Case 1: A veterinary technician was infected through contact of broken skin with saliva. The man had scratched skin on his hand, which he put in the mouth of a rabid cow during a procedure. This situation brings to mind several important points:
- All veterinary personnel in rabies endemic areas should be vaccinated against rabies. I don’t know about rabies vaccine supply issues in Iran, and that might be a limiting factor, but there are still too many unprotected veterinary personnel in most countries.
- This person seemed to have known that rabies was suspected in the cow, but apparently didn’t consider this kind of contact to constitute exposure, so he didn’t seek treatment. Once he started to get sick, he actually suspected rabies well before his physicians, so he obviously was well informed about the disease.
- There is a need to consider rabies when evaluating any animal, to use proper barriers (e.g. gloves) when handling rabies suspects, to test for rabies when there is any chance an animal has died of the disease, and to get post-exposure treatment if there has been a potential exposure to the virus. These steps aren’t always straightforward, especially since signs of rabies in cattle can be quite variable.
Cases 2-4: There were three members of the same family tending a herd of sheep and one of the sheep was attacked by a rabid wolf. The three individuals were believed to have been exposed while tending to the sheep, since their hands were scratched in the process and it was thought that rabies virus-laden saliva still on the sheep’s wounds got into those scratches.
- This one surprises me. It’s not a route of rabies exposure we typically consider, since rabies virus is quite labile (i.e. rabies virus does not survive long once it’s exposed to the environment, even on the outside surface of a wound). I guess it makes sense if the three individuals were scratched and exposed to saliva right after the attack. I don’t think this indicates broad risk to people who take care of animals that have been attacked, but it’s something to think about when dealing with an animal that has just been attacked. It’s another reason that we should be wearing gloves when handing open wounds (typically, gloves are recommended to protect the individual with the wound, but it goes both ways) and take care to perform proper hand hygiene. However, both of these are hard to do while tending a flock of sheep in rural Iran.
Case 5-6: These individuals were infected through corneal transplants from the same donor. The donor was reported to have died from "food poisoning," although undiagnosed rabies must have been the true cause (unless you have the very unlikely situation that the person was infected but coincidentally died of food poisoning just before signs of rabies developed).
- Corneal transplants have been associated with transmission of various diseases, and transplant-associated infections of many kinds have caused many deaths. That’s why there are strict protocols for screening donors, both in terms of what they died of and what testing is required. I’m surprised they’d use tissues from someone who died with an inexact diagnosis such as "food poisoning," especially since that can have an infectious cause.
Overall, these non-bite associated cases account for a small minority of human rabies cases that occur every year, but unusual routes of exposure need to be considered in any case.