As we've discussed previously, rabies has been a big problem in Bali since 2008. Previously rabies-free, this densely populated island has been struggling with a large and persistent canine rabies outbreak that has resulted in numerous deaths and much debate about control measures.
- Dog bites are very common on the island, with a daily average of nearly 100 bites reported over the study period. Since many bites don't get reported, even this large number is an underestimate.
- The average age of affected people was 36 years, with a range of 3-84 years. All 104 died.
- Most of the cases (57%) were male. This is common, although whether it is because men are more likely to be bitten (because of greater exposure or greater provocation) or less likely to seek medical care after a bite is not known.
- There was a history of a dog bite in 96/104 infected people. It's likely a bite occurred for the others as well, but in those cases the patient was unconscious at the time rabies was suspected and family members did not know of any bites.
- The incubation period ranged from 12 day to 2 years. It was less than 1 year in 98% of cases. Very short incubation periods, like the 12 day one reported here, are almost always associated with bites to the head or neck, since it's a shorter distance for the virus to travel up nerves to the brain.
- Early signs of disease are often vague. Pain or numbness at the location of the bite (37%), nausea or vomiting (30%), fever (22%), aches (17%), headache (16%) and insomnia (7%) were most common.
- 81% of people that developed rabies did not undergo any type of treatment. 11% washed the wound themselves. Only 6% went to the hospital on the day of the bite. The people who went to the hospital received a course of rabies vaccines but did not receive rabies immunoglobulin (RIG, which is anti-rabies antibodies). So, while they were treated, they didn't get the full recommended treatment. This is incredibly frustrating since rabies is almost 100% preventable if people get proper medical care. Failure of most of these cases to even seek care is a huge issue, and inadequate treatment of people who sought medical care compounds the problem. Not all of the vaccinated people completed the full vaccine course before developing signs of rabies. These were individuals who had short incubation periods because of bites to the head and neck.
These results are not surprising but demonstrate a few important concepts, including:
- the need for education of the general public to seek medical care after a bite.
- the need for proper education of healthcare providers so that people who are bitten get proper medical care.
- the need for adequate supplies of rabies vaccine and immunoglobulin. It wasn't stated whether people didn't receive RIG because it wasn't offered or (as is common in some regions) it wasn't available.
- rabies may not be considered initially when signs first start appearing, as many of these people ended up being treated for various other potential problems before rabies was considered. While rabies is almost always fatal, there have been very few "successfully" treated individuals (meaning they didn't die, but they can still have long-term neurological impairment), but to have any chance at success, treatment needs to be administered as quickly as possible.
- control of canine rabies is a key part of controlling human rabies.