Paratyphoid fever (Human)

Primary reference(s)

WHO, 2019. Typhoid. World Health Organization (WHO). Accessed 13 December 2019.

Additional scientific description

Paratyphoid fever is caused by Salmonella Paratyphi A and B (or uncommonly Paratyphi C) and is similar to Typhoid (WHO, 2019).

Humans are the only source of these bacteria; no animal or environmental reservoirs have been identified (WHO, 2018).

The onset of illness is insidious, with gradually increasing fatigue and a fever that increases daily from low-grade to high. Headache, malaise, and anorexia are nearly universal, and abdominal pain, diarrhoea, or constipation are common (Appiah et al., 2019).

Paratyphoid fever is usually described as less severe than typhoid fever (Appiah et al., 2019; WHO, 2019).

Blood culture is the mainstay of diagnosis in typhoid and paratyphoid fever. Bone marrow and stool cultures can also be used (Gupta et al., 2008; Appiah et al., 2019).

There are no definitive rapid diagnostic tests for paratyphoid fever. Initial diagnosis often has to be made clinically. Paratyphoid and typhoid fevers are clinically indistinguishable (Gupta et al., 2008; Appiah et al., 2019).

The Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) have published guidance on case classification and surveillance standards (Appiah et al., 2019; WHO, 2019).

Metrics and numeric limits

Not available.

Examples of drivers, outcomes and risk management

Paratyphoid fever is acquired through consumption of water or food contaminated by faeces of an acutely infected or convalescent person or a chronic, asymptomatic person (WHO, 2019).

Safe food and water precautions and frequent handwashing (especially before meals) are important preventative measures. Outreach efforts and effective health messaging to communities in high-risk countries are essential for helping prevent paratyphoid fever in these areas (WHO, 2019).