Enrico Fabian for The New York Times
A man at the Yamuna River, an ideal breeding ground for mosquitoes. Filthy standing water abounds in New Delhi. More Photos »
By GARDINER HARRIS
Published: November 6, 2012
NEW DELHI — An epidemic of dengue fever in India is fostering a growing sense of alarm even as government officials here have publicly refused to acknowledge the scope of a problem that experts say is threatening hundreds of millions of people, not just in India but around the world.
India has become the focal point for a mosquito-borne plague that is sweeping the globe. Reported in just a handful of countries in the 1950s, dengue (pronounced DEN-gay) is now endemic in half the world’s nations.
“The
global dengue problem is far worse than most people know, and it keeps
getting worse,” said Dr. Raman Velayudhan, the World Health
Organization’s lead dengue coordinator.
The
tropical disease, though life-threatening for a tiny fraction of those
infected, can be extremely painful. Growing numbers of Western tourists
are returning from warm-weather vacations with the disease, which has
reached the shores of the United States and Europe. Last month, health
officials in Miami announced a case of locally acquired dengue
infection.
Here in
India’s capital, where areas of standing water contribute to the
epidemic’s growth, hospitals are overrun and feverish patients are
sharing beds and languishing in hallways. At Kalawati Saran Hospital, a
pediatric facility, a large crowd of relatives lay on mats and blankets
under the shade of a huge banyan tree outside the hospital entrance
recently.
Among
them was Neelam, who said her two grandchildren were deathly ill inside.
Eight-year-old Sneha got the disease first, followed by Tanya, 7, she
said. The girls’ parents treated them at home but then Sneha’s
temperature rose to 104 degrees, a rash spread across her legs and
shoulders, and her pain grew unbearable.
“Sneha has been given five liters of blood,” said Neelam, who has one name. “It is terrible.”
Officials
say that 30,002 people in India had been sickened with dengue fever
through October, a 59 percent jump from the 18,860 recorded for all of
2011. But the real number of Indians who get dengue fever annually is in
the millions, several experts said.
“I’d
conservatively estimate that there are 37 million dengue infections
occurring every year in India, and maybe 227,500 hospitalizations,” said
Dr. Scott Halstead, a tropical disease expert focused on dengue
research.
A senior Indian government health official, who agreed to speak
about the matter only on the condition of anonymity, acknowledged that
official figures represent a mere sliver of dengue’s actual toll. The
government only counts cases of dengue that come from public hospitals
and that have been confirmed by laboratories, the official said. Such a
census, “which was deliberated at the highest levels,” is a small subset
that is nonetheless informative and comparable from one year to the
next, he said.
“There
is no denying that the actual number of cases would be much, much
higher,” the official said. “Our interest has not been to arrive at an
exact figure.”
The
problem with that policy, said Dr.
Manish Kakkar, a specialist at the Public Health Foundation of India,
is that India’s “massive underreporting of cases” has contributed to the
disease’s spread. Experts from around the world said that India’s
failure to construct an adequate dengue surveillance system has impeded
awareness of the illness’s vast reach, discouraged efforts to clean up
the sources of the disease and slowed the search for a vaccine.
“When
you look at the number of reported cases India has, it’s a joke,” said
Dr. Harold S. Margolis, chief of the dengue branch at the Centers for
Disease Control and Prevention in Atlanta.
Neighboring Sri Lanka, for instance, reported nearly three times as many dengue cases as India
through August, according to the World Health Organization, even though India’s population is 60 times larger.
Part
of India’s problem is that some officials view reports of dengue
infections as politically damaging. In September, Mamata Banerjee, the
chief minister of West Bengal, dismissed reports of an increasing number
of dengue-related deaths, saying doctors were misdiagnosing. “So
everyone is earning a bad name,” she said at a news conference.
A
central piece of evidence for those who contend that India suffers
hundreds of times more dengue cases than the government acknowledges is a
recent and as yet unpublished study of
dengue infections in West Bengal that found about the same presence of
dengue as in Thailand, where almost every child is infected by dengue at
least once before adulthood.
“I
would say that anybody over the age of 20 in India has been infected
with dengue,” said Dr. Timothy Endy, chief of infectious disease at
Upstate Medical University in Syracuse.
For
those who arrive in India as adults, “you have a reasonable expectation
of getting dengue after a few months,” said Dr. Joseph M. Vinetz, a
professor at the University of California at San Diego. “If
you stay for a longer period, it’s a certainty.”
The
reason that such an extensive epidemic can hide in plain sight is that
as many as 80 percent of dengue infections cause only mild symptoms of
fatigue, said Anthony S. Fauci, director of the National Institute of
Allergy and Infectious Diseases. For many, the disease is experienced as
“maybe just a fever that someone shrugs off.”
But the remaining 20 percent may be affected by more serious flulike symptoms, with high
fever, vomiting,
searing pain behind the eyes, skin rash, and muscle and joint aches
that can be so intense that the illness has been dubbed “breakbone
fever.”
The acute
part of the illness generally passes within two weeks, but symptoms of
fatigue and depression can linger for months. In about 1 percent of
cases, dengue advances to a life-threatening cascade of immune responses
known as hemorrhagic or shock dengue.
This
potentially mortal condition
generally happens only after a second dengue infection. There are four
strains of the dengue virus, and infection with a second strain can fool
the immune system, allowing the virus to replicate. When the body
finally realizes its mistake, it floods the system with so many immune
attackers that they are poisonous. Such patients must be provided
intravenous fluids and round-the-clock care to avoid death.
Twenty
years ago, just one of every 50 tourists who returned from the tropics
with fever was infected by dengue; now, it is one in six, said Dr.
Velayudhan, the W.H.O. official. The Portuguese archipelago of Madeira
is in the midst of an epidemic.
On Oct. 9, Puerto Rico’s Health Department declared a dengue
epidemic after at least six people died and nearly 5,000 people were sickened.
The
great danger of having hundreds of millions of people in India with
undiagnosed and unacknowledged primary infections is that a sudden shift
in the circulating dengue strain could cause a widespread increase in
life-threatening illnesses.
“We
have been fortunate so far,” said Dr. Kakkar of the Indian public
health group. “But if, God forbid, we come across that situation we
probably need far better health-care management and inpatient care
facilities.”
Trucks spewing pesticides against
mosquitoes are now a regular presence in New Delhi neighborhoods, but
rapid and disorderly urbanization — a hallmark of India’s development —
increases the risks of dengue proliferation, so few believe the
government here can do much to halt its spread.
The best hope for relief is a vaccine, but a recent trial of the most advanced vaccine candidate largely failed.
“I think we’re looking at 10 to 12 years before we see an effective vaccine, and that’s
if we’re lucky,” Dr. Halstead said. “In the meantime, we’re in trouble.”
Hari Kumar contributed reporting.