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Nipah virus infection is an emerging disease endemic in Southeast Asia. This virus is carried in

fruit bats of the genus Pteropus, a host to which it seems well adapted. It emerges periodically to

affect humans, pigs and occasionally other domesticated animals.

The virus is named after the Malaysian village where it was first discovered. This virus along

with Hendra virus comprises a new genus designated Henipavirus in the sub family

Paramyxovirinae. 1.1 History of Nipah Virus Infection Nipah virus infections were first described during widespread outbreaks that occurred in

Malaysia in 1998-1999. The virus had apparently circulated in domesticated swine since 1996,

but because the mortality rate was low and the disease resembled other porcine infections, it was

not identified immediately as a new disease. The epidemic was recognized when Nipah virus

spread to pig farmers and abattoir workers in Malaysia and Singapore, causing severe, often fatal

encephalitis in approximately 260 people. Some other species, including cats and dogs, were also

affected. The Malaysian outbreaks were controlled in both domesticated animals and humans by

culling more than one million pigs. In addition, pig farming was permanently banned in some

high-risk areas.

Since 2001, human outbreaks and clusters of cases have been reported periodically in

Bangladesh and a neighboring region of northern India. In some of these outbreaks, Nipah virus

seems to have been transmitted directly from bats to humans, with person-to-person transmission

the most significant means of spread. Why Nipah virus periodically emerges into humans and

domesticated animals is not known; however, fruit bat populations in Southeast Asia are being

disrupted by various factors that may alter their foraging patterns and behavior, and bring them

into closer contact with domesticated animals and humans.

Chapter (1)

At a glance

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1.2 Reservoir of the virus The primary reservoir for Nipah virus is flying foxes (also known as fruit bats) of the genus

Pteropus. Transmission of Nipah virus from bats to swine has not been shown conclusively;

however, there are various biologically plausible means for infected secretions of primary hosts

to enter pigs, including direct contact with infected secretions contaminated fruit or dead bats.

Scavenging animals may also play a role in the transport of virus into proximity of pigs. Flying

foxes are able to carry the virus without being affected by it. Investigation of potential secondary

hosts (peridomestic species) has also been conducted. Rats, house shrews, dogs, and chickens

have been tested, but no indication of a secondary host has been found.

1.3 Geographic Distribution Nipah virus infections have been documented in Malaysia, Bangladesh and northern India.

Cases were also reported in abattoir workers in Singapore who contacted pigs imported from

Malaysia. This virus has been isolated from bats in Cambodia, and seropositive and RNA-

positive bats have been reported from Thailand. Although Nipah virus should be considered

Figure(1) : Birth of Nipah Virus

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Endemic in Southeast Asia, outbreaks seem to cluster in certain geographic areas.

1.4 The mode of Transmission The momentous reservoir host of Nipah Virus is the Bats of the generous Pteropus (flying

foxes/fruit bats). Nipah virus has been found in the urine of wild Pteropus bats and in partially

eaten fruit. In experimentally infected bats, this virus was isolated from the urine, kidney and

uterus, but not from conjunctival, nasal, tonsillar or rectal swabs. Despite high seroprevalence

rates, only a few bats in a colony may shed the virus at any given time, and excretion from the

colony may be sporadic. The route of transmission from bats to domesticated animals is

uncertain, but pigs, cows and goats might be infected by eating fruit that has been contaminated

with bat saliva or urine, by drinking contaminated water, or by eating aborted bat fetuses or birth

products. Humans may also be infected from bats via contaminated fruit or juice; some

infections have been linked to the consumption of unpasteurized date palm juice.

Figure(2) : Geographic Distribution of NiV

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Humans can be infected by direct contact with infected swine, probably through the mucous

membranes but possibly also through skin abrasions. Humans could theoretically be infected by

contact with domesticated animals other than pigs, but this has not been demonstrated. Direct or

indirect bat-to-human transmission was apparently responsible for some recent outbreaks.

Ingestion of virus in contaminated, unpasteurized date palm juice may have been the source of an

outbreak in Bangladesh in 2005. Person-to-person transmission has been reported after close

direct contact, and appears to have been the major route of spread in some recent outbreaks. In

humans, Nipah virus can be shed in upper respiratory secretions and urine.

Nipah virus may be transmitted on fomites. How long this virus can survive in the environment

is unknown; however, unpublished experiments suggest that it can survive for days in fruit juice

or fruit bat urine the gastrointestinal tract, renal impairment and other complications can occur in

severely ill patients. Cases that have progressed to encephalitis are often fatal. Surviving patients

may have mild to severe residual neurological deficits, or remain in a vegetative state.

Patients who recover from neurologic disease may relapse with encephalitis several months to

several years later. Encephalitis can also occur as long as four years or more after an

asymptomatic or non-encephalitic infection.

Figure (3) : Transmission Pathway Fruit

Bats

Nipah Virus

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1.5 Public Health Hazard Nipah Virus is a zoonotic disease. The mode of transmission to humans in Malaysia and Singapore has almost always been from direct, contact with the excretions or secretions of infected pigs but reports from outbreaks in Bangladesh suggest transmission from bats without an intermediate Host by drinking raw palm sap contaminated with bat excrement, or climbing trees coated in bat excrement. In Bangladesh and India, there have been reports of possible human to human transmission of the disease so precautions are necessary for hospital workers caring for infected patients. Precautions should also be taken when submitting and handling laboratory samples, as well as in slaughterhouses. Typically the human infection presents as an encephalitic syndrome marked by fever, headache, drowsiness, disorientation, mental confusion, coma, and potentially death. During the outbreak of NiV in Malaysia, up to 50% of clinically apparent human cases died.

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.

Human-to-human transmission of NiV has been reported in recent outbreaks demonstrating a

risk of transmission of the virus from infected patients to healthcare workers through contact

with infected secretions, excretions, blood or tissues. 2.1 Incubation Period The incubation period in human body is usually 4 to 20 days; however, incubation periods as

short as two days or as long as a month has been reported. Some people may remain

asymptomatic during the initial infection, but develop serious neurological disease up to four

years later.

2.2 Clinical Signs Although some Nipah virus infections can be asymptomatic or mild, most recognized clinical

cases present with acute neurological signs. The initial symptoms are flu-like, with high fever,

headache and myalgia. In patients who develop encephalitis, the symptoms may include

drowsiness, disorientation, convulsions and/ or coma. Nausea and vomiting can also be seen.

Less often, patients develop respiratory signs, which may include acute respiratory distress

syndrome. Septicemia, bleeding from the gastrointestinal tract, renal impairment and other

complications can occur in severely ill patients. Cases that have progressed to encephalitis are

often fatal. Surviving patients may have mild to severe residual neurological deficits, or remain

in a vegetative state. Patients who recover from neurologic disease may relapse with encephalitis

several months to several years later. Encephalitis can also occur as long as four years or more

after an asymptomatic or non-encephalitic infection

Chapter (2)

Infection in Human

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2.3 Diagnostic Test In humans, Nipah virus infections can be diagnosed by virus isolation, the detection of antigens

or nucleic acids, and serology. Histopathology also helps support the diagnosis.

Nipah virus can be recovered in many cell lines including Vero (African green monkey kidney),

RK-13, BHK and porcine spleen cells. This virus can be identified in cultures by

immunostaining or virus neutralization. Electron microscopy and immunoelectron microscopy

can aid identification. In humans, Nipah virus has been isolated from blood, throat or nasal

swabs, cerebrospinal fluid (CSF) and urine samples, as well as from a variety of postmortem

tissues. Nipah virus is most likely to be recovered from clinical samples early in the illness. This

virus is classified as a biosafety level 4 (BSL4) pathogen, which restricts the number of

laboratories able to perform virus isolation.

Viral antigens can be detected in formalin-fixed tissues by immunohistochemistry. Antigens are

most likely to be found in the central nervous system (CNS), followed by the lung or kidney.

Reverse transcription-polymerase chain reaction (RT-PCR) techniques are in routine use at some

laboratories.

Antibodies to Nipah virus may be found in serum and/or CSF. Acute and convalescent samples

are collected whenever possible. Serologic tests used in humans include enzyme-linked

immunosorbent assays (ELISAs) and serum neutralization.

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2.4 Treatment No effective drug therapies available yet. Treatment is limited to supportive care. Because Nipah

virus encephalitis can be transmitted person-to-person, standard infection control practices and

proper barrier nursing techniques are important in preventing hospital-acquired infections

(nosocomial transmission).

The drug ribavirin has been shown to be effective against the viruses in vitro, but human

investigations to date have been inconclusive and the clinical usefulness of ribavirin remains

uncertain.

Passive immunization using a human monoclonal antibody targeting the Nipah G glycoprotein

has been evaluated in the post-exposure therapy in the ferret model and found to be of benefit. 2.5 Risk Factors An outbreak of acute febrile encephalitis affecting pig-farm workers and owners was recognized

in peninsular Malaysia as early as September 1998.Information and understanding the risks of

Nipah virus infections and modes of transmission strengthened the directions of prevention,

control and communication strategies. A number of epidemiological surveillances and field

investigations which were broadly divided into 3 groups covering human health sector, animal

health sector and reservoir hosts were carried out as forms of risk assessment to determine and

assess the factors and degree of risk of infections by the virus. Data showed that there was

significant association between Nipah virus infection and performing activities involving close

contact with pigs, such as processing of piglets, administering injection or medication to pigs,

assisting in the birth of piglets, assisting in pig breeding, and handling of dead pigs in the

affected farms. A complex process of anthropogenic driven deforestation, climatic changes

brought on by El Nio-related drought, forest fire and severe haze, and ecological factors of

mixed agro-pig farming practices and design of pig-sties led to the spillovers of the virus from its

wildlife reservoir into pig population.

Drinking raw date palm sap collected during winter months, which is a delicacy in rural

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Bangladesh was first identified as a risk factor for Nipah infection in an outbreak in Tangail in

2005. This has also been identified as a risk factor in three more outbreaks so far. Several

sporadic cases have also reported history of drinking raw date palm sap within 30 days before the

onset of illness.

2.6 Prevention and Control Nipah virus infection can be prevented by avoiding exposure to sick pigs and bats in endemic

areas and not drinking raw date palm sap.

Additional efforts focused on surveillance and awareness will help prevent future outbreaks.

Research is needed to better understand the ecology of bats and Nipah virus, investigating

questions such as the seasonality of disease within reproductive cycles of bats. Surveillance tools

should include reliable laboratory assays for early detection of disease in communities and

livestock, and raising awareness of transmission and symptoms is important in reinforcing

standard infection control practices to avoid human-to-human infections in hospital settings

(nosocomial infection).

There is no effective treatment for Nipah virus disease, but ribavarin may alleviate the symptoms

of nausea, vomiting, and convulsions.Treatment is mostly focused on managing fever and the

neurological symptoms. Severely ill individuals need to be hospitalized and may require the use

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of a ventilator. Human-to-human transmission of NiV has been reported in recent outbreaks

demonstrating a risk of transmission of the virus from infected patients to healthcare workers

through contact with infected secretions, excretions, blood or tissues. Healthcare workers caring

for patients with suspected or confirmed.NiV should implement Standard Precautions when

caring for patients and handling specimens from them. Preventing infections in pigs can decrease

the risk of infection for humans. To take the following steps to prevent illness:

In endemic areas, Pigs and fruit bats should be avoided whenever possible.

Fruit tree plantations should be removed from areas where pigs are kept.

Unpasteurized juices should not be drunk, and fruit should be washed thoroughly, peeled,

or cooked.

Good personal hygiene, including hand washing, also reduces the risk of infection.

Wire screens can help prevent contact with bats when pigs are

raised in open-sided pig sheds.

Run-off from the roof should be prevented from entering pig

pens.

During an outbreak, equipment and other fomites should be

cleaned and disinfected.

In addition, dogs and cats should be prevented from

contacting infected pigs or roaming

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A subunit vaccine, using the Hendra G protein, produces cross-protective antibodies against

HENV and NIPV has been recently used in Australia to protect horses against Hendra virus. This

vaccine offers great potential for Nipahvirus protection in humans as well.

2.7 Morbidity and Morality Nipah virus has emerged repeatedly into humans in Southeast Asia since 1997. The first cases

were reported in Malaysia in 1998-1999, although retrospective diagnosis shows that human

infections also occurred in 1997. Abattoir workers in Singapore who contacted imported pigs

also became ill. During these outbreaks, most people were infected by contact with pigs, and

human cases were not seen after seropositive animals had been culled. In contrast, some

outbreaks in Bangladesh seem to be caused by direct or indirect transmission from fruit bats to

humans, and may have been sustained by person-to-person transmission. These outbreaks have

generally been seen from January to May, and usually occur in the same areas of the country. An

outbreak in Siliguri, India in 2001 was linked to nosocomial transmission in hospitals, and ended

after effective barrier nursing precautions were put in place.

Serologic studies suggest that some human infections are asymptomatic. In the Malaysian

outbreak, the subclinical infection rate was estimated to be 8%-15%. The case fatality rate in the

various outbreaks has varied from 33% to approximately 75%; the overall case fatality rate for

all outbreaks in Bangladesh between 2001 and February 2005 is 64%. Among surviving patients,

an estimated 25% have residual neurological deficits. Nearly 10% of the patients in the

Malaysian outbreak had late onset encephalitis with a case fatality rate of 18%.

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Table 1: Morbidity and mortality due to Nipah or Nipah-like virus, Asia-Pacific Region, 1999-2012

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The most common spread of NiV virus is between animals to animals more

precisely when domestic animals consume foods where high risk of bats existence

is evident then Nipah virus easily get dissolved in the animal bodies and that

affected animal spread these horrendous disease , creating a hazardous ecosystem. 3.1 Species effected Fruit bats of the genus Pteropus are the main reservoir hosts. P. hypomelanus, the island flying

fox, and P. vampyrus, the Malayan flying fox; are thought to be the most important hosts in

Malaysia. P. lylei may be the major host in Thailand and Cambodia. Antibodies occur in P.

giganteus in Bangladesh. In addition, there is evidence of infection in other species of fruit bats

and insectivorous bats including Cynopterus brachyotis, Eonycteris spelaea and Scotophilus

kuhlii in Malaysia, and Hipposideros larvatus in Thailand. P. poliocephalus has been infected

experimentally.

Nipah virus infections have also been reported in pigs, dogs, cats, horses and goats. Some

authors have suggested that sheep may have been infected in Malaysia, but reports are

conflicting. Nipah virus can be maintained in pig populations; other domesticated animals appear

to be spillover hosts. Experimental infections have established in cats, pigs and golden hamsters

(Mesocricetus auratus). 3.2 Incubation Period The incubation period in pigs is estimated to be 7 to 14 days, but may be as short as four days. In

experimentally infected cats, incubation periods of six to eight days have been reported.

Chapter (3)

Infection in Animals

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3.3 Clinical Sings Symptomatic infections are usually acute febrile illnesses, but fulminating infections and sudden

death have also been seen.

The clinical signs may include fever, nasal discharge, open mouth breathing, rapid and labored respiration and a loud barking cough. Hemoptysis can occur in severe cases.

Neurological signs are sometimes seen; reported symptoms include trembling, twitching,

muscle spasms, myoclonus, weakness in the hind legs, spastic paresis, lameness,

uncoordinated gait when driven or hurried, and generalized pain that is particularly

evident in the hind quarters

Similar symptoms occur in sows and boars, although neurologic disease appears to be more common in sows than younger animals. Neurological signs that have been reported

include agitation, head pressing, nystagmus, chomping of the mouth, tetanus-like spasms,

seizures and apparent pharyngeal muscle paralysis. Some sows may abort, generally

during the first trimester. Sudden death may also be seen.

3.4 Diagnostic Test Nipah virus infections can be diagnosed by virus isolation, the detection of antigens or nucleic

acids, and serology. Histopathology also aids diagnosis. In swine, Nipah virus can be found in

respiratory secretions, blood and various tissues including the lung, spleen, kidney and brain. In

experimentally infected cats, this virus has been found in the lung and spleen, and less often, in

the kidney, lymph nodes and other organs. It can also be detected in feline blood, urine and

respiratory secretions. In dogs, viral antigens or RNA have been found in the brain, lung, spleen,

kidney, adrenal gland and liver.

Nipah virus can be isolated in many cell lines including Vero, RK-13, BHK and porcine spleen

cells. This virus can also be cultured in embryonated chicken eggs, but due to the ease of culture

in cells, this system is not generally used. Nipah virus can be identified in cultures by

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immunostaining or virus neutralization. Electron or immunoelectron microscopy can also be helpful.

Nipah virus is a BSL4 pathogen and culture is conducted under high-security conditions. When Nipah

virus infection is only one of many possible diagnoses, some laboratories may conduct primary virus

isolation under BSL3 conditions; however, stringent precautions should be employed to protect laboratory

personnel. Histological examination of tissues can help indicate whether Nipah virus is a likely diagnosis

and BSL4 conditions should be used initially. Suspect cultures that develop a paramyxovirus-like

cytopathic effect are generally transferred to a BSL4 laboratory.

Viral antigens can be detected by immunoperoxidase or immunofluorescence assays on

formalinfixed tissues. RTPCR, used on either fresh or formalin-fixed tissues, is available in

some laboratories. Serology can also be helpful. Serologic tests used in animals include virus

neutralization and ELISAs. Cross-reactions can occur between Hendra and Nipah viruses in all

serologic assays including virus neutralization; however, reactions to Nipah virus can be

identified by comparative neutralization tests. 3.5 Treatment No specific treatment is available; animals with Nipah virus infections are generally slaughtered

to prevent human infections.

3.6 Prevention and Control Good biosecurity is important in preventing infections on pig farms; strategies should target routes of contact with other pigs as well as fruit bats. Fruit tree plantations should be removed from areas where pigs are kept. Wire screenscan help prevent contact with bats when pigs are raised in open-sided pig sheds. Run-off from the roof should be prevented from entering pig- pens.

Early recognition of infected pigs prevents disease in other animals and humans. Due to the

highly contagious nature of the virus, mass culling of seropositive animals may be necessary.

Quarantines are also important in containing an outbreak; in Malaysia, Nipah virus mainly

seemed to spread between farms in infected pigs. Transmission on fomites is also possible; re-

used vaccination needles may have contributed to the spread of the virus in Malaysia. During an

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outbreak, fomites and equipment should be cleaned and disinfected. In addition, dogs and cats

should be prevented from contacting infected pigs or roaming between farms.

Although vaccines are not yet available, promising results were reported from one recent

experiment in cats.

3.7 Morbidity and Mortality Fruit bats (flying foxes) of the genus Pteropus seem to be the primary hosts for Nipah virus.

Studies from Malaysia reported that 9%-17% of Pteropus vampyrus and 21%-27% of P.

hypomelanus had antibodies to Nipah virus, while the seroprevalence in Cynopterus brachyotis,

Eonycteris spelaea and Scotophilus kuhlii was 2%-5%. Illness or deaths have not been reported

in any bat species.

Nipah virus was widespread in pigs during the 1998-1999 outbreak in Malaysia. Before this

virus was eradicated from domesticated swine, seropositive animals were found on

approximately 5.6% of all pig farms. The morbidity rate is estimated to approach 100%, but the

mortality rate is low except in piglets. On one farm, more than 95% of all sows and 90% of the

piglets were seropositive. Another study reported a 69% prevalence of sick pigs on farms in the

cull area of Negri Sembilan and 73% in Selangor. The mortality rate in 1 to 6 month old pigs is

approximately 1%-5%. In contrast, the mortality rate in piglets was approximately 40% in

Malaysia; however, neglect by ill sows may have contributed to the high death rate.

During the Malaysian outbreaks, Nipah virus infections were reported in non-porcine species in

affected regions. Although symptomatic infections were documented in only two dogs, a number

of dogs are said to have died on infected farms. Farmers also reported sickness in cats.

Serological surveys found seroprevalence rates of 15%-55% in dogs, 4%-6% in cats, and 1.5% in

goats. Infections in horses seem to be rare: only five horses out of more than 3200 were positive

by serology, and viral antigens were found in a single horse that died with symptoms of

meningitis. Infections in non-porcine species appear to be uncommon or nonexistent in the

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absence of infected pigs. Infections were not reported in swine or other domesticated animals

during the outbreaks in Bangladesh or India. In 2004, no seropositive animals were found among

feral cats living near an infected bat colony on Tioman Island, Malaysia.

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In this chapter illustrative study of the distribution and determinant of Nipah virus in populations is performed to seek the cause of both health and diseases. In order to diagnose NiV virus vividly the epidemiologist will make sure to seek answers to these basic question and then epidemiologist will prescribe the medicine to eradicate the effect and impacts of NiV virus.

What is the

Problem?

Out-Break

of Nipahvirus

Where is the

Problem?

Bangladesh

,more precisely north west

portion of

Bangladesh

When is the Proble

m ?

Harvesting date juice from

December

through

March

Why is the Problem?

Deadly effects of

Nipah virus is exposed to human population

via domestic animals or person to person or fruit juice

i.e. for Bangladesh date sap

How to control

and prevent?

After culling,

the burial sites are disinfecte

d with

chlorinated lime.

biosecurity

practices

Chapter (4)

Epidemiology Bangladesh

Figure (4) : Process of Performing Epidemiology

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.

4.1 Out Break of Nipah Virus in Bangladesh A total of 11 human outbreaks of NiV infection in Bangladesh were reported from 2001 through

2012, all occurring between December and May. There have been 11 outbreaks in Bangladesh

during the period 2001-2012 killing 150 of 196 infected persons with case fatality rate 77%. In

addition to the outbreaks, between 2001 and 2011, 27 other NiV transmission events, ranging

from single sporadic human cases to clusters of 24 human cases were recognized in 22 districts

of Bangladesh. One outbreak of NiV occurred in Siliguri, India, 15 kilometers north of the

Bangladesh border in January and February 2001 and a second NiV outbreak was reported by

newspapers in Nadia District, India also close to the border with Bangladesh, in 2007.

In Bangladesh NiV transmission from bats to human is repeated and ongoing. The variation of

NiV strains isolated from Bangladesh also supports multiple introductions of the virus from bats

into human populations even within a single year. Among 4 NiV isolates from human NiV cases

in 2004, the sequences of the nucleoprotein open reading frames of the isolates differed by 0.9%

in nucleotide homology, in contrast to the sequences obtained from all of the human cases in

Malaysia which were nearly identical to each other19-21. The clinical presentation of NiV

infection in Bangladesh differed from Malaysia. In Bangladesh, severe respiratory disease is

more common, with 62% of cases having cough, 69% developing respiratory difficulty, and

available chest radiographs showing diffuse bilateral opacities covering the majority of the lung

fields.

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Table 2: Clinical characteristics of Nipah cases in Bangladesh

Clinical Characteristics Number (%) Fever

196 (100)

Altered Mental Status 131 (67)

Severe Weakness / lethargy 123 (63)

Headache 108 (55)

Cough 105 (54)

Vomiting

Myalgia 81 (41)

Convulsions 59 (30)

4.2 Epidemiology of Nipah Virus in Bangladesh Epidemiological investigations in Bangladesh have identified three pathways of transmission of

NiV from bats to people. The most frequently implicated route is ingestion of fresh date palm

sap. Date palm sap is harvested from December through March, particularly in North West

portion of Bangladesh. A tap is cut into the tree trunk and sap flows slowly overnight into an

open clay pot. Infrared camera studies confirm that P. giganteus bats frequently visit date palm

sap trees and lick the sap during collection.

NiV can survive for days on sugar-rich solutions such as fruit pulp. Most date palm sap is

processed at high temperature to make molasses, but some is enjoyed as a fresh juice, drunk raw

within a few hours of collection. In the 2005 Nipah outbreak in Tangail District, Bangladesh, the

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only exposure significantly associated with illness was drinking raw date palm .Twenty-one of

the 23 index NiV case patients recognized in Bangladesh developed their initial symptoms

during the December through March date palm sap collection season.

A second route of transmission for NiV from bats to people in Bangladesh is via domestic

animals. Fruit bats commonly drop partially eaten saliva-laden fruit. Domestic animals in

Bangladesh forage for such food. Date palm sap that is contaminated with bat droppings and so

is unfit for human consumption is also occasionally fed to domestic animals. The domestic

animals may become infected with NiV, and shed the virus to other animals, including humans.

Contact with a sick cow in Meherpur, Bangladesh in 2001 was strongly associated with Nipah

infection.

Some people may come into direct contact with NiV infected bat secretions. In the Goalando

area outbreak in 2004, persons who climbed trees were more likely to develop NiV infection

than were control patients. Several Bangladesh Nipah outbreaks resulted from person-to person

transmission. The clearest illustration of person-to-person NiV transmission occurred during the

outbreak in Faridpur district of central Bangladesh in 2004.

In a review of the 142 Nipah case patients identified in Bangladesh from 2001 through 2011, 75

(68%) developed illness after close contact with another Nipah patient.

Respiratory secretions appear to be particularly important for person-to-person transmission of

NiV. NiV RNA is readily identified in the saliva of infected patients. Anthropological

investigations during the Faridpur outbreak highlighted multiple opportunities for the transfer of

NiV contaminated saliva from a sick patient to care providers. Social norms in Bangladesh

require family members to maintain close physical contact during illness. The more severe the

illness, the more hands-on care is expected. Family members and friends without formal health

care or infection control training provided nearly all the hands on care to Nipah patients both at

home and in the hospital38. Care providers during the Faridpur outbreak continued to share

eating utensils and drinking glasses with sick patients. Leftovers of food offered to ill Nipah

patients were commonly distributed to other family members. Family members maintained their

regular sleeping arrangements, which often involved sleeping in the same bed with a sick,

coughing Nipah patient. There was a particularly strong desire to have close physical contact

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near the time of death demonstrated by such behaviors as cradling the patients head on the family

members lap, attempting to give liquids to the patient with a spoon or glass between bouts of

coughing, or hugging and kissing the sick patient.

In both the Faridpur outbreak in 2004 and the Thakurgaon outbreak in 2007, persons who were

in a room when a Nipah patient was coughing or sneezing were at increased risk of Nipah virus

infection Across all recognized outbreaks in Bangladesh from 2001 through 2007, Nipah patients

with respiratory symptoms were more likely to transmit Nipah. Health care workers in

Bangladesh have much less direct physical contact with patients than in western hospitals.

Hands-on care is generally provided by family members and friends. No health care workers in

Bangladesh who cared for identified Nipah patients have been identified with illness, although

confirmed cases include 1 physician whose source of infection is unknown. A sero survey among

105 health care workers who cared for at least 1 of 7 patients admitted with Nipah infection at

one hospital in Bangladesh identified 2 health care workers with serological evidence of NiV

infection; however, their antibody responses (IgG only, no IgM) and lack of symptoms suggest a

previous infection, not recent nosocomial transmission. The pattern of the outbreaks in

Bangladesh suggests that person-to-person transmission is more dependent on the characteristics

of the occasional Nipah transmitter than a specific strain. The review of human Nipah infection

in Bangladesh, secondary cases were no more or less likely to become Nipah transmitters than

were primary cases. All persons who transmitted Nipah died, suggesting that late stages of

infection, presumably with high virus titers, increase the risk of transmission. In Bangladesh, P.

giganteus bats live in close proximity to human populations, often roosting in trees located in

rural Bangladeshi villages. Thus, bat urine, intermittently laced with NiV, contaminates the

immediate physical environment in many villages in Bangladesh. Yet in each of the Nipah

outbreaks investigated in Bangladesh, an association between living near a bat roost and

infection with Nipah was looked for but was never found. This suggests that the quantity of

viable virus shed in bat urine is too low to initiate clinically apparent infection in humans. Eating

bat-bitten fruit is often suggested as a pathway of transmission for human Nipah infection. NiV

was recovered from fruit dropped by Pteropus bats in Malaysia. It is the most commonly

suggested pathway for NiV transmission from bats to domestic animals. In contrast to general

environmental contamination with urine, punctured fruit contaminated with bat saliva may favor

virus survival. Villagers, especially children, commonly report consuming fruit which was

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partially eaten by bats. However, in the NiV outbreak investigations where the question was

asked, case patients never reported consuming partially eaten fruit significantly more than did

controls. P. giganteus are widely distributed across Bangladesh16, and wherever Pteropus bats

have been tested they have antibody to henipavirus. When Pteropus bats are experimentally

infected with NiV they do not become clinically ill15, which suggest that NiV likely coevolved

with its Pteropus hosts over longtime.

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Prognosis of Nipah Virus

Nipah virus will infect pigs of all ages. Clinical observations in the Malaysian outbreak suggested a different clinical picture in different classes of animals. For examplesows were noted to present primarily a neurologic syndrome and porkers a respiratory syndrome.

Researching a presumptive diagnosis in farm:

Nipah virus affects both the nervous system and the respiratory system. The clinical signs in

swine include:

Fever;

Loud, barking cough;

Respiratory distress (open mouthed breathing, rapid and labored respiration);

Trembling;

Muscle spasms;

Weakness in the hind limbs; and

lack of coordination.

In sows and boars particularly, the following signs can be observed:

Agitation

Head pressing

Increased salivation and nasal discharge;

Seizures

Chapter (5)

Prognosis

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Sudden death.

Abortions have been reported in affected sows.

The illness can affect 100 per cent of the herd, but mortality is generally less than five per cent.

The incubation period is estimated to be 7 to 14 days. It could be orally and by parenteral

inoculation.Neutralizing antibodies were detectable 10-14 days post-infection. Except in piglets,

where it is higher.

Incubation:

Other infected animals are dogs horse mosquitosper domestic small mammals including rodent and bird species on and around infected pig farms. In our country human is mainly infected by bats.

Others susceptible domestic species

Necropsy findings in pigs

Necropsies should be conducted of recently dead and acutely diseased pigs. Animals chosen should be representative of the affected ages and types, and should include a number of animals to increase the sensitivity of the sampling procedure.

The post-mortem findings due to Nipah virus infection in pigs are relatively non-specific. The lung and the meninges were the key organs affected. The majority of the cases showed mild to severe lung lesions with varying degrees of consolidation.

Confirmatory laboratory diagnosis:

Laboratory diagnosis of a patient with a clinical history of Nipah virus can be made during the

acute phase of the disease by using a combination test. They are

Serology

Histopathology

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Serum neutralization

Enzyme-linked immunosorbent assay (ELISA)

Polymerase chain reaction (PCR) assay

Immunofluorescence assay

Electron microscopy

Virus isolation attempts and real time polymerase chain reaction from throat and nasal swabs,

cerebrospinal fluid, and blood should be performed in the early stages of disease. Antibody

detection by ELISA can be used later on. In fatal cases, immunohistochemistry on tissues

collected during autopsy may be the only way to confirm it. Most countries in the South-East

Asia Region do not have adequate facilities for diagnosing the virus or on ways of controlling it.

Bangladesh, India and Thailand have developed laboratory capacity for diagnostic and research

purposes. Nipah virus is classified internationally as a biosecurity level (BSL) 4 agent. BSL 2

facilities are sufficient if the virus can be first inactivated during specimen collection.19

There are a few laboratories in which the virus can be studied safely without a risk

of it escaping and infecting more people.

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There is two momentous loopholes of Public Health Admistration on global scale when it comes to eradicate immediately the affects of hazardous NiV virus. In Figure ( ) gives a detailed view of the flaws that was adapted by the Public Health Administrators.

There should have been illustrated promotion of preventive methods and cause

and effect of Nipah virus along with how to protect agriculture, human and

domestic humans from NiV horrendous hazard

When Nipa virus was first detected there was no diagnosis that it has the characteristics of direct human to human transmission

Chapter (6)

Public Health-Loopholes

Figure(5) : Public Health loop Holes

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Recommendation

Public Health Administrator

globally should have conducted seminars

to promote awareness when Nivwas first out-broken

Extensive research should have

performed by the epidemiologist so that human would have been familiar and more cautious

Chapter (7)

Recommendation

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To conclude, Nipah encephalitis, a fatal zoonotic disease, recurrently claims lives in

Bangladesh following the initial reports of outbreaks in other countries. A combination of

Event-based and sentinel surveillance systems is an innovative strategy to detect encephalitis

outbreaks which has been successful in detecting Nipah outbreaks in Bangladesh.

Multidisciplinary outbreak investigations can be an important tool in exploring novel

characteristics and risk factors of emerging infectious zoonotic diseases in resource-poor

settings.

It is very much vital that infectious virus like Niv should be radicated from the ecosystem in

order to provide transparency, longevity and certainty to the biosphere so that our future

generation can rejoice the blessing and beauty of Mother Nature

.

.

Chapter (8)

Conclusion

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Centers for Disease Control and Prevention. Hendra Virus Disease and Nipah Virus Encephalitis

http://www.cdc.gov/ncidod/dvrd/spb/mnpages/dispages/nipah.htm

Food and Agriculture Organization of the United Nations. Manual on the Diagnosis of Nipah

Virus Infection in Animals. http://www.fao.org/DOCREP/005/AC449E/AC449E00.htm

Henipavirus Ecology Collaborative Research Group http://www.henipavirus.org

The Merck Veterinary Manual http://www.merckvetmanual.com/mvm/index.jsp

World Health Organization (WHO) Nipah Virus Fact Sheet.

http://www.who.int/mediacentre/factsheets/fs262/en/

WHO Epidemic and Pandemic Alert and Response: Nipah Virus

http://www.who.int/csr/don/archive/disease/nipah_virus/en/

World Organization for Animal Health (OIE) http://www.oie.int

OIE Manual of Diagnostic Tests and Vaccines for Terrestrial Animals

http://www.oie.int/international-standard-setting/terrestrial-manual/access-online/

Chapter (9)

Reference