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.
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.
HIV is a virus which attacks the immune system and causes a lifelong severe illness with a long incubation period. The end-stage of the infection, acquired immunodeficiency syndrome (AIDS), results from the destruction of the immune system.
Campylobacteriosis is a diarrhoeal disease caused by Campylobacter bacteria, found in animals such as poultry, cattle, pigs, wild birds and wild mammals
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.
Diphtheria is spread through droplets from coughing or sneezing. Most often the disease causes a sore throat and low grade fever in the first few days of the illness.