Intestinal helminths cause or mimick acute appendicitis?

Intestinal helminths cause or mimick acute appendicitis?

Charith Nanayakkara1

1 General Sir John Kotelawala Defence University, Ratmalana, Sri Lanka

Keywords: acute appendicitis, helminths, appendectomy


Background:Infestation with helminths is a recognized cause for acute appendicitis in both adults and children.

Objective: To determine whether helminths play an active role in causing acute appendicitis or whether it mimics symptoms of appendicitis leading to a negative appendicectomy.

Methods:A retrospective study using the histology reports of patients who underwent appendicectomy at a Surgical Unit, of a teaching hospital from January 2013 to July 2014, following a diagnosis of acute appendicitis. A total of sixty seven reports were reviewed for the presence of helminths and features of inflammation.

Results :Five of the sixty seven histology reports were positive for infestation with helminths (7.24%). Nine (13.04%) appendices were not inflamed, of which three (33.3%) were infested with helminths. Only two (3.33%) of the fifty eight inflamed appendices had infestation with helminths (P=0.0151).

Conclusion: Helminths can mimic acute appendicitis without causing inflammation by causing nonspecific abdominal pain especially when confined to the right iliac fossa. The symptoms were due to the mere presence of helminths and not due to inflammation of appendix. We recommend mass scale eradication programs for intestinal helminths which could prevent abdominal symptoms that leads to an unnecessary/ avoidable appendicectomy.

Corresponding Author: Charith Nanayakkara, E-mail: Received: May 2016, Accepted revised version August 2016, Published: August 2016 Competing Interests: Author has declared that no competing interests exist


Acute appendicitis is a common surgical problem that presents as an acute abdomen to the general surgical casualty. Teaching hospital Karapitiya (THK), being the second largest hospital in Sri Lanka, receives a significant number of patients with this condition each month. Following a clinical diagnosis of appendicitis, most cases are managed surgically with appendicectomy. Sri Lanka is a tropical country with many parasitic infestations found in abundance. Intestinal helminths harbored and transmitted from soil are one such common group of parasites. Therefore any association between helminthic infestation and acute appendicitis will have an augmented impact within the Sri Lankan community. The association between helminthic infestation and appendicitis has long been considered in other countries. In 1984 a study which analyzed the pathological changes in appendices such as inflammation and granuloma formation in the presence of Enterobius vermicularis was published. Having analysed over 30,000 samples they concluded that there is a higher Journal of the Postgraduate Institute of Medicine 2016; 3:E27:1-4 doi: 2 incidence of granuloma formation in the presence of Enterobius vermicularis, possibly due to chronic inflammation1 . In 1987, another group pointed out that the appendices infested with Enterobius vermicularis were rarely associated with histological changes of acute appendicitis2 . A group of researchers studied children undergoing surgery for acute appendicitis and the association with Enterobius vermicularis infestation in 1988. According to the study there are a greater number of negative cases of appendicitis in the presence of the parasite. They concluded that the parasite causes symptoms resembling those of acute appendicitis3 . Similar results were seen in a study in 1991, where they concluded that the parasite mayt be mimicking the symptoms of appendicitis or that the parasites leaves or do not enter an inflamed appendix4 . During the period 2005 to 2014, more researchers have concluded that the intestinal helminths can mimick the symptoms of acute appendicitis5-9 . Having studied 1,600 surgically removed appendices in 2008, it was concluded that parasitic infestation of the appendix is an uncommon cause for acute appendicitis in children and adolescents10 . Although these studies hinted of the possible association between the parasitic infestation and the presentation of acute appendicitis, none of them had statistically significant results to back up their claims. Only one out of the ten studies was conducted in the South Asian region, and none in the Sri Lankan community6. These reasons prompted us to design a study to find out whether there is an association between the helminthic infestations and acute appendicitis.


A retrospective study was conducted using the histology reports of patients who underwent surgery for acute appendicitis from January 2013 to July 2014 at a surgical unit of Teaching Hospital Karapitiya, Galle, Sri Lanka. These reports were analysed for the presence of intestinal helminths and whether the appendices were inflamed or not. All relevant data was obtained from the database in the department of pathology at Teaching Hospital Karapitiya. The data was analysed using the SPSS software for the mean, standard deviation and the chi square association between the different data sets.


Five (7.24%) of the sixty seven histology reports were positive for infestation with helminths. Fifty eight (86.6%) appendices were inflamed and nine (13.4%) were not inflamed.

Journal of the Postgraduate Institute of Medicine 2016; 3:E27:1-4 doi: 3

There was a significant association between infestation with helminths (Enterobius and Tapeworms based on microscopy), and the presence of inflammation. Only two (3.33%) of the fifty eight inflamed appendices had infestation with helminths. The calculated chi-square value for this association is 6.54 and yielded a P value of 0.0151 which is statistically significant.


Intestinal helminths have been considered to be a causative factor for acute appendicitis. Although it is not proven in available literature, different studies have shown conflicting evidence. Sri Lanka has a very high prevalence of Helminthic infestation with a prevalence as high as 29% in the plantation sector, even after eradication programs. The prevalence is higher amongst the younger population11 . Our results show that intestinal helminths can lead to symptoms that closely mimic acute appendicitis resulting in surgical interventions. The statistically significant association between infestation with intestinal helminths and non-inflamed appendices proves this point. Misdiagnosis is higher in the extremes of age which has a higher operative risk than that of the rest of the population. To reduce misdiagnosis in clinical practice, we suggest a longer period of observation for the extremes of age and for those with atypical appendicitis, while carefully monitoring the patients. Antihelminthic medication can also be administered to such patients during the period of observation.


Helminths can mimic acute appendicitis without causing inflammation. This leads to a misdiagnosis of Appendicitis. It is well-known that infestation and infection of the gastro intestinal tract leads to abdominal pain. These symptoms are not due to inflammation of appendix but due to the mere presence of helminths. When abdominal pain is confined to the right iliac fossa, a misdiagnosis of appendicitis can be made leading to surgery with the associated risks and costs of surgery, anaesthesia and medication. Helminthic infestation can easily be eradicated with antihelminthic drugs which could prevent abdominal symptoms that lead to an unnecessary / avoidable appendicectomy. Based on the study, we would like to recommend that mass scale preventive methods to eradicate helminths would greatly benefit a population with a significant prevalence of infestation with helminths. We would also like to suggest the use of anthelminthic medication in atypical mild abdominal pain during the period of observation and to test faeces for amoebae ova and cysts. Using this as a pilot study, we plan to expand the research to the entire country which would help us to further evaluate of our findings.


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Author: CeylonMediweb