Dengue incidence and length of viremia by RT-PCR in a prospective observational community contact cluster study from 2005-2009 in Indonesia.

BACKGROUND: Dengue has become a major global health threat since being recognized three centuries ago. Important gaps remain in understanding the transmission dynamics of dengue virus (DENV) infection. This study reports the results of a prospective observational cluster study that investigated the incidence of symptomatic and asymptomatic infections and length of viremia among close community contacts of hospitalized DENV-infected patients. METHODOLOGY/PRINCIPAL FINDINGS: Between 2005 and 2009, dengue-confirmed cases (n = 97) admitted to Hasan Sadikin Hospital in Bandung, Indonesia, were enrolled as index cases. Subsequently, twenty close community contacts (n = 1928) living with and around the index cases were included and followed up for up to 14 days. Body temperature was measured daily; blood samples were collected every 3-4 days and when reported fever. DENV infection was confirmed using Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR), IgM rapid test, and Enzyme-linked Immunosorbent Assay (ELISA). Among the 1928 community contacts, a total of 72 (3.7%) acute DENV infections were diagnosed, which equates to an incidence of 636 cases per 1,000 person-years (95% Confidence interval (CI) 588 to 687 cases per 1,000 person-years). Twenty-nine cases (40%) were symptomatic (22 dengue fever (DF) & 7 dengue hemorrhagic fever (DHF)), and 43 (60%) were asymptomatic. Primary and secondary DENV infections were detected in 18 (25%) and 54 (75%) subjects. Among the RT-PCR positives, viremia was observed as early as seven days before fever onset and converted to negative as late as seven days after the onset of fever. CONCLUSIONS: DENV infections are common among close community contacts of hospitalized dengue patients. The high number of asymptomatic infections and the observation that viremia precedes the onset of fever for up to seven days highlight the importance of unrecognized dengue transmission and the need for improved transmission control.

Knowledge, attitudes, and practices associated with zoonotic disease transmission risk in North Sulawesi, Indonesia.

BACKGROUND: Hunters, vendors, and consumers are key actors in the wildlife trade value chain in North Sulawesi, Indonesia, and potentially face an elevated risk of exposure to zoonotic diseases. Understanding the knowledge, attitudes, and practices (KAP) associated with the risk of zoonotic disease transmission in these communities is therefore critical for developing recommendations to prevent or mitigate zoonotic outbreaks in the future. METHODS: Qualitative and quantitative methods were combined to understand KAP associated zoonotic diseases transmission risk in communities involved in the wildlife trade in North Sulawesi. Qualitative data were collected through semi-structured ethnographic interviews and focus group discussions (FGDs) while quantitative data were collected using questionnaires. We conducted 46 ethnographic interviews and 2 FGDs in 2016, and 477 questionnaire administrations in 2017-2018 in communities from five districts in North Sulawesi. We also collected biological specimens, including nasal swab, oropharyngeal swab, and blood, from 254 participants. The study sites were targeted based on known wildlife consumption and trade activities. The participants for qualitative data collection were purposively selected while participants for quantitative data collection were randomly selected. Biological samples were tested for five viral families including Coronaviridae, Filoviridae, Flaviviridae, Orthomyxoviridae and Paramyxoviridae. RESULTS: Knowledge regarding disease transmission from animals to humans was similar across the participants in qualitative focus groups, including knowledge of rabies and bird flu as zoonotic diseases. However, only a small fraction of the participants from the quantitative group (1%) considered that contact with wild animals could cause sickness. Our biological specimen testing identified a single individual (1/254, 0.004%) who was sampled in 2018 with serological evidence of sarbecovirus exposure. Overall, participants were aware of some level of risk in working with open wounds while slaughtering or butchering an animal (71%) but most did not know what the specific risks were. However, significant differences in the attitudes or beliefs around zoonotic disease risk and health seeking behaviors were observed across our study sites in North Sulawesi. CONCLUSIONS: Our study showed variable levels of knowledge, attitudes, and practices associated with the risk of zoonotic disease transmission among study participants. These findings can be used to develop locally responsive recommendations to mitigate zoonotic disease transmission.

Japanese encephalitis virus infection in non-encephalitic acute febrile illness patients.

Although Japanese encephalitis virus (JEV) is considered endemic in Indonesia, there are only limited reports of JEV infection from a small number of geographic areas within the country with the majority of these being neuroinvasive disease cases. Here, we report cases of JEV infection in non-encephalitic acute febrile illness patients from Bali, Indonesia. Paired admission (S1) and discharge (S2) serum specimens from 144 acute febrile illness patients (without evidence of acute dengue virus infection) were retrospectively tested for anti-JEV IgM antibody and confirmed by plaque reduction neutralization test (PRNT) for JEV infection. Twenty-six (18.1%) patients were anti-JEV IgM-positive or equivocal in their S2 specimens, of which 5 (3.5%) and 8 (5.6%) patients met the criteria for confirmed and probable JEV infection, respectively, based on PRNT results. Notably, these non-encephalitic JE cases were less likely to have thrombocytopenia, leukopenia, and lower hematocrit compared with confirmed dengue cases of the same cohort. These findings highlight the need to consider JEV in the diagnostic algorithm for acute febrile illnesses in endemic areas and suggest that JEV as a cause of non-encephalitic disease has likely been underestimated in Indonesia.

Detection of central nervous system viral infections in adults in Manado, North Sulawesi, Indonesia.

Central nervous system (CNS) viral infections are important causes of morbidity and mortality worldwide but the systematic survey of patients admitted to hospitals with CNS infections in many countries, including Indonesia, is limited. To obtain more information regarding the causes of CNS infections in Indonesia, this study was performed to detect and identify viral agents associated with CNS infections amongst in-patients at a referral hospital in Manado, North Sulawesi, Indonesia. Adult patients admitted to R.D. Kandou General Hospital with presumed CNS infection were enrolled. Cerebrospinal fluid, serum, and throat swab samples were collected and tested using molecular, serological, and virus isolation assays. A confirmed viral etiology was established in three and a probable/possible in 11 out of 74 patients. The most common was herpes simplex virus 1 (7/74, 9.5%), followed by Epstein-Barr virus (2/74, 2.7%), cytomegalovirus (1/74, 1.4%), enterovirus D68 (1/74, 1.4%), rhinovirus A (1/74, 1.4%), dengue virus (1/64, 1.6%), and Japanese encephalitis virus (1/64, 1.6%). There were 20 fatal cases (27.0%) during hospitalization in which eight were associated with viral causes. We identified herpes simplex virus 1 as the most common cause of CNS infection among adults in North Sulawesi with most of the cases remaining undiagnosed. Our study highlights the challenges in establishing the etiology of viral CNS infections and the importance of using a wide range of molecular and serological detection methods to identify CNS viruses.

Presentation, etiology, and outcome of brain infections in an Indonesian hospital: A cohort study.

BACKGROUND: Little detailed knowledge is available regarding the etiology and outcome of CNS infection, particularly in HIV-infected individuals, in low-resource settings. METHODS: From January 2015 to April 2016, we prospectively included all adults with suspected CNS infection in a referral hospital in Jakarta, Indonesia. Systematic screening included HIV testing, CSF examination, and neuroimaging. RESULTS: A total of 274 patients with suspected CNS infection (median age 26 years) presented after a median of 14 days with headache (77%), fever (78%), seizures (27%), or loss of consciousness (71%). HIV coinfection was common (54%), mostly newly diagnosed (30%) and advanced (median CD4 cell count 30/µL). Diagnosis was established in 167 participants (65%), including definite tuberculous meningitis (TBM) (n = 44), probable TBM (n = 48), cerebral toxoplasmosis (n = 48), cryptococcal meningitis (n = 14), herpes simplex virus/varicella-zoster virus/cytomegalovirus encephalitis (n = 10), cerebral lymphoma (n = 1), neurosyphilis (n = 1), and mucormycosis (n = 1). In-hospital mortality was 32%; 6-month mortality was 57%. The remaining survivors had either moderate or severe disability (36%) according to Glasgow Outcome Scale. CONCLUSION: In this setting, patients with CNS infections present late with severe disease and often associated with advanced HIV infection. Tuberculosis, toxoplasmosis, and cryptococcosis are common. High mortality and long-term morbidity underline the need for service improvements and further study.

Occurrence of measles genotype D8 during a 2014 outbreak in Banjarmasin, South Kalimantan, Indonesia.

OBJECTIVES: An outbreak of measles symptoms occurring in children in Banjarmasin, South Kalimantan, Indonesia in 2014 was investigated. METHODS: Nasal swabs were collected from 23 children (median age 41 months) with fever and other symptoms of measles hospitalized in Ulin General Hospital and Islamic Hospital, Banjarmasin, South Kalimantan. Viral RNA was extracted for cDNA synthesis, followed by PCR and sequencing using paramyxovirus family consensus and N-gene primers. RESULTS: Sixteen measles-positive patients (70%) were identified. Fifteen virus strains belonged to genotype D8 and the remaining one strain was confirmed as belonging to genotype D9. CONCLUSION: Measles virus genotype D8 was detected in an outbreak of measles in South Kalimantan, Indonesia, in 2014.

Chikungunya fever outbreak identified in North Bali, Indonesia.

Background: Chikungunya virus (CHIKV) infections have been reported sporadically within the last 5 years in several areas of Indonesia including Bali. Most of the reports, however, have lacked laboratory confirmation. Method: A recent fever outbreak in a village in the North Bali area was investigated using extensive viral diagnostic testing including both molecular and serological approaches. Results and conclusions: Ten out of 15 acute febrile illness samples were confirmed to have CHIKV infection by real-time PCR or CHIKV-specific IgM enzyme-linked immunosorbent assay (ELISA). The outbreak strain belonged to the Asian genotype with highest homology to other CHIKV strains currently circulating in Indonesia. The results are of public health concern particularly because Bali is a popular tourist destination in Indonesia and thereby the potential to spread the virus to non-endemic areas is high. GenBank accession numbers: KY885022, KY885023, KY885024, KY885025, KY885026, KY885027.

Immunogenicity of a Candidate DNA Vaccine Based on the prM/E Genes of a Dengue Type 2 Virus Cosmopolitan Genotype Strain.

The development of a dengue virus vaccine is a major priority in efforts to control the diseases. Several researchers are currently using the Asian 1 and Asian 2 genotypes as vaccine candidates for dengue type 2 virus (DENV-2). However, in this study, we constructed a recombinant plasmid-based prM/E gene, from a DENV-2 Cosmopolitan genotype strain as a dengue DNA vaccine candidate. The protein expression of the recombinant plasmid in CHO cells was analyzed using an enzyme-linked immunosorbent assay, western blotting, and sucrose gradient sedimentation. After being used to immunize ddY mice three times at doses of 25 or 100 µg, the DNA vaccine induced humoral immune responses. There was no difference in the neutralizing antibody titer (focus reduction neutralization test 50% value) of mice immunized with 25 and 100 µg DNA vaccine doses. When challenged with 3 × 10(5) FFU DENV-2, immunized mice could raise anamnestic neutralizing antibody responses, which were observed at day 4 and day 8 post-challenge. Analysis of immunogenicity using BALB/c mice showed that their antibody neutralization titers were lower than those of ddY mice. In addition, the antibodies produced after immunization and challenge could also neutralize a DENV-2 Asian 2 genotype (New Guinea C) strain. Therefore, the DENV-2 Cosmopolitan genotype may be a DENV-2 vaccine candidate.