COVID-19 onslaught is masking the 2021 dengue outbreak in Dhaka, Bangladesh

Understanding dengue outbreaks in Rajshahi district, Bangladesh: A comprehensive case study

Background and aims

The 2023 dengue outbreak in Bangladesh marked an unprecedented increase in fatalities, particularly in Dhaka, and demonstrated extensive prevalence nationwide, including Rajshahi district. Dengue fever remains a significant public health challenge in Southeast Asia, with complex epidemiological patterns. Previous research has mainly focused on den serotypes in Dhaka. Therefore, this study aims to identify serotypes in the Rajshahi district under endemic conditions.

Methods

Blood samples from suspected dengue patients were collected at Rajshahi Medical College Hospital. Initial rapid detection of dengue-positive cases was performed using (Nonstructural Protein 1 L) NS1, (Immunoglobulin G) IgG, and (Immunoglobulin M) IgM tests. Upon confirmation of dengue positivity, viral RNA was extracted for molecular testing. The dengue serotype was identified using real-time reverse transcription-polymerase chain reaction (rRT-PCR).

Results

The study revealed that 93.3 % of the patient were infected with (Dengue virus type 2) DENV2 and rest 6.7 % of the patient were (Dengue virus type 3) DENV3 among 30 dengue positive patients. Demographic observations show the distribution of dengue over nine upazilas. In Paba upazila, we found two DENV3 alongside DENV2.

Conclusion

The study concludes that the 2023 dengue outbreak in Rajshahi district, Bangladesh, predominantly involved the DENV2 serotype. Geospatial analysis underscores the importance of understanding regional distribution patterns to enhance targeted interventions against dengue fever in endemic areas.

The Epidemiologic and Clinical Characteristics of the 2023 Dengue Outbreak in Bangladesh

The ongoing 2023 dengue outbreak is the worst ever case reported in Bangladesh. There is a lack of epidemiological studies on the outbreak. A 2-tailed t test was performed. Multivariable logistic regression analysis was conducted. We found about 277 801 cases and 1393 deaths from the 2023 dengue outbreak. About 52% of the cases were from outside of Dhaka. The male:female ratio was about 3:2. The highest frequency of cases was found among people aged 19-29 years (28.7%, 79 673 of 277 801; P = .001). The overall case fatality rate (CFR) was 0.5%. The highest CFR was found among children aged 0-10 years (12%). Fever (99%) was the most prevalent, followed by joint pain (86%). We found significantly higher odds of fatalities (adjusted odds ratio [aOR], 4.21; 95% CI, 3.93-4.74; P = .05), cases (aOR, 3.85; 95% CI, 3.25-4.12; P = .001) and hospitalizations (aOR, 3.26; 95% CI, 3.11-4.04; P = .006) during the 2023 outbreak compared with previous outbreaks during 2008-2022. This is one of the early reports of epidemiological and clinical characteristics of ongoing dengue outbreak.

Simultaneous COVID-19 Pandemic and Dengue Epidemic: A Double Challenge to Geriatric Health Security in Bangladesh

Bangladesh faces distinct challenges as a resource-poor country due to the combined effects of the COVID-19 pandemic and simultaneous dengue outbreaks. Older adults are particularly vulnerable to infection and death from COVID-19. While overall health and life expectancy in the general population have improved substantially in Bangladesh, health services for older adults are still lacking. No specialized geriatric units have been established in hospitals, and no home care programs have been established for older adults. COVID-19 mortality rates were highest among older adults ages 61 to 70 years (35%), and 71 to 80 years (20%) in 2022. Although the country's average COVID-19 mortality rate was low at 1.76%, in older adults, it was much higher (55%), accounting for 14,797 deaths, despite that most cases (55%) were recorded in young adults. During the COVID-19 pandemic, Bangladesh also experienced a dengue epidemic. Around 21,193 dengue patients were admitted to hospitals between January 1 and October 8, 2022. Without a well-established and all-encompassing social care program, the indirect socioeconomic burden of COVID-19 continues to fall on older adults. There is an immediate need for robust healthcare and support services, especially for older adults in Bangladesh, which are particularly susceptible to the dual threats posed by the COVID-19 pandemic and the dengue epidemic. Recommendations are made to protect older adults from the devastating effects of the 2 simultaneous epidemics.

Excess mortality during the COVID-19 pandemic (2020-2021) in an urban community of Bangladesh

Measuring COVID-19-related mortality is vital for making public health policy decisions. The magnitude of COVID-19-related mortality is largely unknown in low- and middle-income countries (LMICs), including Bangladesh, due to inadequate COVID-19 testing capacity and a lack of robust civil registration and vital statistics systems. Even with the lack of data, cemetery-based death records in LMICs may provide insightful information on potential COVID-19-related mortality rates; nevertheless, there is a dearth of research employing cemetery-based death records. This study aimed to assess the excess mortality during the COVID-19 pandemic in an urban setting in Bangladesh using a cemetery-based death registration dataset. A total of 6,271 deaths recorded between January 2015 and December 2021 were analysed using a Bayesian structural time series model. Exploratory analysis found that the average monthly number of deaths was 69 during the pre-COVID-19 period (January 2015-February 2020), but significantly increased to 92 during the COVID-19 period (March 2020-December 2021). The increase in male deaths was twice as large as the increase in female deaths. Model-based results were not statistically significant (relative effect 17%, 95% credible interval: -18%, 57%), but there was an overall increasing trend during the COVID-19 period, and specific months or shorter periods had a substantial increase. This first-of-its-kind study in Bangladesh has assessed the excess mortality in an urban community during the COVID-19 pandemic. Cemetery-based death registration appears to aid in tracking population mortality, especially in resource-limited countries where collecting data on the ground is challenging during crisis periods; however, additional large-scale research is required.

Twenty-two years of dengue outbreaks in Bangladesh: epidemiology, clinical spectrum, serotypes, and future disease risks

Dengue is the most rapidly spreading mosquito-borne disease and has become a major public health threat, particularly for tropical and subtropical countries including Bangladesh. This comprehensive review aims to summarize the overall scenario of dengue, including disease burden, clinical spectrum, seroprevalence, circulating serotypes/genotypes, and spatial distribution since the first recorded outbreak in Bangladesh. Since the first recorded outbreak in 2000, dengue epidemiology has shown the typical epidemic pattern with more frequent and bigger outbreaks and gradual geographic expansion to non-endemic regions in Bangladesh. For instance, highly confined Rohingya refugee camps that provide shelters to nearly 1.2 million forcibly displaced vulnerable Myanmar nationals in Cox's Bazar district confronted a massive outbreak in 2022. Recent major outbreaks are found to be associated with the emergence of serotype DENV-3, which was undetected for a long time. Consequently, changes in serotypes might be attributed to increased severity in clinical manifestation in recent years. The existing weak surveillance and risk management systems are inadequate to deal with impending dengue risks. The healthcare system, particularly at the district level, is not prepared to manage impending large-scale dengue outbreaks in Bangladesh. Our findings would contribute to the development of strategies for dengue control and management in Bangladesh as well as other similar settings elsewhere in the world.

Simulations and fractional modeling of dengue transmission in Bangladesh

Dengue is one of the most infectious diseases in the world. In Bangladesh, dengue occurs nationally and has been endemic for more than a decade. Therefore, it is crucial that we model dengue transmission in order to better understand how the illness behaves. This paper presents and analyzes a novel fractional model for the dengue transmission utilizing the non-integer Caputo derivative (CD) and are analysed using q-homotopy analysis transform method (q-HATM). By using the next generation method, we derive the fundamental reproduction number $ R_0 $ and show the findings based on it. The global stability of the endemic equilibrium (EE) and the disease-free equilibrium (DFE) is calculated using the Lyapunov function. For the proposed fractional model, numerical simulations and dynamical attitude are seen. Moreover, A sensitivity analysis of the model is performed to determine the relative importance of the model parameters to the transmission.

Dengue and COVID-19: Managing Undifferentiated Febrile Illness during a "Twindemic"

BACKGROUND

During the COVID-19 pandemic, distinguishing dengue from COVID-19 in endemic areas can be difficult, as both may present as undifferentiated febrile illness. COVID-19 cases may also present with false-positive dengue serology. Hospitalisation protocols for managing undifferentiated febrile illness are essential in mitigating the risk from both COVID-19 and dengue.

METHODS

At a tertiary hospital contending with COVID-19 during a dengue epidemic, a triage strategy of routine COVID-19 testing for febrile patients with viral prodromes was used. All febrile patients with viral prodromes and no epidemiologic risk for COVID-19 were first admitted to a designated ward for COVID-19 testing, from January 2020 to December 2021.

RESULTS

A total of 6103 cases of COVID-19 and 1251 cases of dengue were managed at our institution, comprising a total of 3.9% (6103/155,452) and 0.8% (1251/155,452) of admissions, respectively. A surge in dengue hospitalisations in mid-2020 corresponded closely with the imposition of a community-wide lockdown. A total of 23 cases of PCR-proven COVID-19 infection with positive dengue serology were identified, of whom only two were true co-infections; both had been appropriately isolated upon admission. Average length-of-stay for dengue cases initially admitted to isolation during the pandemic was 8.35 days (S.D. = 6.53), compared with 6.91 days (S.D. = 8.61) for cases admitted outside isolation (1.44 days, 95%CI = 0.58-2.30, p = 0.001). Pre-pandemic, only 1.6% (9/580) of dengue cases were admitted initially to isolation-areas; in contrast, during the pandemic period, 66.6% (833/1251) of dengue cases were initially admitted to isolation-areas while awaiting the results of SARS-CoV-2 testing.

CONCLUSIONS

During successive COVID-19 pandemic waves in a dengue-endemic country, coinfection with dengue and COVID-19 was uncommon. Routine COVID-19 testing for febrile patients with viral prodromes mitigated the potential infection-prevention risk from COVID-19 cases, albeit with an increased length-of-stay for dengue hospitalizations admitted initially to isolation.

Megacity-centric mass mobility during Eid holidays: a unique concern for infectious disease transmission in Bangladesh

Human mobility, particularly during certain festivals in rapidly growing megacities in low- and middle-income countries, has critical implications in infectious diseases surveillance and preparedness. In this perspective, we present the interesting case of Dhaka megacity, the capital of Bangladesh with a population of over 20 million. In recent times, three massive infectious disease outbreaks in Dhaka (chikungunya, dengue and COVID-19) coincided with Muslim religious Eid festivals. From a public health standpoint, it is very important to share this information with the international community to fight against emerging infectious diseases around the world.