The Differentiation of the Polymorphic Trypanosomes

Fairbairn, H.; Culwick, A. T.

doi:10.1080/00034983.1949.11685397

Cited by 16 publications

(11 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Okiwelu (1977) collected tsetse from fly rounds in Zambia and noted that there was a higher infection rate in males in G. morsitans than in females. Laboratory observation seems to show that males are more susceptible to trypanosome infection than females (Fairbairn and Culwick, 1950;Harley, 1970). Laboratory observation seems to show that males are more susceptible to trypanosome infection than females (Fairbairn and Culwick, 1950;Harley, 1970).…”

Section: Discussionmentioning

confidence: 95%

Trypanosome infections in wild tsetse, Glossina pallidipes Austen on the Kenya coast

Tarimo

Snow

Butler

1984

Int. J. Trop. Insect Sci.

View full text Add to dashboard Cite

Trypanosome infection rates in tsetse, Glossina pallidipes Austen in five areas along the Kenya coast were studied for 2 years (1980)(1981)(1982). The total percentage infection rates were 12.62, 7.24, 9.50, 7.86 and 7.97 for Ukunda, Diani, Muhaka, Shimba Hills and Mwalewa, respectively. The respective values for males were 3.13, 4.16, 5.17, 5.03 and 8.13. Overall there were more trypanosome infections due to; Trypanosome congolense followed by T. vivax and T. brucei, although these varied among the localities. The age of the flies, their feeding patterns and regular use of chemoprophylaxis in local cattle were the main factors affecting infection rates.

show abstract

Section: Discussionmentioning

confidence: 95%

Trypanosome infections in wild tsetse, Glossina pallidipes Austen on the Kenya coast

Tarimo

Snow

Butler

1984

Int. J. Trop. Insect Sci.

View full text Add to dashboard Cite

show abstract

“…The only climatic factor so far known to influence the development of trypanosomes in Glossina is temperature; at higher temperatures the time required to complete the development is shorter (Fairbairn & Culwick, 1950;Desowitz & Fairbairn, 1955). But changes in the rate of development should make little difference to the numbers found infected, because early (immature) stages of infection are detectable by the methods used.…”

Section: Discussionmentioning

confidence: 99%

Seasonal and diurnal variations in physiological age and trypanosome infection rate of females of Glossina pallidipes Aust., G. palpalis fuscipes Newst. and G. brevipalpis Newst

Harley¹

1966

Bull. Entomol. Res.

View full text Add to dashboard Cite

A series of 24-hr. catches of Glossina from bait-oxen was carried out during 16 months in 1962–63 at Lugala, Uganda, where G. pallidipes Aust., G. palpalis fuscipes Newst. and G. brevipalpis Newst. occur. Female flies were dissected to determine their physiological age and the presence or absence of trypanosomes. Five age-categories were distinguished, depending on whether a fly had ovulated 0, 1, 2, 3 or more (4 + ) times. Flies remained in each of the first four categories for about 11 days and the fifth therefore comprised those over 40–50 days old. Trypanosome infections were classified as brucei-type, vivax-iype or congolense-type (i.e., attributable to trypanosomes of the groups of Trypanosoma brucei, T. vivax and T. congolense) according to the sites in which they were found.In all three species of Glossina, vivax-tjpe infections were commonest and alone showed seasonal fluctuations in incidence. Infections of the brucei-type were rare. The total infection rate (all types) in G. pallidipes and G. palpalis fuscipes was highest in or immediately after months of greatest rainfall and relatively lower in dry months; the highest infection rates in G. brevipalpis occurred a month later than those of the other two species. Over 80 per cent, of infections in all three were found in category 4+ flies, the percentage of which in the catches varied in much the same way as the total infection rate, suggesting not only that the flies live longest during wet periods but also that fluctuations of infection rate are largely due to changes in mean age. The regression of total infection rate on percentage of category 4 + flies was significant for G. palpalis fuscipes over 14 months, and for G. pallidipes over 12 months, but insignificant for G. brevipalpis.The age-composition of catches of G. pallidipes and G. brevipalpis but not G. palpalis fuscipes varied during the day. In G. pallidipes, the percentage of older flies was higher in the middle of the day than in the early morning and late evening, and these contrasts were reflected in the infection rate, which was highest in samples taken in the middle of the day. In G. brevipalpis, the percentage of oldier flies and also the infection rate were lower during the night than during the day.Estimates were made of the mean number of bites by infected females that would be received by one ox in one day. The number varied from month to month, with peaks shortly after periods of high rainfall, mainly as a result of changes in fly density and relatively little as a result of changes in infection rate. G. pallidipes, the most numerous species, was responsible for most of the potentially infective bites.

show abstract

“…There is much evidence on the important influence of both pupal-maintenance temperature and fly-maintenance temperature on the development of trypanosome infections in Glossina. Burtt (1946) and Fairbairn & Culwick (1950) demonstrated relationships between temperature and infections of T. rhodesiense in G. morsitans; high pupal-maintenance temperatures favoured high infection rates. In male flies " the infection rate is not influenced by the temperature to which the adult flies are exposed.…”

Section: Some {Actors Affecting Trypanosome Infection Rates In Glossinamentioning

confidence: 98%

“…In male flies " the infection rate is not influenced by the temperature to which the adult flies are exposed. In female flies, the infection rate is governed both by the pupal temperature and the temperature of fly-maintenance " (Fairbairn & Culwick, 1950). Fairbairn & Watson (1955) (L 1671) B found that the infection rate of T. vivax in G. palpalis (E.-D.) increased with increasing pupal-maintenance temperature but decreased with increasing flymaintenance temperature.…”

Section: Some {Actors Affecting Trypanosome Infection Rates In Glossinamentioning

confidence: 99%

Trypanosome infection rates inGlossina morsitans submorsitansNewst. in Northern Nigeria

Jordan

1964

Bull. Entomol. Res.

View full text Add to dashboard Cite

Previous records and new data on trypanosome infection rates inGlossina morsitans submorsitansNewst. in Northern Nigeria are presented, and discussed in relation to the hosts fed on by this tsetse fly. The new observations were carried out in three areas: at Mando and Gamagira, both lying in a fly-belt north of Kaduna, and in the Yankari Game Reserve in Bauchi Province.Infection rates were obtained by dissection of flies, and the trypanosomes were identified by their locus; the validity of this method of identification is discussed. All infections withTrypanosomaspp. were attributable either to thevivaxgroup or to theconrgolensegroup; nobrucen-group trypanosomes were identified. More than 260 flies from each area were examined during March 1962, at the end of the dry season, and similar numbers during October 1962, at the end of the wet season.There was no significant difference between dry-season and wet-season infection rates in any area. Taking the two seasons together, the rate at Yankari (12%) was significantly higher than the rates at Mando (5%) and Gamagira (3%), which did not differ significantly. These contrasting infection rates could be related to the host species principally fed on by flies in the different areas as shown by blood-meal determinations. The lowest infection rates occurred where Suidae furnished a high proportion of meals (Mando, 51%; Gamagira, 67%) and Bovidae a small proportion (Mando, 16%; Gamagira, 9%). The high infection rate at Yankari was associated with a high proportion of Bovid meals (53%), especially from buffalo (Syncerus nanus) and bushbuck (Tragelaphus scriptus), and a lower proportion of Suid meals (33%). For the three areas the relationship between infection rate and percentage of Bovid meals was statistically significant.The species groups of infecting trypanosomes showed further contrasts between the three areas which were unrelated to the total infection rates. At Gamagira, 81 per cent, of infections werecongolensegroup, and this proportion was significantly higher than that at Mando (45%) or Yankari (37%). The differences could be related to the types of host from which blood-meals were principally derived. The highest proportion ofcongolense-group infections occurred where the highest percentage of meals came from Suidae (Gamagira, 67%), and lower proportions occurred at Mando and Yankari where Suid feeds were relatively fewer (51% and 33%, respectively).These findings are discussed in the light of existing evidence on the factors governing infection rates inGlossina. It is concluded that, within the over-riding influence exerted by temperature through geographical latitude, infection rates are determined by the type of host that forms the principal source of food. In some populations of Glossina the influence of the nature of the main food source can be sufficient to obscure the general effect of temperature in determining the level of infection. Some of the reasons for these relationships are discussed.

show abstract

The Differentiation of the Polymorphic Trypanosomes

Cited by 16 publications

References 4 publications

Trypanosome infections in wild tsetse, Glossina pallidipes Austen on the Kenya coast

Trypanosome infections in wild tsetse, Glossina pallidipes Austen on the Kenya coast

Seasonal and diurnal variations in physiological age and trypanosome infection rate of females of Glossina pallidipes Aust., G. palpalis fuscipes Newst. and G. brevipalpis Newst

Trypanosome infection rates inGlossina morsitans submorsitansNewst. in Northern Nigeria

Contact Info

Product

Resources

About