PMC5540382_01
Microphotographs of Wuchereria bancrofti microfilaria in blood smears. (a-d) Thin blood films; (e-k) thick blood films; (a, e, j) full size microfilaria; (b) head and body details; (c, f) head details; (d) body and tail details; (g, h) body details; (i) tapered tail tip details free of terminal nuclei; (k) detail of the inner body. Coloured arrows represent sheath (orange), cephalic space (blue), nerve ring (red), excretory pore (pink), excretory cell (purple), inner body (black), germinal cells (green), and anal pore (brown) across the different pictures. Scale bars: (a, e, j) = 50 microm; (b-d, f-i, k) = 10 microm.
CRIID2017-1972587.001.jpg
PMC5540382_01_CRIID2017-1972587.001.jpg
fig1
The two original thin blood films provided by NUH laboratory were entirely screened at low magnification and revealed the presence of one MF in each blood film within the thick part of the smear (Figures 1(a) and 1(b)).
Molecular phylogeny of common parasitic human roundworms based on the cox1 gene. The analysis is inferred by ML method with GTR+Gamma model of evolution. It included 37 DNA sequences downloaded from GenBank (accession number provided between vertical bars) and the sequence obtained from the present case. The parasites of the order Trichocephalida serve as outgroup to root the tree. The tree with the highest log likelihood (-5385.0252) is displayed. One thousand nonparametric bootstrap analyses were used to assess nodal robustness and tree topology reliability, branch support > 70% only shown. Lines highlight lymphatic filaria (blue); among them are the Wuchereria parasites (green) and within this genus the sequence obtained from the present case (red), respectively.
CRIID2017-1972587.002.jpg
PMC5540382_01_CRIID2017-1972587.002.jpg
fig2
This analysis showed that the cox1 sequence of the W. bancrofti strain presented here clustered with other sequences from India and Sri Lanka (Figure 2), corroborating the epidemiological data and the idea of an imported parasite.