Invasive amoebiasis: an unusual presentation

A rare case of extraintestinal amebiasis

Background

Amoebiasis is caused by the protozoan Entamoeba histolytica, which is a rare infectious disease in developed countries. If the trophozoites enter the blood, it can spread through the body, such as brain, and lungs. Cases of simultaneous infection of multiple organs are extremely rare.

Case presentation

Here we report a case of simultaneous infection of amoeba in pulmonary pleura, urinary system and central nervous system. Although the patient received anti amoeba treatment, the prognosis of the patient was poor.

Conclusions

In this patient, multiple extraintestinal amebic infections in the absence of clinically confirmed intestinal amebiasis or amebic liver abscess are rare and pose diagnostic challenges. The disseminated amebiasis has significantly increased the mortality. Early diagnosis and appropriate treatment may reduce the mortality of disseminated amebiasis.

Fistulae involving the appendix: a systematic review of the literature

BACKGROUND

The appendix has a unique place in surgical history. Although the first ever appendicectomy involved a fistula to the skin, fistulae involving the appendix remain uncommon and can lead to unique surgical considerations.

METHODS

A systematic review of the literature was performed for case reports of appendiceal fistulae. We excluded cases in which the patient had a history of appendicectomy. Cases were categorized by site and aetiology, with information regarding relative frequency and demographics obtained.

RESULTS

A total of 301 case reports of fistula involving the appendix were found. The most common sites of these fistulae were to the bladder (148 cases), skin (40 cases), vasculature (19 cases), umbilicus (16 cases) and to the gastrointestinal tract. The most common aetiology in sub-analysis was appendicitis alone (150 cases), with less common causes including appendiceal adenocarcinoma (32 cases) and congenital abnormalities (18 cases). There were significantly more appendiceal fistulae in males than in females, with a ratio of 1.7:1. In patients with appendiceal adenocarcinoma as a cause for fistula, there were significantly more females than males with a ratio of 2.3:1.

CONCLUSION

In conducting a systematic review of case reports of fistulae involving the appendix, we identified 301 unique case reports, with a range of different sites and aetiologies.

COMPARISON OF MULTIPLEX SINGLE ROUND PCR AND MICROSCOPY IN DIAGNOSIS OF AMOEBIASIS

Background:

Amoebiasis, the cause of dysentery and extra-intestinal abscesses, now becomes second fatal parasitic disease in the world. As routine microscopic diagnosis cannot differentiate causative Entamoeba histolytica from non-pathogenic E. dispar and E. moshkovskii, better diagnosis has to be searched.

Materials and Methods:

Multiplex single round PCR was tested and compared with results of microscopy of wet preparation on 30 samples of diarrheic stools and extra intestinal lesions from amoebiasis suspected patients.

Results:

Microscopy examination showed that 21 (70%) of the samples were positive for E. histolytica/E. dispar/E. moshkovskii complex and 18 (86%) of them contained hematophagous trophozoites. Multiplex single round PCR showed 12 positive results, from which seven were positive for E. histolytica, two were positive for E. moshkovskii, and three showed mixed of E. histolytica and E. moshkovskii. No samples were positive for E. dispar. High positive rate of microscopy might be related with highly suspected amoebiasis cases, while lower positive PCR might be caused by low parasite density and time-related trophozoite disintegration.

Conclusion:

The study showed that multiplex single-round PCR is a valuable diagnostic tool for species differentiation, but cannot replace microscopy in the diagnosis of amoebiasis because of its low sensitivity and impossibility to discriminate the form of E. histolytica and whether it is in the disease-causing stage, while microscopic examination is capable to demonstrate the presence of hematophagous trophozoites that indicates it is invasive and at the disease-causing stage of E. histolytica.

Amoebic liver abscess: an unusual cause for a right iliac fossa mass: a case report

Background

Amoebic liver abscess is the most common extra intestinal manifestation of amoebiasis in tropical countries. It usually presents with right hypochondrial pain, fever and anorexia. Amoebic liver abscess has gained clinical significance due to the wide variety of clinical presentations which can cause diagnostic dilemmas and high mortality in untreated cases.

Case presentation

We report a case of a 63-year-old male with a history of anorexia for 3 weeks, fever for 4 days and examination findings of tender hepatomegaly with a liver span of 15 cm in the mid clavicular line and a firm irregular mass in the right iliac fossa. Ultrasound scan of the abdomen showed two large liver abscesses with one of them leaking into the peritoneal cavity causing a localized pus collection, which had been walled off in the right iliac fossa. He was treated with metronidazole and liver abscesses were drained percutaneously under ultrasound scan guidance. The diagnosis of Entamoeba histolytica infection was confirmed with the serology and subsequently by PCR from the aspirated material. He made an uneventful recovery with resolution of the symptoms and right iliac fossa mass.

Conclusion

Recognition of variable presentation of amoebic liver abscess is vital, considering the curable nature of this disease and potentially fatal outcome of untreated abscess. An intra-abdominal mass in a patient with amoebic liver abscess should raise the suspicion of a localized collection of pus and impending generalized peritonitis. Early diagnosis and prompt intervention can prevent the dreaded complication of peritonitis and toxemia, and hence reduce the consequent morbidity and mortality.

Amebic acute appendicitis: systematic review of 174 cases

BACKGROUND

This study aimed to determine the clinical and demographic features of acute amebic appendicitis by reviewing the reported cases.

METHODS

The PubMed and MEDLINE databases were searched to identify articles related to amebic appendicitis using key words. The search included all articles published between 1935 and 2012 without restricting language, journal, or country.

RESULTS

A total of 174 cases of amebic appendicitis reported in 42 articles were analyzed. The mean age of the patients was 23.5 years (range 2 months-83 years). The majority of patients were male (74.0 %), and the majority of cases were reported from countries with high/moderate risk for amebiasis (76.5 %). A history of traveling to a high/moderate-risk country was cited in 64.0 % of the overall cases. The interval between travel and onset of clinical symptoms ranged from months to years. History of or coexisting dysenteric diarrhea was present in only 7.0 and 14.0 % of overall cases, respectively. A preoperative diagnosis of amebiasis was cited for only five cases (3.0 %). Complicated appendicitis was present in 30.7 % of cases, some of which required colon resection. Severe postoperative intraabdominal complications (e.g., liver abscess, abdominal sepsis, gastrointestinal fistula, hemorrhage) occurred in 19.4 % of surgery-treated patients. The overall mortality rate was 3.2 %.

CONCLUSION

Appendectomy specimens should be routinely sent for histopathologic examination. In the case of suspected amebic acute appendicitis, extra precautions-early appendectomy, metronidazole for antibiotic prophylaxis, wet-preparation examination, obtaining a timely pathology result, increasing the awareness of uncommon complications of appendectomy-can hasten appropriate therapeutic intervention and improve outcome.