Nipah encephalitis, a fatal encephalitis with bats as reservoir
Avindra Nath, Joseph R. Berger in Clinical Neurovirology, 2020
Nipah virus has been found to be widely distributed in at least 10 genera and 23 species of bats in large part of Asia and Africa [51]. Therefore, clinicians should be open to emergence of Nipah virus infection, even though the infection has not been known to be endemic. The clinical features that may indicate possible Henipavirus infection are: (1) History of illness in animals, such as pigs or horses, that may be exposed to Pteropus or other fruit bats; (2) clustering of cases in the same household or geographic area that may suggest an outbreak; (3) clustering of cases that may suggest zoonosis or person-to-person spread of infection; e.g., illness involving animal workers, healthcare workers, or family members; (4) Acute febrile illness involving neurologic or respiratory systems [52].
Responding to Uncertainty
Kevin Bardosh in One Health, 2016
This chapter examines uncertainty, the assessment of the risk of zoonotic disease emergence and associated policy responses, through the example of fruit bats and Henipavirus (Nipah and Hendra)1 in Ghana.2 It argues that a ‘politics of precaution’ has operated around this uncertainty in which the control of knowledge has became a sensitive issue. As discussed below, the discovery that Ghana’s bats hosted zoonotic pathogens revealed the many latent tensions between the preservation of human health and of wildlife, and militated against immediate public disclosure. Furthermore, uncertainty around the emergence of bat-associated zoonoses facilitates a lack of clarity over which government sector should take responsibility and which type(s) of surveillance activities should be prioritized. Broad plans for ‘big system’ surveillance, currently proposed by the WHO and other international players, pose additional challenges surrounding detection and public health system constraints.
Health promotion and vector-borne disease outbreaks
Glenn Laverack in Health Promotion in Disease Outbreaks and Health Emergencies, 2017
The NiV infection is a Henipavirus, a genus of RNA viruses naturally harboured by pteropid fruit bats (flying foxes) and several species of microbats. The finding of henipaviruses in Africa, Australia and Asia indicates that it has the potential to become endemic in a country (Drexler et al. 2009). The term ‘Nipah’ refers to the place, Kampung Baru Sungai Nipah in Negeri Sembilan state, Malaysia, the source of the human case from which the virus was first isolated. Nipah virus was first identified in April 1999, when it caused an outbreak of neurological and respiratory disease on pig farms in Malaysia, resulting in 257 human cases, including 105 human deaths and the culling of 1 million pigs. Symptoms of infection during the outbreak were primarily encephalitic in humans, and it was initially diagnosed as Japanese encephalitis. The Ministry of Health launched a nationwide campaign to educate people on the dangers of Japanese encephalitis and its vector, Culex mosquitoes. However, it was later noticed that people who had been vaccinated against Japanese encephalitis were not protected. Because the disease can be difficult to diagnose based on clinical signs alone, surveillance tools are essential for the NiV and include reliable laboratory assays for early detection of the disease in people and livestock. The transmission of the NiV from flying foxes to pigs was thought to be due to an overlap between bat habitats and piggeries in Malaysia. Eight more outbreaks of the NiV have occurred since 1999, all within Bangladesh, Singapore and neighbouring parts of India (Lo Presti et al. 2015).
Post-exposure prophylactic vaccine candidates for the treatment of human Risk Group 4 pathogen infections
Published in Expert Review of Vaccines, 2020
James Logue, Ian Crozier, Peter B Jahrling, Jens H Kuhn
Nipah virus (NiV; Paramyxoviridae: Henipavirus), is responsible for encephalitis outbreaks in Southern and Southeast Asia (in particular, Bangladesh, Malaysia, and India) that have been increasing in regularity and severity. After an incubation period generally ranging from a few days to-14 days, human disease most often presents with fever, headache, and other nonspecific symptoms. Patients may present with respiratory symptoms and signs, but most prominently they will rapidly progress to encephalitis and coma within 5 to 7 days. Disease sequelae have been reported, including relapsing encephalitis developing months or years following recovery [117]. Transmission of NiV to humans has been linked to domestic pigs (Sus scrofa domesticus Erxleben, 1777) that have come into contact with NiV natural reservoir hosts (pteropodid bats) [118]. As potential routes of infection are well documented for NiV, PEP vaccination may have the potential to minimize the spread of NiV among humans, especially if implemented following noticeable disease in domestic pigs. Though no currently licensed vaccine for the prevention of NiV infection is available, multiple candidate vaccines have been developed, including rVSIV-vectored and rabies virus-vectored vaccines, which have variable efficacy in animal studies if administered prior to infection [119,120]. These candidate vaccines should be evaluated for PEP efficacy as soon as possible. Likewise, similar candidate PEP vaccines ought to be developed for NiV’s closest relative, Hendra virus, which, thus far, has caused a handful of lethal encephalitis cases [121].
A review of mechanistic models of viral dynamics in bat reservoirs for zoonotic disease
Published in Pathogens and Global Health, 2020
Anecia D. Gentles, Sarah Guth, Carly Rozins, Cara E. Brook
Following lyssaviruses, understanding of henipavirus dynamics in bat reservoirs shows the most promise to date – in part a reflection of the feasibility of noninvasive viral surveillance through under-roost urine collection in these systems [82]. Our analysis identified only five studies focused on bat-henipaviruses, but three of these five studies presented mechanistic models fitted to field-derived data [25,27,71]. All three studies reported that waning antibodies post-seroconversion contributes to observed henipavirus dynamics, consistent with findings for bat filoviruses. Collectively, these studies also suggested a possible role for recrudescent infection or loss of immunity and reinfection in recovering henipavirus persistence. Broadly, data-fitted henipavirus models assumed no elevated mortality in infectious individuals; however, [25,suggested this as a possible mechanism for observed declines in seroprevalence in older bats, as also posited for filoviruses. Generalizable trends for bat henipaviruses remain somewhat muddled largely due to the idiosyncratic nature of the datasets modeled – including one purely cross-sectional study [27], one eighteen-month time series [25], and one time series derived from a captive colony [71]. Notably, no existing study has yet to fit a compartmental transmission model to the Australian bat reservoirs for Hendra virus, despite claims that this system is a model system for understanding bat virus spillover [83].
Related Knowledge Centers
- Genome
- Mononegavirales
- Nipah Virus
- Paramyxoviridae
- Zoonosis
- Lipid
- Negative-Strand Rna Virus
- Hendra Virus
- Select Agent
- Pleomorphism