Published Date: 2004-09-11 23:50:00
Subject: PRO/AH> Leptospirosis, human, canine - USA (TX)(03)
Archive Number: 20040911.2527
LEPTOSPIROSIS, HUMAN, CANINE - USA (TEXAS)(03)
A ProMED-mail post
PrOMED-mail, a program of the
International Society for Infectious Diseases
Date: 11 Sep 2004
From: Peggy Carter, DVM <PeggyCarter@ln.amedd.army.mil>
My previous entry was my 1st to ProMED. What an interesting
experience; I did not expect so much media interest. Hopefully the
update below will answer any remaining questions.
The ongoing epidemiologic investigation may clarify the source of the
leptospirosis, but it seems unlikely that the disease was brought in
from an exotic location. This area of Texas has an abundant small
mammal population and has recently had unusual quantities of rain.
The military dogs are housed in fenced enclosures away from routine
traffic, but because the dog kennels have outdoor access, it is
possible that small mammals might gain entry.
It has been a long-standing DoD [Department of Defense] veterinary
policy that all military working dogs (MWD) be annually vaccinated
against leptospirosis, but with the specific vaccine choice left to
the attending military veterinarian based on local circumstance.
Thus the MWD population as a whole has variability in vaccination
status as regards serovars.
The dogs that became ill had been most recently vaccinated with a
multivalent vaccine that included inactivated _L. canicola_ and _L.
Regarding the information previo
usly reported here, the 1st dog presented with significant renal disease in
early August 2004. Due to his failure to respond to aggressive medical
therapy and his advanced age, the dog was euthanized. On necropsy, the
pathologist found moderate to severe oxalate crystals and a leptospirosis
titer of 1:800 against pomona. The veterinarians at the DoD MWD Services were
considering toxicosis and infectious disease as differential diagnoses (even
though toxins are very unlikely, since the dogs are so closely monitored).
During the last week of August 2004, 2 dogs presented with apparently
acute renal failure in quick succession. This cluster of symptoms,
unusual in military working dogs, caused the clinicians to look at
infectious disease, specifically leptospirosis, as a primary
The dog handlers came down with their flu symptoms during the same
week. The 2nd dog had titers to _L. grippotyphosa_ - 1:51 200, _L.
pomona_ - 1:25 600 and _L. bratislava_ - 1:12 800; and the urine from
the 3rd dog was taken to the DoD Food Analysis and Diagnostic Lab
(FADL), where they found leptospira organisms via dark field
microscopy. I incorrectly reported that FADL had done the
preliminary titers; the titers were run at a private lab, but
afterwards FADL confirmed the result with positive microscopic
agglutination tests (MAT) in the 2nd dog as well as a 4th dog. FADL
titer results on the 4th dog were bratislava - 1:3200; canicola -
1:400; grippotyphosa - 1:800; icterohaemorrhagiae -1:200; pomona -
1:400. Further lab work is pending.
The attending infectious disease physician said today that the class
of 11 student dog handlers and 3 dog handler instructors have been
evaluated for potential disease. Serum collected from 13 of these
subjects has been tested both by commercial IgM ELISA and MAT
performed at FADL and found to be negative. Serum was not collected
from one subject. Serum for repeat (convalescent) MAT will be
collected in 2-3 weeks.
My thanks to all who sent in comments and suggestions,
LTC Peggy Carter, DVM, MS
Director, Animal Medicine and Veterinary Operations
US Army Veterinary Command
[The clarification from Dr. Carter is appreciated. Overall, Texas has
had a milder summer and a bit more rain than usual, which has
prompted more small mammal activity. If small mammal contact is the
problem, then the base should consider trapping to remove the
animals. - Mod.TG]