Marina was tidying up the garden at dusk when she felt something lightly touch her arm. It was a bat, which fell to the ground shortly afterwards and began to thrash about. She saw no bite mark or scratch, just that quick touch. Uncertain, she sought medical care the same day and was advised to begin the rabies vaccination schedule. She was surprised: "but it didn't even bite me". The answer is precisely the central point of this text.

"The data and clinical case cited in this article are fictitious and are merely illustrative, serving to facilitate understanding of the topic addressed."

Why the bat is a special case

With dogs and cats, the risk of rabies is usually linked to a bite, scratch, or contact of saliva with broken skin or mucous membrane. With the bat, however, guidance in Brazil is more cautious: any direct contact with the animal, even without visible skin injury, is considered an exposure that indicates the start of prophylaxis. This happens because a bat bite can be small, superficial and go unnoticed, and because there is no well-defined incubation period for this animal as there is for other species. For this reason, touching a bat, even if it seems like harmless contact, is already reason to seek medical evaluation as soon as possible.

Bite or scratch: here the type of animal changes everything

When the contact is a bite or scratch, the conduct depends on which animal caused the injury:

Dog or cat with owner, healthy and able to be observed for 10 days: in these cases, it is often possible to observe the animal instead of vaccinating immediately. If it remains healthy at the end of this period, the risk of rabies is considered ruled out. If the animal becomes ill, dies or disappears during observation, vaccination is started without delay.

Dog or cat without owner, showing signs of illness, or that cannot be observed: prophylaxis is usually started immediately, without waiting the 10 days.

Wild animals (bats, monkeys, foxes and others) or production animals such as cattle and horses in areas at risk: as it is not possible to safely observe these animals, the general guidance is to start vaccination at the first evaluation.

In addition to the type of animal, the health professional assesses the severity of the wound (location, depth, number of lesions) to decide whether, in addition to the vaccine, it is necessary to add rabies antiserum or immunoglobulin, reinforcement indicated in the most severe cases.

The symptoms when rabies establishes itself in a person

Rabies has a highly variable incubation period, ranging from days to years, but averaging around 45 days in humans, and may be shorter in children. Before any more obvious sign, an initial non-specific phase appears, with malaise, low-grade fever, headache, loss of appetite and, often, tingling or altered sensitivity near the bite site. After this phase, the disease progresses to more serious neurological conditions, which may include agitation, confusion, spasms and, in some cases, progressive paralysis. It is a disease with severe progression, and it is precisely for this reason that prevention before symptoms appear is so important.

Warning signs in the animal

It is also worth knowing how to recognise possible signs in dogs and cats: sudden change in behaviour (a docile animal that becomes aggressive, or an active animal that becomes very quiet and hides), difficulty swallowing, excessive salivation, barking with altered sound, lack of motor coordination and, in more advanced stages, paralysis. In the case of bats, the animal may show no sign at all, which reinforces why any direct contact with them should already be evaluated.

What to take from this text

If contact was with a bat, even without visible bite, seek medical care to assess the vaccine. If it was a bite or scratch from another animal, the type of animal, its apparent health and the possibility of observation will guide the conduct. When in doubt, the safest thing is always to seek medical evaluation quickly: early initiation of prophylaxis is what guarantees protection.

This content is informative in nature and does not replace medical consultation. In case of contact or animal bite, seek medical care as soon as possible for individualised evaluation.

Dr. Rebeca Soares Andrade CRM - GO 39335