West Nile virus is a mosquito-borne flavivirus that is maintained in an enzootic cycle between mosquitoes and birds. Humans and horses are incidental dead-end hosts.
Meningococcal disease is caused by Neisseria meningitidis, a bacterium with human carriers as the only reservoir. It is carried in the nose, where it can remain for long periods without producing symptoms.
Poliovirus is highly contagious and infected individuals shed virus in the faeces and from oral secretions, thus the mode of transmission is person-to-person, both via the faecal-oral and the oral-oral routes.
Marburg virus disease (MVD), formerly known as Marburg haemorrhagic fever, is a severe disease in humans caused by Marburg marburgvirus (MARV). Although MVD is uncommon, MARV has the potential to cause epidemics with significant case fatality rates.
Yellow fever (YF) is a mosquito-borne infection, distributed in west, central and east Africa and in South America. The disease can cause a wide spectrum of symptoms, from mild to fatal. In severe cases there may be spontaneous haemorrhage. Mortality of these clinical cases can be as high as 80%, on a par with Ebola, Marburg and other haemorrhagic viral infections.
Meningococcal disease is caused by Neisseria meningitidis, a bacterium with human carriers as the only reservoir. It is carried in the nose, where it can remain for long periods without producing symptoms.
Yellow fever (YF) cause a wide spectrum of symptoms, from mild to fatal. In severe cases there may be spontaneous haemorrhage. Mortality of these clinical cases can be as high as 80%, on a par with Ebola, Marburg and other haemorrhagic viral infections.
West Nile virus (WNV) infection is a mosquito-borne zoonosis. The virus is transmitted among birds via the bite of infected mosquitoes and incidentally humans and other mammals may become infected.
Poliomyelitis, also known as polio or infantile paralysis, is a vaccine-preventable systemic viral infection affecting the motor neurons of the central nervous system (CNS). Historically, it has been a major cause of mortality, acute paralysis and lifelong disabilities but large scale immunisation programmes have eliminated polio from most areas of the world.