Prevalence of dengue and chikungunya virus infections in north-eastern Tanzania: a cross sectional study among participants presenting with malaria-like symptoms.
BACKGROUND
In spite of increasing reports of dengue and chikungunya activity in Tanzania, limited research has been done to document the general epidemiology of dengue and chikungunya in the country. This study aimed at determining the sero-prevalence and prevalence of acute infections of dengue and chikungunya virus among participants presenting with malaria-like symptoms (fever, headache, rash, vomit, and joint pain) in three communities with distinct ecologies of north-eastern Tanzania.


METHODS
Cross sectional studies were conducted among 1100 participants (aged 2-70 years) presenting with malaria-like symptoms at health facilities at Bondo dispensary (Bondo, Tanga), Hai hospital (Hai, Kilimanjaro) and TPC hospital (Lower Moshi). Participants who were malaria negative using rapid diagnostic tests (mRDT) were screened for sero-positivity towards dengue and chikungunya Immunoglobulin G and M (IgG and IgM) using ELISA-based kits. Participants with specific symptoms defined as probable dengue and/or chikungunya by WHO (fever and various combinations of symptoms such as headache, rash, nausea/vomit, and joint pain) were further screened for acute dengue and chikungunya infections by PCR.


RESULTS
Out of a total of 1100 participants recruited, 91.2 % (n = 1003) were malaria negative by mRDT. Out of these, few of the participants (<5 %) were dengue IgM or IgG positive. A total of 381 participants had fever out of which 8.7 % (33/381) met the defined criteria for probable dengue, though none (0 %) was confirmed to be acute cases. Chikungunya IgM positives among febrile participants were 12.9 % (49/381) while IgG positives were at 3.7 % (14/381). A total of 74.2 % (283/381) participants met the defined criteria for probable chikungunya and 4.2 % (11/263) were confirmed by PCR to be acute chikungunya cases. Further analyses revealed that headache and joint pain were significantly associated with chikungunya IgM seropositivity.


CONCLUSIONS
In north-eastern Tanzania, mainly chikungunya virus appears to be actively circulating in the population. Continuous surveillance is needed to determine the contribution of viral infections of fever cases. A possible establishment of arboviral vector preventive control measures and better diagnosis of pathogens to avoid over-treatment of other diseases should be considered.
Faculty of Medicine, Kilimanjaro Christian Medical University College, Moshi, Kilimanjaro, Tanzania. d7kajeguka@gmail.com.
Debora C
DC
Kajeguka
Faculty of Medicine, Kilimanjaro Christian Medical University College, Moshi, Kilimanjaro, Tanzania.
Robert D
RD
Kaaya
Faculty of Medicine, Kilimanjaro Christian Medical University College, Moshi, Kilimanjaro, Tanzania.|Kilimanjaro Clinical research institute, Moshi, Kilimanjaro, Tanzania.
Steven
S
Mwakalinga
Faculty of Medicine, Kilimanjaro Christian Medical University College, Moshi, Kilimanjaro, Tanzania.
Rogathe
R
Ndossi
Kilimanjaro Clinical research institute, Moshi, Kilimanjaro, Tanzania.
Arnold
A
Ndaro
Faculty of Medicine, Kilimanjaro Christian Medical University College, Moshi, Kilimanjaro, Tanzania.|Kilimanjaro Clinical research institute, Moshi, Kilimanjaro, Tanzania.
Jaffu O
JO
Chilongola
Faculty of Medicine, Kilimanjaro Christian Medical University College, Moshi, Kilimanjaro, Tanzania.
Franklin W
FW
Mosha
Global Health Section, Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
Karin L
KL
Schiøler
Faculty of Medicine, Kilimanjaro Christian Medical University College, Moshi, Kilimanjaro, Tanzania.|Kilimanjaro Clinical research institute, Moshi, Kilimanjaro, Tanzania.
Reginald A
RA
Kavishe
Centre for Medical Parasitology, Department Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark.
Michael
M
Alifrangis
D000293:Adolescent; D000328:Adult; D000368:Aged; D000914:Antibodies, Viral / Q000097:blood; D018771:Arthralgia / Q000209:etiology; D065632:Chikungunya Fever / Q000453:epidemiology* / Q000473:pathology; D002646:Chikungunya virus / Q000235:genetics / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003715:Dengue / Q000453:epidemiology* / Q000473:pathology; D003716:Dengue Virus / Q000235:genetics / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005076:Exanthema / Q000209:etiology; D005260:Female; D006261:Headache / Q000209:etiology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D015995:Prevalence; D012367:RNA, Viral / Q000032:analysis / Q000378:metabolism; D013636:Tanzania / Q000453:epidemiology; D055815:Young Adult
D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D012367:RNA, Viral
Arbovirus; Chikungunya; Dengue; Prevalence; Tanzania