Infectious disease occurs when a pathogenic microorganism, such as bacterium, fungus or virus, or its products cause harmful alterations to the physiological or metabolic state of the host resulting from an infection (Craft, Gordon & Tiziani 2010; Lee & Bishop 2013). Pertussis is an infectious disease with characteristic clinical signs that is fatal in infants and young children (Jansen & Miedema 2009). However, norovirus is an important pathogen that causes illness such as gastroenteritis which is severe or life threatening to the immunocompromised patients and elderly (Koopmans 2008). Both pertussis and norovirus infection are transmissible from one individual to another through direct, indirect, or droplet contact (Lee & bishop 2013) and vulnerable populations are at high risk of developing complications and death (Glass, Parashar & Estes 2009). Therefore, prevention and control of infectious diseases are of paramount importance in protecting public health (Laws & Hillman 2012). This essay discusses on similarities and differences of disease description between pertussis and norovirus including clinical manifestations, incidence or occurrence, transmission and risk of acquisition to health care workers (HCWs), as well as the management of spread within the community and the health care setting.

Pertussis, also known as ‘whooping cough’ is an acute, highly contagious respiratory disease due to Gram-negative coccobacillus, Bordetella pertussis (Senanayake 2007) which is characterized by spasmodic coughing, whooping and post-tussive vomiting (Spartling & Carmon 2010). Nevertheless, noroviruses, often referred to as ‘winter vomitting’ (Gould 2008), are diverse group of single-stranded, positive-sense RNA viruses in the Caliciviridae family (Bruggink & Marshall 2010) that causes infection to gastrointestinal tract (Marshall & Bruggink 2011). These viruses replicate and invade the gastrointestinal tract inducing inflammation and damage to the epithelial cells (Gould 2008; Craft, Gordon & Tiziani 2010). Similarly, Bordetella pertussis produces adhesins and toxins that enable the organism to attach to and cause inflammation and damage to the ciliated epithelial cells of the respiratory tract which are responsible for the symptoms observed during the disease (Guiso 2009). In addition, these bacterial factors are also capable of intervening immune functions of the host and cause lymphocytosis, an abnormal increase in the number of lymphocytes in the blood (Guiso 2009; Lee & Bishop 2013).

Norovirus is one of the most common causes of gastroenteritis (Australian Government Department of Health and Ageing 2010), an inflammation of the gastrointestinal tract that results in diarrhoea and vomiting (Hall et al. 2011). The viruses elicit damage to the epithelial cells causing gastrointestinal hypermotility and increased water excretion leading to diarrhoea and destruction of mucosal barrier (Ma et al. 2011). Noroviruses also cause vomiting, nausea, fever and abdominal cramps (Hall et al. 2011). Dehydration may occur due to excessive loss of fluid and electrolytes caused by vomiting and diarrhoea ('Diarrhoea and vomiting' 2009), and in severe cases hypovolemic shock and death results (Garretson & Malberti 2007). Conversely, the bacterial products of Bordetella pertussis increase mucus secretions and cause accumulation of the mucus in the airway resulting in paroxysmal whooping cough in which infants can develop severe complications such as cerebral hypoxia that can lead to brain damage and death (Lee & Bishop 2013).

Classic pertussis affects young children (Senanayake 2007) and can be asymptomatic or range from mild cough illness to severe chronic cough illness in adolescents and adults (Murphy et al. 2008). The illness commences after an incubation period, typically seven to ten days with a range of one to three weeks (Senanayake 2007). The clinical course of classical