Seroprevalence of chikungunya virus (CHIKV) infection on Lamu Island, Kenya, October 2004 (original) (raw)
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Human and entomologic investigations of chikungunya outbreak in Mandera, Northeastern Kenya, 2016
PLOS ONE
Chikungunya is a reemerging vector borne pathogen associated with severe morbidity in affected populations. Lamu, along the Kenyan coast was affected by a major chikungunya outbreak in 2004. Twelve years later, we report on entomologic investigations and laboratory confirmed chikungunya cases in northeastern Kenya. Patient blood samples were received at the Kenya Medical Research Institute (KEMRI) viral hemorrhagic fever laboratory and the immunoglobulin M enzyme linked immunosorbent assay (IgM ELISA) was used to test for the presence of IgM antibodies against chikungunya and dengue. Reverse transcription polymerase chain reaction (RT-PCR) utilizing flavivirus, alphavirus and chikungunya specific primers were used to detect acute infections and representative PCR positive samples sequenced to confirm the circulating strain. Immature mosquitoes were collected from waterholding containers indoors and outdoors in the affected areas in northeastern Kenya. A total of 189 human samples were tested; 126 from Kenya and 63 from Somalia. 52.9% (100/189) tested positive for Chikungunya virus (CHIKV) by either IgM ELISA or RT-PCR. Sequence analysis of selected samples revealed that the virus was closely related to that from China (2010). 29% (55/189) of the samples, almost all from northeastern Kenya or with a history of travel to northern Kenya, tested positive for dengue IgM antibodies. Entomologic risk assessment revealed high house, container and Breteau indices of, 14.5, 41.9 and 17.1% respectively. Underground water storage tanks were the most abundant, 30.1%, of which 77.4% were infested with Aedes aegypti mosquitoes. These findings confirm the presence of active chikungunya infections in the northeastern parts of Kenya. The detection of dengue IgM antibodies concurrently with chikungunya virus circulation emphasizes on the need for improved surveillance systems and diagnostic algorithms with the capacity to capture multiple causes of arbovirus infections as these two viruses share common vectors and ecosystems. In addition sustained entomological surveillance and vector control programs targeting most productive containers are needed to monitor changes in vector densities, for early detection of the viruses and initiate vector control efforts to prevent possible outbreaks.
Sero-Activity of Chikungunya Virus at the Kenyan Coast after the 2004 Epidemic
2016
Chikungunya virus (CHIKV) is an alphavirus of Semliki Forest virus antigenic complex. Seroprevalence of CHIKVwas measured after the reported 2004CHIKV epidemic in Coastal Kenya and factors associated with seropositivity determined.The total anti-CHIKV antibodies were measured by in-house ELISA’s and neutralizing antibodiesdetermined by focus reduction neutralization test (FRNT) in a cross sectional serosurvey, comparisons of means done using Student’s t test, prevalence rates determined using descriptive statistics, tests of associations performed using Chi-square, and Fisher’s exact test.Of 452 samples, 134 (29.6%) were seropositive for CHIKV antibodies by in-house ELISA; 105 (23.2%) had CHIKV neutralizing antibodiesby FRNT. Age, the month of July, and herding wereassociatedwith CHIKV seropositivity;OR=0.53 (P=0.051, 95% CI: 0.28-1.02), OR=0.14 (P=0.012, 95% C.I 0.02 – 0.8) and OR=6.34 (P= 0.014, 95% CI:1.55-30.61) respectively. Myalgia is likely present in CHIKV infection odds 3.7...
Chikungunya Outbreaks from 2000 to 2015: A Review
Chikungunya is a mosquito-borne disease caused by an alphavirus from the Togaviridae family. The Chikungunya virus (CHIKV) is transmitted by the Aedes mosquitoes. The usual clinical signs of chikungunya are non-specific flu-like symptoms, a distinctive rash and severe joint pains. The disease shares some clinical signs with dengue and can be misdiagnosed in areas where dengue is endemic. There is no vaccine nor a specific antiviral treatment for CHIKV. CHIKV was initially seen in the early 1950s at the boundary of Tanzania and Mozambique. For the past 5 decades, CHIKV was limited to sub-Saharan Africa in addition to Southeast Asia. The situation worsened when CHIKV re-emerged in Kenya in 2004 and reached several other countries in and around the Indian Ocean. The epidemic swiftly reached regions like India and Southeast Asia and transmission of CHIKV was reported for the first time in Europe in 2007 in Italy. The purpose of this review is to summarize CHIKV outbreaks that have been reported in the 15-year period from 2000 to 2015 to show that periodic outbreaks have occurred not only in Asia and Africa, but in Europe and the Americas. It is evident that CHIKV is not restricted to a single region but has become a global public health challenge. As many citizens from non-endemic countries visit areas endemic for CHIKV fever, medical professionals must learn to recognize such cases among travelers returning from such areas with non-specific symptoms such as fever, arthralgia and skin eruptions. In endemic areas for mosquito-borne diseases, clinicians must be educated about the recognition, diagnosis and timely reporting of chikungunya virus disease cases.
Global Biosecurity
Background: Chikungunya is a serious emerging arbovirus in Indonesia. On 12 October 2013, an outbreak of chikungunya was reported in Serdang Bedagai District, North Sumatera, Indonesia. Objective: An epidemiological investigation was conducted to identify the risk factors for the outbreak and recommend control measures. Methods: A 1:1 matched case-control study was conducted. A case of chikungunya was defined as a previously well resident of Sei Suka Subdistrict who had clinical symptoms of chikungunya fever such as fever, arthralgia, myalgia, rash and headache of at least two days duration between 8 August and 17 November 2013. Cases were identified by active case finding through the affected area; a control was defined as a neighbor of a case that did not have clinical signs and symptoms of chikungunya, matched for age and gender. Blood samples were tested using ELISA assay to confirm the presence of anti-CHIKV specific IgM antibody. Results: Total of 94 cases and 94 controls were included in the case control study. Age ranged from 1 year to 76 years (median 35 years) and 57% were female. In multivariate analyses, being a household contact of a chikungunya case (adjusted OR=11.4, 95%CI=4.69-27.55) and lack of routinely eliminating mosquito breeding sites were risk factors (adjusted OR=3.3, 95%CI=1.50-7.05). Six out of ten cases were positive for CHIKV IgM antibody. Conclusions: In this confirmed outbreak of chikungunya, using anti mosquito measures were protective, reinforcing the need for routine elimination of mosquito breeding sites as well as control measures in affected households and communities.
Emergence and Surveillance of Chikungunya
Current Tropical Medicine Reports, 2015
Chikungunya virus (CHIKV), an arbovirus transmitted by Aedes mosquitoes, causes a disease characterised by fever, headache, skin rash, myalgias and severe arthralgias: the latter can persist for years. Following the first report in Africa in 1952, sporadic epidemics have been registered in Africa and in Asia before 2000. Since 2005, huge outbreaks have been reported, caused by globalisation (increasing displacement of humans and mosquitoes) and by an evolutionary success related to the adaptation of CHIKV to the mosquito vector: Therefore, CHIKV spread also in Europe, Oceania and the Americas. In endemic areas, seroprevalence studies could contribute to early detection of epidemics and to have a real picture of the burden of this disease. In temperate areas where Aedes aegypti and/or Aedes albopictus are present, CHIKV control measures require surveillance of imported and autochthonous cases, rapid diagnosis to detect local outbreaks and entomological surveillance.
Seroprevalence of Chikungunya Virus in Febrile Patients in the Kenyan Coast
2019
Fever is one of the main complaints in patients seen at the Coast Provincial General Hospital in Mombasa, Kenya. There is anecdotal evidence to suggest that Chikungunya virus is a cause of some of those fevers, but published data is scanty.This was a hospital based cross sectional study conducted in patients presenting with fevers of unknown origins. We tested for CHIKV antibodies using Enzyme-linked Immunosorbent Assay (ELISA) and confirmed using Focus Reduction Neutralization Test (FRNT). Prevalence rates were determined using proportions and rates. Odds ratio was used to measure the association between CHIKV seropositivity and associated risk factors. Of the 488 eligible participants who were recruited for this study, 269 (54.7%) were males, 213 (46.3%) were female while 6 (1.2%) did not indicate their gender. A total of 90 (18.4%) participants had been vaccinated against yellow fever .The overall seroprevalence of CHIKV was 9.84% (48). Age, gender, yellow fever vaccination statu...
Chikungunya Epidemiology: A Global Perspective
After being discovered on the borders of Mozambique and Tanzania in 1952, the Chikungunya Virus (CHIKV) is now classified as a category C priority pathogen, as it has spread to over 40 countries worldwide. As the virus circulates through either human or mosquito vectors, it is important to closely monitor its progression within vulnerable countries, as it mimics the tenacity of other dangerous diseases such as the Dengue virus and more recently the Zika virus that has caused an outbreak in Brazil and has spread to other Latin American regions. The purpose of this study is to provide an overview of the Chikungunya viral infection by relating the history with the spread of the disease as well as its impact on global populations. Understanding the transmission of the virus, as well as its current spread (in relation to Central / East Africa), will enable conclusions to be made about which treatment and prevention methods should be implemented in order to target those specific demographics. The demographics that were found to have the highest prevalence of Chikungunya include Southeast Asia and Central Africa. Since this virus has the ability for global spread, containing it and preventing further spread, requires preventative measures that must be undertaken globally.
Viruses
Early March 2019, health authorities of Matadi in the Democratic Republic of the Congo alerted a sudden increase in acute fever/arthralgia cases, prompting an outbreak investigation. We collected surveillance data, clinical data, and laboratory specimens from clinical suspects (for CHIKV-PCR/ELISA, malaria RDT), semi-structured interviews with patients/caregivers about perceptions and health seeking behavior, and mosquito sampling (adult/larvae) for CHIKV-PCR and estimation of infestation levels. The investigations confirmed a large CHIKV outbreak that lasted February–June 2019. The total caseload remained unknown due to a lack of systematic surveillance, but one of the two health zones of Matadi notified 2686 suspects. Of the clinical suspects we investigated (n = 220), 83.2% were CHIKV-PCR or IgM positive (acute infection). One patient had an isolated IgG-positive result (while PCR/IgM negative), suggestive of past infection. In total, 15% had acute CHIKV and malaria. Most adult m...
Serological Evidence of Chikungunya Infection in Kaltungo, Gombe State, Nigeria
Journal of Advances in Microbiology
Introduction: Chikungunya is a re-emerging arthropod-borne viral disease that displays a large cell organ tropism, and causes a broad range of clinical symptoms in humans. The virus is listed on the WHO blueprint priority pathogens. However, Chikungunya is a neglected tropical disease in Nigeria and has never been investigated in Kaltungo. Chikungunya virus resembles malaria/typhoid fever in clinical syndrome; misdiagnosis is often common among clinicians. Aim/Objectives: A descriptive cross-sectional hospital-based study was carried out aimed at “serological evidence of acute chikungunya virus infection among outpatients with febrile illness attending general hospital Kaltungo, Gombe State Nigeria”. Materials and Methods: Rapid Test Device (RTD) and enzyme-linked immunosorbent assay (ELISA) were used to demonstrate the presence of acute infection due to CHIKV. A well-structured pre-tested questionnaire along with the consent forms was used to collect both demographic and clinical i...