ECTOPARASITES

Causative organism	Pubic lice is caused by Pthirus pubis Scabies is caused by Sarcoptes scabiei var hominis See STI Guidelines
Incubation period	P. pubis– 7-10 days Scabies –2-6 weeks; or 1-4 days after re-infestation
How far to trace back	P. pubis– 7-10 days before onset of symptoms Scabies –6 weeks
Usual testing method	P.pubis– Visual inspection Scabies –Visual inspection +/- skin scrapings
Common symptoms	P. pubis – itching in the genital area Scabies –intense itching particularly at night or after a hot shower/bath
Likelihood of transmission per act of condomless intercourse	Unknown but possible
Likelihood of long-term sexual partner being infected	Probable
Protective effect of condoms	Unknown but unlikely
Transmission by oral sex	P. pubis–lice can infest facial hair including eyelashes Scabies – n/a
Duration of potential infectivity	Until treatment completed. Concurrent laundering of personal clothing and bed linen required.
Important sequelae	Secondary infection of lesions caused by scratching; Lymphadenitis
Direct benefit of detection and treatment of contacts	Cure
Usual management of contacts	P. pubis–treatment with effective chemical & advised to launder personal underwear and bed linen used in the previous 7 days prior to treatment Scabies –Isolate until after treatment. Advised to launder bed linen and personal clothing used in the 48 hours prior to treatment Note: For outbreaks in closed communities, such as residential aged care facilities, all residents and staff who have had contact with residents with scabies require treatment. Quarantine the affected area if possible. If staff from the affected area have worked elsewhere, that area should also be assessed. The source of a scabies outbreak in a residential aged care facility should be identified because the patient may have crusted scabies. If a school-aged child has scabies, notify the school. Treatment of children who do not have scabies is not required. Children with scabies can return to school when two treatments for scabies, 1 week apart, are completed.
Contact tracing priority	Sexual partners and close household contacts
Notification	Not required

References:

www.betterhealth.vic.gov.au

Heymann D, 2015 Control of Communicable Diseases Manual An Official Report of the American Public Health Association

Page last updated May 2021