Mapping clusters of chikungunya and dengue transmission in northern Tanzania using disease exposure and vector data

Background: Dengue and chikungunya are mosquito-borne viral diseases that are of public health importance throughout the tropical and subtropical regions of the world. Seasonal variations in transmission of these viruses have been suggested owing to the ecology of their mosquito vectors. However, little is known about the epidemiology of the diseases Tanzania. To address this gap, seasonal community-based cross-sectional surveys were undertaken to identify potential clusters of transmission in Hai district in northern Tanzania. Methods: Epidemiological and entomological data from two cross-sectional surveys were used to examine the spatial pattern of dengue and chikungunya transmission. Six villages namely, Boma Ng’ombe, Magadini, Rundugai, Nshara and Kware were involved in the study. Serological measures of dengue and chikungunya virus infections were derived using enzyme-linked immunosorbent assays, and all participants were geo-referenced to the household level using a global positioning system. Potential clusters of individual exposed to dengue and chikungunya virus , as well as clusters of Aedes mosquitoes in the wet and dry seasons were detected using SaTScan. All significant clusters (with p≤0.05) were mapped using ArcGIS. Results: A large, widely dispersed cluster of chikungunya exposed individuals was detected spanning Rundugai and parts of Magadini villages (RR = 2.58, p= 0.01), while no significant clustering was observed in the dry season. Spatial clusters of Aedes aegypti were detected in Rundugai in both the wet and dry seasons (RR = 2.56, p< 0.001 and RR = 2.24, p=0.05, respectively). In the dry season a small cluster was also detected in Kware (RR = 2.25, p=0.05). No significant clusters of dengue were detected in both seasons. Conclusion: Clusters of chikungunya-exposed individuals and Aedes mosquitoes indicate on-going transmission of chikungunya virus in Hai district of northern Tanzania.

[1]  G. Ippolito,et al.  Clinical, Virologic, and Epidemiologic Characteristics of Dengue Outbreak, Dar es Salaam, Tanzania, 2014 , 2016, Emerging infectious diseases.

[2]  M. Alifrangis,et al.  Prevalence of dengue and chikungunya virus infections in north-eastern Tanzania: a cross sectional study among participants presenting with malaria-like symptoms , 2016, BMC Infectious Diseases.

[3]  J. Crump,et al.  Distribution of Aedes mosquitoes in the Kilimanjaro Region of northern Tanzania , 2016, Pathogens and global health.

[4]  D. Masiga,et al.  Repetitive dengue outbreaks in East Africa: A proposed phased mitigation approach may reduce its impact , 2016, Reviews in medical virology.

[5]  L. Mboera,et al.  The Risk of Dengue Virus Transmission in Dar es Salaam, Tanzania during an Epidemic Period of 2014 , 2016, PLoS neglected tropical diseases.

[6]  D. Diop,et al.  Chikungunya outbreaks from 2000 to 2015: a review , 2015 .

[7]  E. Nsoesie,et al.  Spatial and Temporal Clustering of Chikungunya Virus Transmission in Dominica , 2015, PLoS neglected tropical diseases.

[8]  Mohammad Sohel Rahman,et al.  An Outbreak of Chikungunya in Rural Bangladesh, 2011 , 2015, PLoS neglected tropical diseases.

[9]  R. O’Hara,et al.  Risk Factors for the Presence of Chikungunya and Dengue Vectors (Aedes aegypti and Aedes albopictus), Their Altitudinal Distribution and Climatic Determinants of Their Abundance in Central Nepal , 2015, PLoS neglected tropical diseases.

[10]  M. Heise,et al.  High Rates of O’Nyong Nyong and Chikungunya Virus Transmission in Coastal Kenya , 2015, PLoS neglected tropical diseases.

[11]  O. Horstick,et al.  Modeling tools for dengue risk mapping - a systematic review , 2014, International Journal of Health Geographics.

[12]  Majige Selemani,et al.  Dengue and Chikungunya Fever among Viral Diseases in Outpatient Febrile Children in Kilosa District Hospital, Tanzania , 2014, PLoS neglected tropical diseases.

[13]  J. Gaudart,et al.  Spatio-temporal analysis of malaria within a transmission season in Bandiagara, Mali , 2013, Malaria Journal.

[14]  T. Scott,et al.  House-to-house human movement drives dengue virus transmission , 2012, Proceedings of the National Academy of Sciences.

[15]  M. Petzold,et al.  Estimating dengue vector abundance in the wet and dry season: implications for targeted vector control in urban and peri-urban Asia , 2012, Pathogens and global health.

[16]  A. Eiras,et al.  Dengue Fever Occurrence and Vector Detection by Larval Survey, Ovitrap and MosquiTRAP: A Space-Time Clusters Analysis , 2012, PloS one.

[17]  G. Ippolito,et al.  Clinical research in the context of rapidly emerging public health threats , 2012, International Journal of Infectious Diseases.

[18]  S. Blacksell,et al.  Commercial Dengue Rapid Diagnostic Tests for Point-of-Care Application: Recent Evaluations and Future Needs? , 2012, Journal of biomedicine & biotechnology.

[19]  Lalit Kumar,et al.  Assessing the risk for dengue fever based on socioeconomic and environmental variables in a geographical information system environment. , 2012, Geospatial health.

[20]  K. Praianantathavorn,et al.  Multiplex real–time RT–PCR for detecting chikungunya virus and dengue virus , 2012, Asian Pacific Journal of Tropical Medicine.

[21]  M. Hoelscher,et al.  High Seroprevalence of Rift Valley Fever and Evidence for Endemic Circulation in Mbeya Region, Tanzania, in a Cross-Sectional Study , 2012, PLoS neglected tropical diseases.

[22]  Hassan M. Khormi,et al.  Modeling spatio-temporal risk changes in the incidence of Dengue fever in Saudi Arabia: a geographical information system case study. , 2011, Geospatial health.

[23]  K. To,et al.  Clinical and Virological Factors Associated with Viremia in Pandemic Influenza A/H1N1/2009 Virus Infection , 2011, PloS one.

[24]  V. Deubel,et al.  Clinical and Virological Factors Influencing the Performance of a NS1 Antigen-Capture Assay and Potential Use as a Marker of Dengue Disease Severity , 2011, PLoS neglected tropical diseases.

[25]  Phaisarn Jeefoo,et al.  Spatio-Temporal Diffusion Pattern and Hotspot Detection of Dengue in Chachoengsao Province, Thailand , 2010, International journal of environmental research and public health.

[26]  Rosanna W. Peeling,et al.  Evaluation of diagnostic tests: dengue , 2010, Nature Reviews Microbiology.

[27]  Philippe Buchy,et al.  Dengue Incidence in Urban and Rural Cambodia: Results from Population-Based Active Fever Surveillance, 2006–2008 , 2010, PLoS neglected tropical diseases.

[28]  Mary E. Wilson,et al.  Dengue and chikungunya infections in travelers , 2010, Current opinion in infectious diseases.

[29]  H. Zeller,et al.  Chikungunya outbreak in a rural area of Western Cameroon in 2006: A retrospective serological and entomological survey , 2010, BMC Research Notes.

[30]  A. P. Adams,et al.  Genome-Scale Phylogenetic Analyses of Chikungunya Virus Reveal Independent Emergences of Recent Epidemics and Various Evolutionary Rates , 2010, Journal of Virology.

[31]  S. Weaver,et al.  Present and future arboviral threats. , 2010, Antiviral research.

[32]  Shannon K. McClintock,et al.  Dry season production of filariasis and dengue vectors in American Samoa and comparison with wet season production. , 2009, The American journal of tropical medicine and hygiene.

[33]  Reinaldo Souza-Santos,et al.  Spatial heterogeneity of dengue fever in local studies, City of Niterói, Southeastern Brazil. , 2009, Revista de saude publica.

[34]  R. Sugumaran,et al.  Spatio-temporal cluster analysis of county-based human West Nile virus incidence in the continental United States , 2009, International journal of health geographics.

[35]  Marlize Coleman,et al.  Using the SaTScan method to detect local malaria clusters for guiding malaria control programmes , 2009, Malaria Journal.

[36]  D. Harmsen,et al.  Spatiotemporal Analysis of Invasive Meningococcal Disease, Germany , 2006, Emerging infectious diseases.

[37]  P. Reiter,et al.  Aedes albopictus as an epidemic vector of chikungunya virus: another emerging problem? , 2006, The Lancet. Infectious diseases.

[38]  M. Drebot,et al.  A single tube RT-PCR assay for the detection of mosquito-borne flaviviruses , 2006, Journal of Virological Methods.

[39]  M. Geier,et al.  Carbon dioxide instantly sensitizes female yellow fever mosquitoes to human skin odours , 2005, Journal of Experimental Biology.

[40]  R. Vrijenhoek,et al.  DNA primers for amplification of mitochondrial cytochrome c oxidase subunit I from diverse metazoan invertebrates. , 1994, Molecular marine biology and biotechnology.

[41]  L. Maboko,et al.  Emerging viral infectious disease threat: Why Tanzania is not in a safe zone , 2016 .

[42]  P. Martens,et al.  Hot spot detection and spatio-temporal dispersion of dengue fever in Hanoi, Vietnam. , 2013, Global health action.

[43]  D. Gubler,et al.  Chikungunya and dengue fever among hospitalized febrile patients in northern Tanzania. , 2012, The American journal of tropical medicine and hygiene.

[44]  Martin Kulldorff,et al.  Prospective time periodic geographical disease surveillance using a scan statistic , 2001 .

[45]  Yiau-Min Huang.  A pictorial key for the identification of the subfamilies of culicidae, genera of culicinae, and subgenera of aedes mosquitoes of the afrotropical region (diptera: Culicidae) , 2001 .

[46]  M. Kulldorff.  A spatial scan statistic , 1997 .