Long-Lasting Immune Protection and Other Epidemiological Findings after Chikungunya Emergence in a Cambodian Rural Community, April 2012

Abstract

The East/Central/South African genotype of Chikungunya virus with the E1-A226V mutation emerged in 2011 in Cambodia and spread in 2012. An outbreak of 190 cases was documented in Trapeang Roka, a rural village. We surveyed 425 village residents within 3–4 weeks after the outbreak, and determined the sensitivity and specificity of case definitions and factors associated with infection by CHIKV. Self-reported clinical presentation consisted mostly of fever, rash and arthralgia. The presence of all three clinical signs or symptoms was identified as the most sensitive (67%) and specific (84%) self-reported diagnostic clinical indicator compared to biological confirmation by MAC-ELISA or RT-PCR used as a reference. Having an indoor occupation was associated with lower odds of infection compared with people who remained at home (adjOR 0.32, 95%CI 0.12–0.82). In contrast with findings from outbreaks in other settings, persons aged above 40 years were less at risk of CHIKV infection, likely reflecting immune protection acquired when Chikungunya circulated in Cambodia before the Khmer Rouge regime in 1975. In view of the very particular history of Cambodia, our epidemiological data from Trapeang Roka are the first to support the persistence of CHIKV antibodies over a period of 40 years.

Comprehensive Genome Scale Phylogenetic Study Provides New Insights on the Global Expansion of Chikungunya Virus

“…CHIKF outbreaks in Southeast Asia have been markedly episodic, with long interepidemic intervals. This can be at least partially attributed to durable immunity, as suggested by serosurveys in Thailand (59), the Philippines (60, 61), and Cambodia (62). However, the recent introduction into the region of the IOL has resulted in large-scale epidemics in both Malaysia and Thailand in 2008 and 2009.…”

The neurological complications of chikungunya virus: A systematic review

“…In acute symptomatic infection, following an incubation period of approximately 3 days, there is an abrupt onset of fever, headache, rash, arthralgia, and myalgia, which typically last for 1 to 2 weeks . After this, seroconversion likely confers lifelong immunity . As well as neurological manifestations, chikungunya virus is associated with complications of the cardiovascular, renal, respiratory, hepatic, gastrointestinal, and adrenal systems, sometimes collectively referred to as “atypical features.” However, a disorder of the nervous system appears to be the most common severe complication of chikungunya infection (Table ).…”

Beyond Fever and Pain: Diagnostic Methods for Chikungunya Virus

“…Although it has been reported that a high proportion of CHIKV infections are symptomatic (80 to 97%) (1,27,(49)(50)(51), the ratio of symptomatic to inapparent CHIKV infections (S/I ratio) has varied markedly in the literature (5,27,(52)(53)(54)(55)(56). Factors associated with the S/I ratio include the presence of preexisting neutralizing antibodies to CHIKV (52,55) and patient age (52,54,56,57). Notably, both negative (54,57) and positive (52) associations between age and symptomatic infection have been reported.…”