Hydatid disease is an uncommon diagnosis in New Zealand. This parasitic tapeworm infection presents non-specifically and can be difficult to diagnose. In the early 1960s a national eradication strategy was implemented and by 2002, New Zealand declared “provisional freedom” from the disease.[[3]] This case report presents a recent instance of incidentally discovered hydatid disease in a patient presenting to primary care with back pain in the Whanganui District Health Board (DHB) and is a reminder that the diagnosis should not be forgotten in the New Zealand population.
A 55-year-old man presented to his general practitioner with back pain. Review of systems identified no other symptoms. Of note, he was a life-long farmer and had prolonged contact with canines. A lumbar X-ray revealed an incidental finding of a calcified lesion in the left upper quadrant, raising the possibility of a hydatid cyst (Figure 1). Ultrasound imaging confirmed an intrasplenic cystic structure. Serological testing for Echinococcus granulosus was indeterminant. Liver biochemistry and inflammatory markers were unremarkable. Retrospective review of historical chest x-rays performed up to 11 years prior to presentation showed left-sided subphrenic calcifications.
Abdominal computerised tomography (CT) imaging showed a peripherally calcified cystic lesion within the superior aspect of the spleen measuring 85x74x67mm consistent with a hydatid cyst (Figure 2). There was no other organ involvement. The patient was referred to the general surgeons and a laparoscopic splenectomy was performed electively. A large cystic structure was seen in the spleen and this was excised without perforation (Figure 3). Histology revealed sections that were compatible with an “ancient” hydatid cyst. The patient received his vaccinations as part of the splenectomy protocol.
The patient had an uneventful post-operative recovery and was discharged with no ongoing surgical follow-up.
View Figures 1–3.
The incidence of hydatid disease in New Zealand is extremely low. Between 2006 and 2017, less than eight cases were reported per year. Whanganui DHB had no documented cases for the past 15 years.[[4]]
Hydatid disease is caused by the tapeworm, Echinococcus granulosus. Canines are the definitive hosts, while humans are involved as incidental hosts in the parasites lifecycle.[[1,2]] Usual intermediate hosts include cattle, sheep, goats and horses. The parasite causes cysts that may affect most systems of the body. Humans ingest the eggs, which migrate via the splanchnic venous drainage. Thus, the most common organs affected are the liver (50–75% of cases) and lungs (15–30%).[[2,10]] Splenic involvement is rare (approx. 5% of cases).[[7,10]]
Hydatids are often asymptomatic and can remain so for decades.[[8]] Symptoms typically develop with increasing cyst size. Pulmonary cysts may cause cough, dyspnoea and chest pain and hepatic cysts may result in right upper quadrant abdominal pain, nausea and malaise.[[1,5]]
Complications of hydatid cysts can arise from the cysts mass effects including obstruction of lymphatic and venous drainage systems. The cysts may become secondarily infected by bacteria or can rupture. Anaphylaxis following rupture has been described.[[6]]
There is serological testing available to aid in the diagnosis of hydatid disease. This testing typically includes IgG antibodies. The diagnostic accuracy varies depending on organ involvement. Sensitivity of serology testing in the presence of liver, lung and spleen involvement is 80–100%, 50–56% and 25–56%, respectively.[[9]]
Diagnosis of hydatid disease uses a combination of imaging, serology and clinical suspicion. Ultrasonography is the imaging modality of choice, but CT offers benefit for extra-hepatic lesions and anatomical mapping.
Treatment depends upon cyst classification, anatomical location and risk of complications. Antiparasitic agents, most commonly albendazole, can be definite or adjunctive therapies. Surgical removal of intact hydatid cysts or the use of the PAIR procedure (puncture, aspiration, installation [of a protoscolicidal agent] reaspiration) are interventional treatments.
This rare case highlights the persistent possibility of hydatid disease in the New Zealand population.
• Although uncommon, cases of hydatid disease in New Zealand still exist. Cases likely relate to distant disease (if acquired in New Zealand) or brought in from areas of the world with a greater prevalence.
• The complications of hydatid disease can be life-threatening.
• Cysts can develop outside of the liver and lungs. These cysts may have a different appearance on imaging than those seen in the liver.
• Serological testing sensitivity for E. granulosus varies depending upon organ involvement.
1) Kasper D, Fauci AS. Harrison’s Infectious Diseases. 3[[rd]] ed. New York: McGraw Hill Medical; 2016. p.1248-50.
2) Santivanez S, Garcia H. Pulmonary Cystic Echinococcus. Curr Opin Pulm Med. 2010 May;16(3):257-61.
3) O’Connor D. Freedom from Hydatids. Beehive Speeches. [Internet]. Wellington. 2002 Oct 8. [Cited Oct 2022]. Available from: www.beehive.govt.nz/speech/freedom-hydatids/.
4) Monthly notifiable disease surveillance report – Sep 2018. [Internet]. Institute of Environmental Science and Research Limited. [Cited Oct 22]. Available from: https://surv.esr.cri.nz/PDF_surveillance/MthSurvRpt/2018/09Sep/201809_September18.pdf.
5) Loscalzo J, Fauci AS, Kasper DL, Hauser SL, Longo, DL, Jameson JL. Harrison’s Principles of Internal Medicine. 21st ed. New York: McGraw Hill Medical; 2022. p.1762-63.
6) Mouaqit O, Hibatallah A, Oussaden A, et al. Acute intraperitoneal rupture of hydatid cysts: a surgical experience with 14 cases. World J Emerg Surg. 2013 July 26;8(28).
7) Rasheed K, Zargar SA, Telwani AA. Hydatid Cyst of Spleen: A Diagnostic Challenge. N Am J Med Sci. 2013 Jan;5(1):10-20.
8) Frider B, Larrieu E, Odriozola M. Long-term outcome of asymptomatic liver hydatidosis. J Hepatol. 1999 Feb;30(2):228-31.
9) Bennett JE, Dolin R, Blaser MJ. Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases. 9th ed. Philadelphia: Elsevier; 2020. p.3233-35.
10) Sabouni F, Ferdosian F, Mamishi S, et al. Multiple organ involvement with hydatid cysts. Iran J Parasitol. 2010 Jun;5(2): 65-70.
Hydatid disease is an uncommon diagnosis in New Zealand. This parasitic tapeworm infection presents non-specifically and can be difficult to diagnose. In the early 1960s a national eradication strategy was implemented and by 2002, New Zealand declared “provisional freedom” from the disease.[[3]] This case report presents a recent instance of incidentally discovered hydatid disease in a patient presenting to primary care with back pain in the Whanganui District Health Board (DHB) and is a reminder that the diagnosis should not be forgotten in the New Zealand population.
A 55-year-old man presented to his general practitioner with back pain. Review of systems identified no other symptoms. Of note, he was a life-long farmer and had prolonged contact with canines. A lumbar X-ray revealed an incidental finding of a calcified lesion in the left upper quadrant, raising the possibility of a hydatid cyst (Figure 1). Ultrasound imaging confirmed an intrasplenic cystic structure. Serological testing for Echinococcus granulosus was indeterminant. Liver biochemistry and inflammatory markers were unremarkable. Retrospective review of historical chest x-rays performed up to 11 years prior to presentation showed left-sided subphrenic calcifications.
Abdominal computerised tomography (CT) imaging showed a peripherally calcified cystic lesion within the superior aspect of the spleen measuring 85x74x67mm consistent with a hydatid cyst (Figure 2). There was no other organ involvement. The patient was referred to the general surgeons and a laparoscopic splenectomy was performed electively. A large cystic structure was seen in the spleen and this was excised without perforation (Figure 3). Histology revealed sections that were compatible with an “ancient” hydatid cyst. The patient received his vaccinations as part of the splenectomy protocol.
The patient had an uneventful post-operative recovery and was discharged with no ongoing surgical follow-up.
View Figures 1–3.
The incidence of hydatid disease in New Zealand is extremely low. Between 2006 and 2017, less than eight cases were reported per year. Whanganui DHB had no documented cases for the past 15 years.[[4]]
Hydatid disease is caused by the tapeworm, Echinococcus granulosus. Canines are the definitive hosts, while humans are involved as incidental hosts in the parasites lifecycle.[[1,2]] Usual intermediate hosts include cattle, sheep, goats and horses. The parasite causes cysts that may affect most systems of the body. Humans ingest the eggs, which migrate via the splanchnic venous drainage. Thus, the most common organs affected are the liver (50–75% of cases) and lungs (15–30%).[[2,10]] Splenic involvement is rare (approx. 5% of cases).[[7,10]]
Hydatids are often asymptomatic and can remain so for decades.[[8]] Symptoms typically develop with increasing cyst size. Pulmonary cysts may cause cough, dyspnoea and chest pain and hepatic cysts may result in right upper quadrant abdominal pain, nausea and malaise.[[1,5]]
Complications of hydatid cysts can arise from the cysts mass effects including obstruction of lymphatic and venous drainage systems. The cysts may become secondarily infected by bacteria or can rupture. Anaphylaxis following rupture has been described.[[6]]
There is serological testing available to aid in the diagnosis of hydatid disease. This testing typically includes IgG antibodies. The diagnostic accuracy varies depending on organ involvement. Sensitivity of serology testing in the presence of liver, lung and spleen involvement is 80–100%, 50–56% and 25–56%, respectively.[[9]]
Diagnosis of hydatid disease uses a combination of imaging, serology and clinical suspicion. Ultrasonography is the imaging modality of choice, but CT offers benefit for extra-hepatic lesions and anatomical mapping.
Treatment depends upon cyst classification, anatomical location and risk of complications. Antiparasitic agents, most commonly albendazole, can be definite or adjunctive therapies. Surgical removal of intact hydatid cysts or the use of the PAIR procedure (puncture, aspiration, installation [of a protoscolicidal agent] reaspiration) are interventional treatments.
This rare case highlights the persistent possibility of hydatid disease in the New Zealand population.
• Although uncommon, cases of hydatid disease in New Zealand still exist. Cases likely relate to distant disease (if acquired in New Zealand) or brought in from areas of the world with a greater prevalence.
• The complications of hydatid disease can be life-threatening.
• Cysts can develop outside of the liver and lungs. These cysts may have a different appearance on imaging than those seen in the liver.
• Serological testing sensitivity for E. granulosus varies depending upon organ involvement.
1) Kasper D, Fauci AS. Harrison’s Infectious Diseases. 3[[rd]] ed. New York: McGraw Hill Medical; 2016. p.1248-50.
2) Santivanez S, Garcia H. Pulmonary Cystic Echinococcus. Curr Opin Pulm Med. 2010 May;16(3):257-61.
3) O’Connor D. Freedom from Hydatids. Beehive Speeches. [Internet]. Wellington. 2002 Oct 8. [Cited Oct 2022]. Available from: www.beehive.govt.nz/speech/freedom-hydatids/.
4) Monthly notifiable disease surveillance report – Sep 2018. [Internet]. Institute of Environmental Science and Research Limited. [Cited Oct 22]. Available from: https://surv.esr.cri.nz/PDF_surveillance/MthSurvRpt/2018/09Sep/201809_September18.pdf.
5) Loscalzo J, Fauci AS, Kasper DL, Hauser SL, Longo, DL, Jameson JL. Harrison’s Principles of Internal Medicine. 21st ed. New York: McGraw Hill Medical; 2022. p.1762-63.
6) Mouaqit O, Hibatallah A, Oussaden A, et al. Acute intraperitoneal rupture of hydatid cysts: a surgical experience with 14 cases. World J Emerg Surg. 2013 July 26;8(28).
7) Rasheed K, Zargar SA, Telwani AA. Hydatid Cyst of Spleen: A Diagnostic Challenge. N Am J Med Sci. 2013 Jan;5(1):10-20.
8) Frider B, Larrieu E, Odriozola M. Long-term outcome of asymptomatic liver hydatidosis. J Hepatol. 1999 Feb;30(2):228-31.
9) Bennett JE, Dolin R, Blaser MJ. Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases. 9th ed. Philadelphia: Elsevier; 2020. p.3233-35.
10) Sabouni F, Ferdosian F, Mamishi S, et al. Multiple organ involvement with hydatid cysts. Iran J Parasitol. 2010 Jun;5(2): 65-70.
Hydatid disease is an uncommon diagnosis in New Zealand. This parasitic tapeworm infection presents non-specifically and can be difficult to diagnose. In the early 1960s a national eradication strategy was implemented and by 2002, New Zealand declared “provisional freedom” from the disease.[[3]] This case report presents a recent instance of incidentally discovered hydatid disease in a patient presenting to primary care with back pain in the Whanganui District Health Board (DHB) and is a reminder that the diagnosis should not be forgotten in the New Zealand population.
A 55-year-old man presented to his general practitioner with back pain. Review of systems identified no other symptoms. Of note, he was a life-long farmer and had prolonged contact with canines. A lumbar X-ray revealed an incidental finding of a calcified lesion in the left upper quadrant, raising the possibility of a hydatid cyst (Figure 1). Ultrasound imaging confirmed an intrasplenic cystic structure. Serological testing for Echinococcus granulosus was indeterminant. Liver biochemistry and inflammatory markers were unremarkable. Retrospective review of historical chest x-rays performed up to 11 years prior to presentation showed left-sided subphrenic calcifications.
Abdominal computerised tomography (CT) imaging showed a peripherally calcified cystic lesion within the superior aspect of the spleen measuring 85x74x67mm consistent with a hydatid cyst (Figure 2). There was no other organ involvement. The patient was referred to the general surgeons and a laparoscopic splenectomy was performed electively. A large cystic structure was seen in the spleen and this was excised without perforation (Figure 3). Histology revealed sections that were compatible with an “ancient” hydatid cyst. The patient received his vaccinations as part of the splenectomy protocol.
The patient had an uneventful post-operative recovery and was discharged with no ongoing surgical follow-up.
View Figures 1–3.
The incidence of hydatid disease in New Zealand is extremely low. Between 2006 and 2017, less than eight cases were reported per year. Whanganui DHB had no documented cases for the past 15 years.[[4]]
Hydatid disease is caused by the tapeworm, Echinococcus granulosus. Canines are the definitive hosts, while humans are involved as incidental hosts in the parasites lifecycle.[[1,2]] Usual intermediate hosts include cattle, sheep, goats and horses. The parasite causes cysts that may affect most systems of the body. Humans ingest the eggs, which migrate via the splanchnic venous drainage. Thus, the most common organs affected are the liver (50–75% of cases) and lungs (15–30%).[[2,10]] Splenic involvement is rare (approx. 5% of cases).[[7,10]]
Hydatids are often asymptomatic and can remain so for decades.[[8]] Symptoms typically develop with increasing cyst size. Pulmonary cysts may cause cough, dyspnoea and chest pain and hepatic cysts may result in right upper quadrant abdominal pain, nausea and malaise.[[1,5]]
Complications of hydatid cysts can arise from the cysts mass effects including obstruction of lymphatic and venous drainage systems. The cysts may become secondarily infected by bacteria or can rupture. Anaphylaxis following rupture has been described.[[6]]
There is serological testing available to aid in the diagnosis of hydatid disease. This testing typically includes IgG antibodies. The diagnostic accuracy varies depending on organ involvement. Sensitivity of serology testing in the presence of liver, lung and spleen involvement is 80–100%, 50–56% and 25–56%, respectively.[[9]]
Diagnosis of hydatid disease uses a combination of imaging, serology and clinical suspicion. Ultrasonography is the imaging modality of choice, but CT offers benefit for extra-hepatic lesions and anatomical mapping.
Treatment depends upon cyst classification, anatomical location and risk of complications. Antiparasitic agents, most commonly albendazole, can be definite or adjunctive therapies. Surgical removal of intact hydatid cysts or the use of the PAIR procedure (puncture, aspiration, installation [of a protoscolicidal agent] reaspiration) are interventional treatments.
This rare case highlights the persistent possibility of hydatid disease in the New Zealand population.
• Although uncommon, cases of hydatid disease in New Zealand still exist. Cases likely relate to distant disease (if acquired in New Zealand) or brought in from areas of the world with a greater prevalence.
• The complications of hydatid disease can be life-threatening.
• Cysts can develop outside of the liver and lungs. These cysts may have a different appearance on imaging than those seen in the liver.
• Serological testing sensitivity for E. granulosus varies depending upon organ involvement.
1) Kasper D, Fauci AS. Harrison’s Infectious Diseases. 3[[rd]] ed. New York: McGraw Hill Medical; 2016. p.1248-50.
2) Santivanez S, Garcia H. Pulmonary Cystic Echinococcus. Curr Opin Pulm Med. 2010 May;16(3):257-61.
3) O’Connor D. Freedom from Hydatids. Beehive Speeches. [Internet]. Wellington. 2002 Oct 8. [Cited Oct 2022]. Available from: www.beehive.govt.nz/speech/freedom-hydatids/.
4) Monthly notifiable disease surveillance report – Sep 2018. [Internet]. Institute of Environmental Science and Research Limited. [Cited Oct 22]. Available from: https://surv.esr.cri.nz/PDF_surveillance/MthSurvRpt/2018/09Sep/201809_September18.pdf.
5) Loscalzo J, Fauci AS, Kasper DL, Hauser SL, Longo, DL, Jameson JL. Harrison’s Principles of Internal Medicine. 21st ed. New York: McGraw Hill Medical; 2022. p.1762-63.
6) Mouaqit O, Hibatallah A, Oussaden A, et al. Acute intraperitoneal rupture of hydatid cysts: a surgical experience with 14 cases. World J Emerg Surg. 2013 July 26;8(28).
7) Rasheed K, Zargar SA, Telwani AA. Hydatid Cyst of Spleen: A Diagnostic Challenge. N Am J Med Sci. 2013 Jan;5(1):10-20.
8) Frider B, Larrieu E, Odriozola M. Long-term outcome of asymptomatic liver hydatidosis. J Hepatol. 1999 Feb;30(2):228-31.
9) Bennett JE, Dolin R, Blaser MJ. Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases. 9th ed. Philadelphia: Elsevier; 2020. p.3233-35.
10) Sabouni F, Ferdosian F, Mamishi S, et al. Multiple organ involvement with hydatid cysts. Iran J Parasitol. 2010 Jun;5(2): 65-70.
The full contents of this pages only available to subscribers.
Login, subscribe or email nzmj@nzma.org.nz to purchase this article.