scholarly journals Natural infection rates and transmission of Theileria annulata by Hyalomma anatolicum anatolicum ticks in the Sud

2005 ◽  
Vol 72 (4) ◽  
pp. 303-307 ◽  
Author(s):  
D.A. Salih ◽  
O.E. Sharieff ◽  
A.G. Lazarus ◽  
S.M. Hassan
Keyword(s):  
Salivary Glands ◽  
Natural Infection ◽  
Severe Form ◽  
Hyalomma Anatolicum ◽  
Infection Rates ◽  
Intensity Of Infection ◽  
Hyalomma Anatolicum Anatolicum ◽  
Mean Intensity ◽  
Central Sudan ◽  
The Mean

Hyalomma anatolicum anatolicum nymphs were collected from two localities in the Sudan: Eddamer in Northern Sudan and Wad-Medani in Central Sudan. They were allowed to moult to adult ticks, which were assessed for Theileria infection in their salivary glands using Feulgen stain. At Eddamer, 49.6 % of 123 ticks examined were infected with Theileria and the mean intensity of infection was 1.3 (i.e. the number of infected acini / number of infected ticks). At Wad-Medani, 8.6 % of 162 ticks were infected and the mean intensity of infection was 7.9. The prevalence of infection was higher in female than in male ticks at both localities. When adult H. a. anatolicum were applied onto two susceptible calves, both animals developed the severe form of theileriosis.

scholarly journals Natural infection rates and transmission of Theileria annulata by Hyalomma anatolicum anatolicum ticks in the Sudan

2005 ◽  
Vol 72 (4) ◽  
Author(s):  
D.A. Salih ◽  
O.E. Sharieff ◽  
A.G. Lazarus ◽  
S.M. Hassan ◽  
A.M. El Hussein
Keyword(s):  
Salivary Glands ◽  
Natural Infection ◽  
Severe Form ◽  
Hyalomma Anatolicum ◽  
Infection Rates ◽  
Intensity Of Infection ◽  
Hyalomma Anatolicum Anatolicum ◽  
Mean Intensity ◽  
Central Sudan ◽  
The Mean

Hyalomma anatolicum anatolicum nymphs were collected from two localities in the Sudan: Eddamer in Northern Sudan and Wad-Medani in Central Sudan. They were allowed to moult to adult ticks, which were assessed for Theileria infection in their salivary glands using Feulgen stain. At Eddamer, 49.6 % of 123 ticks examined were infected with Theileria and the mean intensity of infection was 1.3 (i.e. the number of infected acini / number of infected ticks). At Wad-Medani, 8.6 % of 162 ticks were infected and the mean intensity of infection was 7.9. The prevalence of infection was higher in female than in male ticks at both localities. When adult H. a. anatolicum were applied onto two susceptible calves, both animals developed the severe form of theileriosis.

scholarly journals Gastrointestinal nematode infections in sheep raised in Botucatu, state of São Paulo, Brazil

2014 ◽  
Vol 23 (3) ◽  
pp. 348-354 ◽  
Author(s):  
Maurício Orlando Wilmsen ◽  
Bruna Fernanda Silva ◽  
César Cristiano Bassetto ◽  
Alessandro Francisco Talamini do Amarante
Keyword(s):  
Haemonchus Contortus ◽  
Natural Infection ◽  
Gastrointestinal Nematode ◽  
Gastrointestinal Nematodes ◽  
Sao Paulo ◽  
São Paulo ◽  
Mean Intensity ◽  
Oesophagostomum Columbianum ◽  
The Mean ◽  
In Parenthesis

Gastrointestinal nematode infections were evaluated in sheep raised in Botucatu, state of São Paulo, Brazil between April 2008 and March 2011. Every month, two tracer lambs grazing with a flock of sheep were exposed to natural infection with gastrointestinal nematodes for 28 consecutive days. At the end of this period, the lambs were sacrificed for worm counts. Haemonchus contortus presented 100% of prevalence. The seasons exerted no significant influence on the mean intensity of H. contortus, which ranged from 315 worms in November 2010 to 2,5205 worms in January 2011. The prevalence of Trichostrongylus colubriformis was also 100%, with the lowest mean intensity (15 worms) recorded in February 2011 and the highest (9,760 worms) in October 2009. In the case of T. colubriformis, a significant correlation coefficient was found between worm counts vs. rainfall (r = −0.32; P <0.05). Three other nematodes species were found in tracer lambs, albeit in small numbers. Their prevalence and mean intensity (in parenthesis) were as follows: Oesophagostomum columbianum 28% (25.2), Cooperia curticei 7% (4.5) and Trichuris spp. 2% (1). In conclusion, the environmental conditions of the area proved to be highly favorable for the year-round transmission of H. contortus and T. colubriformis.

The relationship between IgA activity against 4th-stage larvae and density-dependent effects on the number of 4th-stage larvae ofTeladorsagia circumcinctain naturally infected sheep

Parasitology ◽  
2004 ◽  
Vol 129 (3) ◽  
pp. 363-369 ◽  
Author(s):  
M. J. STEAR ◽  
K. BAIRDEN ◽  
G. T. INNOCENT ◽  
S. MITCHELL ◽  
S. STRAIN ◽  
...  
Keyword(s):  
Negative Binomial Distribution ◽  
Binomial Distribution ◽  
Negative Binomial ◽  
Infection Intensity ◽  
Intensity Of Infection ◽  
Mean Intensity ◽  
Teladorsagia Circumcincta ◽  
The Mean ◽  
Low Levels ◽  
The Relationship

The number ofTeladorsagia circumcincta4th-stage larvae in naturally infected lambs from a single farm varied among lambs and among different years. Within each year the distribution of 4th-stage larvae among lambs was similar to that expected from a negative binomial distribution. The ratio of 4th-stage larvae to adultT. circumcinctawas low in two years with a low mean intensity of infection but high in two years with a higher mean intensity of infection. The negative binomial distribution is defined by the mean and byk, a parameter that measures dispersion;kwas low when mean infection intensity was low but higher when mean infection intensity was high. Askis an inverse index of overdispersion this indicated that the distribution of 4th-stage larvae was more overdispersed at low levels of infection. In a combined analysis, the number of adultT. circumcinctaand the plasma IgA activity against 4th-stage larvae were both associated with increased numbers of 4th-stage larvae. There was a statistical interaction between the number of adults and IgA activity that moderated their combined effect.

scholarly journals Factors influencing the development of Plasmodium gallinaceum in Aedes fluviatilis

1983 ◽  
Vol 78 (1) ◽  
pp. 83-94 ◽  
Author(s):  
Mariana V. Tasón de Camargo ◽  
Rotfaut A. G. B. Cônsoli ◽  
Paul Williams ◽  
Antoniana U. Krettli
Keyword(s):  
Salivary Gland ◽  
Salivary Glands ◽  
Health Hazard ◽  
Infection Rates ◽  
Plasmodium Gallinaceum ◽  
Potential Health ◽  
Aedes Fluviatilis ◽  
Potential Health Hazard ◽  
The Mean ◽  
Mosquito Infection

Aedes fluviatilis is susceptible to infection by Plasmodium gallinaceum and is a convenient insect host for the malaria parasite in countries where Aedees aegypti cannot be maintained in laboratories. In South America, for instance, the rearing of A. aegypti the main vector of urban yellow fever, is not advaisable because of the potential health hazard it represents. Our results of the comparative studies carried out between the sporogonic cycle produced with two lines of P. gallinaceum parasites into A. fuviatilis were as follows. As proved for A. aegypti, mosquito infection rates were variable when A. fluviatilis blood-fed on chicks infected with and old syringe-passaged strain of P. gallinaceum. Oocysts developed in 41% of those mosquitos and the mean peak of oocyst production was 56 per stomach. Salivary gland infections developed in about 6% of the mosquitos. The course of sporogony was unrelated to the size of the inoculum administered to chicks or to the route by which the birds were infected. The development of infected salivary glands was unrelated to oocyst production. Sporogony of P. gallinaceum was more uniform when mosquitos blood-fed on chicks infected with a sporozoite-passaged strain. Oocysts developed in about 50% of those mosquitoes and the mean peak of oocyst production was 138 per stomach, with some individuals having as many as 600-800 oocysts. Infected salivary glands developed in a mean of 27% of the mosquitos but, in some batches, was a high as 50%. Patterns of salivary gland parasitism were similar to those of oocyst production. The course of sporogony of P. gallinaceum in A. fluviatilis is analized in relation to degree of parasitemia and gametocytemia in the vertebrate host.

Studies on the life-cycle of Asymphylodora tincae Modeer, 1790) Trematoda: Monorchiidae) in a small lake near Amsterdam: Part 2: The relations between Asymphylodora tincae and its definitive host, Tinca tinca

1981 ◽  
Vol 55 (4) ◽  
pp. 239-246 ◽  
Author(s):  
M. A. Zietse ◽  
Elisabeth Van Den Broek ◽  
Elze E. A. Erwteman-Ooms
Keyword(s):  
Life Cycle ◽  
Definitive Host ◽  
Natural Infection ◽  
Early Spring ◽  
Summer Season ◽  
Tinca Tinca ◽  
Mean Intensity ◽  
The Mean ◽  
Infection Experiments

ABSTRACTThe natural infection of tench by Asymphylodora tincae in a lake was studied during one summer season. The incidence of infection was 57%, the mean intensity about 50. The distribution of the digencans along the host's intestine showed a maximum in the second half; this could be modified by the presence of other helminth species. Tench caught in early spring and kept in the laboratory retained their natural infection throughout the summer. Starvation of hosts during two months caused disappearance of the infection. Experiments showed that metaecrcariae, introduced into the intestine of tench, can excyst within one hour. In vitro, cysts in contact with tench bile opened within 15 seconds. Bile of several other cyprinid fisli species caused excystment within 60 seconds. Asymphylodora eggs appeared in tench faeces 7 to 10 days after infection. Progenetic specimens of A. tincae probably disintegrate in the intestine of the tench and their eggs arc passed out with the faeces.

scholarly journals Helminth communities and host-parasite relationships in argentine brown rat (Rattus norvegicus)

2008 ◽  
Vol 45 (3) ◽  
pp. 126-129 ◽  
Author(s):  
I. Gomez Villafañe ◽  
M. Robles ◽  
M. Busch
Keyword(s):  
Rattus Norvegicus ◽  
Parasite Fauna ◽  
Individual Characteristics ◽  
Hymenolepis Diminuta ◽  
Nippostrongylus Brasiliensis ◽  
Intensity Of Infection ◽  
Mean Intensity ◽  
Poultry Farms ◽  
Syphacia Muris ◽  
The Mean

AbstractThe aims of this research were: 1) to determine the helminth parasite fauna of seventy two Rattus norvegicus (Berkenhout, 1769) individuals inhabiting poultry farms in the Pampean region of Argentina; 2) to examine the relationship between parasitism and individual characteristics of the hosts, and 3) to analyze the associations among helminths. The study was carried out in twenty-four poultry farms from autumn 2000 to winter 2001. Nematodes were found in the intestine or caecum rectum of the 74 % of rats and cestodes were found along all the intestine of the 28 % of rats. Heterakis spumosa (Travassos 1914) was a central species, whereas Syphacia muris, Yamaguti 1941, Nippostrongylus brasiliensis (Travassos 1914) and Hymenolepis diminuta (Rudolphi 1819) were satellite species. Helminths do not affect rat survival and growth of rats. Rats parasitized with H. spumosa and H. diminuta were larger and older than non-parasitized rats. The intensity of infection with H. spumosa significantly increased with rat age. Rats parasitized with Nippostrongylus brasiliensis and Syphacia muris did not differ in size and age with respect to non-parasitized ones. The mean intensity of infections per host was 33.74, 74.28, higher than 200, and 3.10 for H. spumosa, S. muris, N. brasiliensis and H. diminuta, respectively. The mean intensity of infection with H. spumosa was higher in summer than in the other seasons, while the higher mean intensity of infection with N. brasiliensis and S. muris occurred in autumn. Infections with Heterakis spumosa and Syphacia muris, and with Syphacia muris and Nippostrongylus brasiliensis were independent; while Heterakis spumosa and Nippostrongylus brasiliensis were negatively associated.

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