[leish-l] Trypanosomatidae sp. "strain Eva"

[Jaclamothe at aol.com]

Ive sent a letter to a english veterinary rewiew (  The veterinary record) 
about the risks of the  use of meglumine antimoniate in canine leishmaniasis )

(I know that it is probably too late, but i had mentioned these facts in 
previous papers) 

Lamothe J   Use of meglumine antimoniate in canine leishmaniasis.Vet Rec. 
2004 Mar 20;154(12):378 
    
Regards 


SIR


Dogs are reservoirs of visceral leishmaniasis, a zoonosis caused bythe 
parasite Leishmania infantum. The annual incidence is estimated at
500,000 cases throughout more than 88 countries (Desjeux 1996).
Leishmaniasis is found in Latin America, the Mediterranean Basin and Asia.
The two important groups of humans infected are children under the age of
three years old and HIV infected adults.
The disease is transmitted from dogs to humans by sandflies. The treatment
for canine leishmaniasis is a combination of meglumine antimoniate and
allopurinol; after clinical cure maintenance treatment with allopurinol
alone is given for the rest of the dog¹s life. Widespread use of antimonials
can result in the selection of resistant strains; strains isolated from
treated dogs are from eight to 41 times more resistant than those isolated
from the same dog before treatment (Gramiccia 1992). and there is potential 
for
resistant strains to spread as a result of transmission between dogs.
It is also possible that resistant strains harboured by dogs might be
transmitted to humans by sandflies.Failures of antimonials in the treatment 
of human disease (adults or  children) have been reported for many years. In a 
study performed in the
south of France (Faraut-Gambarelli and others 1997), the susceptibility of
strains isolated from 11 non-immunocompromised children and 19 young adults
infected by HIV was measured before and after the treatment. Out of 20
patients tested before treatment, six patients had the susceptibility
modified, (the strain was more resistant to meglumine antimoniate) and four
of them relapsed. A study regarding the susceptibility of 43 human and
canine strains to meglumine antimoniate in Spain indicated similar results
to those obtained in the south of France (Carrio and others 2001).
Obviously, it is difficult to prove that those resistant strains come from
the canine reservoir, but it is also difficult to find another explanation
considering that dogs are the unique reservoir of visceral leishmaniasis.
In my view allopurinol alone should be the first line of treatment for dogs.
Almost all published studies report satisfactory results and the treatment
leads to 50 per cent of clinical cure after four months treatment and 80 per
cent after nine months. Long term studies have shown a 78 per cent chance of
survival for more than four years (Slappendal and others 1999).
I would question the justification for meglumine antimoniate use in dogs
when other drugs may have the same efficacy, even though the clinical cure
is obtained less quickly.
In France where this resistance problem has been found, and perhaps in other
countries where it is likely to be found, the risk of causing resistance in
human strains outweighs the convenience in using the drug in dogs.




References
Carrio, J., Riera, C., Gallego, M. &Portus, M. (2001) In vitro activity of
pentavalent antimony derivatives on promastigotes and intracellular
amastigotes of Leishmania infantum strains from humans and dogs in Spain.
Acta Tropica 79, 179-183Desjeux, P. (1996) Leishmaniasis. Public health 
aspects and control.Clinical Dermatology 14, 417-423
Faraut-Gambarelli, F., Piarroux, R., Deniau, M., Giusiano, B., Marty, P.,
Michel, G., Faugere, B. &Dumon, H. (1997) In vitro and in vivo resistance
of Leishmania infantum to meglumine antimoniate: a study of 37 strains
collected from patients with visceral leishmaniasis. Antimicrobial Agents
and Chemotherapy 41, 827-830
Slappendal, R. J. &Teske, E. (1999) A review of canine leishmaniasis
presenting outside endemic areas. In Canine Leishmaniasis: an Update.
Proceedings of a Canine Leishmaniasis Forum. Ed R. Killick-Kendrick.
Barcelona, Intervet. pp 54-59
Gramiccia, M., Gradoni, L., Orsini, S. (1992) Decreased sensitivity to 
meglumine antimoniate (Glucantime ®) of Leishmania infantum isolated from dogs after 
several courses of drug treatment. Annals of Tropical Medicine and 
Parasitology. 86, 613-20 




Dr Jacques Lamothe

Clinique veterinaire 

 1  rond point de la roya 
F 06510  CARROS 
(0)4 93 29 06 95

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