To the Editor: We conducted a prospective observational study of 27 neonates admitted to an outborn tertiary care neonatal intensive care unit between July 2017 and July 2021 with confirmed chikungunya infection by RT-PCR / serum anti-CHIK IgM.

The common clinical manifestations were encephalopathy (96%), fever (74%) and hyperpigmentation (63%). In all the cases, hyperpigmentation appeared in 2nd to 3rd wk of illness. Convulsions were the presenting symptom in 19 (70%) neonates.

There was history of fever prior to delivery in 13 (48%) mothers. Chikungunya IgM was positive in 25 (92%) mothers.

In our series, encephalopathy was the most common presenting feature in contrast to many reports by Latin American studies where it is infrequently reported and this higher incidence might be due to increased viral load and slow clearance of virus [1].

Hyperpigmentation especially over central part of face, called “brownie nose” is characteristic of chikungunya infection which is primarily a post inflammatory response with intra epidermal melanin dispersion or retention [2]. In one-third of our cases, the diagnosis of neonatal chikungunya was made retrospectively after noting the classical hyperpigmentation.

Magnetic Resonance Imaging showed diffusion restriction involving the subcortical lobes, periventricular white matter, corpus callosum, occipital and frontotemporal lobes which was seen in 73% neonates and similar findings were observed in Indian and Columbian studies [1, 3].

Nearly 80% of the cases were perinatally acquired, similar to other Indian and Columbian studies, highlighting the importance of maternal history of fever and joint pains in neonates presenting with encephalopathy [1, 4].

Neonatal chikungunya is a serious infection with high incidence of neurological involvement. A high degree of suspicion of should be kept in any neonate presenting with fever, encephalopathy and delayed hyperpigmentation, especially from endemic zones.