Evidence of Chikungunya virus seroprevalence in Myanmar among dengue-suspected patients and healthy volunteers in 2013, 2015, and 2018

Abstract

Introduction Chikungunya virus (CHIKV) is a mosquito-borne virus known to cause acute febrile illness associated with debilitating polyarthritis. In 2019, several institutions in Myanmar reported a CHIKV outbreak. There are no official reports of CHIKV cases between 2011 and 2018. Therefore, this study sought to determine the seroprevalence of CHIKV infection before the 2019 outbreak. Methods A total of 1,544 serum samples were collected from healthy volunteers and patients with febrile illnesses in Yangon, Mandalay, and the Myeik district in 2013, 2015, and 2018. Participants ranged from one month to 65 years of age. Antibody screening was performed with in-house anti-CHIKV IgG and IgM ELISA. A neutralization assay was used as a confirmatory test. Results The seroprevalence of anti-CHIKV IgM and anti-CHIKV IgG was 8.9% and 28.6%, respectively, with an overall seropositivity rate of 34.5%. A focus reduction neutralization assay confirmed 32.5% seroprevalence of CHIKV in the study population. Age, health status, and region were significantly associated with neutralizing antibodies (NAbs) and CHIKV seropositivity (p < 0.05), while gender was not (p = 0.9). Seroprevalence in 2013, 2015, and 2018 was 32.1%, 28.8%, and 37.3%, respectively. Of the clinical symptoms observed in participants with fevers, arthralgia was mainly noted in CHIKV-seropositive patients. Conclusion The findings in this study reveal the circulation of CHIKV in Myanmar’s Mandalay, Yangon, and Myeik regions before the 2019 CHIKV outbreak. As no treatment or vaccine for CHIKV exists, the virus must be monitored through systematic surveillance in Myanmar.

Seroprevalence of Chikungunya in an Asymptomatic Adult Population in North and South Sulawesi, Indonesia

“…Differences in exposure could reflect adaptation of the Aedes vector for resting and breeding inside water-holding containers situated indoors or outdoors. 23 IgG seropositivity tends to be higher in males than females (Table 1); similar trends were reported from Myanmar and the southern part of Thailand, 16,17 which may reflect similarities in cultural habits and behavior patterns that predispose males to more bites by Aedes species. Nevertheless, these results must be interpreted with caution because there was a preponderance of males in this study, which may have biased the outcomes.…”

“…In our study, we evaluated the environmental factor (urban versus rural), demographic (age and sex), and occupation in eastern Indonesia, where the data are limited, and the burden of infectious diseases is high. In general, seroprevalence in Sulawesi was higher than that reported elsewhere in the region: 5.9% for Malaysia 14 ; 1.9% for Singapore 15 ; 34.5% for Myanmar 16 ; 26.8% for Thailand 17 ; and 13.4% for Vietnam. 18 Comparing CHIK serosurveys across different countries and regions is undeniably challenging due to differences in the study population, demography, stratification of age groups, antibody detection method used, and study approach.…”

“…Conversely, IgM seropositivity was higher in females in North and South Sulawesi (Table 1), which differs from a recent regional report in Myanmar. 16 There are a few notable limitations in this study: lack of participant occupation data from South Sulawesi and unequal participant distribution between North and South Sulawesi for a comprehensive analysis. In addition, a confirmatory neutralization assay was not conducted to exclude other alphaviruses.…”

Immuno-Colorimetric Neutralization Test: A Surrogate for Widely Used Plaque Reduction Neutralization Tests in Public Health Virology

“…Previously, many sero-epidemiological investigations of viruses of public health importance, i.e., DENV, CCHFV, Rift Valley fever virus, WNV, Usutu virus, CHIKV, Bourbon virus, Hantavirus, ZIKV, and SARS-CoV-2, have been carried out to confirm the presence of virus-specific IgM and IgG antibodies, and subsequently, case confirmation using gold standard PRNTs or by virus isolation [74][75][76][77][78][79][80][81][82][83][84]. Due to cross-reactivity amongst the arboviruses, cell culture-based NTs are the preferred serological tool for case confirmation.…”

Sylvatic Transmission of Chikungunya Virus among Nonhuman Primates in Myanmar

“…However, in 2017, we detected CHIKV antibodies in NHPs that were <5 years of age, indicating exposure during an interepidemic period. Human cases of CHIKV were not reported by the Myanmar Ministry of Health during 2011–2018 ( 12 ), and CHIKV outbreaks are not commonly underreported because a large proportion of infected persons have indicative arthritic manifestations. In 2019, health officials reported widespread outbreaks of CHIKV in Mandalay, Nay Pyi Taw, Kachin State, Tanintharyi, and Yangon regions of Myanmar, indicating reemergence of the virus ( 12 ).…”