HEMOLYTIC COMPLEMENT AND CLASS-SPECIFIC ANTIBODY-LEVELS IN GOATS DURING INFECTION WITH TRYPANOSOMA-EVANSI AND AFTER TREATMENT WITH DIMINAZENE ACETURATE
W. Olahomukani et al., HEMOLYTIC COMPLEMENT AND CLASS-SPECIFIC ANTIBODY-LEVELS IN GOATS DURING INFECTION WITH TRYPANOSOMA-EVANSI AND AFTER TREATMENT WITH DIMINAZENE ACETURATE, Small ruminant research, 22(3), 1996, pp. 241-247
Following infection with Trypanosoma evansi, goats mounted a strong cl
ass-specific antibody response, characterized by elevation of IgM and
IgG antibody levels. Concomitant with the rising antibody levels and p
arasitaemia, was a drop (P < 0.0001) in the total haemolytic complemen
t. These changes were accompanied by pyrexia (> 39 degrees C), slight
dyspnoea, and fall in haematocrit levels (P < 0.01), Clinical examinat
ion revealed evidence of muscle wasting, lethargy and paleness of muco
us membranes, Post-mortem examination carried out on one goat showed e
nlargement of lymph nodes, spleen and liver and oedema of the lungs an
d kidneys and a flabby heart. There was accumulation of sere-sanguineo
us fluid in the peritoneal, thoracic and pleural cavities and petechia
l haemorrhages on the serosa, pleura and intestinal mucosae. The brain
was oedematous and showed evidence of congestion and meningeal petech
iation. Cerebrospinal fluid (CSF) taken from infected goats did not sh
ow changes suggestive of any central nervous system (CNS) invasion by
the parasites. Following treatment with diminazene aceturate, and the
disappearance of parasites from the blood, the haematocrit status and
haemolytic complement levels recovered by the 4th week. There was a ra
pid fall in the IgM-specific antibodies to near pre-infection levels.
However, IgG-specific antibody levels were still elevated by the end o
f the study. The study shows that infection with this parasite may sig
nificantly affect goat production, because it causes changes which may
lead to immunosuppression and organ failure. With the exception of Ig
G class-specific antibodies, these changes are quickly reversed by che
motherapeutic intervention, Levels of IgM and IgG class-specific antib
odies may be a suitable indicator of the exposure status of goats to t
his parasite because the former fall rapidly after treatment or cure,
while the latter may persist for long periods.