The New York Times - A Coffin for Rabies

January 16, 2008

Blog post on rabies (mostly refers to Africa) by Olivia Judson in

The New York Times

if you want to read it and the comments (43 so far), here's the link:

http://judson.blogs.nytimes.com/2008/01/15/a-coffin-for-

rabies/#comments

(you have to register to view it)

January 15, 2008, 6:59 pm

A Coffin for Rabies

On June 26, 2007, a dog walked into Lupiro, a small village in

southern Tanzania. It bit eight people and 11 other dogs before

anyone managed to kill it. It had rabies or, as the French call it,

la rage.

Neither of the nearby hospitals had any vaccine. The closest place

with a supply was a private clinic in Dar es Salaam — a 9-hour drive

away. The clinic had enough for a full course — five doses — of

vaccine for two people, or a single dose for each person. It would

be $40 per dose. In Tanzania, the average income per person is just

$340 a year, and Lupiro is in one of the poorest regions.

Exposure to rabies requires immediate treatment: the first dose of

vaccine should be taken the day you are bitten; every hour counts.

Full treatment requires the four remaining doses to be taken, on a

schedule, over the course of the month. In addition, if it's

available, rabies immunoglobulin — antibodies that can attack the

virus at once — should be injected at the wound. For although not

all bites from a rabid animal lead to infection, you won't know if

you've been infected or not. If you have been, and you do not get

treatment, you will die: rabies is fatal. And it is a horrible death.

The virus that causes the disease is spread by the saliva of

infected animals. On arriving in a new victim, it travels through

the nerves to the spinal cord and up into the brain, where it

multiplies rapidly before spreading to other parts of the body,

including the salivary glands. The time between being bitten and

developing disease can vary from a few days to months or,

occasionally, years. Depending on which part of the brain the virus

ravages, the disease can take different forms, but the most common

is known as furious rabies. This will kill you within a week of

symptoms beginning to appear.

Often the first symptom is itching around the site of the bite.

Sometimes, it's an itching so intense that people will tear open

their own skin as they scratch. The victim becomes afraid of water,

to the point where drinking becomes impossible, no matter how great

the thirst: the sight of a glass of water will induce spasms of

terror so severe that the victim will hurl the glass away and may

retch so violently as to tear the lining of the throat. The vocal

cords become paralyzed, distorting the voice. Saliva may become

thick and heavy. And then comes the madness.

" At the peak of excitement, the patient's whole nervous system seems

to be aroused. He is in a state of extreme agitation and has

frightening hallucinations. His face is a mask of terror. He shouts

incomprehensibly at the top of his distorted voice. His body is

racked with tremors or spasms. He may struggle frantically and

powerfully to free himself from constraints and try to escape from

the room. "

Episodes of madness continue until the victim falls into a coma;

this is followed by paralysis and death. Sometimes the madness

includes ferocious, biting, attacks on anyone nearby. Sometimes it

includes a sexual frenzy and attempted rape.

If you arrived in a Western hospital with symptoms of rabies, you'd

be sedated until you died. In poor countries, where hospitals are

scarce and sedatives scarcer, often nothing can be done, and the

victim may be locked into a room, alone, to die. Usually, the

victims are children.

In Lupiro, in June, the eight survived. A group of western

scientists, working on malaria at a research station in the nearby

town of Ifakara, heard about the problem and stumped up the money,

which otherwise would have been prohibitive. The available doses of

the vaccine were packed on ice and sent down from Dar es Salaam in a

truck; each person was given one. This gave enough time to find a

source for the remaining doses. But that day signaled the start of a

rabies epidemic among the local dogs, and since then around 80

people have been bitten; so far nine have died.

Each year, the disease kills about 55,000 people — that's 150 a day —

almost all of them in the poorest parts of Africa and Asia, and

more than 7 million people receive post-exposure treatment after

being bitten by a rabid animal. Treatment is not just expensive, but

time-consuming: a full course of vaccination requires five visits to

a hospital or health clinic during one month. Which, if you live in

rural Africa, can mean many hours of travel and time not working.

Indeed, the global economic cost of rabies is estimated to be more

than $583 million. And that doesn't count the trauma that deaths

from rabies inflict on families and communities. For though rabies

kills many fewer people than malaria, it causes far, far more fear.

And here's the most shocking thing about rabies: all the deaths

could be prevented. Rabies could be eliminated in as little as five

years. We have the knowledge and the tools. All that lacks is the

will.

The virus can infect a variety of mammals, including bats, raccoons,

skunks, foxes and mongooses. But by far the most important source of

human rabies is the domestic dog. (This is why children are so often

the victims: being small, they are more likely to be bitten on the

head or the neck, and such bites carry the biggest risk of

infection.) To eliminate the disease from humans, therefore, it

needs to be eliminated from dogs. And the way to do that is through

dog vaccination. (At first, it may seem perverse to vaccinate dogs

rather than humans, given that it's humans we want to protect. But

because rabies is spread by dogs, not people, we can't break the

chain of transmission unless we vaccinate the animals that spread

it.)

The crucial factor in predicting the spread of an infectious disease

is a quantity known as the basic reproductive number, or R0.

Technically defined as the average number of infections one sick

individual will cause if everyone else is susceptible, it's a

measure of how easily a disease spreads. If R0 is smaller than one,

the disease can't get going. The bigger R0, the more difficult the

disease is to control.

For rabies in dogs, current estimates put R0 at less than two. This

is good news. With such a small R0, the proportion of dogs you need

to vaccinate is only 70 percent. We know dog vaccination on this

scale is feasible: programs in Kenya, Tanzania and Chad have shown

that high levels of cover can reliably be reached. Moreover, it

works. After two big vaccination campaigns in the northwest of

Tanzania, for instance, dog rabies fell by 97 percent, and 90

percent fewer people were being bitten.

And vaccinating dogs is cheap. The vaccine costs about $1.50 per

animal, and that includes the cost of delivering it. A country like

Tanzania has around 5 million domestic dogs. To vaccinate 70 percent

of them for one year would cost less than $6 million. That is a lot

for governments in poor countries, but very little for us in the

west. Better yet, since rabies carries such a large economic cost, a

dog vaccination program would soon begin to pay for itself: as

exposure to rabies falls, so does the demand for treatment, and thus

the expense of handing it out. On the other hand, doing nothing will

actually make the current problem worse. In countries such as

Tanzania, the dog population is growing fast. If the dogs are left

unvaccinated, more dogs means more people will be exposed to rabies.

Is it possible to send rabies the way of smallpox, and drive it from

the face of the Earth? Probably not. Rabies can lurk in too many

different species. However, it is eminently feasible to eradicate it

from dogs, and thus drive the number of human cases close to zero.

In principle — if we were super-organized — we could do this with

one huge and coordinated dog vaccination campaign. More

realistically, however, a concerted effort would take four or five

years to do the job. Would vaccination programs need to be

maintained indefinitely? Not necessarily. That depends on whether

the disease is likely to be reintroduced to dogs from another

species. And in most parts of Africa, for example, it isn't: the

disease spreads from dogs to other kinds of wildlife, not the other

way around.

So many of the problems we face are huge and hard to solve — climate

change, malaria, war in the Middle East, destruction of the rain

forests. Rabies is not on that list. To deal with it is just a

matter of logistics and money. We should act. Now.

NOTES:

The account of the epidemic in Lupiro was communicated to me by

telephone and e-mail by Dr. Heather Ferguson, at the University of

Glasgow.

I took the average per capita annual income of Tanzania from the

World Bank's Web site ($340 was the GNI per capita in 2005).

The description of rabies symptoms comes from Kaplan, C., Turner,

G.S., and Warrell, D. A. 1986. " Rabies: The Facts. " Second edition.

Oxford University Press. The quotation describing the madness

appears on page 38. I also follow their account of how the virus

travels through the body, which is given on pages 31-32.

For the treatment of rabies, see pages 965-966 of Warrell, M. J. and

Warrell, D. A. 2004. Rabies and other lyssavirus diseases. " The

Lancet " 363: 959-969.

For the number of people killed by rabies each year, for the number

of people receiving treatment, and for the global cost of rabies,

see Knobel, D. L., Cleaveland, S., Coleman, P. G., Fèvre, E. M.,

Meltzer, M. I., Miranda, M. E. G., Shaw, A., Zinsstag, J., and

Meslin, F.-X. 2005. " Re-evaluating the burden of rabies in Africa

and Asia. " " Bulletin of the World Health Organization " 83: 360-368.

The R0 of rabies in dogs was communicated to me by Dr. Katie Hampson

at the University of Sheffield.

For dog vaccination successfully reducing the incidence of rabies in

Tanzania, see Cleaveland, S., Kaare, M., Tiringa, P., Mlengeya, T.,

Barrat, J. 2003. A dog rabies vaccination campaign in rural Africa:

impact on the incidence of dog rabies and human dog-bite injuries.

Vaccine 21: 1965-1973. For a more general account of how dog

vaccination has been successful in eliminating rabies from many

parts of the world, see the first table in the supplementary

information to: Hampson, K., Dushoff, J., Bingham, J., Brückner, G.,

Ali, Y. H., and Dobson, A. 2007. Synchronous cycles of domestic dog

rabies in sub-Saharan Africa and the impact of control

efforts. " Proceedings of the National Academy of Sciences USA " 104:

7717-7722.

For the cost of dog vaccination programmes, see (1) Kayali, U.,

Mindekem, R., Hutton, G., Ndoutamia, A. G., Zinsstag, J. 2006. Cost-

description of a pilot parenteral vaccination campaign against

rabies in dogs in N'Djaména, Chad. " Tropical Medicine and

International Health " 11: 1058-1065, and (2) Cleaveland, S.,

Hampson, K., Kaare, M. 2007. Living with rabies in Africa. " The

Veterinary Record " 161: 293-294.

January 18, 2008

Thu, 17 Jan 2008 17:44:47 -0800 (PST)

" Prof. Henry Wilde " <wildehenry

Re: The New York Times - A Coffin for Rabies

Merritt Clifton <anmlpepl,

Supaporn Wacharapluesadoo <spwa,

Thiravat Hemachudha <fmedthm, fonn_rainy

Greetings from Bangkok:

Thanks for sending us this good report. It might

have also mentioned the fact that you can reduce

the cost of rabies vaccine by using the WHO

approved Thai Red Cross Intradermal postexposure

schedule. See the attached literature. It can do

so by up to 75%. I introduced this schedule to

the Flores, Indonesia outbreak with WHO help.

Best wishes, Henry

Henry Wilde, MD, FACP

Professor of Medicine

Division of Research Affairs

Faculty of Medicine

Chulalongkorn University

Rama IV Road, Bangkok, Thailand 10330

<wildehenry

Merritt Clifton <anmlpepl wrote: