The Nipah virus outbreak of 2018 in India is the third occurrence of
- Humans coming in closer contact with bats due to
urbanization could be the main reason for re-emergence of Nipah infections.
- Bangladesh strain of virus
(NiVB) is found to be responsible for the current outbreak in Kerala.
- NiVB spreads directly from bats
to humans and does not have an intermediate source.
; the first two times were in 2001 and 2007. The current outbreak has claimed 14 lives
in Kerala's Kozhikode and Malappuram districts so far
. There are a
total of 16 confirmed cases and 12 suspected cases.
There are reports of suspect cases in other states as well.
The Nipah virus disease in Kerala is not a major outbreak and is only a
says the Central High-level Team led by the National
Centre for Disease Control (NCDC) under the directions of the Union Health
Minister, Shri J P Nadda. The NCDC is closely monitoring the outspread of the
disease and stringent efforts are being made to contain the disease.
Why has the virus re-emerged?
natural science experts are attempting to look at the reasons why the virus has
emerged in India after 2001 and 2007.
‘Nipah virus has struck for the third time in India. A plausible explanation for the outbreak could be rapid urbanization that has led to humans and bats being in closer contact now than before.’
experts claim that Nipah virus
has existed in bats for centuries and has
not undergone an evolutionary change, but then why is it that this infection is
spreading only now.
Rapid urbanization, coupled with changing climate in recent
, have been stated as some of the
reasons for the re-emergence of the Nipah Virus in India.
looking at the causes of the re-emergence of the virus. Specialized team at our
strong network of laboratories are trying to find out the causes of outbreak,"
said A.C. Dhariwal, adviser, National Vector Borne Disease Control Programme.
"India is witnessing a rapid urbanization and animals and birds including bats
are losing their natural habitats. In recent years, humans are animals are
coming in contact with each other which is also causing outbreak of diseases
such as Nipah," he said.
Singh is an environmental science expert who has studied Nipah virus and
climate change closely. Her research paper, Nipah Virus: Effects of
Urbanization and Climate Change,
states that the
most prominent ecological factor that contributes to the emergence of the Nipah
virus is human intervention into
the bat-infested areas due to rapid urbanization.
Bangladesh and India,an outbreak
could be causeddue to the increased
human-bat interaction; humans could easily get infected by drinking date palm
juice contaminated by bat urine or saliva.
Scientists at the National Institute of Virology (NIV)
in Pune have confirmed that the Bangladesh strain of
Nipah virus (NiVB) is responsible for
the current outbreak in Kerala
. The scientists decoded the full genome of the virus
drawn from the throat swab sample of an infected patient to come to this
The NivB strain is one of the two strains of the Nipah virus, the other one being the Malaysia strain
(NiVM). Fatality rates of both the strains are very high.
Malaysian virus goes from pigs to humans, but the Bangladesh strain travels
directly from bats to humans.
deforestation of pulpwood (a natural habitat for NiV carrying bats) and
mismanagement of large piggeries could cause an outbreak in Malaysia.
History of the Nipah Virus
The first ever outbreak of the Nipah
virus occurred in Malaysia in 1998. According to World Health Organization
(WHO), the virus can be transmitted from animal-to-human and human-to-human.
Subsequent outbreaks in India and
Bangladesh have occurred with high fatalities. The first identification of
Nipah virus as a cause of an outbreak of encephalitis was reported in 2001 in
Meherpur district of Bangladesh. Since then, outbreaks of Nipah virus
encephalitis have been reported almost every year in selected districts of
Bangladesh. From 1998 to 2015, a total of 600 Nipah virus cases in humans have
Nipah in India
Both the earlier outbreaks (2001 and
2007) of Nipah virus encephalitis occurred in the eastern state of West Bengal
in India, bordering Bangladesh. A total of 71 cases with 50 deaths (70% of the
cases) were reported in the two outbreaks.
In 2001, there was an outbreak of
febrile illness with neurological symptoms in Siliguri, West Bengal. The second
outbreak in 2007 witnessed around 30 cases of fever with acute respiratory distress
and/or neurological symptoms
in Nadia district of West Bengal. All five cases that turned out to be fatal
among the 30 tested positive for NiV. The source was later found as a horde of
bats hanging from the trees around a patients' residence which suggests direct
contact of the liquor with bat fluids.
Not much is
known about the effects of urbanization and climate change in Siliguri and
Nadia regions. However, there should be tighter wildlife surveillance due to
the region's proximity to the Nipah Belt of Bangladesh where the NiVB strain is
The Nipah virus (NiV) causes severe
disease in both animals and humans. Its natural host is the fruit bat. It is
named after the Malaysian village Kampung Sungai
Nipah, where it was first discovered and belongs to the genus
Henipavirus. Pigs are the intermediate hosts in the Malaysian strain whereas
there are no intermediate hosts in the Bangladesh strain. Humans get infected
by consuming fruits that have been infected by droplets of saliva and urine of
the fruit bats.
The virus is capable of human-to-human
transmission in people in close proximity as was documented in a hospital
setting in India and seen currently in 2018. It spreads through human
secretions and excretions. The major symptoms of the infection are fever,
and vomiting that mostly leads to
encephalitis or inflammation of the brain and later to coma
is no vaccine for prevention or cure for
either humans or animals. The primary treatment for human cases is intensive
- Nipah virus infection - (http://www.who.int/csr/disease/nipah/en/)
- Nipah virus - (http://www.searo.who.int/entity/emerging_diseases/links/nipah_virus/en/)
- Nipah virus disease is not a major outbreak. It is only a local occurrence - (http://www.searo.who.int/india/topics/emergencies/mohfw-niv-press-release-24may2018.pdf)