The effect of trypanosomosis on pregnancy in trypanotolerant Orma Boran cattle.

A study was undertaken to investigate the influence of trypanosomosis on the outcome of pregnancy in trypanotolerant Orma Boran (Bos indicus) exposed to natural tsetse challenge in an area of Kenya infested predominantly with Glossina pallidipes. Of 73 pregnant Orma heifers, 58 (79.5%) produced live calves at term, 13 (17.8%) aborted and 2 (2.7%) died of trypanosomosis. Of the 71 surviving animals, 22 (31%) were infected with Trypanosoma vivax , 21 (29.6%) T. congolense, and 26 (36.6%) had mixed infections with T. vivax and T. congolense. These results suggest that in areas of high trypanosomosis risk reproductive function is affected even in trypanotolerant cattle, and that both T. vivax and T. congolense can be responsible for the abortions observed in the field. It is suggested that maintenance of pregnancy in the face of trypanosome challenge was dependent on individual variation among the Orma cattle, but as challenge increased beyond the limits of effectiveness of trypanotolerance, disruption of pregnancy occurred.

Studies on the haemolytic complement of the dromedary camel (Camelus dromedarius). II. Alternate complement pathway haemolytic activity in serum.

Fresh camel serum caused lysis of unsensitised red blood cells (RBC) of chicken, rabbit and guinea pig. Homologous RBC were resistant to lysis. There was only minimal lysis of goat, sheep, rat and cattle RBC. Lysis of heterologous RBC was attributed to the presence of alternate complement activity (ACP) in the serum as adsorption with respective RBC and addition of 10 mM ethylene glycol-bistetraacetate (EGTA) in the SVBS diluent did not abrogate the haemolytic activity. Guinea pig RBC were the most sensitive to lysis, giving a mean ACP activity of 41.5 +/- 1.8 CH50 units ml-1. Clotting, followed by storing of blood between 0 and 37 degrees C for 1 h did not significantly affect ACP activity. However, considerable activity was lost when blood was clotted and stored at 44 degrees C for 1 h, or when serum was kept at 4 degrees C for 24 h. Treatment with zymosan, or incubation at 56 degrees C for 30 min inhibited ACP activity. Maximum ACP activity occurred in the presence of 8 mM Mg2+ in the SVBS-EGTA diluent, at pH 7.3 and incubation time of 2 h at 37 degrees C. Levels of ACP activity were determined in 79 healthy camels of different age groups, ranging from 3 months to 15 years. Calves between 3 months and 1 year of age had higher ACP activity than camels in the age group of 5 years and above. Highest mean ACP activity of 89 +/- 7.9 CH50 units ml-1 were recorded in 1-5 year old camels (P < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Studies on the haemolytic complement of the dromedary camel (Camelus dromedarius). I. Classical pathway haemolytic activity in serum.

Classical pathway haemolytic complement (CPHC) of the dromedary was assayed under standardised conditions. A total of 14 indicator systems of red blood cells (RBC) and haemolysins were investigated. Highest CH50 titre was obtained with rabbit RBC sensitised with goat haemolysin. Among the factors investigated were: ionic strength, Mg2+, Ca2+, ethylenediaminetetraacetic acid (EDTA) concentration, pH, incubation time and temperature. The standard system of titrating the HC levels consisted of rabbit RBC sensitised with goat haemolysin, sucrose veronal buffer (SVBS) pH 7.4, ionic strength 0.14 M and Ca2+ and Mg2+ concentrations of 4.0 x 10(-4) M and 1 x 10(-3) M, respectively. Incubation at 37 degrees C for 120 min gave the highest HC activity. Using these standardised conditions HC levels were determined in 79 camels aged between 3 months and 15 years. Highest mean HC value of 873 +/- 26.6 CH50 units ml-1 were recorded in the age group of 1-5 year old camels and the lowest mean HC value of 598 +/- 120.8 CH50 units ml-1 in the age group of 10-15 year old camels. Adult males in the age group 5-10 years had significantly higher mean HC levels than their female counterparts (P < 0.0001).

Immunoassay of circulating trypanosomal antigens in sleeping sickness patients undergoing treatment.

Sera from 99 patients infected with Trypanosoma brucei rhodesiense and undergoing treatment, were analyzed for circulating trypanosomal antigens using a sandwich antigen-trapping enzyme-linked immunosorbent assay (ELISA). Trypanosomal antigens were detected in 83 (84%) of the patients. Post-treatment antigen profile in 67 patients showed five distinct patterns: in 48% of the patients antigen levels remained elevated throughout the time of hospitalisation and follow-up; in 31%, antigens dropped to the negative value by the second month; in 7.5%, antigens dropped to the negative level and became elevated afterwards; in 7.5%, antigen levels were negative initially, but later, became elevated and remained so throughout the observation period; in 6%, antigen levels remained below the negative value throughout. All patients who relapsed on follow-up had earlier shown evidence of elevated antigen profile. There were no cases of relapses among 21 patients whose antigen levels dropped subsequent to treatment. This ELISA trypanosome antigen detection test could be useful in evaluating treatment success, when used together with parasitological diagnostic techniques.

Evaluation of Procyclic Agglutination Trypanosomiasis Test (PATT) for the immunodiagnosis of Trypanosoma brucei rhodesiense sleeping sickness in Kenya.

Documented sera from 156 patients admitted to Alupe Sleeping Sickness Hospital in Western Kenya were tested to determine the potential usefulness of Procclic Agglutination Trypanosomiasis Test (PATT) for the diagnosis of Trypanosoma brucei rhodesiense African sleeping sickness. A total of 490 serum samples were tested, including 42 controls. Anti-trypanosome antibodies were detected in 99% of the sera taken prior to trypanocidal drug therapy. Antibody levels remained high during course of treatment. In cured cases antibodies declined to negative or low levels 4 months to one year after treatment. High antibody levels persisted in patients who relapsed. Although the results showed a high sensitivity and specificity, confirming the potential usefulness of the test for serodiagnosis of African sleeping sickness, PATT, in its present form is unsuitable for routine diagnosis. This is due to difficulties inherent in the use of live trypanosomes as detector antigen.

The daily activity pattern and feeding habits of glossina longipenis cort (diptera; glossinidie) at Galana Ranch; South-Eastern Kenya

Sampling of Glossina lognipennis Corti for 24 hours using baited F-3 traps; mobile and stationary electric screens; stationary ox and ox-fly round showed two main activity peaks at dawn and dusk. The evening peak was more pronounced than the morning one. Very little activity was recorded during the rest of the day. An incompete ring of electric screens arranged round a cattle enclosure showed that G. longipennis is attracted to; and feeds on cattle; especially during peak activity times with a feeeding success of about 7. The number of flies caught on the outside and inside of the elctric screens was significantly different at the 5 level. Analysis of blood meal samples from fed flies indicated a wide diversity of host for G. longipennis with a preference to suids. Over 65 of the total identified blood meal samples were from suids of which 60 alone were from bushpig; while bovines other than buffalo; collected in an area where cattle are kept; provided only 7 of the feeds

Circurating trypanosomal antigen levels in sleeping sickness patients under going treatment at Alupe

Sera from 99 sleeping sickness patients admitted to Alupe Hospital were analyzed for circulating trypanosomal antigens using a sandwich antigen-trapping enzyme immunosorbent assay. Trypanosomal antigens were detected in 83 (84) of the patients. Post-treatment antigen profile in 67 patients showed five distinct patterns: in 48 of the patients antigen levels remained elevated thoughout; in 31 of the patients antigens dropped to the; negative value; and became elevated afterward; in 6.0 of the patients antigen levels were negative initially; but became elevated later; in 7.5 of the patients antigen levels remained below the negative value thoughout. The significance of these observations in the clinical management of sleeping sickness is discussed

Infectious bovine rhinotracheitis-infectious pustular vulvovaginitis viral isolates from cattle with epididymitis and vaginitis.

Infectious bovine rhinotracheitis-infectious pustular vulvovaginitis (IBR-IPV) viral isolates were obtained from cattle affected with epididymitis-vaginitis. Isolation of virus from the diseased animals indicated that the genital form of IBR-IPV virus infection exists in Kenya and that epididymitis-vaginitis may be associated with IBR-IPV virus. Serums prepared from cattle having the genital form of the disease did not always have detectable antibody titers.