Eighteen (18) cases of Chikungunya (or a very close related virus) infection, a newly observed clinical entity in the Philippines, are presented. Diagnosis was established by serological studies consisting of hemagglutination- inhibition (HI) and complement fixation (CF) tests. The clinical picture is characterized by a symptom-complex consisting essentially of fever, severe, incapacitating, recurrent joint pains and a rash. There is no involvement of the respiratory system and no bleeding tendencies were observed. The erythrocyte sedimentation rate was elevated, more so towards the later part of the illness. The platelet counts were normal. No residual joint deformity morbidity or mortality was encountered.
Chikungunya virus

Alphavirus Infections ; epidemiology ; Chikungunya virus ; Humans

Chikungunya virus (CHIKV) is a mosquito-borne alphavirus which causes epidemic fever, rash and polyarthralgia in Africa and Asia. Two outbreaks have been reported in Malaysia, in Klang, Selangor (1998) and Bagan Panchor, Perak (2006). It is not known if the outbreaks were caused by the recent introduction of CHIKV, or if the virus was already circulating in Malaysia. Seroprevalence studies from the 1960s suggested previous disease activity in certain parts of the country. In Asia, CHIKV is thought to be transmitted by the same mosquitoes as dengue, Aedes aegypti and Ae. albopictus. Due to similarities in clinical presentation with dengue, limited awareness, and a lack of laboratory diagnostic capability, CHIKV is probably often underdiagnosed or misdiagnosed as dengue. Treatment is supportive. The prognosis is generally good, although some patients experience chronic arthritis. With no vaccine or antiviral available, prevention and control depends on surveillance, early identification of outbreaks, and vector control. CHIKV should be borne in mind in sporadic cases, and in patients epidemiologically linked to ongoing local or international outbreaks or endemic areas.
increasing incidence ; Dengue ; Chikungunya virus ; Infection as complication of medical care ; control

Alphavirus Infections ; diagnosis ; epidemiology ; virology ; Animals ; Chikungunya Fever ; Chikungunya virus ; genetics ; isolation & purification ; physiology ; Humans ; Viral Proteins ; genetics ; metabolism

OBJECTIVES: Dengue epidemic is a dynamic and complex phenomenon that has gained considerable attention due to its injurious effects. The focus of this study is to statically analyze the nature of the dengue epidemic network in terms of whether it follows the features of a scale-free network or a random network. METHODS: A multifarious network of Aedes aegypti is addressed keeping the viewpoint of a complex system and modelled as a network. The dengue network has been transformed into a one-mode network from a two-mode network by utilizing projection methods. Furthermore, three network features have been analyzed, the power-law, clustering coefficient, and network visualization. In addition, five methods have been applied to calculate the global clustering coefficient. RESULTS: It has been observed that dengue epidemic follows a power-law, with the value of its exponent γ = −2.1. The value of the clustering coefficient is high for dengue cases, as weight of links. The minimum method showed the highest value among the methods used to calculate the coefficient. Network visualization showed the main areas. Moreover, the dengue situation did not remain the same throughout the observed period. CONCLUSIONS: The results showed that the network topology exhibits the features of a scale-free network instead of a random network. Focal hubs are highlighted and the critical period is found. Outcomes are important for the researchers, health officials, and policy makers who deal with arbovirus epidemic diseases. Zika virus and Chikungunya virus can also be modelled and analyzed in this manner.
Administrative Personnel ; Aedes ; Arboviruses ; Chikungunya virus ; Critical Period (Psychology) ; Dengue Virus ; Dengue ; Humans ; Methods ; Zika Virus

Chikungunya virus (CHIKV), a tropical pathogen, has re-emerged and has massive outbreaks abruptly all over the world. Containing many dominant epitopes, the envelope E2 protein of CHIKV has been explored for the vaccination or diagnosis. In the present study, the antigenicity of a recombinant expressed intrinsically disorder domain (IUD) of E2 was tested for the detection of the antibody against CHIKV through western blot method. The gene of the IUD of E2 was inserted into 2 different vectors and expressed as recombinant GST-E2 and recombinant MBP-E2 fusion protein, respectively. Two kinds of fusion proteins were tested with 30 CHIKV patient sera and 30 normal sera, respectively. Both proteins were detected by 25 patients sera (83.3%) and 1 normal serum (3.3%). This test showed a relatively high sensitivity and very high specificity of the recombinant E2 proteins to be used as diagnostic antigens against CHIKV infection.
Blotting, Western* ; Chikungunya virus ; Diagnosis ; Disease Outbreaks ; Epitopes ; Humans* ; Sensitivity and Specificity ; Vaccination

Chikungunya virus ; genetics ; isolation & purification ; China ; Genome, Viral ; RNA, Viral ; genetics ; Sequence Analysis, RNA

To establish a MacELISA method for the detection of IgM antibodies against Chikungunya virus (CHIKV), we prepared virus like particle (VLP) antigens of CHIKV using the whole structural protein C-E3-E2-6K-E1 encoding gene with a baculovirus expression system in Sf9 insect cells. The VLPs were purified and used to immunize Kunming mice. Then, polyclonal antibodies were purified from the samples of ascites with a protein G HiTrap SP column and labeled with horseradish peroxidase. A MacELISA method for the detection of IgM antibodies against CHIKV was assembled with goat anti-human IgM antibody, VLP antigens and an enzyme-labeled polyclonal antibody. The results were evaluated with a serum panel containing serum samples from laboratory-confirmed CHIK, HFRS patients, healthy donors, and commercially available CHIKV IgM as a quality control. It was shown that the MacELISA had a specificity of 99% (99/100), the coefficients of variation (CoV) within a plate were <10%, and the CoV of different ELISA plates in terms of the plate variation coefficient was <15%. A comparative analysis was performed to compare the current method against a commercial CHIKV IgM antibody detection kit for IIFA-IgM. The detection limit of MacELISA was significantly lower than that of the IIFA-IgM commercial kit (P< 0.0001). Here, we demonstrate that the VLP-based MacELISA is a promising tool for the early diagnosis and epidemiological investigation of CHIKV infection, with a high level of sensitivity and specificity for the detection of IgM antibodies against CHIKV.
Animals ; Antibodies, Viral ; blood ; Chikungunya Fever ; blood ; diagnosis ; virology ; Chikungunya virus ; immunology ; isolation & purification ; Enzyme-Linked Immunosorbent Assay ; methods ; Humans ; Immunoglobulin M ; blood ; Mice

The incidence of chikungunya infection in Singapore has been on the rise since the first reported case in 2006. Acute polyarthritis, a common manifestation among affected patients, may precede fever and present with debilitating arthritis to rheumatologists, orthopaedists, internists and primary care physicians. The diagnosis of chikungunya infection requires careful history taking and a high index of suspicion, with supporting evidence from the reverse transcription-polymerase chain reaction or the chikungunya IgM serology test. Treatment of chikungunya arthritis usually involves non-steroidal anti-inflammatory drugs. Rarely, polyarthritis in chikungunya may persist even after resolution of the acute infection, necessitating treatment with disease-modifying anti-rheumatic drugs. In this article, we present the different manifestations of chikungunya arthritis in our local setting and review the literature.
Aged ; Alphavirus Infections ; complications ; Anti-Inflammatory Agents, Non-Steroidal ; therapeutic use ; Arthritis ; drug therapy ; virology ; Chikungunya Fever ; Chikungunya virus ; Female ; Humans ; Male ; Middle Aged

BACKGROUND: Chikungunya virus (CHIKV) is a mosquito- borne  alphavirus  of  the  family  Togaviridae  transmitted  to humans by the Aedes spp. mosquitoes, causing Chikungunya   Fever  (CHIKF).
OBJECTIVE: This study aims to describe the course and outcome of musculoskeletal (MSK) manifestations in patients  with  CHIKF  seen  over  a   three-month     period.
DESIGN: This is a prospective descriptive  study.  Seventy  patients  with  fever,  rash,  and  arthritis  seen   at the University of the Philippines-Philippine General Hospital  and  private  arthritis  clinics  were  collected from August - December 2012.  Demographics  and course   of   arthritis   were  described.
RESULTS:  Seventy   patients,   53   (68.6%)   female,   with  a mean age  of  39.2  ±13.50  were  diagnosed  with CHIKF. All cases were from the Metropolitan  Manila area. Of these, 15 (21.4%) had  family  members  affected. Twenty-four patients (34.3%) were either employed or students. The most common presenting symptoms were fever (94.3%), arthritis or athralgia  (98.6%), and rash (87.1%).  The  most  common  joint  areas involved were the ankles  (60.0%),  the  wrists (40.0%) and the small joints of the hand (51.4%). Twenty-seven (47.3%) had symmetric  arthritis.  Thirty- seven   cases   (52.9%)   had   arthralgia   or   arthritis    for at least  six  weeks.  By  the  end  of  the  follow-up  period, only four (5.7%) had persistent musculoskeletal symptoms. Age and  sex  were not  found to  be  factors in  determining  chronicity  of  arthritic  symptoms  (p   =   0.104   and   p=0.58  respectively). Of the seventy patients, 31 (44. 3%) were confirmed  cases  of  CHIKF--  29 had  (+)   CHIKV  IgM   by ELISA,  and  two   had   (+)   CHIKV   PCR.   Twenty-  one (67.7%) had  persistent  arthritis  of  at least  six  weeks. Treatment  consisted  of continuous  NSAIDs  for  at  least  two   weeks   and   some   received   steroids.  In this subgroup, age and sex were not shown to  correlate with chronic arthritis (p=0.47 and p=0.05 respectively).
CONCLUSION: This report on a recent outbreak of CHIKF showed the classic triad of fever, rash,  and  arthritis.  There  was  no  correlation  between  age  and  chronicity of  arthritic  symptoms.  Sex,  likewise,  did  not  appear   to influence chronicity. The disease occurred in family clusters. Patients required continuous treatment with NSAIDs and  some  had  to  be given  steroids.  Most cases   resolved   by   12 weeks.

Human ; Male ; Female ; Middle Aged ; Adult ; Chikungunya Fever ; Chikungunya Virus ; Togaviridae ; Anti-inflammatory Agents, Non-steroidal ; Arthralgia ; Arthritis ; Exanthema ; Enzyme-linked Immunosorbent Assay