Ascariasis A015

Current RMA Instruments

Changes from previous Instruments

ICD Coding:

• ICD-10-AM Codes: B77, B77.9

Brief description

Ascariasis is a parasitic intestinal infection caused by roundworms. It is most common in impoverished rural areas with warm, humid climates, including remote communities in northern Australia. Transmission occurs primarily through ingestion of food or water contaminated with roundworm eggs.  Poor hygiene further facilitates spread, with soil contaminated by faeces serving as a source of infection via hands.  Most cases are asymptomatic and do not result in symptoms. However, in rare instances, ascariasis may cause pulmonary involvement or intestinal obstruction.

Confirming the diagnosis

The diagnosis is typically established by stool microscopy for eggs, or by direct identification of adult worms in sputum, vomitus, stool or gastrointestinal aspirates. As eggs do not appear in stool until at least 40 days after infection, early cases may be missed on microscopy.

General practitioners often confirm this diagnosis based on consistent clinical history and stool microscopy results. However, Infectious Diseases physicians often become involved in complicated or severe cases. 

Additional diagnoses covered by SOP

• Roundworm
• Infection with Ascaris lumbricoides or Ascaris suum.

Conditions that are excluded from SOP

• Hookworm Disease *
• Whipworm infection #

* another SOP applies

# non-SOP condition

Clinical onset

In asymptomatic ascariasis, the clinical onset is defined as the time of diagnosis.  Intestinal manifestations may appear six to eight weeks after ingestion of eggs and are usually non-specific, including abdominal discomfort, anorexia, nausea, vomiting, and/or diarrhoea. Adult worms may occasionally be observed macroscopically in stool.  Less commonly, early pulmonary symptoms occur, lasting five to ten days. These include dry cough, shortness of breath, fever, wheezing, substernal discomfort, and blood-tinged sputum. Pulmonary features typically develop 4 to 16 days after egg ingestion. 

Clinical worsening

Treatment of ascariasis with a single dose or short course of an oral benzimidazole is highly effective. Worsening disease is suggested by the development of complications, such as bowel obstruction, biliary obstruction or pancreatitis.