Abstract:
In Kenya, 50-60% of suspected measles cases remain undiagnosed as their etiology
remains unknown. Clinical symptoms of rash and fever are common manifestations of
several infectious disease etiologies, including arboviruses and malaria. Lack of
diagnostic capacity has led to the under-reporting of specific causes of febrile rash
illness, including arbovirus infections in Kenya. This study aimed to determine the
recent and past circulation of arboviral infections amongst suspected cases of measles in
Kenya which confirmed negative IgM for measles as well as rubella serological assays.
A retrospective study was conducted on 392 randomly selected serum samples collected
between 2008 and 2014 from health facilities in Nairobi, North-Eastern and Coastal
regions of Kenya. Samples were screened for the presence of IgG and IgM antibodies
against dengue, chikungunya, and Zika viruses by Enzyme-Linked Immuno-sorbent
Assay (ELISA). Positive samples by ELISA were confirmed by Plaque Reduction
Neutralization Test (PRNT) for samples that were positive for either dengue (DEN),
Zika (ZIK), or chikungunya (CHIK) viruses. Out of the 392 samples, 5(45.5%) were
confirmed to have an active infection of DEN, while 1(0.3%) had an active infection of
CHIK and 3 had an active infection of ZIK. Past infection of DEN was confirmed in 17
(56.7%) while 1 (10.0%) sample was positive for CHIKV. Other viruses included were
West-Nile (WN), Yellow Fever (YF), Sindbis (SIN), Semliki Forest (SF) and O’nyong
Nyong (ONN) viruses. 9(90.0%) samples were confirmed to be ONN, 3 (10.0%) to be
WN and 2 (6.7%) to be YF. Dengue, chikungunya and Zika were detected in all years of
study 2008-2014 and all study sites except Tana-River and Wajir Counties. The results
showed that the prevalence of CHIK and DEN was significantly higher in those aged 14-
60 years. The study confirms patients' exposure to these arboviral infections DEN, ZIK
and CHIK arboviruses in Nairobi, North-Eastern and Coast Regions. The study
recommends that arbovirus diagnosis be included in a comprehensive differential
diagnosis for cases presenting with fever and rash from suspected measles cases.
Additionally, clinicians should be sensitized to consider testing for arboviruses for those
fever and rash cases that are negative for measles and rubella.
