Bartonella DNA in Dog Saliva
These data, in conjunction with previous case reports (3–5), suggest that potentially viable Bartonella organisms may be transmitted to humans after a dog bite. The detection of DNA by PCR does not necessarily indicate the viability of Bartonella organisms. However, due to the extremely slow growth characteristics of Bartonella spp., isolation from the oral cavity does not seem feasible, because of competition with numerous other rapidly growing oral bacterial species. Recently, Bartonella DNA has been amplified from peripheral lymph nodes of healthy dogs (14). B. henselae was also amplified from salivary gland tissues from a dog with saladenitis (15). There are several plausible routes by which a Bartonella sp. could gain entry to the oral cavity. Future studies should determine if the tonsilar lymphoid tissues, salivary glands, or periodontal, gingival, or other oral tissues can serve as sources of Bartonella spp. contamination of canine saliva. As Bartonella infection may represent an occupational risk for veterinary professionals and others with extensive animal contact (6), additional studies should address the risk of transmission from dogs to humans following bite wounds.
Oral shedding of Bartonella in cats: correlation with bacteremia and seropositivity
Cats are the main reservoirs of zoonotic Bartonella henselae, B. clarridgeiae and B. koehlerae, transmitted among cats by cat fleas. No study has investigated the presence of Bartonella in the saliva of bacteremic and non-bacteremic cats to correlate it to the level of bacteremia and the presence or absence of oral lesions. Shelter cats from northern California (n=130) and Michigan (n=50) were tested for Bartonella bacteremia by blood culture, presence of Bartonella antibodies and Bartonella DNA in oral swabs. Bacteremia was detected in 45 (25%) cats, mainly from northern California (n=40), which were highly flea infested and were 4 times more likely to be bacteremic than the non-flea-infested cats from Michigan. Overall, 69 (38.3%) cats had Bartonella PCR positive oral swabs. Bacteremic cats were almost 3 times (P=0.003) more likely to have PCR positive oral swabs (59%, 26/44) than non-bacteremic cats (32.5%, 44/135). However, there was no correlation between cats being bacteremic and having oral lesions. Antibody prevalences for B. henselae and B. clarridgeiae were 30% and 42.8%. B. henselae and B. clarridgeiae seropositive cats were almost 4 times (P=0.0001) and 3 times (P=0.003) more likely to have oral lesions than seronegative cats. Despite a higher prevalence (odds ratio=1.73; 95% confidence interval=0.88-3.38) of oral lesions in cats with oral swabs testing PCR positive, no statistical association could be demonstrated in this cat population.
Bartonella can survive in the feces of fleas and lice, supposedly they can be viable up to a year. Rickettsia has been proven to spread by inhalation of dried fecal dust.
Right on, acarined! Exactly.
You all might want to consider how transmissible and viable Brucella is and how closely Bartonella is related to it. Consider also they both are aerobic and need oxygen, so just because they are exposed to oxygen or are outside a living animal, this will not necessarily kill them. UV light from the sun may, but they are very hardy, and yes, they are known to survive for months outside a host. Brucella is infective through the air and has been used in biowarfare attacks, particularly in WWII.
As long as you have flea feces in the dust in your home, potentially any scratch could cause infection with Bartonella. I don't know how many Bartonella organisms it typically takes to cause infection, but minimum infectious exposure is 10-100 organisms for Brucella.