Rabies: once bitten...

Rabies is a serious and deadly disease. Here's what you should do if you are bitten by an animal on your travels

5 mins

I heard a distressing story recently – one that made me very cross with my medical colleagues. Fortunately, perhaps, I was brought in on the unfolding tale and was able to do a little to redress the shameful misinformation that had been dispensed to one unfortunate traveller.

Susanne went on a tour to take in the best wildlife spots in Madagascar. Now, Madagascar is a very civilised country but it does have problems. Travel is sometimes difficult because the roads are bad, and healthcare services are challenged by lack of money and resources. French medics and scientists have been involved in Madagascar for decades and have done a lot to collate information on the prevalences of various diseases. They have also supported development of local vaccine production, but healthcare – especially in remote regions – is patchy; medicines and supplies are often just not available.

Rabid lemurs?

Susanne was touring Madagascar with an experienced guide. Around the middle of the trip, when the group was a long way from the capital, Susanne was bitten on the forearm by a lemur; her skin was only just broken.

The lemur was a protective mother, carrying a baby and acting quite naturally, squabbling with troop-mates over who would get titbits from the tourists. Everyone realised, though, that rabies was a risk from even such a slight nip and for the rest of the trip Susanne, the group leader and everyone else agonised about the possibility of rabies.

Susanne returned home to Germany where she started receiving anti-rabies shots 18 days after being bitten. Her doctors told her that she’d left it much too late for protection to be certain.

I then got involved in a series of email consultations and I was horrified by the way Susanne’s doctors had failed to reassure her.

Susanne wrote: “Today I had my second injection and my – otherwise nice – doctor wasn’t very encouraging. She said that I will have to wait about three months before I can be 95% sure that I won’t get rabies. This wasn’t too great to hear. Yesterday – after a lot of searching – I got an additional, monster injection of rabies globulin, which cost €995! I insisted on getting this because I knew that if one starts late with injections, one should definitely add rabies-immune immunoglobulin. Well, another three – normal – shots and everything will have been done which can be done.

"As soon as I think about possible symptoms – like a lot of saliva production – my mouth fills with saliva. I will have to stop thinking like that! One thing to consider, though, is that my boyfriend is visiting next week and I was looking forward to a romantic reunion after my weeks away. But I definitely don’t want to infect him. So we shouldn’t kiss and we should use condoms.”

I started to assess the risk to Susanne. I wanted to come up with some reassuring information. The thing at the front of my mind was that in parts of Madagascar doctors still administer the less-than-safe and outdated Semple vaccine. It gives some protection and is considerably better than nothing if there are no other options, but for those – like Susanne – with the money and resources to get something better it is not a wise option.

Semple vaccine is a 5% suspension of animal brains given, painfully, into the abdomen on 21 consecutive days, followed by booster doses. Serious reactions to it happen as frequently as one in 76 courses (with 41% of those having a reaction to the vaccine dying), and its efficacy is poor. I have heard of people in Nepal receiving Semple vaccine after being bitten by dogs and dying of rabies anyway. There is also HIV/AIDS on Madagascar, so any treatment involving injections could carry an HIV – and also hepatitis B – risk.

Assessing the actual risk

I then tried to find out whether anyone has found the rabies virus in wild lemurs. It is often difficult to find reliable information on issues relating to travel health because nasty things that happen to travellers in remote places may not be recorded at all, or there may be no proper diagnosis ever made. But there is some information.

Studies by scientists at the Institut Pasteur de Madagascar found plenty of rabies in dogs – and there are tens of deaths on the Great Red Island each year after rabid dog bites – but there didn’t seem to be any evidence that lemurs are commonly infected. And Susanne’s lemur was in a nature reserve where dogs – which might infect a lemur – would be unlikely to stray. The lemur may not have been rabid, then, but if it was, what would have been the risk of the virus entering Susanne’s nerves?

A rare but gruesome plague of vampire bats swept through a Brazilian village in 1991; 314 people were bitten and three died of rabies. Brazil is in a region where rabies is very common – in vampire bats as well as in dogs. And a consideration in that instance is that bats feed in a messy way that promotes transmission of the rabies virus. Even during this ‘plague’, however, 97% of people bitten avoided contracting rabies and survived. It seemed to me that the chances of Susanne having been infected were minuscule.

How dangerous is rabies?

It is difficult to give 100% water-tight advice but it is important to be clear that once symptoms of rabies appear it is an incurable, invariably fatal disease, and the mode of death is unspeakably horrible. The incubation period between the bite and the onset of symptoms depends on the distance of the bite from the brain and the severity of the bite.

Generally the incubation interval is between two and eight weeks, but it can be a little as four days and as much as a year. Those who die quickly are usually toddlers who are savagely bitten on the face. People nipped on a finger-tip die in about six weeks. The virus travels along the nerves and only causes encephalitis and hydrophobia when it arrives at the brain. At this point there is no treatment that will save the victim.

The advice still stands that anyone bitten by a mammal in a country where rabies exists – and that includes most of the world outside the British Isles and Australia – should get the post-bite jabs as soon as possible. Equally, the risks of receiving treatment in a less well-resourced clinic must also be weighed up.

In retrospect we can see that this particular traveller would have spent less money by getting immunised against rabies before her trip, but she’d been bewildered before departure by different advice from different clinics. Personally, I advocate immunisation for anyone going on extended trips in the developing world – if only for peace of mind. 

What else could have been done?

In the bad old days when Semple vaccine was all that doctors could give after a bite, the advice that used to be given was to catch the animal that had bitten and tie it up – if it was still alive after ten days then it could not have been rabid. I can’t imagine any traveller being able to arrange this and, even if they could, wouldn’t that action risk further bites from a potentially rabid beast?

After any rabies-prone bite, effective first-aid treatment can be given, although this has to be done vigorously and rather brutally. The wound needs to be washed under running water – under a running tap or poured from a water bottle. Use plenty of soap and, if possible, the wound should be scrubbed, too. The cleaning process should last five minutes and should be timed with a watch.

Thereafter the wound can be flooded with whisky, gin, rum or any strong antiseptic fluid. It then needs to be covered and dressed by a doctor as soon as possible. It shouldn’t be sutured. Such a bite will be prone to tetanus, so the victim needs protection against that serious infection too – more injections.

After an accidental animal bite it is advisable to make enquiries about the local medical services. In most countries it is likely that there will be a reliable clinic in the capital city where safe anti-rabies vaccine may be available. Embassies, expatriates and sometimes big international hotels should be able to offer information on local health facilities. The client’s medical insurance – if it is underwritten by a reliable insurer – will have a 24-hour advice line and information on the nearest reliable clinics and hospitals. 

The moral

The moral of this tale is this: if you are going on a trip of more than a couple of weeks, and which takes you into remote parts of a developing country, getting pre-trip immunisation against rabies would be wise.

Dog bites are the commonest route of infection worldwide. African game reserves are home to canny vervet monkeys which, like the lemurs of Madagascar, are greedy and have learned not to fear man. The temples of India and Nepal are also populated by cheeky rhesus monkeys. All of these primates bite quite often and can carry rabies; in the Indian subcontinent people are often bitten by monkeys or dogs. Anyone entering a cave in the Americas should also be covered against rabies, and intrepid kids should be protected too.

Susanne, by the way, remains well.

Dr Jane Wilson-Howarth is the author of the health chapter in the Bradt guidebook to 'Madagascar'. She has also written 'Lemurs of the Lost World' (Impact Traveller’s Tales), a travel narrative about Madagascar

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