Not vaccinating beyond rabies hot zone leads to more human rabies deaths on Bali

From ANIMAL PEOPLE, September 2009:

TABANAN, Bali–The rabies situation on
Bali “remains dire,” assessed International
Society for Infectious Diseases ProMed forum
moderator Craig Pringle on September 15, 2009.
“Little progress appears to have been
achieved in containing the outbreak,” agreed
fellow ProMed moderator Tam Garland on September
18.
The most recent human victim, Ni Ketut
Sari, 47, died on September 14. “She got bit
by her own dog,” who “was suddenly destroying
her kitchen” on July 20, reported the Bali Post.
“She was rushed to the health clinic in Kediri
and got a tetanus shot,” but was not given
post-exposure rabies vaccination–apparently
because her home in Tabanan was outside the
radius of officially acknowledged rabies cases.
“According to her husband Ketut Sunarta,”
the Bali Post said, “a few weeks after being
bitten she was scared of water and wind, but was
always thirsty and shivered.”

On September 12, the Bali Post
continued, she “experienced drastic sweating
around her head, chest pains, and had difficulty
to breath. She was then taken to Tabanan
Hospital,” and received “two types of
medications,” but “was told to rest at home.”
Only on September 13, 24 hours before Sari died,
was her condition recognized as rabies.
Because Bali is a hub of tourism,
including by yachters who carry dogs aboard,
rabies experts are increasingly concerned that
Bali may become the point from which canine
rabies jumps to Australia and other Southeast
Asian islands which are now free of rabies.
Boat traffic is believed to have brought
a rabid dog to Bali from Java at some point in
early to mid-2008.
Human rabies deaths in Tabanan in July,
August, and early September 2009 demonstrated
that the Bali outbreak has now spread from the
Bukit peninsula, at the far south of the island,
to possibly the whole of Bali. Beween the Bukit
peninsula and Tabanan is Denpasar, the Bali
capital city.
“Bali is divided into eight regencies and
one city, Denpasar. Three of these– Badung,
Denpasar, and now Tabanan–must be considered
confirmed or probable rabies epidemic areas,”
warned Garland.
The “confirmed or probable” area now
covers the whole of the most densely populated
part of Bali.
The first known bite of a human by a
rabid dog came on September 6, 2008. That bite
and others leading to eight human fatalities
through March 2009 were all on the Bukit
peninsula. As the Bukit peninsula is almost
entirely cut off from the rest of Bali by the
Denpasar airport and access roads, a vigorous
vaccination program combined with halting all
transport of dogs from the peninsula could have
stopped the outbreak right there.
Instead, ineffective efforts were made
to massacre dogs in the afflicted areas before
any vaccination was done. The Bali government
enforced a policy in effect since 1926–since
Indonesia was under Dutch rule –against allowing
any dogs to be vaccinated outside of areas where
rabies was already officially recognized to
exist. Private dogcatchers continued to trap and
transport dogs from the Bukit peninsula and
nearby parts of Bali to dog meat restaurants on
the north coast.
The official response to the Tabanan deaths was little different.
“Officials have killed 320 stray dogs
and have ordered owned dogs to be chained inside
houses and to be vaccinated,” Bali animal
husbandry department chief Ida Bagus Alit told
the Bali Post on September 14, 2009. “At the
moment,” Alit said, “they have vaccinated 5,700
dogs from 10,000 available anti-rabies vaccines,
which are provided for Tabanan only. Nyoman
Sutedja, the head of the Bali health department,
has been in correspondence with the central
government to request more vaccines.
“In regards to closing the borders in
different regencies,” to curtail the possible
movement of infected dogs by meat traffickers,
Sutedja “strongly suggests to all head villagers
that that they should monitor animal transport
and have ports quarantine any incoming animals
from Java,” Alit summarized. “Local governments
with Animal Husbandry are accelerating mass
elimination of all stray dogs and stranded dogs,”
Alit said. “A stranded dog,” he defined, “is
an owned dog who is left wander around outside
with no food or care. There are many of these
dogs in Bali.”
The extermination campaign continued to
rely on distributing poisoned meat. The same
edition of the Bali Post that reported Alit’s
remarks mentioned that a 44-year-old man “was
taken to hospital this week after eating a spicy
Balinese-style pork sausage that had been covered
in poison to kill dogs. The victim was found
unconscious at his home in Banjar Dukuh,
Penebei.”
Exactly what poison was used was unclear.
Bali officials have repeatedly claimed to be
using strychnine, after rejecting the use of
injectible substances that would require workers
to have direct contact with dogs, but three
ProMed experts including cofounder Jack Woodall
agreed that the victim probably would not have
survived ingesting strychnine.
The spread of rabies on Bali both refuted
the most optimistic claims and underscored the
fears expressed in two papers presented at the
May 2009 Australian Veterinary Conference by
Helen Scott-Orr, director of an Australian
Centre for International Agricul-tural Research
aid project in Bali. Scott-Orr has advised the
Bali rabies control program, and arranged for it
to receive $100,000 in Australian aid funding,
she told Sarina Locke of the Australian
Broadcasting Corporation.
“About 42,000 dogs [were] vaccinated and
2,000 strays eliminated in the target area near
confirmed outbreaks by May 2009,” Scott-Orr and
Indonesian colleagues reported. “An intensive
program of rabies post-exposure prophylaxis of
people bitten by dogs was instituted,” which
“has so far prevented further human deaths,”
Scott-Orr stated before the most recent deaths
occurred, “but may be masking further spread of
the virus in dogs. Massive effort only achieved
an approximate 40% vaccination coverage of the
estimated total dog population in the target
area. This is well below the minimum 70% needed
to break the rabies virus transmission cycle.”

Counting dogs

Scott-Orr and colleagues guesstimated
that the present Bali dog population is about
700,000, more than twice the ANIMAL PEOPLE
estimate projected from local counts in various
parts of the island, done in September 2008.
Scott-Orr et al noted that the Bali dog
population was estimated at 220,000 by the World
Health Organization in 1984, but was said to be
875,000 by a local source; was said to be
125,000 by another local source in 1992, but was
projected to be 540,000 ten years later by the
Yudisthira Foundation; and was estimated at
425,000 by the Badung Livestock Service in early
2009.
Similar discrepancies have plagued the
rabies control program in Flores, the focus of
the other Scott-Orr paper presented to the
Australian Veterinary Conference.
“Rabies entered Flores in 1997 and
gradually spread east to the adjacent island of
Lembata and west throughout Flores island. It is
now endemic, with approximately 1,000
post-exposure prophylactic treatments and some
human deaths each year,” reported Scott-Orr and
colleagues. “A strategy of mass dog vaccination
with effective oral and injectible vaccines is
being developedŠThis mass vaccination would aim
to achieve at least 80% coverage of the dog
population across Flores and Lembata within a
period of one month. It would be repeated
annually for one or more years depending on
disease and population modeling, as well as the
results of intensive surveillance of subsequent
rabies incidence in humans and dogs, and of
vaccination coverage and immune response in the
dog population.”
Dogs “are eaten as a major source of
animal protein and are required for particular
ceremonies in different parts of the island,”
Scott-Orr et al wrote. “This leads to a lot of
dog trading between districts and the import of
dogs from other islandsŠDogs are also highly
valued as guards,” around houses and villages,
and “also to guard crops on steep mountainsides
from wild pigs and monkeys. As well, they are
used for hunting wild deer and pigs, and are
considered essential companions for fishers
undertaking long trips in small boats.”
Due largely to cultural resistance,
Scott-Orr et al concluded, “Rabies will not be
eradicated from Flores and Lembata in the
foreseeable future using the current tools of
injectible killed vaccines and dog elimination.”
Australian veterinarian Stephen Cutter in
an influential 2003 paper entitled Rabies & Dog
Ecology in Flores estimated that the Flores dog
population was about 600,000, or two dogs for
every human resident, when rabies arrived. This
would have been more than twice the ratio of dogs
to humans found in the U.S. and Costa Rica,
which have the highest documented ratios of dogs
to humans of any nations, and would have been
more than four times the highest ratio ever found
in Asia.
The Cutter number was derived from
interviewing residents about the numbers of dogs
kept by their households, rather than by
actually counting dogs.
Government officials during the first
four years of the rabies outbreak reported
killing 295,569 dogs. The Flores dog population
by 2002 was officially down to 127,482, rose to
169,035 in 2003, soared to 250,372 in 2005, and
was 203,478 in 2007. Throughout this time the
dogs to humans ratio has remained close to 1/12.
Taking into account the effects of the
four-year dog purge, the carrying capacity
implied by the post-2002 data, and the
reproduction rate of dogs, ANIMAL PEOPLE
projects that the actual Flores dog population in
1997 was probably 125,000 to 150,000, was not
more than 200,000, and was probably down to
about 57,000 in 2000, when the dog purge was at
peak intensity.
Using the Cutter estimate of the dog
population when rabies arrived has allowed
Indonesian officials to claim that killing dogs
had an effect in reducing rabies which could be
accurately attributed only to subsequent
vaccination efforts. The success of the
vaccination campaign, in contrast to the earlier
emphasis on killing dogs, was detailed in The
Rabies Epidemic on Flores Island, Indonesia,
2001-2003, by Caecelia Windiyaningsih, Henry
Wilde, Francois Meslin, et al.