Hydatid disease in childhood: revisited report of an interesting case
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- Jairajpuri, Z.S., Jetley, S., Hassan, M.J. et al. J Parasit Dis (2012) 36: 265. doi:10.1007/s12639-012-0127-y
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Hydatid disease is a zoonosis caused by the tapeworm of Echinococcus spp. The disease is widely endemic in many sheep and cattle rearing locales. However, hydatidosis does not remain restricted to endemic geographical locales anymore but rather is a global health concern. It is a major public health burden causing significant morbidity and mortality. Echinococcus granulosus involvement in children has a different pattern than adults. Children of all age groups are susceptible and localization of the disease in the lungs is more commonly seen. Multiple liver cysts in the paediatric age group is relatively uncommon. We report an interesting case of multiple liver cysts in a 5-year old boy which was diagnosed as hydatid cysts on histopathological examination.
Hydatid disease is a zoonosis caused by the tapeworm of Echinococcus spp. It is prevalent where livestock is raised in association with dogs. The disease is widely endemic in many sheep and cattle rearing locales such as Australia, Latin America, Africa and Middle Eastern countries like Iran. (Akhter et al. 2011). India, though not primarily a sheep and cattle rearing country, hydatid disease has been reported from many diverse locations such as Madras, Ahmedabad and some parts of Himachal Pradesh (Vamsy et al. 1991). With increased migration of populations the prevalence of the disease has spread to other regions also (Sumer et al. 2009). Hence, contrary to the popular perception, hydatidosis does not remain restricted to endemic geographical locales anymore but rather is a global health concern, particularly in the rural countryside and semi-urban localities. It is a major public health burden causing significant morbidity and mortality. Hydatid disease is a parasitic infestation caused by Echinococcus spp., the most common being Echinococcus granulosus; others are E. multilocularis and E. vogeli. The primary hosts are dogs while humans are accidental intermediate hosts infected through ingestion of contaminated food with dog faeces or through direct contact with dogs (Sherwani et al. 2003). Most infected persons are asymptomatic and clinical manifestations vary according to the anatomic location of the cyst (Zargar-Shoshtari et al. 2007). The disease can occur in any organ and many unusual presentations of Echinococcus have been reported (Abu-Eshy 1998).
Echinococcus granulosus involvement in children has a different pattern than adults. In adults, liver is the most common site of localization of the larval forms whilst in children it is more common in the lungs. However, multiple liver cysts in the paediatric age group is relatively uncommon. We report an interesting case of multiple liver cysts in a 5-year old boy which was reported as hydatid cysts in the liver. This report also attempts to review literature on hydatid disease with reference to the pediatric age group.
Hydatid disease is an important health problem in many endemic countries and needs epidemiologic measures for its eradication (Tantawy 2010). Accidental ingestion of the embryonated eggs of E. granulosus following close contact with dogs is usually the starting point of this disease. Although many of the recorded cases of cystic Echinococcus are in adults, most human infections occur during childhood and adolescence, the disease being more prevalent among the rural populations (Todorov and Boeva 2000). Most cysts found in adults are generally hepatic in location and relatively few are seen in the lungs (Todorov and Boeva 2000; Mirshemirani et al. 2011). Several studies of hydatid disease in children however, have recorded a higher incidence of pulmonary hydatidosis (Recep et al. 2000; Mamishi et al. 2007), while Şehitoğullari (2007) showed that hydatid cysts in the liver were more common (Şehitoğullari 2007). In contrast, an equal incidence of hydatid cyst in lung and liver in pediatric patients was also reported. (Talaiezadeh and Maraghi 2006). The authors also postulated that the less dense nature of the liver tissue in children as compared to adults allows the scoleces to cross the liver barriers into the lungs. Our patient presented with multiple liver cysts, an uncommon presentation as compared to other pediatric case reports.
Despite an almost equal distribution of the disease in both sexes in adults (Bulent et al. 2008) the predominance in boys over girls has been described in many series (Senyuz et al. 1999; Talaiezadeh and Maraghi 2006 Tantawy 2010; Mirshemirani et al. 2011) This has been attributed to behavioral differences between both the sexes, with more outdoor exposure of boys, as suggested by Tantawy (2010). Patients age is known to range from 1 to 14 years although hydatid cyst in a 6 month old infant has also been reported (Prashant et al. 2007). Hence children of all age groups are susceptible. In concurrence with trends in literature, our patient was a 5-year old male child.
Most of the cases of hydatid disease come from rural areas or from people who have settled in urban localities after spending a majority of their life in villages. Many patients usually acquire the disease during childhood, but do not present with the clinical signs and symptoms until late adulthood (Lewall and Mc Corkell 1986). Errors in the clinical diagnosis of hydatid disease are frequent due to lack of any typical clinical presentation of the disease and imaging features which can also be variable. The variation of clinical presentation depends on the size and site of the lesion as well as the accessibility of the organ involved in the clinical examination (Tekinbas et al. 2009). The two most common sites of involvement are lungs and liver, however no organ is spared. Abdominal mass is the most common complaint in cases of liver involvement as seen in our case, and similar to other studies (Talaiezadeh and Maraghi 2006). The natural progression of untreated cyst may include calcification and death of the cyst, however, more frequently, the cyst gradually enlarges in size (Ammann and Eckert 1996). Hydatid cyst fluid is highly allergenic and carries a risk of anaphylaxis, thus the intraperitoneal rupture of a hydatid cyst is a life threatening emergency that can be potentially fatal (Sumer et al. 2009).
Hydatidosis can affect the brain, heart, kidney, ureter, spleen, uterus, fallopian tube, pancreas, diaphragm, bone, and muscles (Abu-Eshy 1998). Mamishi et al. (2007), in a retrospective study on hydatidosis in 31 children reported multiorgan involvement in only three of the cases. In contrast, higher incidences of multi-organ hydatid cyst disease in adults have been reported by other workers (Ishikawa et al. 2009; Mishra et al. 2010). Intra-cranial hydatid cysts are more common in the paediatric age group and cerebrospinal fluid cytosmears may provide confirmatory evidence of scolices (Sherwani et al. 2003). Diagnostic possibilities of cystic hepatic lesions are many especially when confronted with the presence of a complex hepatic cyst. Simple hepatic cysts are often encountered and when found in children, tend to be small. However, large cysts, greater than 4 cm, are also known to occur (Blonski et al. 2006).They can be complicated by peripheral calcification and internal hemorrhage. The appearance of hydatid cysts on sonography is variable and depends on the stage of maturity (Caremani et al. 2003). Hydatid cysts may at first appear similar to simple cysts on imaging. Multiple echogenic foci due to hydatid sand may be seen within the lesion and may be mistaken for simple cyst with haemorrhage, as was in the present case. The diagnosis can be difficult in these complex cases and therefore, differentiation from hydatid cyst is necessary.
We postulated that the history of fall and the ambiguous sonographic findings led to the initial diagnosis of a complicated simple liver cyst. Surgical intervention was necessary to relieve the patient’s symptoms and also to confirm the clinical diagnosis. In conclusion, though hydatid cysts are seen in children of all ages, localization in the lungs is more common than the liver and no organ is spared. This case had an unusual presentation in the form of multiple liver cysts in a 5-year old boy. Prevention of the disease by breaking the transmission cycle is of paramount importance as with all zoonotic diseases. Measures like proper education, creating awareness and maintaining hygiene will help to control the spread of the disease.