A case of subacute effusive constrictive pericarditis with a probable amoebic aetiology

Use of PCR in the diagnosis of pericardial amebiasis: a case report and systematic review of the literature

Background

Entamoeba histolytica (E. histolytica) is rarely identified as a cause of amebic pericarditis. We report a case of amebic pericarditis complicated by cardiac tamponade, in which the diagnosis was missed initially and was made retrospectively by polymerase chain reaction (PCR) testing of a stored sample of pericardial fluid. Furthermore, we performed a systematic review of the literature on amebic pericarditis.

Case presentation

A 71-year-old Japanese man who had a history of sexual intercourse with several commercial sex workers 4 months previously, presented to our hospital with left chest pain and cough. He was admitted on suspicion of pericarditis. On hospital day 7, he developed cardiac tamponade requiring urgent pericardiocentesis. The patient’s symptoms temporarily improved, but 1 month later, he returned with fever and abdominal pain, and multiple liver lesions were found in the right lobe. Polymerase chain reaction of the aspiration fluid of the liver lesion and pericardial and pleural fluid stored from the previous hospitalization were all positive for E. histolytica. Together with the positive serum antibody for E. histolytica, a diagnosis of amebic pericarditis was made. Notably, the diagnosis was missed initially and was made retrospectively by performing PCR testing. The patient improved with metronidazole 750 mg thrice daily for 14 days, followed by paromomycin 500 mg thrice daily for 10 days.

Conclusions

This case suggests that, although only 122 cases of amebic pericarditis have been reported, clinicians should be aware of E. histolytica as a potential causative pathogen. The polymerase chain reaction method was used to detect E. histolytica in the pericardial effusion and was found to be useful for the diagnosis of amebic pericarditis in addition to the positive results for the serum antibody testing for E. histolytica. Because of the high mortality associated with delayed treatment, prompt diagnosis should be made.

Blastocystis spp., Cryptosporidium spp., and Entamoeba histolytica exhibit similar symptomatic and epidemiological patterns in healthcare-seeking patients in Karachi

In this study, we collected data on the incidence of enteric parasites in healthcare-seeking individuals along with their symptoms to quantify the potential roles of factors such as age, sex, and seasonality in infection. We performed analysis to identify factors which could help differentiate parasitic infection from other causes of gastrointestinal illness in a community. The size of the patient population (n = 339), patient selection methodology, collection methods, and statistical analysis followed approaches from similar studies in core clinical journals. Ethical approval was obtained from the University of Karachi's Ethical Review Board. Fecal specimens (n = 339) submitted by symptomatic patients were collected from two clinical laboratories, along with information about the patients' age, sex, and symptoms. We found that symptoms of fever, vomiting, and constipation were 100 % predictive of finding a parasitic infection, while diarrhea was 88 % predictive of a parasitic infection. Gastrointestinal parasite-positive patients reported diarrhea (~60 %), vomiting (~30 %), fever (~25 %) and constipation (~25 %), while parasite-negative patients exhibited a symptomatic profile without fever, vomiting, and constipation. The distribution of symptoms in parasite-positive patients remained relatively invariant regardless of the parasite identified. Blastocystis spp.-mono-infected patients reported a similar profile to patients positive for Entamoeba histolytica/Entamoeba dispar and Cryptosporidium spp. Most parasitic infections exhibited a strong seasonal pattern, with a peak incidence in summer months. Infection by Blastocystis spp. was the most prevalent, and it was the only infection mathematically correlated to rainfall by Pearson's method. We observed no increase in healthcare-seeking behavior following a stressful community event, namely, the attempted assassination of Benazir Bhutto in Karachi. The data suggest that parasitological testing would produce a high yield of positive results when performed on healthcare-seeking patients in Karachi in 2007 with symptoms of fever, vomiting, or constipation and a low yield when performed on patients noting only abdominal pain. Parasitological testing also produces a higher yield on patients seen in summer months.

Salmonella: a rare cause of subacute effusive-constrictive pericarditis

A 36 year old woman had emergency pericardectomy because of subacute effusive-constrictive pericarditis. The pericardial fluid and tissue culture showed that this was caused by infection with Salmonella enteritidis. Cardiac involvement with salmonella does not usually present in such an aggressive manner and it has not previously been reported to cause this rare type of cardiac constriction.