Distinct Dengue Disease Epidemiology, Clinical, and Diagnosis Features in Western, Central, and Eastern Regions of Indonesia, 2017-2019

Detection and molecular characterization of dengue among patients suspected of having malaria in Timika, Central Papua, Indonesia

BACKGROUND

Dengue and malaria are major public health problems in Indonesia. Dengue is hyperendemic nationwide, while malaria remains endemic in specific regions, especially in eastern Indonesia. Timika in Central Papua province is a highly malaria-endemic area; however, this city is historically known as a low endemic area for dengue. With the increasing incidence of dengue in Papua, this study aimed to assess dengue prevalence, possible co-infection and to molecularly characterize the dengue virus (DENV) in patients suspected of having malaria.

METHODS

Archived samples of patients suspected of having malaria were screened for dengue using RT-PCR. Dengue serological and antigen detection was performed and whole genome sequencing was employed to determine the genetic characteristics of viruses. Detection of other arboviruses was also performed.

RESULTS

Among 119 patients, 30 (25.2%) were positive for dengue. Most samples (n=29) were infected by DENV-3, while one was positive for DENV-2. Dengue and malaria co-infections were found in six patients. Phylogenetic analysis classified DENV-2 as the Cosmopolitan genotype that is closely related to strains from the Indonesian city of Makassar, while DENV-3 was classified as Genotype I, which is closely related to a strain from Singapore.

CONCLUSIONS

Dengue significantly contributes to febrile illness among patients suspected of having malaria in Timika, Central Papua. Virus importation from surrounding regions is likely to contribute to the dispersion of DENV into eastern parts of Indonesia. Our findings reveal the underestimation of this viral disease in a highly malaria-endemic area.

Investigation of severe dengue outbreak in Maumere, East Nusa Tenggara, Indonesia: Clinical, serological, and virological features

BACKGROUND

Dengue, an acute febrile disease caused by dengue virus (DENV) infection, is endemic to Indonesia. During early 2020, an outbreak of severe dengue occurred in Maumere, East Nusa Tenggara province, a region with low dengue endemicity with limited data on the characteristics of the circulating DENV. By 18 March 2020, 1396 cases were reported with 14 fatalities. Investigation was conducted to understand the cause and characteristics of the outbreak.

METHODS

Sera were collected from 133 patients with dengue-like symptoms through random sampling at TC Hillers Hospital, Maumere during outbreak between February and June 2020. Dengue was confirmed using NS1 and/or RT-PCR detection. Serological status was determined using IgG/IgM ELISA and plaque reduction neutralization test (PRNT). DENV serotyping and genome sequencing were performed to identify the DENV serotype and genotype.

RESULTS

We recruited suspected dengue patients attending the hospital during the outbreak. Dengue was confirmed in 72.2% (96/133), while 18.8% (25/133) were diagnosed as probable dengue. Children under 18 years old accounted for 85.1% (103/121) of dengue cases. Severe dengue accounted for 94.2% (81/86) of cases. Secondary infections made up 92.6% (112/121) of cases. Serotyping detected 87.3% (62/71) as DENV-3, 7.0% (5/71) as DENV-4, 2.8% (2/71) as DENV-1, and 2.8% (2/71) as DENV-2. Phylogenetic analysis revealed close evolutionary relationship of Maumere DENV to viruses from other Indonesian regions, especially Bali and Kupang. PRNT on DENV-3 secondary infections patients detected the presence of DENV-2 and DENV-4 neutralizing antibodies.

CONCLUSION

The severe dengue outbreak in Maumere is caused by DENV-3 introduced from nearby islands. The high proportion of secondary infections likely contributes to the severity of the disease. The high percentage of anti-dengue neutralizing antibodies for multiple serotypes and the high proportion of anti-dengue IgG in young children suggests a history of dengue transmission with a high infection rate in the area.

Recent advances in the control of dengue fever using herbal and synthetic drugs

Dengue virus represents a global public health threat, being prevalent in tropical and subtropical regions, with an increasing geographical distribution and rising incidence worldwide. This mosquito-borne viral agent causes a wide range of clinical manifestations, from mild febrile illness to severe cases and potentially fatal outcomes due to hemorrhage and shock syndrome. The etiological agent, dengue virus (DENV), has four distinct serotypes, each capable of inducing severe clinical outcomes. The current therapeutic landscape remains limited, with management strategies mainly focused on supportive cares. However, recent advances in pharmaceutical research have yielded promising developments in anti-dengue drugs. Extensive investigations have been conducted on various synthetic compounds, including JNJ-1802, 1,4-pyran naphthoquinones, and arylnaphthalene lignan derivatives. Additionally, natural compounds derived from medicinal plants such as Hippophae rhamnoides, Azadirachta indica, and Cymbopogon citratus have demonstrated potential antiviral properties in both in vitro and in vivo studies, based on inhibition of DENV replication. However, none of these compounds are to date approved by the U.S. Food and Drug Administration (FDA). Although many vaccines have been recognized as candidates in various stages of clinical trials, only a limited number of these have demonstrated a protective efficacy against the infection. This aspect underscores the need for both highly effective immunization strategies and therapeutic interventions, whether derived from botanical sources or through synthetic manufacturing, that exhibit low adverse effects. This review examines innovative approaches to DENV prevention and treatment, encompassing both phytochemical and synthetic therapeutic strategies.

Impact of pre-existing cross-reactive antibodies on cyclic dengue outbreaks in the hyperendemic region of Bali, Indonesia

The four serotypes of the dengue virus (DENV) cause a range of diseases ranging from mild fever to severe conditions. Understanding the immunological interactions among the four serotypes is crucial in comprehending the dynamics of serotype shifting during outbreaks in areas where all four serotypes co-circulate. Hence, we evaluated the neutralizing antibody and antibody-dependent enhancement responses against the four DENV serotypes using acute-phase plasma samples collected from 48 laboratory-confirmed dengue patients during a dengue outbreak in Bali, Indonesia in 2022. Employing single-round infectious particles to exclusively investigate immunogenicity to the structural surface proteins of DENV, which are the targets of antibodies, we found that individuals with a probable prior history of DENV-1 infection exhibited increased susceptibility to secondary DENV-3 infection, attributed to cross-reactive antibodies with limited neutralizing activity against DENV-3 (geometric mean 50 % neutralization titer (GMNT50) = 47.6 ± 11.5). This susceptibility was evident in vitro, with a mean fold enhancement of 28.4 ± 33.9. Neutralization titers against DENV-3 were significantly lower compared to other serotypes (DENV-1 GMNT50 = 678.1 ± 9.0; DENV-2 GMNT50 = 210.5 ± 8.7; DENV-4 GMNT50 = 95.14 ± 7.0). We demonstrate that prior immunity to one serotype provides limited cross-protection against the other serotypes, influencing the dominant serotype in subsequent outbreaks. These findings underscore the complexity of dengue immunity and its implications for vaccine design and transmission dynamics in hyperendemic regions.

Clinical and laboratory profile of Expanded Dengue Syndrome: experience of 2019 outbreak from Dhaka, Bangladesh

BACKGROUND OBJECTIVES

Bangladesh is afflicted with periodic dengue outbreak every few years and one of the worst upsurges was recorded in 2019 during which there was an increasing trend of dengue with unusual symptoms which were not so common before. This study aims to describe the experience of three tertiary care centres of Dhaka regarding the clinical and laboratory, hospital outcome and management profile of the Expanded Dengue Syndrome (EDS) cases admitted from the 2019 outbreak.

METHODS

The current work was a cross-sectional observational study which took place from August 1 to December 31 2019 at three major tertiary care centres in Dhaka, Bangladesh. Out of total 2017 screened dengue cases, 49 met the inclusion criteria and 39 were enrolled after taking informed written consent. Data was analysed using Microsoft Excel and Graph pad prism 9.3.1. A probability value of p<0.05 was considered statistically significant.

RESULTS

Out of the 39 cases, majority were male (79.49%) with median (±IQR) age of 33(±9) years. Hypertension (4; 10.26%) was the most commonly associated co-morbidity. Among the systemic manifestations, most prevalent was hepatitis (38.49%) followed by encephalopathy (12.82%). Majority of the patients were suffering from primary infection (85%). Case fatality rate was 15.38%. Hepatitis and meningoencephalitis were the predominant cause of death. This study records the only known case report of Acute respiratory dress syndrome (ARDS) complicating dengue from Bangladesh. None of the patients from our cohort were managed by steroids. Only two (5.13%) out of 39 cases received antibiotics.

INTERPRETATION CONCLUSION

In the year 2019, an unusual rise in EDS cases with about 15.4% fatalities were observed in this study. Hepatitis was the most common presentation and cause of death. Here, we report the first ARDS case encountered in Bangladesh. Despite the multifaceted presentation of EDS, indiscriminate use of antibiotics and steroid was minimal. Early recognition of multifarious features of EDS is important for choosing the targeted treatment option which can avert many deaths. The results of this study underline the necessity for more in-depth research into the risk factors that are contributing to mortality in EDS cases.

Genetic Association Studies of MICB and PLCE1 with Severity of Dengue in Indonesian and Taiwanese Populations

Dengue is an arboviral disease that has spread globally and become a major public health concern. A small proportion of patients may progress from symptomatic dengue fever (DF) to dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS). Findings from a previous genome-wide association study (GWAS) demonstrated that variations in the major histocompatibility complex (MHC) class I chain-related B (MICB) and the phospholipase C epsilon 1 (PLCE1) genes were related to DSS in a Vietnamese population. This study investigated associations of variations in MICB (rs3132468) and PLCE1 (rs3740360, rs3765524) with dengue severity and thrombocytopenia in both the Indonesian and Taiwanese populations. We sampled 160 patients from the Indonesian population and 273 patients from the Taiwanese population. None of the patients had DSS in the Taiwanese population. Based on age demographics, we found that dengue is more prevalent among younger individuals in the Indonesian population, whereas it has a greater impact on adults in the Taiwanese population. Our results showed the association between MICB rs3132468 and DSS. In addition, an association was identified between PLCE1 rs3740360 and DHF in secondary dengue in Indonesian patients. However, there is no association of MICB or PLCE1 variants with thrombocytopenia. This study highlights the value of genetic testing, which might be included in the clinical pathway for specific patients who can be protected from severe dengue.

World Dengue Day: A call for action

Commemorating the 2021 ASEAN Dengue Day and advocacy for World Dengue Day, the International Society for Neglected Tropical Diseases (ISNTD) and Asian Dengue Voice and Action (ADVA) Group jointly hosted the ISNTD-ADVA World Dengue Day Forum–Cross Sector Synergies in June 2021. The forum aimed to achieve international and multisectoral coordination to consolidate global dengue control and prevention efforts, share best practices and resources, and improve global preparedness. The forum featured experts around the world who shared their insight, research experience, and strategies to tackle the growing threat of dengue. Over 2,000 healthcare care professionals, researchers, epidemiologists, and policy makers from 59 countries attended the forum, highlighting the urgency for integrated, multisectoral collaboration between health, environment, education, and policy to continue the march against dengue. Sustained vector control, environmental management, surveillance improved case management, continuous vaccine advocacy and research, capacity building, political commitment, and community engagement are crucial components of dengue control. A coordinated strategy based on science, transparency, timely and credible communication, and understanding of human behavior is needed to overcome vaccine hesitancy, a major health risk further magnified by the COVID-19 pandemic. The forum announced a strong call to action to establish World Dengue Day to improve global awareness, share best practices, and prioritize preparedness in the fight against dengue.

The growing threat of dengue poses a significant public health burden endangering the well-being and socioeconomic development of many countries across the world. The International Society for Neglected Tropical Diseases (ISNTD) and Asian Dengue Voice and Action (ADVA) group brought together the collaborative efforts of healthcare care professionals, researchers, epidemiologists, environmentalists, and policy makers to coordinate international dengue control strategy. A strong call to action to establish a World Dengue Day was announced to improve global awareness, share best practices, and prioritize preparedness in the fight against dengue. The World Dengue Day highlighted the need for all governments, healthcare professionals, civil societies, public and private sectors, schools and universities, and citizens in dengue-endemic countries to form a strong coalition to encourage and accelerate a collective dengue control response.

Molecular epidemiology of dengue in North Kalimantan, a province with the highest incidence rates in Indonesia in 2019

OBJECTIVES

Dengue is endemic to Indonesia, a country that has largely varied geographical and demographic conditions across different regions. In 2019, dengue epidemic occurred in North Kalimantan province and recorded as the highest incidence rate in Indonesia. This study aims to investigate the molecular epidemiology of dengue during outbreak in the province and compare the epidemiological characteristics between two cities/towns in North Kalimantan, namely Malinau, an inland town surrounded by a dense rainforest, and Tarakan, an island city.

METHODS

A cross sectional study was conducted between September 2018 and July 2019. Dengue-like illness patients were recruited in hospitals and tested for dengue NS1 and IgG/IgM. Serological prevalence was measured using IgG ELISA, dengue virus (DENV) serotyping was conducted using RT-PCR and Envelope gene sequencing was performed to infer the virus origins and phylogeny. Clinical, demographical, and diagnostics data were also recorded and analyzed.

RESULTS

We recruited 523 patients, 261 from Malinau and 262 from Tarakan. Among them, 349 patients were confirmed dengue. Cases in Malinau had a higher proportion of confirmed dengue (82.0%) compared to those in Tarakan (51.5%). Cases in Malinau were more likely to be dengue hemorrhagic fever with more severe hematological features compared to those in Tarakan. All four DENV serotypes were detected in both cities, the most prevalent serotype being DENV-2. The genetic characteristics of the viruses in the two towns was similar except for DENV-3. No sylvatic DENV was detected as well as alphaviruses and non-dengue flaviviruses during the outbreak.

CONCLUSIONS

The molecular epidemiology of dengue in North Kalimantan revealed the similar virological characteristics but different clinical and demographic aspects in Malinau and Tarakan. The distinct dengue dynamics between different regions of Indonesia is prominent and this knowledge will be important for understanding future patterns of DENV transmission in the region.

Outbreak of severe dengue associated with DENV-3 in the city of Manado, North Sulawesi, Indonesia

BACKGROUND

In early 2019, an outbreak of severe dengue was reported in Manado, North Sulawesi Province, Indonesia. This epidemic raised public concern and recorded the highest number of cases in the last 10 years. This study aimed to determine the clinical spectrum, disease aetiology and virological characteristics associated with this outbreak of severe dengue.

METHODS

Dengue was diagnosed using non-structural protein 1 detection, reverse transcription polymerase chain reaction and immunoglobulin (Ig)G/IgM serology. Envelope gene sequencing was conducted to determine the phylogeny of the dengue virus (DENV).

RESULTS

In total, 146 patients with a median age of 8 years (interquartile range IQR 5-11 years) were recruited. Most patients experienced expanded dengue syndrome, characterized by severe organ involvement including liver enlargement, stomach ache and coagulation problems. During the outbreak, DENV-3 was the dominant serotype (75.9%). Smaller numbers of DENV-1, -2 and -4 were also detected. Phylogenetically, the dominant DENV-3 strains were grouped in multiple clusters and were related to other Indonesian strains, suggesting the emergence of heterogenous local viruses.

CONCLUSION

The occurrence of an outbreak of severe dengue in Manado was confirmed, and DENV-3 was found to be the dominant serotype during the outbreak. This study shows the benefits of virological surveillance in understanding the aetiological agents responsible for outbreaks of severe dengue.