Nipah virus and other emerging infections

A brief guide to some important emerging infections and their impact in Bangladesh.          

Nipah virus

• Nipah viruswas first discovered in 1998 in Malaysia and was first seen in Bangladesh in 2001.
• Nipah virus infection causes potentially lethal inflammation of the brain (encephalitis); in Bangladesh, about three-quarters of those infected with Nipah virus have died.
• Between 2001 and 2014, 33 outbreaks of Nipah virus encephalitis were reported in Bangladesh and India.
• During 2004–12, 157 Nipah virus infectionswere reported in Bangladesh
• Nipah virus is usually transmitted by bats, but it can also be spread from one infected person to another.
• In Bangladesh, Nipah virus is usually acquired through consumption of date palm sap contaminated with bat saliva or urine.

Avian influenza virus (bird flu)

• Highly pathogenic H5N1 avian influenza was first detected in Bangladesh in 2007.
• Since 2007, seven human infections with H5N1 avian influenza have been confirmed in Bangladesh, with one death.
• H5N1 is endemic within poultry in Bangladesh.
• Two cases of H9N2 avian influenza, which causes a mild disease, have been detected in Bangladesh.

Dengue virus

• Dengue virusis spread by mosquitoes and can cause high fever, severe headache, and pain behind the eyes, in muscle and in joints.
• Dengue occurred sporadically in Bangladesh from the 1960s to 2000, when a large epidemic established it within the country.
• The largest dengue epidemic occurred in 2002, when 6,132 cases and around 60 deaths were reported.
• The number of recorded cases is now much lower, but many infections are likely to be unrecorded; a global study on the burden of dengue estimated there were 16 million dengue infections in Bangladesh during 2010, 4 million of them symptomatic.
• Globally, around 96 million symptomatic episodes and approximately 20,000 deaths occur each year; however, most cases are mild.

Chikungunya virus

• Chikungunya virusis transmitted by mosquitoes and causes fever and joint pain.
• Chikungunya virus was first identified in Tanzania in 1952; the first recorded outbreak in Bangladesh occurred in 2008.
• A further small outbreak occurred in 2011, and evidence of Chikungunya infection was found in analysis of blood samples from people living in Dhaka in 2014.

Anthrax

• Anthrax (‘Torka’) is an infection caused by the bacterium Bacillus anthracis; most infections are skin lesions, although the bacterium can infect the lungs, intestine and bloodstream.
• Anthrax is spread through exposure to Bacillus anthracisspores; it is usually caught following exposure to infected animals – it does not normally spread from person to person.
• By 2011, 600 cases of human anthrax had been reported, but many more cases probably go unreported.
• Anthrax is probably endemic in Bangladesh livestock; the disease is most prevalent in Sirajganj(site of an anthrax outbreak in 2016) and nearby districts.

Middle East respiratory syndrome coronavirus, MERS-CoV

• MERS-CoVis a novel virus causing severe respiratory disease, first identified in Saudi Arabia in 2012.
• More than 1,700 cases have been notified to the WHO, and more than 600 deaths have been reported.
• MERS-CoV has not been detected in Bangladesh; a possible infection reported in 2014 was later found to be a false alarm.

Sources

http://www.searo.who.int/entity/emerging_diseases/links/nipah_virus_outbreaks_sear/en/

Islam MS et al. Nipah VirusTransmission from Bats to Humans Associated with Drinking Traditional Liquor Made from Date Palm Sap, Bangladesh, 2011-2014.Emerg Infect Dis. 2016;22(4):664-70.

Gerloff NA et al.Genetically Diverse Low Pathogenicity AvianInfluenza A Virus Subtypes Co-Circulate among Poultry in Bangladesh.PLoS One. 2016;11(3):e0152131.

Sharmin S, Viennet E, Glass K, Harley D. The emergence of dengue in Bangladesh: epidemiology, challenges and future disease risk.Trans R Soc Trop Med Hyg. 2015;109(10):619-27.

Bhatt Set al. The global distribution and burden of dengue.Nature. 2013;496(7446):504-7.

Khatun S et al. An Outbreak of Chikungunya in Rural Bangladesh, 2011.PLoSNegl Trop Dis.2015;9(7):e0003907.

Islam MS et al.Risk practices for animal and human anthrax in Bangladesh: an exploratory study.Infect EcolEpidemiol. 2013;3.

http://www.who.int/emergencies/mers-cov/en/