Etiology of the 1965 epidemic of febrile illness in Nagpur city, Maharashtra State, India

An investigation of an extensive outbreak of febrile illness during the months of April, May, and June 1965, in the city of Nagpur, Maharashtra State, showed that the main etiological agent was chikungunya virus. Dengue type 4 and Chandipura viruses were also active during this period. In all, 26 strains of virus were isolated from 60 acute phase human sera, and of these strains, 23 were identified as chikungunya virus, 2 as Chandipura, and 1 as dengue type 4. Five strains of chikungunya virus and 9 strains of dengue type 4 virus were isolated from 34 pools of Aedes aegypti collected from the affected areas. Results of complement fixation tests with acute—convalescent paired serum samples and single convalescent sera confirmed that chikungunya virus was the main etiological agent. The significance of these findings is discussed.     

Reappearance of Chikungunya,Formerly Called Dengue,in the Americas

After an absence of ≈200 years, chikungunya returned to the American tropics in 2013. The virus is maintained in a complex African zoonotic cycle but escapes into an urban cycle at 40- to 50-year intervals, causing global pandemics. In 1823, classical chikungunya, a viral exanthem in humans, occurred on Zanzibar, and in 1827, it arrived in the Caribbean and spread to North and South America. In Zanzibar, the disease was known as kidenga pepo, Swahili for a sudden cramp-like seizure caused by an evil spirit; in Cuba, it was known as dengue, a Spanish homonym of denga. During the eighteenth century, dengue (present-day chikungunya) was distinguished from breakbone fever (present-day dengue), another febrile exanthem. In the twentieth century, experiments resulted in the recovery and naming of present-day dengue viruses. In 1952, chikungunya virus was recovered during an outbreak in Tanzania, but by then, the virus had lost its original name to present-day dengue viruses.     

Chikungunya outbreak in Guangdong Province, China, 2010

A disease outbreak with dengue-like symptoms was reported in Guangdong Province, China, in October 2010. Testing results confirmed that the pathogen causing the outbreak was chikungunya virus. Phylogenic analysis indicated that this virus was a member of the Indian Ocean clade of the East/Center/South African subgroup of chikungunya virus.     

Reemergence of Chikungunya Virus in Bo,Sierra Leone

We diagnosed 400 possible IgM-positive cases of chikungunya virus in Bo, Sierra Leone, during July 2012–January 2013 by using lateral flow immunoassays. Cases detected likely represent only a small fraction of total cases. Further laboratory testing is required to confirm this outbreak and characterize the virus.     

Chikungunya fever as a risk factor for endemic Burkitt's lymphoma in Malawi

The geographical and age distributions of endemic Burkitt's lymphoma (eBL), in Africa, parallel those of certain arboviruses, which include chikungunya fever. Increased incidences of antibodies to assorted arboviruses, including chikungunya, have been found in eBL sera compared to controls. An increased incidence and space-time case-clusters of eBL occurred during a chikungunya fever epidemic which were confirmed by serology and clinical observation. The present study, conducted in 1987-89, involved 108 eBL patients, and 97 local and 111 hospital controls. We examined, as hospital controls, patients with afebrile, non-malignant conditions admitted to Kamuzu Central Hospital, Malawi, during the eBL patients' first admission there. Analyses were for hospital controls and eBL patients at the end of their first admission and for local controls and eBL patients at the beginning of their third admission, about 8 weeks after the day of first admission, because of the local controls' temporal bias. Patients in case-clusters were among those seropositive for chikungunya virus, with a history compatible with arbovirus infection preceding the lymphoma, suggesting involvement of chikungunya virus in the case-clusters and a possible association between recent infection with this virus and development of the lymphoma. eBL patients were significantly more likely to be seropositive for chikungunya virus antibody (68x5%) than either hospital controls (46.8%) or local controls (50x5%) (P = 0x002 and 0x009, respectively), raising the possibility of an association between infection with an arbovirus and developing eBL in children already primed by holoendemic malaria and Epstein-Barr virus infection.     

Co-circulation of Dengue and Chikungunya Viruses,Al Hudaydah,Yemen, 2012

We investigated 400 cases of dengue-like illness in persons hospitalized during an outbreak in Al Hudaydah, Yemen, in 2012. Overall, 116 dengue and 49 chikungunya cases were diagnosed. Dengue virus type 2 was the predominant serotype. The co-circulation of these viruses indicates that mosquitoborne infections represent a public health threat in Yemen.     

Epidemiologic History and Genetic Diversity Origins of Chikungunya and Dengue Viruses,Paraguay

Paraguay has been severely affected by emergent Zika and chikungunya viruses, and dengue virus is endemic. To learn more about the origins of genetic diversity and epidemiologic history of these viruses in Paraguay, we deployed portable sequencing technologies to strengthen genomic surveillance and determine the evolutionary and epidemic history of arthropod-borne viruses (arboviruses). Samples stored at the Paraguay National Central Laboratory were sequenced and subjected to phylogenetic analysis. Among 33 virus genomes generated, we identified 2 genotypes of chikungunya and 2 serotypes of dengue virus that circulated in Paraguay during 2014–2018; the main source of these virus lineages was estimated to be Brazil. The evolutionary history inferred by our analyses precisely matched the available travel history of the patients. The genomic surveillance approach used was valuable for describing the epidemiologic history of arboviruses and can be used to determine the origins and evolution of future arbovirus outbreaks.     

An outbreak of yellow fever with concurrent chikungunya virus transmission in South Kordofan, Sudan, 2005

From September through December 2005, an outbreak of hemorrhagic fever occurred in South Kordofan, Sudan. Initial laboratory test results identified IgM antibodies against yellow fever (YF) virus in patient samples, and a YF outbreak was declared on 14 November. To control the outbreak, a YF mass vaccination campaign was conducted and vector control implemented in parts of South Kordofan. Surveillance data were obtained from the Sudan Federal Ministry of Health. Clinical information and serum samples were obtained from a subset of patients with illness during the outbreak. Nomads, health personnel and village chiefs were interviewed about the outbreak. Mosquitoes were collected in 11 villages and towns in North and South Kordofan. From 10 September to 9 December 2005 a total of 605 cases of outbreak-related illness were reported, of which 45% were in nomads. Twenty-nine percent of 177 patients seen at clinics in Julud and Abu Jubaiyah had illness consistent with YF. Five of 18 unvaccinated persons with recent illness and 4 of 16 unvaccinated asymptomatic persons had IgM antibodies to YF virus. IgM antibodies to chikungunya virus were detected in five (27%) ill persons and three (19%) asymptomatic persons. These results indicate that both chikungunya and YF occurred during the outbreak.     

First evidence of chikungunya virus infection in Assam, Northeast India

During June-September 2008, an illness characterized by fever, headache and joint pain was reported in Assam state, northeast India. It presented characteristic features resembling chikungunya or dengue virus infection based on clinical symptoms. Dengue and chikungunya IgM antibody was detected in 10.0% (28/280) and 3.6% (10/280) patients respectively. The chikungunya positive patients did not travel to and from any endemic region confirming indigenous transmission. Persistent arthralgia and hearing loss has been observed in a recovered patient. Entomological surveys revealed the presence of vectors viz. Aedes aegypti and Aedes albopictus. This is the maiden report of chikungunya occurrence in Northeast India.     

Increased mortality rate associated with chikungunya epidemic, Ahmedabad, India

In 2005-2006, Réunion Island in the Indian Ocean reported approximately 266,000 cases of chikungunya; 254 were fatal (case-fatality rate 1/1,000). India reported 1.39 million cases of chikungunya fever in 2006 with no attributable deaths; Ahmedabad, India, reported 60,777 suspected chikungunya cases. To assess the effect of this epidemic, mortality rates in 2006 were compared with those in 2002-2005 for Ahmedabad (population 3.8 million). A total of 2,944 excess deaths occurred during the chikungunya epidemic (August-November 2006) when compared with the average number of deaths in the same months during the previous 4 years. These excess deaths may be attributable to this epidemic. However, a hidden or unexplained cause of death is also possible. Public health authorities should thoroughly investigate this increase in deaths associated with this epidemic and implement measures to prevent further epidemics of chikungunya.     

Chikungunya infection in travelers

The largest described outbreak of chikungunya virus has been occurring on the islands of the southwest Indian Ocean since March 2005. We describe the manifestations of chikungunya virus infection in travelers returning from these islands, with focus on skin manifestations.     

Yellow fever infection after recent convalescence from chikungunya fever: report of a fatal case

An epidemic of chikungunya fever occurred in Luanda, Angola, at the end of 1970, being followed by, and partly concurrent with, an epidemic of yellow fever. In March 1971, a 16-year-old white boy, who had chikungunya fever 3 weeks before, was admitted to hospital with yellow fever. He had a severe illness ending in death on the 8th day. Serum taken on admission yielded YF virus designated as strain 47FA; it is essentially identical to YF (Asibi strain) virus. This serum had HI antibody only to CHIK virus, of 11 arbovirus antigens tested. A positive CF test for CHIK antibody in this serum confirmed the earlier infection with CHIK virus. The authors speculate that persons convalescent from chikungunya fever may be less resistant to infection with YF virus.     

Chikungunya virus, southeastern France

In September 2010, autochthonous transmission of chikungunya virus was recorded in southeastern France, where the Aedes albopictus mosquito vector is present. Sequence analysis of the viral genomes of imported and autochthonous isolates indicated new features for the potential emergence and spread of the virus in Europe.     

First case of chikungunya diagnosed in the Netherlands

A 52-year-old man was seen in the Diagnostic Centre for Tropical Diseases of the Havenziekenhuis, Rotterdam, presenting with arthralgia, fever and exanthema following a stay in Mauritius. Infection with the Dengue virus infection is a common diagnosis for this combination of complaints, but nowadays chikungunya should also be considered. This is particularly the case when a patient has visited a country in or around the Indian Ocean. Risk areas are La Réunion and Mauritius, where, in February 2005 and April 2005 respectively, epidemics broke out. Chikungunya is a viral infection. The causative virus is an Alpha virus, transmitted by mosquitoes. The symptoms include arthralgia, myalgia, diffuse maculopapular rash, fever and headache. In contrast to dengue, chikungunya is not associated with haemorrhagic diathesis. Treatment takes place in response to the symptoms, since there is no targeted therapy available. The main preventive measure is to prevent mosquito bites. The disease is not deadly and healing is spontaneous. To our knowledge this is the first case of chikungunya diagnosed in the Netherlands during this epidemic. The disease has recently been reported in Italy, where native mosquitoes transmit it.     

Reemergence of endemic Chikungunya, Malaysia

Chikungunya virus infection recently reemerged in Malaysia after 7 years of nondetection. Genomic sequences of recovered isolates were highly similar to those of Malaysian isolates from the 1998 outbreak. The reemergence of the infection is not part of the epidemics in other Indian Ocean countries but raises the possibility that chikungunya virus is endemic in Malaysia.     

The study transplacental chikungunya virus antibody kinetics, Thailand

Antibodies to chikungunya virus were detected by hemagglutination-inhibition assay in 33.6% of 2,000 infants' cord sera at delivery. Follow-up of 24 seropositive infants showed that the half-life of antibody persistence was 35.5 days. Chikungunya virus infection is common in Thailand, and routine use of diagnostic assays is needed.