A case investigation of fatal acute encephalitis caused by amoeba in Muang district, Udonthani province, Thailand, June 2014

Abstract

Background: On 7June 2014, Udonthani Provincial Health Office was notified by The Office of Disease Prevention and Control Region 6 Khonkaen province according to the acute severe meningoencephalitis case after exposure in the swimming pool in a school. On 8 June 2014, he was died. Thus the surveillance rapid response teams from the Udonthani Provincial Health Office immediately conducted an investigation with the aimed to confirm the diagnosis and to identify the sources of infection and to implement prevention and control measure in the area.
Methods: Descriptive epidemiological study was done. We collected illness information from family, medical records, and laboratory results from the related hospitals. We collected water from the swimming pool at the school where the boy had exposure. The water samples were sent to protozoa culture at Siriraj Hospital, Bangkok. We inspected and tested the residual chlorine in the swimming pools in Meaung district, Udon Thani.
Results: The patient was 12 years old boy. He developed high fever, headache, vomiting and abdominal cramp on 3 June 2014. One week ago, he had a history of swimming in the pool. He was brought to Udonthani Hospital, his clinical progressed rapidly, for proper treatment on the following day. He had been admitted with good consciousness, high fever and stiff neck. The CT Brain revealed normal. And few hours later, his clinical was worsening. He was drowsiness, answered to the questions slowly and the pupils were unequal responded to light. And second CT brain demonstrated diffuse swelling. On 5 June 2014, he was still unconsciousness and the pupils were fixed dilated both eyes. He had needed respirator support and referred to Sri-nakarin Hospital, Khonkaen University. He was treatment in pediatric intensive care unit with empiric antibiotics treatment but he was not responsive to medication. He was treated as palliative care until he died on 8 June 2014. His CSF special stain revealed amoebic tropocoite suspected Naegleria fowleri. The final diagnosis was acute meningoencephalitis suspected cerebral edema and brain dead caused from amoeba suspected Naegleria fowleri. In contrast, the suspected sources in the pool found Acanthamoeba species only. Moreover; the residual chlorine in surveyed swimming pools reached to standard level was only 28.57 percent.
Conclusions: The case’s clinical presentation was rapidly progressive 4-5 days after onset. His clinical manifestration was similar to the brain eating amoeba infection, Naegleria fowleri and his CSF also found amoeba. But the suspected contamination in the water sources was positive amoeba. This result indicated that the swimming pool was contamination and sub-standard. For the surveillance, all cases with acute meningoencephalitis should be investigated to confirmed diagnosis and verify the swimming pool exposure.