Dengue seroprevalence study in Bali.

INTRODUCTION: Dengue infection poses significant public health problems in tropical and subtropical regions worldwide. The clinical manifestations of dengue vary from asymptomatic to severe dengue manifestations. This serological survey highlighted the high incidence of asymptomatic cases. This study aimed to determine the prevalence of dengue in healthy and ill adults in Bali. METHODS: Cross-sectional seroprevalence surveys were performed between July 2020 and June 2021 among healthy and ill adults in Denpasar Bali. Blood samples were collected from 539 randomly selected urban sites in Denpasar. Immunoglobulin G antibodies against the dengue virus were detected in serum using a commercial enzyme-linked immunosorbent assay kit. RESULTS: Overall, the dengue seroprevalence rate among the 539 clinically healthy and ill adults was high (85.5%). The median age was 34.1 (18-86.1). Most of the participants in the study were younger than 40 years (61.2%). Men were the dominant sex (54.5%). The study found a significant association between dengue seropositivity among people aged > 40 years and healthy status (p = 0.005; odds ratio [OR] = 0.459 and p < 0.001; OR = 0.336, respectively). The study reported that as many as 60% of the subjects had a history of previously suspected dengue infection. This study reflected the proportion of asymptomatic dengue patients requiring better assessment with a serological test. CONCLUSION: The current study highlighted that real cases of dengue infection may be higher than reported, with a high prevalence of dengue seropositivity and a relatively dominant proportion of asymptomatic cases. The study guides physicians to be aware of every dengue infection in tropical countries and prevent the spread of the disease.

Misidentification of S. suis as a Zoonotic Agent.

BACKGROUND: Streptococcus suis is an emerging zoonotic pathogen. This bacterium commonly causes meningitis in human and is often associated with hearing and vestibular dysfunction. S. suis tends to be misidentified, leading to under-diagnosis. CASE PRESENTATION: A previously healthy 50-year-old man was admitted to one of the district hospitals in Bali Province, Indonesia, due to meningitis. He had a history of consuming homemade raw pork product two days before the onset of illness. Streptococcus mitis was identified from the cerebrospinal fluid culture by using VITEX 2 COMPACT (Biomeriuex) with a 99% probability score. This patient had clinical symptoms and risk factor identical to S. suis infection. Therefore, we performed confirmation tests for the cerebrospinal fluid by PCR (using primer specific for gdh and recN) and sequencing of those PCR products. Both of the confirmation tests showed a positive result for S. suis. CONCLUSION: There are few reports of S. suis infections in Indonesia, but we believe that the cases in Indonesia, especially Bali, are not uncommon. The under-reported cases are perhaps due to the difficulties in differentiating S. suis from other Streptococcus species by culture method, particularly Streptococcus mitis. Therefore, confirmation by PCR is necessary.