We read with interest the recent paper on determinants of vitamin A
deficiency (VAD) [1] and the accompanying editorial [2]. The exceedingly
high prevalence of VAD documented in the survey needs detailed
examination prior to drawing any operational inferences. Apart from the
serious analytic flaws pointed out in the editorial, we have the
following additional concerns and comments.
It is unclear whether the survey regions, namely 6 of
1212 Villages and 4 peri-urban areas of 70 municipal wards, were chosen
through an unbiased randomization process accounting at least for the
socio-economic status. Apparently, the data primarily pertains to the
marginalized and lower socio-economic population. The survey was largely
conducted during the non winter period, when VAD estimates are usually
higher. The authors have also not provided cluster adjusted estimates
and 95% confidence intervals. It would therefore be inappropriate to
extrapolate the findings from this survey to the entire Aligarh
District.
As the crucial data were primarily collected by
postgraduate students, the reader would need reassurance regarding the
validity of the measure through information on training imparted,
quality control and quantification of inter and intra-observer
variability.
The possibility of adopting an "invalid" operational
definition for identification of corneal ulceration and corneal scar
cannot be excluded. The investigators might have included "any corneal
opacity" as a marker of Xerophthalmia. This criterion is fallacious,
particularly in the current era, unless history of traumatic injury, use
of tropical traditional medicines, and history of infections has been
excluded. An earlier study documented history of previous corneal injury
in 65.4% of such children [3]. The District Nutrition Profile Survey of
1,64,512 children conducted by ICMR in 16 districts of country in 2001,
documented a prevalence of Bitot’s spots above 0.5 % in only 3 districts
(Bikaner, Gaya and Patna); none of these districts had children with
corneal ulceration [4].
In order to provide meaningful programmatic input,
receipt of mega-dose Vitamin A supplementation (VAS) should have been
recorded. In Uttar Pradesh (including Aligarh), biannual rounds of VAS
are being carried for 8 years with the help of UNICEF for the age group
6-60 months. Such a high prevalence of VAD despite these massive inputs
needs a thorough introspection.
Nevertheless, we agree that VAD of public health
magnitude does exist in isolated geographical pockets in the country.
These regions are drought prone, flood prone and have issues related to
food availability. There is an urgent need of identifying such pockets
and institute appropriate remedial measures including interim VAS.
References
1.
Sachdeva S, Alam S, Beig FK, Khan Z, Khalique N. Determinants of vitamin
A deficiency amongst children in Aligarh district, Uttar Pradesh. Indian
Pediatr. 2011;48:861-6.
2. Arlappa N. Vitamin A deficiency is still a public
health problem in India. Indian Pediatr. 2011;48:853-4.
3. Districts of Aligarh Mandal. http://aligarh,nic.in/web2009/aligarh_profile.htm.
Accessed on 30 November 2011.
4. Srinivasan M, Christine AG, Celine G, Cevallos V,
Mascarenhas JM ,Asokan B, et al. Epidemiology and aetiological
diagnosis of corneal ulceration in Madurai, South India. Br J Ophthalmol.
1997;81:965-71.
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