Risk factors for mortality in patients with chikungunya: A systematic review and meta-analysis

INTRODUCTION

Chikungunya fever is a debilitating arthritic disease that can lead to atypical severe complications and sometimes be fatal. The risk factors for fatal outcomes of chikungunya fever have not been thoroughly studied. This systematic review and meta-analysis aimed to identify mortality risk factors in patients with chikungunya. These findings will aid clinicians in targeting high-risk groups with severe chikungunya for timely interventions, ultimately improving patient outcomes.

OBJECTIVE

The objective of this study is to identify mortality risk factors in patients with chikungunya.

METHODS

We conducted a systematic review and meta-analysis by searching the MEDLINE, Embase, Cochrane, BVS, BDTD and OpenGrey databases to identify eligible observational studies on patients with chikungunya. These studies analysed mortality risk factors, providing adjusted risk measures along with their corresponding confidence intervals (CIs). We estimated the pooled weighted mean difference and 95% CIs using a random-effects model, and the methodological quality was assessed using the Newcastle-Ottawa Scale.

RESULTS

Our search yielded a total of 334 records. After removing duplicates, we screened 275 records, reviewed 31 full articles and included seven studies in the systematic review and four in the meta-analysis, with a total of 220,215 patients and 908 fatal cases. Diabetes Mellitus (OR = 2.86, 95% CI 1.75-4.69), hypertension (OR = 3.10, 95% CI 2.02-4.77), age ≥ 60 years (OR = 19.49, 95% CI 1.98-191.88), chronic kidney disease (OR = 5.81, 95% CI 1.30-25.99), male sex (OR = 2.07, 95% CI 1.71-2.51) and vomiting (OR = 2.18, 95% CI 1.75-2.73) are significantly and positively associated with mortality in chikungunya.

CONCLUSION

Elderly men with chronic diseases have a higher risk of death from chikungunya; therefore, they deserve more careful evaluation.

Chikungunya: From Hypothesis to Evidence of Increased Severe Disease and Fatalities

Chikungunya virus infection often manifests as an acute, self-limiting febrile illness, with arthralgia and musculoskeletal symptoms being the most commonly reported. Arthralgia can persist for months or even years, and approximately 50% of cases progress to chronic conditions. However, recent outbreaks have revealed a rising number of severe cases and fatalities. This review examines evidence from the past decade that suggests a higher incidence of severe chikungunya virus (CHIKV) infections and increased mortality rates, challenging official reports and guidelines from many countries. The literature review includes case reports, series, and studies with comparison groups to assess whether CHIKV-related mortality is underreported. Evaluating excess mortality involves analyzing consistent findings across different regions, biological plausibility, and systemic manifestations that contribute to severe outcomes. These findings aim to expand disease classifications in international guidelines and raise awareness among healthcare professionals to better identify severe CHIKV cases and related deaths. Studies were identified through PubMed using the search terms "chikungunya", "death", "severe", "pathogenesis", and "pathophysiology".

Chikungunya Outbreak Risks after the 2014 Outbreak, Dominican Republic

The 2014 chikungunya outbreak in the Dominican Republic resulted in intense local transmission, with high postoutbreak seroprevalence. The resulting population immunity will likely minimize risk for another large outbreak through 2035, but changes in population behavior or environmental conditions or emergence of different virus strains could lead to increased transmission.

A meta-analysis of Chikungunya virus in neurological disorders

Chikungunya disease typically presents with the fever-arthralgia-rash symptom triad. However, an increase in the number of atypical clinical manifestations, particularly neurological disorders, has occurred. The current evidence regarding the pooled prevalence of Chikungunya virus (CHIKV)-associated neurological cases (CANCs) suspected of having an arboviral aetiology is not well-understood. Therefore, this meta-analysis included 19 studies (n = 7319 patients) and aimed to determine the pooled rate of exposure to CANC. The pooled positivity rate of CANC was 12 % (95 % CI: 6-19), and Brazil was overrepresented (11/19). These estimations varied between 3 and 14 % based on the diagnostic method (real-time PCR vs. ELISA-IgM) and biological samples (cerebrospinal fluid or blood specimens) used for detection of CHIKV. Regarding the frequency of CHIKV in neurological clinical subgroups, the rates were higher among patients with myelitis (27 %), acute disseminated encephalomyelitis (27 %), Guillain-Barré syndrome (15 %), encephalitis (12 %), and meningoencephalitis (7 %). Our analysis highlights the significant burden of CANC. However, the data must be interpreted with caution due to the heterogeneity of the results, which may be related to the location of the studies covering endemic periods and/or outbreaks of CHIKV. Current surveillance resources should also focus on better characterizing the epidemiology of CHIKV infection in neurological disorders. Additionally, future studies should investigate the interactions between CHIKV and neurological diseases with the aim of gaining deeper insight into the mechanisms underlying the cause-and-effect relationship between these two phenomena.

Global geotemporal distribution of chikungunya disease, 2011-2022

BACKGROUND

Chikungunya virus is a mosquito-borne alphavirus, transmitted by Aedes mosquitoes. Humans serve as the primary reservoir. Chikungunya infections typically appear with an abrupt onset of fever, rash, and severe joint pain. Some 40% of cases develop chronic rheumatologic complications that can persist months to years.

OBJECTIVES

To improve precision of risk characterization by analyzing cases of chikungunya by year and by country and depicting this geotemporal distribution in map form.

METHOD

Chikungunya case counts by year were compiled from national or regional health authorities from 2011 to 2022. These data were augmented by published reviews plus the Program for Monitoring Emerging Diseases (ProMED). Country-level distribution was categorized into four groups based on recency and magnitude. Data for India were mapped on a per-state basis.

RESULTS

The global map depicts distribution of chikungunya disease from 2011 through 2022. Most cases are reported in tropical and subtropical areas, but notable exceptions include the northern coast of the Mediterranean Sea. Countries of high recency and frequency include India, Brazil, Sudan, and Thailand. Countries with high frequency, but few cases reported in 2019-22 include many Latin American and Caribbean countries. Subnational foci are discussed in general and mapped for India. The range of Aedes mosquitoes is broader than the geography where chikungunya infection is typically diagnosed.

CONCLUSIONS

These maps help identify geographical regions where residents or travelers are at greatest risk of chikungunya. Once vaccines are licensed to help prevent chikungunya, maps like these can help guide future vaccine decision-making.

Chikungunya fever

Chikungunya virus is widespread throughout the tropics, where it causes recurrent outbreaks of chikungunya fever. In recent years, outbreaks have afflicted populations in East and Central Africa, South America and Southeast Asia. The virus is transmitted by Aedes aegypti and Aedes albopictus mosquitoes. Chikungunya fever is characterized by severe arthralgia and myalgia that can persist for years and have considerable detrimental effects on health, quality of life and economic productivity. The effects of climate change as well as increased globalization of commerce and travel have led to growth of the habitat of Aedes mosquitoes. As a result, increasing numbers of people will be at risk of chikungunya fever in the coming years. In the absence of specific antiviral treatments and with vaccines still in development, surveillance and vector control are essential to suppress re-emergence and epidemics.

Molecular and biological characterization of an Asian-American isolate of Chikungunya virus

Chikungunya virus is an arthropod-transmitted virus that causes chikungunya fever, a disease characterized by severe muscle and joint pain. In 2013, the virus was introduced to the Americas and caused approximately 2.7 million cases of infection during the subsequent two years. The lack of knowledge regarding the biological behavior of the viral strains circulating during the outbreak motivated the characterization of an isolate from the Colombian outbreak, starting from analysis of the complete genome to the biological behavior in vitro. The full genome was retrieved using next-generation sequencing. The infective and replicative capacities were evaluated in HEK293T, Huh-7, and MRC-5 cell lines. The infection rates were determined by flow cytometry, and the cytopathic effect was assessed by a resazurin fluorescent metabolic assay. The viral yield was quantified using the virus plaque formation assay, while the viral proteins and genomic RNA kinetics were subsequently evaluated by western-blot and RT-qPCR. The COL7624 isolate clustered with other American and Caribbean sequences in the Asian American lineage. The T669A substitution in E2 protein distinguished it from other Colombian sequences reported in 2014. After 48 h post infection (hpi), the three cell lines analyzed reached infection percentages exceeding 65%, generating a high load of infectious viral progeny. The infection kinetics indicated that the replication peak of this CHIKV isolate is around 24 hpi, although gRNA is detectable in the culture supernatant from 4 hpi onwards. The infection caused the overexpression of interferon and pro-inflammatory cytokines, such as IL-1β, TNF-α, and IL-8. The COL7624 CHIKV isolate exhibited a high infective and replicative capacity as well as activation of cellular immune responses, similar to isolates belonging to the other genotypes.

Overview on Chikungunya Virus Infection: From Epidemiology to State-of-the-Art Experimental Models

Chikungunya virus (CHIKV) is currently one of the most relevant arboviruses to public health. It is a member of the Togaviridae family and alphavirus genus and causes an arthritogenic disease known as chikungunya fever (CHIKF). It is characterized by a multifaceted disease, which is distinguished from other arbovirus infections by the intense and debilitating arthralgia that can last for months or years in some individuals. Despite the great social and economic burden caused by CHIKV infection, there is no vaccine or specific antiviral drugs currently available. Recent outbreaks have shown a change in the severity profile of the disease in which atypical and severe manifestation lead to hundreds of deaths, reinforcing the necessity to understand the replication and pathogenesis processes. CHIKF is a complex disease resultant from the infection of a plethora of cell types. Although there are several in vivo models for studying CHIKV infection, none of them reproduces integrally the disease signature observed in humans, which is a challenge for vaccine and drug development. Therefore, understanding the potentials and limitations of the state-of-the-art experimental models is imperative to advance in the field. In this context, the present review outlines the present knowledge on CHIKV epidemiology, replication, pathogenesis, and immunity and also brings a critical perspective on the current in vitro and in vivo state-of-the-art experimental models of CHIKF.

Rediscovering the chikungunya virus

El virus de chikunguña (CHIKV) es un Alfavirus perteneciente al grupo denominado del Viejo Mundo; estos son virus artritogénicos que causan una enfermedad febril caracterizada por artralgias y mialgias. Aunque la muerte por CHIKV es poco frecuente, la enfermedad puede llegar a ser incapacitante y generar un amplio espectro de manifestaciones atípicas, como complicaciones cardiovasculares, respiratorias, oculares, renales y dérmicas, entre otras. Cuando el dolor articular persiste por tres o más meses, da lugar a la forma crónica de la enfermedad denominada reumatismo inflamatorio crónico poschikunguña, el cual es la principal secuela de la enfermedad. Se considera que este virus no es neurotrópico, sin embargo, puede afectar el sistema nervioso central y generar secuelas graves y permanentes, principalmente, en niños y ancianos.

En África, Asia y Europa se habían reportado anteriormente brotes epidémicos por CHIKV, pero solo hasta finales del 2013 se documentó la introducción del virus a las Américas; desde entonces, el virus se ha propagado a 45 países o territorios del continente y el número de casos acumulados ascendió a cerca de dos millones en dos años.

Esta revisión describe de manera general la biología molecular del virus, sus manifestaciones clínicas, su patogénesis y las principales complicaciones posteriores a la infección. Además, reúne la información de la epidemia en Colombia y el continente americano publicada entre el 2014 y el 2020.

Fast Expansion of the Asian-Pacific Genotype of the Chikungunya Virus in Indonesia

Chikungunya is repeatedly affecting Indonesia through successive outbreaks. The Asian genotype has been present in Asia since the late 1950s while the ECSA-IOL (East/Central/South Africa - Indian Ocean Lineage) genotype invaded Asia in 2005. In order to determine the extension of the circulation of the chikungunya virus (CHIKV) in Indonesia, mosquitoes were collected in 28 different sites from 12 Indonesian provinces in 2016-2017. The E1 subunit of the CHIKV envelope gene was sequenced while mosquitoes were genotyped using the mitochondrial cox1 (cytochrome C oxidase subunit 1) gene to determine whether a specific population was involved in the vectoring of CHIKV. A total of 37 CHIKV samples were found in 28 Aedes aegypti, 8 Aedes albopictus and 1 Aedes butleri out of 15,362 samples collected and tested. These viruses, like all Indonesian CHIKV since 2000, belonged to a genotype we propose to call the Asian-Pacific genotype. It also comprises the Yap isolates and viruses having emerged in Polynesia, the Caribbean and South America. They differ from the CHIKV of the Asian genotype found earlier in Indonesia indicating a replacement. These results raise the question of the mechanisms behind this fast and massive replacement.

Asynchronicity of endemic and emerging mosquito-borne disease outbreaks in the Dominican Republic

Mosquito-borne viruses threaten the Caribbean due to the region's tropical climate and seasonal reception of international tourists. Outbreaks of chikungunya and Zika have demonstrated the rapidity with which these viruses can spread. Concurrently, dengue fever cases have climbed over the past decade. Sustainable disease control measures are urgently needed to quell virus transmission and prevent future outbreaks. Here, to improve upon current control methods, we analyze temporal and spatial patterns of chikungunya, Zika, and dengue outbreaks reported in the Dominican Republic between 2012 and 2018. The viruses that cause these outbreaks are transmitted by Aedes mosquitoes, which are sensitive to seasonal climatological variability. We evaluate whether climate and the spatio-temporal dynamics of dengue outbreaks could explain patterns of emerging disease outbreaks. We find that emerging disease outbreaks were robust to the climatological and spatio-temporal constraints defining seasonal dengue outbreak dynamics, indicating that constant surveillance is required to prevent future health crises.

Risk factors for death among patients with Chikungunya virus infection during the outbreak in northeast Brazil, 2016-2017

BACKGROUND

Chikungunya virus (CHIKV) infection is a current public health problem. The aim of this study was to investigate risk factors for death among patients with CHIKV infection during a large epidemic in northeast Brazil.

METHODS

This is a cross-sectional study with all registered cases of CHIKV in Ceara, Brazil, during 2016-2017. Data from notification reports were collected, and we have compared non-survivors and survivors.

RESULTS

A total of 182 731 cases were reported, with a mean age of 38±19 years, and the majority was female (62%). There were 383 deaths. Non-survivors were elderly, with a predominance of males, and with a lower educational level. Conditions that were significantly more frequent in the non-survivor group were systemic arterial hypertension, diabetes mellitus and chronic kidney disease (p<0.0001). Independent risk factors for death were advanced age (OR 7.35, p<0.0001), male gender (OR 2.05, p<0.0001), leukopenia (OR 3.18, p<0.0001) and vomiting (OR 2.19, p<0.0001), and comorbidities like hypertension (OR 3.74, p<0.0001), diabetes (OR 3.29, p<0.0001) and chronic kidney disease (OR 3.14, p<0.0001).

CONCLUSION

Advanced age and low educational level were associated with higher risk of mortality in CHIKV. Leukopenia and vomiting were signs of severity, as well as the presence of comorbidities, especially hypertension, diabetes and kidney disease.

How Large Was the Mortality Increase Directly and Indirectly Caused by the COVID-19 Epidemic? An Analysis on All-Causes Mortality Data in Italy

Objective: Overall mortality is a relevant indicator of the population burden during an epidemic. It informs on both undiagnosed cases and on the effects of health system disruption. Methods: We aimed at evaluating the extent of the total death excess during the COVID-19 epidemic in Italy. Data from 4433 municipalities providing mortality reports until April 15th, 2020 were included for a total of 34.5 million residents from all Italian regions. Data were analyzed by region, sex and age, and compared to expected from 2015-2019. Results: In both genders, overall mortality was stable until February 2020 and abruptly increased from March 1st onwards. Within the municipalities studied, 77,339 deaths were observed in the period between March 1st to April 15th, 2020, in contrast to the 50,822.6 expected. The rate ratio was 1.11 before age 60 and 1.55 afterwards. Both sexes were affected. The excess was greater in the regions most affected by COVID-19 but always exceeded the deaths attributed to COVID-19. The extrapolation to the total Italian population suggests an excess of 45,033 deaths in the study period, while the number of COVID-19 deaths was 21,046. Conclusion: Our paper shows a large death excess during the COVID-19 epidemic in Italy; greater than the number attributed to it. Possible causes included both the undetected cases and the disruption of the Health Service organization. Timely monitoring of overall mortality based on unbiased nationwide data is an essential tool for epidemic control.

Events preceding death among chikungunya virus infected patients: a systematic review

Since its re-emergence in the late 1990s, there have been reports of Chikungunya fever (CHIK-F) presenting with severe or atypical findings. There is little knowledge regarding the clinical events leading to the death of patients with CHIK-F. This study aimed to systematically review the literature regarding CHIK-F and identify clinical features preceding death. We searched PubMed, Scopus, Embase, Lilacs, and IsiWeb for case-reports, case-series, or cohorts of CHIK-F reporting at least one death, up to December 2019. Fifty-seven reports were analyzed, including 2140 deaths. Data about specific clinical events that precede death are scarce. The central tendency of time between disease onset and death ranged from 2 days to 150 days. The most common clinical findings among decedents were fever (22.0%), arthralgia (15.7%), myalgia (10.7%), and headache (8.2%). Excluding pediatric populations, the reported central tendency of age among the decedents was 53 or older, with a non-weighted median of 67, ranging up to 80 years old. Authors mentioned organic dysfunction in 91.2% reports. Among all the 2140 decedents, the most common dysfunctions were cardiovascular (7.2%), respiratory (6.4%), neurological (5.4%), renal (4.2%), liver (3.0%), and hematological (1.3%) dysfunction. Exacerbation of previous diabetes (5.6%) or hypertension (6.9%) was mentioned as conditions preceding death. Currently, older age, primary neurological, cardiovascular, or respiratory dysfunction and a previous diagnosis of diabetes or hypertension are the main clinical events preceding death.

Estimated mortality rate and leading causes of death among individuals with chikungunya in 2016 and 2017 in Brazil

INTRODUCTION

In 2014, the first cases of autochthonous chikungunya (CHIK) were recorded in Brazil. Lethality associated with this disease is underestimated. Thus, this study aimed to analyze the causes of death among individuals with CHIK in Brazil.

METHODS

A descriptive observational study was conducted on individuals with CHIK who died within 6 months from symptom onset. Data pairing between the Information System for Notifiable Diseases and the Mortality Information System was performed. Deaths were classified according to case confirmation criterion, mention of CHIK in the death certificates (DCs), and disease phase. The lethality rate per 1,000 cases was corrected for underreporting and was estimated according to region, sex, age, years of education, race/color, and cause groups.

RESULTS

We identified 3,135 deaths (mention of CHIK in the DCs, 764 [24.4%]). In 17.6% of these cases, CHIK was the underlying cause. Most deaths occurred in the acute (38.1%) and post-acute (29.6%) phases. The corrected LR (5.7; x1,000) was 6.8 times higher than that obtained from the Information System for Notifiable Diseases (0.8). The highest corrected LRs were estimated for among individuals living in the Northeast region (6.2), men (7.4), those with low years of education and those aged <1 year (8.6), 65-79 years (20.7), and ≥80 years (75.4).

CONCLUSIONS

The LR of CHIK estimates based on information system linkage help to reveal the relevance of this disease as the direct cause or as a cause associated with serious or fatal events, provide timely interventions, and increase the knowledge about this disease.

Chikungunya Case Classification after the Experience with Dengue Classification: How Much Time Will We Lose?

In 2013, cases of chikungunya virus (CHIKV) infection were first detected in the Caribbean. Chikungunya virus rapidly spread through Central and South America, causing explosive outbreaks in naive populations. Since its emergence in 2004, the number of case and series reports describing severe, atypical manifestations seen in chikungunya patients has increased substantially, calling into question whether clinicians and health services are failing to diagnose these atypical cases because of not only insufficient knowledge but also limitations in the case classification. Although this classification based on the duration of the musculoskeletal (acute, subacute, and chronic forms) complaints helped guide therapeutic approaches directed to these manifestations, patients presenting severe or complicated forms, which are less frequent but produce most of the fatal outcomes, were not properly addressed. In Brazil and the Caribbean, a clear temporal and spatial association between excess overall mortality and the occurrence of chikungunya epidemics has been shown, supporting the hypothesis that many of these excess deaths were a consequence of CHIKV infections. Thus, accumulated experience has highlighted that the current chikungunya case classification does not encompass the actual needs presented by certain cases with atypical features nor does it contribute to early detection and management of potentially severe cases. With continued CHIKV circulation in three continents and recent reemergence in Asia and Europe, we need a classification that is prospective and informed both by initial clinical presentation and by progression of signs and symptoms.

Beyond Fever and Pain: Diagnostic Methods for Chikungunya Virus

Chikungunya virus (CHIKV) is an alphavirus that is primarily transmitted by Aedes species mosquitoes. Though reports of an illness consistent with chikungunya date back over 200 years, CHIKV only gained worldwide attention during a massive pandemic that began in East Africa in 2004. Chikungunya, the clinical illness caused by CHIKV, is characterized by a rapid onset of high fever and debilitating joint pain, though in practice, etiologic confirmation of CHIKV requires the availability and use of specific laboratory diagnostics. Similar to infections caused by other arboviruses, CHIKV infections are most commonly detected with a combination of molecular and serological methods, though cell culture and antigen detection are reported. This review provides an overview of available CHIKV diagnostics and highlights aspects of basic virology and epidemiology that pertain to viral detection. Although the number of chikungunya cases has decreased since 2014, CHIKV has become endemic in countries across the tropics and will continue to cause sporadic outbreaks in naive individuals. Consistent access to accurate diagnostics is needed to detect individual cases and initiate timely responses to new outbreaks.

Chikungunya virus infection in Indonesia: a systematic review and evolutionary analysis

Background

Despite the high number of chikungunya cases in Indonesia in recent years, comprehensive epidemiological data are lacking. The systematic review was undertaken to provide data on incidence, the seroprevalence of anti-Chikungunya virus (CHIKV) IgM and IgG antibodies, mortality, the genotypes of circulating CHIKV and travel-related cases of chikungunya in the country. In addition, a phylogenetic and evolutionary analysis of Indonesian CHIKV was conducted.

Methods

A systematic review was conducted to identify eligible studies from EMBASE, MEDLINE, PubMed and Web of Science as of October 16th 2017. Studies describing the incidence, seroprevalence of IgM and IgG, mortality, genotypes and travel-associated chikungunya were systematically reviewed. The maximum likelihood phylogenetic and evolutionary rate was estimated using Randomized Axelerated Maximum Likelihood (RAxML), and the Bayesian Markov chain Monte Carlo (MCMC) method identified the Time to Most Recent Common Ancestors (TMRCA) of Indonesian CHIKV. The systematic review was registered in the PROSPERO database (CRD42017078205).

Results

Chikungunya incidence ranged between 0.16-36.2 cases per 100,000 person-year. Overall, the median seroprevalence of anti-CHIKV IgM antibodies in both outbreak and non-outbreak scenarios was 13.3% (17.7 and 7.3% for outbreak and non-outbreak events, respectively). The median seroprevalence of IgG antibodies in both outbreak and non-outbreak settings was 18.5% (range 0.0–73.1%). There were 130 Indonesian CHIKV sequences available, of which 120 (92.3%) were of the Asian genotype and 10 (7.7%) belonged to the East/Central/South African (ECSA) genotype. The ECSA genotype was first isolated in Indonesia in 2008 and was continually sampled until 2011. All ECSA viruses sampled in Indonesia appear to be closely related to viruses that caused massive outbreaks in Southeast Asia countries during the same period. Massive nationwide chikungunya outbreaks in Indonesia were reported during 2009–2010 with a total of 137,655 cases. Our spatio-temporal, phylogenetic and evolutionary data suggest that these outbreaks were likely associated with the introduction of the ECSA genotype of CHIKV to Indonesia.

Conclusions

Although no deaths have been recorded, the seroprevalence of anti-CHIKV IgM and IgG in the Indonesian population have been relatively high in recent years following re-emergence in early 2001. There is sufficient evidence to suggest that the introduction of ECSA into Indonesia was likely associated with massive chikungunya outbreaks during 2009–2010.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-3857-y) contains supplementary material, which is available to authorized users.

Excess deaths associated with the 2014 chikungunya epidemic in Jamaica

Although traditionally chikungunya virus is considered non-fatal, recent studies suggest that there may be in fact underreporting of deaths in some situations. A major chikungunya epidemic hit Jamaica in 2014 but no chikungunya-associated deaths were reported. We assessed the excess of all-cause deaths during this epidemic. Excess deaths were estimated by difference between observed and expected mortality based on the average age-specific mortality rate of 2012-2013, using the 99% confidence interval. There was an excess of 2,499 deaths during the epidemic (91.9/100,000 population), and a strong positive correlation between the monthly incidence of chikungunya and the excess of deaths (Rho = 0.939, p < 0.005). No significant concomitant epidemiological or climatic phenomenon occurred. Chikungunya is a major contributor to morbidity during epidemics and may be an unrecognized cause of death. Thus, it is urgent to review clinical protocols and improve the investigations of specific-cause deaths during chikungunya epidemics. Excess deaths could be a strategic tool for epidemiological surveillance.