Exposure-Based Screening for Nipah Virus Encephalitis,Bangladesh

We measured the performance of exposure screening questions to identify Nipah virus encephalitis in hospitalized encephalitis patients during the 2012–13 Nipah virus season in Bangladesh. The sensitivity (93%), specificity (82%), positive predictive value (37%), and negative predictive value (99%) results suggested that screening questions could more quickly identify persons with Nipah virus encephalitis.     

Nipah virus infection among abattoir workers in Malaysia, 1998-1999.

BACKGROUND: An outbreak of encephalitis primarily affecting pig farmers occurred during 1998-1999 in Malaysia and was linked to a new paramyxovirus, Nipah virus, which infected pigs, humans, dogs, and cats. Because five abattoir workers were also affected, a survey was conducted to assess the risk of Nipah infection among abattoir workers. METHODS: Workers from all 143 registered abattoirs in 11 of 13 states in Malaysia were invited to participate in this cross-sectional study. Participants were interviewed to ascertain information on illness and activities performed at the abattoir. A serum sample was obtained to test for Nipah virus antibody. RESULTS: Seven (1.6 %) of 435 abattoir workers who slaughtered pigs versus zero (0%) of 233 workers who slaughtered ruminants showed antibody to Nipah virus (P = 0.05). All antibody-positive workers were from abattoirs in the three states that reported outbreak cases among pig farmers. Workers in these three states were more likely than those in other states to have Nipah antibody (7/144 [4.86%] versus 0/291 [0%], P < 0.001) and report symptoms suggestive of Nipah disease in pigs admitted to the abattoirs (P = 0.001). CONCLUSIONS: Nipah infection was not widespread among abattoir workers in Malaysia and was linked to exposure to pigs. Since it may be difficult to identify Nipah-infected pigs capable of transmitting virus by clinical symptoms, using personal protective equipment, conducting surveillance for Nipah infection on pig farms which supply abattoirs, and avoiding handling and processing of potentially infected pigs are presently the best strategies to prevent transmission of Nipah virus in abattoirs.     

Recurrent Zoonotic Transmission of Nipah Virus into Humans, Bangladesh, 2001�C2007

Human Nipah outbreaks recur in a specific region and time of year in Bangladesh. Fruit bats are the reservoir host for Nipah virus. We identified 23 introductions of Nipah virus into human populations in central and northwestern Bangladesh from 2001 through 2007. Ten introductions affected multiple persons (median 10). Illness onset occurred from December through May but not every year. We identified 122 cases of human Nipah infection. The mean age of case-patients was 27 years; 87 (71%) died. In 62 (51%) Nipah virus–infected patients, illness developed 5–15 days after close contact with another Nipah case-patient. Nine (7%) Nipah case-patients transmitted virus to others. Nipah case-patients who had difficulty breathing were more likely than those without respiratory difficulty to transmit Nipah (12% vs. 0%, p = 0.03). Although a small minority of infected patients transmit Nipah virus, more than half of identified cases result from person-to-person transmission. Interventions to prevent virus transmission from bats to humans and from person to person are needed.     

Nipah Virus Infection in Dogs, Malaysia, 1999

The 1999 outbreak of Nipah virus encephalitis in humans and pigs in Peninsular Malaysia ended with the evacuation of humans and culling of pigs in the epidemic area. Serologic screening showed that, in the absence of infected pigs, dogs were not a secondary reservoir for Nipah virus.     

Nipah Virus Detection at Bat Roosts after Spillover Events,Bangladesh, 2012–2019

Knowledge of the dynamics and genetic diversity of Nipah virus circulating in bats and at the human-animal interface is limited by current sampling efforts, which produce few detections of viral RNA. We report a series of investigations at Pteropus medius bat roosts identified near the locations of human Nipah cases in Bangladesh during 2012–2019. Pooled bat urine was collected from 23 roosts; 7 roosts (30%) had >1 sample in which Nipah RNA was detected from the first visit. In subsequent visits to these 7 roosts, RNA was detected in bat urine up to 52 days after the presumed exposure of the human case-patient, although the probability of detection declined rapidly with time. These results suggest that rapidly deployed investigations of Nipah virus shedding from bat roosts near human cases could increase the success of viral sequencing compared with background surveillance and could enhance understanding of Nipah virus ecology and evolution.     

Nipah病毒性脑炎的研究进展

Nipah病毒是近年在东南亚新出现的一种人畜共患病病毒,导致Nipah病毒性脑炎的暴发流行,传染性强,死亡率高。本文主要就近年对Nipah病毒性脑炎的研究进展包括病毒分子生物学、发病机制、流行病学、临床及辅助检查等作一综述。     

Single-dose live-attenuated vesicular stomatitis virus-based vaccine protects African green monkeys from Nipah virus disease

Nipah virus is a zoonotic paramyxovirus that causes severe respiratory and/or encephalitic disease in humans, often resulting in death. It is transmitted from pteropus fruit bats, which serve as the natural reservoir of the virus, and outbreaks occur on an almost annual basis in Bangladesh or India. Outbreaks are small and sporadic, and several cases of human-to-human transmission have been documented as an important feature of the epidemiology of Nipah virus disease. There are no approved countermeasures to combat infection and medical intervention is supportive. We recently generated a recombinant replication-competent vesicular stomatitis virus-based vaccine that encodes a Nipah virus glycoprotein as an antigen and is highly efficacious in the hamster model of Nipah virus disease. Herein, we show that this vaccine protects African green monkeys, a well-characterized model of Nipah virus disease, from disease one month after a single intramuscular administration of the vaccine. Vaccination resulted in a rapid and strong virus-specific immune response which inhibited virus shedding and replication. This vaccine platform provides a rapid means to afford protection from Nipah virus in an outbreak situation.     

Prevalence of henipavirus and rubulavirus antibodies in pteropid bats, Papua New Guinea

To determine seroprevalence of viruses in bats in Papua New Guinea, we sampled 66 bats at 3 locations. We found a seroprevalence of 55% for henipavirus (Hendra or Nipah virus) and 56% for rubulavirus (Tioman or Menangle virus). Notably, 36% of bats surveyed contained antibodies to both types of viruses, indicating concurrent or consecutive infection.     

Nipah virus infection in bats (order Chiroptera) in peninsular Malaysia

Nipah virus, family Paramyxoviridae, caused disease in pigs and humans in peninsular Malaysia in 1998-99. Because Nipah virus appears closely related to Hendra virus, wildlife surveillance focused primarily on pteropid bats (suborder Megachiroptera), a natural host of Hendra virus in Australia. We collected 324 bats from 14 species on peninsular Malaysia. Neutralizing antibodies to Nipah virus were demonstrated in five species, suggesting widespread infection in bat populations in peninsular Malaysia.     

Isolation and molecular identification of Nipah virus from pigs

Nipah viruses from pigs from a Malaysian 1998 outbreak were isolated and sequenced. At least two different Nipah virus strains, including a previously unreported strain, were identified. The findings highlight the possibility that the Malaysia outbreaks had two origins of Nipah virus infections.     

Nipah virus encephalitis reemergence, Bangladesh

We retrospectively investigated two outbreaks of encephalitis in Meherpur and Naogaon, Bangladesh, which occurred in 2001 and 2003. We collected serum samples from persons who were ill, their household contacts, randomly selected residents, hospital workers, and various animals. Cases were classified as laboratory confirmed or probable. We identified 13 cases (4 confirmed, 9 probable) in Meherpur; 7 were in persons in two households. Patients were more likely than nonpatients to have close contact with other patients or have contact with a sick cow. In Naogaon, we identified 12 cases (4 confirmed, 8 probable); 7 were in persons clustered in 2 households. Two Pteropus bats had antibodies for Nipah virus. Samples from hospital workers were negative for Nipah virus antibodies. These outbreaks, the first since 1999, suggest that transmission may occur through close contact with other patients or from exposure to a common source. Surveillance and enhancement of diagnostic capacity to detect Nipah virus infection are recommended.     

Foodborne transmission of Nipah virus, Bangladesh

We investigated an outbreak of encephalitis in Tangail District, Bangladesh. We defined case-patients as persons from the outbreak area in whom fever developed with new onset of seizures or altered mental status from December 15, 2004, through January 31, 2005. Twelve persons met the definition; 11 (92%) died. Serum specimens were available from 3; 2 had immunoglobulin M antibodies against Nipah virus by capture enzyme immunoassay. We enrolled 11 case-patients and 33 neighborhood controls in a case-control study. The only exposure significantly associated with illness was drinking raw date palm sap (64% among case-patients vs. 18% among controls, odds ratio [OR] 7.9, p = 0.01). Fruit bats (Pteropus giganteus) are a nuisance to date palm sap collectors because the bats drink from the clay pots used to collect the sap at night. This investigation suggests that Nipah virus was transmitted from P. giganteus to persons through drinking fresh date palm sap.     

Antibodies to Nipah-like virus in bats (Pteropus lylei), Cambodia

Serum specimens from fruit bats were obtained at restaurants in Cambodia. We detected antibodies cross-reactive to Nipah virus by enzyme immunoassay in 11 (11.5%) of 96 Lyle's flying foxes (Pteropus lylei). Our study suggests that viruses closely related to Nipah or Hendra viruses are more widespread in Southeast Asia than previously documented.     

Transmission Routes for Nipah Virus from Malaysia and Bangladesh

Human infections with Nipah virus in Malaysia and Bangladesh are associated with markedly different patterns of transmission and pathogenicity. To compare the 2 strains, we conducted an in vivo study in which 2 groups of ferrets were oronasally exposed to either the Malaysia or Bangladesh strain of Nipah virus. Viral shedding and tissue tropism were compared between the 2 groups. Over the course of infection, significantly higher levels of viral RNA were recovered from oral secretions of ferrets infected with the Bangladesh strain. Higher levels of oral shedding of the Bangladesh strain of Nipah virus might be a key factor in onward transmission in outbreaks among humans.     

Risk of nosocomial transmission of Nipah virus in a Bangladesh hospital.

We conducted a seroprevalence study and exposure survey of healthcare workers to assess the risk of nosocomial transmission of Nipah virus during an outbreak in Bangladesh in 2004. No evidence of recent Nipah virus infection was detected despite substantial exposures and minimal use of personal protective equipment.     

Isolation of Tioman virus from Pteropus giganteus bat in North-East region of India

Bat-borne viral diseases are a major public health concern among newly emerging infectious diseases which includes severe acute respiratory syndrome, Nipah, Marburg and Ebola virus disease. During the survey for Nipah virus among bats at North-East region of India; Tioman virus (TioV), a new member of the Paramyxoviridae family was isolated from tissues of Pteropus giganteus bats for the first time in India. This isolate was identified and confirmed by RT-PCR, sequence analysis and electron microscopy. A range of vertebrate cell lines were shown to be susceptible to Tioman virus. Negative electron microscopy study revealed the “herringbone” morphology of the nucleocapsid filaments and enveloped particles with distinct envelope projections a characteristic of the Paramyxoviridae family. Sequence analysis of Nucleocapsid gene of TioV demonstrated sequence identity of 99.87% and 99.99% nucleotide and amino acid respectively with of TioV strain isolated in Malaysia, 2001. This report demonstrates the first isolation of Tioman virus from a region where Nipah virus activity has been noticed in the past and recent years. Bat-borne viruses have become serious concern world-wide. A Survey of bats for novel viruses in this region would help in recognizing emerging viruses and combating diseases caused by them.     

Nipah Virus Infection Outbreak with Nosocomial and Corpse-to-Human Transmission,Bangladesh

Active Nipah virus encephalitis surveillance identified an encephalitis cluster and sporadic cases in Faridpur, Bangladesh, in January 2010. We identified 16 case-patients; 14 of these patients died. For 1 case-patient, the only known exposure was hugging a deceased patient with a probable case, while another case-patient’s exposure involved preparing the same corpse for burial by removing oral secretions and anogenital excreta with a cloth and bare hands. Among 7 persons with confirmed sporadic cases, 6 died, including a physician who had physically examined encephalitis patients without gloves or a mask. Nipah virus–infected patients were more likely than community-based controls to report drinking raw date palm sap and to have had physical contact with an encephalitis patient (29% vs. 4%, matched odds ratio undefined). Efforts to prevent transmission should focus on reducing caregivers’ exposure to infected patients’ bodily secretions during care and traditional burial practices.     

Genetic characterization of Nipah virus, Bangladesh, 2004

Until 2004, identification of Nipah virus (NV)-like outbreaks in Bangladesh was based on serology. We describe the genetic characterization of a new strain of NV isolated during outbreaks in Bangladesh (NV-B) in 2004, which confirms that NV was the etiologic agent responsible for these outbreaks.     

Bat Nipah virus, Thailand

Surveillance for Nipah virus (NV) was conducted in Thailand's bat population. Immunoglobulin G antibodies to NV were detected with enzyme immunoassay in 82 of 1,304 bats. NV RNA was found in bat saliva and urine. These data suggest the persistence of NV infection in Thai bats.