Histopathological diagnosis of myocarditis in a dengue outbreak in Sri Lanka, 2009

Abstract

BackgroundIn 2009, an outbreak of dengue caused high fatality in Sri Lanka. We conducted 5 autopsies of clinically suspected myocarditis cases at the General Hospital, Peradeniya to describe the histopathology of the heart and other organs.MethodsThe diagnosis of dengue was confirmed with specific IgM and IgG ELISA, HAI and RT-PCR techniques. The histology was done in tissue sections stained with hematoxylin and eosin.ResultsOf the 319 cases of dengue fever, 166(52%) had severe infection. Of them, 149 patients (90%) had secondary dengue infection and in 5 patients, DEN-1 was identified as the causative serotype. The clinical diagnosis of myocarditis was considered in 45(27%) patients. The autopsies were done in 5 patients who succumbed to shock (3 females and 2 males) aged 13- 31 years. All had pleural effusions, ascites, bleeding patches in tissue planes and histological evidence of myocarditis. The main histological findings of the heart were interstitial oedema with inflammatory cell infiltration and necrosis of myocardial fibers. One patient had pericarditis. The concurrent pulmonary abnormalities were septal congestion, pulmonary haemorrhage and diffuse alveolar damage; one case showed massive necrosis of liver.ConclusionsThe histology supports occurrence of myocarditis in dengue infection.

A case presentation of a fatal dengue myocarditis showing evidence for dengue virus-induced lesion

“…16 Studying 17 DHF/DSS patients with radionuclide ventriculography, Wali et al 17 showed that seven patients had ejection fraction less than 40%, 12 had global hipokinesia, and, after 3 weeks of follow up, all alterations had returned to normal. Weerakoon et al 18 performed autopsies on five patients who died due to dengue complications and showed histopathological evidence of myocarditis. Cardiac arrhythmias are other clinical manifestations of myocarditis.…”

Dengue myocarditis in Singapore: two case reports

“…To date, three DENV serotypes have been reported as causing acute myocarditis, specifically: DENV-2 documented in 17 Indian children with DHF and/ or dengue shock syndrome (DSS) during the 1996 outbreak in the Delhi region; DENV-3 in three Sri Lankan adult patients with myocarditis detected in the early phase of infection during an outbreak in Kandy district in 2005 and DENV-1 in a Colombian child with DHF and fulminant myocarditis in the 2004 outbreak in Neiva city [5,10,11]. Notwithstanding that cardiac involvement during dengue infection has been occasionally reported since the 1940s supported by immunohistochemistry and histopathological studies, its impact on morbidity and mortality remains unclear, probably denoting the lack of notification and/or diagnosis [6,12,13].…”

“…Although the cardiac complications of dengue are rare, asymptomatic myocardial involvement has been documented [3]. Acute myocarditis is the most common cardiac pathology described in cases that succumbed to dengue shock syndrome [4][5][6].…”

Pathogenesis of severe dengue infection

“…Myocarditis during dengue infections is associated with cardiac arrhythmias, reduced left ventricular ejection fraction, T wave inversions, and elevated troponin I and CPK-MB levels reflecting myocardial damage [25][26][27]. Cardiac involvement is thought to be either immune mediated or due to direct infection of myocytes [26].…”

“…Cardiac involvement is thought to be either immune mediated or due to direct infection of myocytes [26]. A few autopsy studies in patients with myocarditis have demonstrated presence of virus antigen within cells of the myocardium [27] associated with a mild inflammatory cell infiltrate [25,27].…”