Chikungunya Masquerading as Acute Rheumatism in an Omani Traveler

Cardiomyopathy and Death Following Chikungunya Infection: An Increasingly Common Outcome

Chikungunya virus (CHIKV) is vectored by Aedes aegypti and Aedes albopictus mosquitoes and is found throughout tropical and sub-tropical regions. While most infections cause mild symptoms such as fever and arthralgia, there have been cases in which cardiac involvement has been reported. In adults, case reports include symptoms ranging from tachycardia and arrythmia, to myocarditis and cardiac arrest. In children, case reports describe symptoms such as arrythmia, myocarditis, and heart failure. Case reports of perinatal and neonatal CHIKV infections have also described cardiovascular compromise, including myocardial hypertrophy, ventricular dysfunction, myocarditis, and death. Myocarditis refers to inflammation of the heart tissue, which can be caused by viral infection, thus becoming viral myocarditis. Since viral myocarditis is linked as a causative factor of other cardiomyopathies, including dilated cardiomyopathy, in which the heart muscle weakens and fails to pump blood properly, the connection between CHIKV and the heart is concerning. We searched Pubmed, Embase, LILACS, and Google Scholar to identify case reports of CHIKV infections where cardiac symptoms were reported. We utilized NCBI Virus and NCBI Nucleotide to explore the lineage/evolution of strains associated with these outbreaks. Statistical analysis was performed to identify which clinical features were associated with death. Phylogenetic analysis determined that CHIKV infections with cardiac symptoms are associated with the Asian, the East Central South African, and the Indian Ocean lineages. Of patients admitted to hospital, death rates ranged from 26-48%. Myocarditis, hypertension, pre-existing conditions, and the development of heart failure were significantly correlated with death. As such, clinicians should be aware in their treatment and follow-up of patients.

Ecological Niche Modeling of West Nile Virus Vector in Northwest of Iran

OBJECTIVES

West Nile virus (WNV) is a microorganism and the leading cause of the spread of fatal diseases in horses, birds, and humans. The etiologic agent of West Nile fever belongs to the genus Flavivirus that is transmitted by Culex mosquitoes in Iran and throughout the world. We aimed to evaluate the distribution of WNV vectors in northwest of Iran ecological niche modeling.

METHODS

This cross-sectional study was conducted in Ardabil province in one year, from January to December with the samples captured from May to November 2017. Forty-five locations from all 10 counties of the province were selected randomly to determine the seasonal activity of mosquitoes. Larval collection was carried out twice a month. MaxEnt version 3.3, ArcMap 10.3 software, jackknife, and crew methods were used to determine the impact of climatic change and environmental factors on the distribution of mosquito species.

RESULTS

A total of 2000 larva were collected, 1789 (89.5%) of which were Culex larvae. Seven species of Culex genus were identified, including Culex pipiens, Cx. modestus, Cx. theileri, Cx. hortensis, Cx. perexiguus, Cx. tritaeniorhynchus, and Cx. mimeticus. Two important ecological niche areas were identified in the north and south of the province. The annual temperature and rainfall in the cold seasons were the most important factors affecting the distribution of Culex species larva. Cx. pipiens was identified as the main vector of WNV vectors with high frequency in Ardabil province.

CONCLUSIONS

Two large areas were found as the ecological niches of larvae of these species. It is recommended that additional investigations be carried out on infection in adult female Cx. pipiens and its hosts in these areas.