-kg (28.6-lb) spayed female Cocker Spaniel was examined because of subcutaneous nodules on the hind limbs and ventral aspects of the thorax and abdomen. Focal areas of erythema and pyoderma were associated with the nodules, and purulent exudate could be expressed from a fistula in the nodules. A nematode approximately 20.5 cm in length was isolated from a draining fistula in 1 nodule and identified as Dracunculus insignis. The dog was treated with ivermectin, fenbendazole, and metronidazole, but the owner was still able to recover worms from multiple nodules for the next year.

Animals↗
PubMed1991

Inoculation of ferrets with ten third-stage larvae of Dracunculus insignis.

Infection with Dracunculus insignis was established in 7 of 10 ferrets experimentally inoculated intraperitoneally with 10 third-stage larvae (L3's). Worm recovery and infection rate were comparable to animals inoculated with 50 L3's. This study demonstrates that once infective larvae traverse the gut and pass into the peritoneal cavity, very few larvae are required to establish infection.

Animals↗
PubMed1990

Dracunculus insignis in ferrets: comparison of inoculation routes.

Three routes of inoculation were compared to determine the best method to infect ferrets with Dracunculus insignis. The traditional method of administering infected cyclops containing L3s through gavage was compared to intraperitoneal (i.p.) and subcutaneous (s.c.) inoculation of L3s. Ten of 18 (56%) gavaged ferrets became infected after receiving copepods containing approximately 100 L3s each; 44 adult worms were recovered from these 10 animals. Twenty-one of 28 (75%) animals inoculated with 50 L3s each became infected i.p.; 92 adult worms were recovered from the positive animals. Four of 5 (80%) ferrets given subcutaneous inoculations of 50 L3s became infected; only 6 worms were recovered from these 4 animals. Inoculation of larvae via the i.p. or s.c. route greatly simplifies the infection procedure and produces more consistent results. A simple procedure is described, which permits rapid recovery of L3s to be used in the i.p. or s.c. inoculations.

Animals↗
PubMed1990

Distribution, behavior, and course of patency of Dracunculus insignis in experimentally infected ferrets.

From 106 ferrets experimentally infected with Dracunculus insignis, 273 female worms and 42 male worms were recovered. The percentage of female worms that mated, the location of all worms, and the rate of emergence of gravid females were recorded. Of 174 mature female worms recovered, only 11% had emerged before necropsy. Eighty-one percent of the male worms and 87% of all unmated (immature) females were found on the trunk of the animal or on the skin overlying it. Gravid female worms were found on the extremities (legs) 88% of the time. Almost one-third of gravid female worms were found on the left front leg. On 4 occasions, females were found in unusual locations: the tail, the cheek, the lumbar region of the spinal cord, and the peritoneal cavity associated with the omentum. The results showed that only a small percentage of mature female worms emerge, which suggests that infected persons harbor many more gravid female worms than indicated by reports of emergent worms. More than one-third of female worms were not mated, but it is likely that these immature females would be capable of further development. Furthermore, male worms have been observed to survive for up to 330 days, suggesting that male or unmated female worms may carry over from one transmission season to the next.

Animals↗
PubMed1985

Relative susceptibilities of cyclops species from Rajasthan State to guinea worm (Dracunculus medinensis) larvae.

The role of eight different species of cyclops as intermediate hosts of Dracunculus medinensis has been studied by investigating their relative preferences for the ingestion of free-living larvae, the time required for larval penetration into the haemocoel, the number of larvae lethal to the copepods, and the threshold of tolerance for successful development of the larvae within the cyclops. On the basis of larval development up to the infective stage, four species of cyclops-Paracyclops fimbriatus, Thermocyclops oithonoides, Mesocyclops leuckarti sensu lato and Microcyclops varicans-were ranked as suitable hosts. Eucyclops serrulatus was partially refractory, and Tropocyclops prasinus and Ectocyclops rubescens were completely refractory. Guinea worm larvae were pathogenic to Macrocyclops distinctus.

Animals↗
PubMed1981

[Dracunculus medinensis infestation following holidays in West Africa. Epidemiological implications (author's transl)].

All 50 patients with dracunculiasis admitted to a Paris hospital during a 3-year period were West African immigrant workers, 70% of whom came from a very limited geographical area. Only 6 of the workers were "first arrival"; the others had contracted filariasis during holidays in their home country. The mean duration of stay in hospital was 40 days. In 40 of the patients who had spent 6 months or less in their home country, the exact dates of first arrival in France, departure to, and return from, Africa and emergence of adult worms were available, so that the duration of the Dracunculus medinensis cycle (mean: 12 +/- 1,7 months) and the period of local transmission could be determined. These epidemiological data account for the seasonal character of infestation and for the occurrence of dracunculiasis in France. They also exclude a diagnosis of filariasis based on more or less suggestive symptoms when the delays after possible infestation are either too long or too short.

Adult↗
PubMed2004

Anticonvulsant activity and chemical composition of Artemisia dracunculus L. essential oil.

Artemisia dracunculus L. (Asteraceae) has been used orally as an antiepileptic remedy in Iranian folkloric medicine. The anticonvulsant potential and composition of the essential oil obtained from the aerial parts of the plant were assessed in this study. The essential oil exerted dose- and time-dependent antiseizure activity in both maximal electroshock (MES) and pentylenetetrazole models of experimental seizures with ED50 values of 0.84 and 0.26 ml/kg, respectively. At some anticonvulsant doses, the essential oil produced sedation and motor impairment assessed by rotarod test. Gas chromatography (GC)/mass spectrometry (MS) analysis of the essential oil revealed the presence of trans-anethole (21.1%), alpha-trans-ocimene (20.6%), limonene (12.4%), alpha-pinene (5.1%), allo ocimene (4.8%), methyl eugenol (2.2%), beta-pinene (0.8%), alpha-terpinolene (0.5%), bornyl acetate (0.5%) and bicyclogermacrene (0.5%) as the main components. The observed anticonvulsant and sedative effects could be related to the presence of monoterpenoids in the essential oil.

Animals↗
PubMed2005

Antihyperglycemic activity of Tarralin, an ethanolic extract of Artemisia dracunculus L.

The studies reported here were undertaken to examine the antihyperglycemic activity of an ethanolic extract of Artemisia dracunculus L., called Tarralin in diabetic and non-diabetic animals. In genetically diabetic KK-A(gamma) mice, Tarralin treatment by gavage (500 mg/kg body wt./day for 7 days) lowered elevated blood glucose levels by 24% from 479+/-25 to 352+/-16 mg/dl relative to control animals. In comparison, treatment with the known antidiabetic drugs, troglitazone (30 mg/kg body wt./day) and metformin (300 mg/kg body wt./day), decreased blood glucose concentrations by 28% and 41%, respectively. Blood insulin concentrations were reduced in the KK-A(gamma) mice by 33% with Tarralin, 48% with troglitazone and 52% with metformin. In (STZ)-induced diabetic mice, Tarralin treatment, (500 mg/kg body wt./day for 7 days), also significantly lowered blood glucose concentrations, by 20%, from 429+/-41 to 376+/-58 mg/dl relative to control. As a possible mechanism, Tarralin was shown to significantly decrease phosphoenolpyruvate carboxykinase (PEPCK) mRNA expression by 28% in STZ-induced diabetic rats. In non-diabetic animals, treatment with Tarralin did not significantly alter PEPCK expression, blood glucose or insulin concentrations. The extract was also shown to increase the binding of glucagon-like peptide (GLP-1) to its receptor in vitro. These results indicate that Tarralin has antihyperglycemic activity and a potential role in the management of diabetic states.

Animals↗
PubMed2001

Alkamides from Artemisia dracunculus.

From the aerial parts of Artemisia dracunculus, one known alkamide, pellitorine, two new alkamides neopellitorine A and neopellitorine B, and one known coumarin herniarine were isolated. Structures were elucidated by means of UV, IR, MS, 1H and 13C NMR. These compounds showed insecticidal activity against Sitophilus oryzae and Rhyzopertha dominica at 200 microg/ml concentrations.

Amides↗