Vitamin A deficiency (VAD) is an important nutritional disorder. Vitamin A is essential for vision (especially dark adaptation), immune response, bone growth, reproduction, maintenance of the surface linings of the eyes, epithelial cell growth and repair, and epithelial integrity of the respiratory, urinary, and intestinal tracts.\[[@ref1]\] VAD is a risk factor for blindness and for mortality from measles and diarrhea in children age 6--59 months. VAD may be secondary to decreased ingestion, defective absorption, altered metabolism, and increased requirements. In humans, vitamin A, a fat-soluble vitamin, is stored in the liver. An adult liver can store up to 1 year\'s reserve of vitamin A, whereas a child\'s liver may have enough storage to last only for several weeks. Hence, children are more often susceptible to VAD. Some ocular signs of VAD denote chronic deficiency (Bitot\'s spot, night blindness), while other signs denote acute deficiency (corneal ulcer, keratomalacia). The World Health Organization (WHO) recommends vitamin A supplementation (VAS) annually (100,000 IU; 30 mg retinol equivalent) in children 6--11 months of age and biannually (200,000 IU; 60 mg retinol equivalent) in children 12--59 months of age.\[[@ref2]\]

In the 1960s, the WHO conducted the first global survey of VAD with associated xerophthalmia and complicated measles.\[[@ref3]\] In 1973, an International Vitamin A Board was set up to alleviate global malnutrition. In India, the National Prophylaxis Program against Nutritional Blindness due to Vitamin A Deficiency (NPPNB due to VAD) was initiated in 1970 in 11 states with the specific aim to prevent nutritional blindness due to keratomalacia.\[[@ref4]\] The National Institute of Nutrition (NIN), Hyderabad, India, evaluated the impact of this program in two participating states 6 years after starting the program. Because the impact was positive, the program was extended to all states in India.\[[@ref5]\] At the same time, a large trial has shown benefit of supplementing VAS with deworming (albendazole 400 mg biannual), the "Deworming and Enhanced Vitamin A Supplementation (DEVTA)" in India.\[[@ref6]\] The WHO has recommended biannual VAS in VAD-endemic countries.\[[@ref7]\]

VAD is associated with the socioeconomic status of the people and country. In the middle- and low-income countries, the prevalence of VAD has decreased from 39% in 1991 to 29% in 2013, though this reduction in VAD has not reflected in the sub-Saharan Africa (prevalence 48%) and south Asia (prevalence 44%). In 2013, VAD accounted for 1.7% of all deaths in children younger than 5 years in the middle- and low-income countries.\[[@ref8]\] It is reported that over the past 40 years, the clinical VAD has declined in India, but not entirely eliminated.\[[@ref9]\] A 2001 national survey conducted by the Indian Council of Medical Research (ICMR) in 16 districts in all five regions of the country still showed prevalence of Bitot\'s spot in 3 of 16 districts.\[[@ref10]\] The National Family Health Survey (2005--06) in India had documented that only 29.7% of children below the age of 5 years had received vitamin A in the prior 6 months.\[[@ref11]\]

VAD is typically a disease of preschool children. Untreated, it could persist in the school-going children too. The Rayagada School Sight Program (SSP) was primarily aimed at detection and treatment of uncorrected refractive error though it also included detection of ocular anomalies using both trained schoolteachers and qualified ophthalmic technicians.\[[@ref12]\] During this program, we detected Bitot\'s spot and night blindness in a few students. Guided by the accredited social health activist (ASHA) workers, a team led by an ophthalmologist visited all houses to examine younger preschool siblings and all under-5 children present at the time of examination in the neighborhood. This communication is based on these visits and underlines the value of opportunistic screening for VAD.

Methods {#sec1-2}
=======

The study was approved by the local district administration and by the institutional ethics committee (2016-15-CB-14). The research protocol adhered to the provision of the Declaration of Helsinki for research involving human beings. The school authorities provided consents for eye examination by optometrists in their premises and the parents provided consent for eye examination of the children in their homes. Written informed consent was obtained from the parents of the children who were referred for examination by ophthalmologist in the hospital.

The Rayagada SSP methodology and the results are already described.\[[@ref12]\] The school children suspected by the examining teachers to have external eye manifestations of VAD (xerosis, Bitot\'s spot, etc.) or complained of having difficulty in dusk/night vision were examined by an optometrist as a part of the SSP and were confirmed by an ophthalmologist after a comprehensive eye examination. The VAD ocular features were classified as per the WHO classification.\[[@ref13]\]

The comprehensive eye examination included external examination, slit-lamp biomicroscopy, refraction, and fundoscopy in addition to the enquiry of night blindness. The VAD-affected children detected in the SSP were tracked to their homes for examination of their preschool siblings; the team also examined under-5 children in the same village and on the same day. In the community, all children were assembled in a central shaded location of the village usually in front of one of the houses. The basic examination was an external eye flashlight test by an ophthalmologist. The parents were asked to comment on the child\'s day and night vision as "good" or "bad." The accompanying healthcare professionals with the help of ASHA workers collected data on the food habit (vegetarian and nonvegetarian, consuming milk and green vegetables), vaccination status, socioeconomic condition, and the environment. All examinations were done in the presence of the parents and village head.

Results {#sec1-3}
=======

The Rayagada SSP was a multistage program that involved 216 trained teachers and eye health personnel; the team screened 153,107 children in 2124 schools in the district. The teachers referred 4519 children for ocular anomaly with or without refractive error. They suspected VAD in 300 children (6.6% of referred). As reported by us earlier and the methodology described, the sensitivity of teachers detecting Bitot\'s spot in the school children was 6.06% \[95% confidence interval (CI): 1.68--19.61\] and the specificity was 95.00% (95% CI: 94.41--95.52).\[[@ref12]\] All these children could not recollect having received VAS in preschool years, and there was no school record to capture the data. The optometrists confirmed VAD in 73 of them (24.3% of teacher\'s examination) and the ophthalmologist confirmed VAD in 70 (95.8% of optometrist exam). Within 3 months, an ophthalmologist-led team reached the house of 65 children located in rural habitats (family of five children had migrated) to their homes and examined 32 under-5 siblings of these 65 school children with VAD. In addition, the ophthalmologist also examined the remaining 250 under-5 children in the same village. The traveling distance from the eye care facility (Rayagada) to these habitats was from 20 to 150 km. Twenty-two siblings of VAD school students and 115 of 250 children in these habitats had ocular signs of VAD. Thus, a total of 207 vitamin A--deficient children were detected out of 4801 children examined in the school or village clusters \[[Fig. 1](#F1){ref-type="fig"}\].

![Flowchart demonstrating the stepwise detection of vitamin A--deficient children](IJO-68-351-g001){#F1}

There was no documented evidence of vaccination and VAS and the parents were vague in their answer. The demography details including the vaccination status are shown in [Table 1](#T1){ref-type="table"}.

###### 

Demographics of the examined population with VAD (*n*=207)

  ------------------------------------------------------------ ----------------------------------------------------------------------------------------------------------------
  Age (±standard deviation) of school children                 11±2.6 years
  Age range of school children                                 5-6 years
  Age (±standard deviation) of siblings                        3.2±1.2 years
  Age (±standard deviation) of children in the habitat         3±1.5 years
  Male: female                                                 5:4
  Average no. of family members                                5.8±2.02 (range: 3-14)
  Antenatal checkup during their pregnancy                     29 (20%)
  Home: hospital delivery among vitamin A-deficient children   15:1
  Mean age of the mother at first child birth                  16.6±1.62 years (range: 15-21 years)
  Average no. of family members                                5.8±2.2 (3-14)
  Birth order of the vitamin A-deficient child in the family   2.3±1.25 (1-5)
  Vaccination and vitamin A supplementation status             Unknown; most children did not have any vaccination card and could not share a reliable history of vaccination
  ------------------------------------------------------------ ----------------------------------------------------------------------------------------------------------------

VAD=Vitamin A deficiency

In this cohort, there were children with conjunctival xerosis (XIA) and Bitot\'s spot (XIB), corneal scar (XS), and night blindness (XN) \[[Table 2](#T2){ref-type="table"}\]. One child had general features of VAD. Only 5% of children consumed cow milk or other dairy products, 12%--38% had regular nonvegetarian food, 81% practiced open-air defecation, 90% of parents were farmers, and the majority lived in asbestos-roofed houses \[[Table 3](#T3){ref-type="table"}\].

###### 

Distribution of VAD ocular features (*n*=270)

  VAD features           School   Siblings   Habitat   Total       Prevalence % *n*=4801                        
  ---------------------- -------- ---------- --------- ----------- ----------------------- ---------- --------- ----------
  Conj. xerosis (X1A)    **70**   **100**    **22**    **100**     **115**                 **100**    **207**   **4.3**
  Age (years)                                                                                                   
   0-5                   0        0          22        100         115                     100        137       2.8
   5-10                  31       44.2       0         0           0                       0          31        0.64
   10-15                 39       55.7       0         0           0                       0          39        0.81
  Gender                                                                                                        
   Male                  39       55.7       12        54.5        64                      55.6       115       2.3
   Female                31       44.2       10        45.4        51                      44.3       92        1.9
  Bitot's spot (X1B)     **70**   **100**    **11**    **50**      **88**                  **76.5**   **169**   **3.5**
  Age (years)                                                                                                   
   0-5                   0        0          11        50          88                      76.5       99        2
   5-10                  29       41.4       0         0           0                       0          29        0.6
   10-15                 41       58.5       0         0           0                       0          41        0.85
  Gender                                                                                                        
   Male                  37       52.8       7         31.8        47                      40.8       91        1.8
   Female                33       47.1       4         18.1        41                      35.6       78        1.6
  Corneal scar (XS)      **1**    **1.4**    **1**     **4.5**     **1**                   **0.86**   **3**     **0.06**
  Age (years)                                                                                                   
   0-5                   0        0          1         4.5         1                       0.86       2         0.04
   5-10                  1        1.4        0         0           0                       0          1         0.02
   10-15                 0        0          0         0           0                       0          0         0
  Gender                                                                                                        
   Male                  0        0          0         0           0                       0          0         0
   Female                1        1.4        1         4.5         1                       0.86       3         0.06
  Night blindness (XN)   **9**    **12.8**   **5**     **22.7**    **21**                  **18.2**   **35**    **0.72**
  Age (years)                                                                                                   
   0-5                   **0**    **0**      **5**     **22.7**    **21**                  **18.2**   **26**    **0.54**
   5-10                  **5**    **7.1**    **0**     **0**       **0**                   **0**      **5**     **0.10**
   10-15                 **4**    **5.7**    **0**     **0**       **0**                   **0**      **4**     **0.08**
  Gender                                                                                                        
   Male                  **5**    **7.1**    **3**     **13.62**   **11**                  **9.53**   **19**    **0.39**
   Female                **4**    **5.7**    **2**     **9.08**    **10**                  **8.6**    **16**    **0.33**

VAD=Vitamin A deficiency. The bold values denote overall value of the specific condition for all age and gender groups

###### 

Environment, socioeconomic status, and food habits of VAD children (*n*=207)

  Variables    Number (%)   Variables             Number (%)   Variables    Number (%)   Variables    Number (%)
  ------------ ------------ --------------------- ------------ ------------ ------------ ------------ ------------
  Bore well    115 (55.6)   Uncovered latrine     39 (18.9)    Farmer       187 (90.5)   Cow milk     11 (5.3)
  Public tap   6 (2.9)      Open air defecation   168 (81.0)   Driver       1 (0.5)      Egg/chichi   79 (38)
  \-           \-           \-                    \-           Fisherman    5 (2.3)      Fish         25 (12)
  \-           \-           \-                    \-           Teacher      1 (0.5)      \-           \-
  \-           \-           \-                    \-           Unemployed   10 (5)       \-           \-

VAD=Vitamin A deficiency

Our term of reference by the local authority was that the government must do all interventions, from spectacles to surgery. Hence, the findings of the study were shared with the concerned district health officials so that immediate and appropriate planning and execution for VAS is done. We guess this was done as per the national guidelines.

Discussion {#sec1-4}
==========

Mass screening method is used to detect the ocular features of VAD in India.\[[@ref14]\] But mass screening is both time-consuming and highly resource-intensive. This study explored the possibilities of an opportunistic detection of VAD using the lead obtained in the routine school screening in a tribal district in India (Odisha) as a complement to the existing system. We chose to conduct this study in Rayagada district in Odisha for two reasons -- first, it is a predominantly tribal population and relatively remote location,\[[@ref15]\] and second, we, the LVPEI, have established a fixed secondary-level eye care facility in this district for delivery of appropriate and affordable eye care. Rayagada ranks 465 in 640 districts in India and the district Human Development Index (HDI) is only 0.18.\[[@ref16]\] A 2007 report has indicated poor nutritional status of children and mothers in Rayagada district.\[[@ref17]\] A 2013 report had observed that the poor VAS coverage in India was related to poor development of the district, rural location, children of less educated mothers, and the children born in higher birth order.\[[@ref11][@ref18]\]

The Indian state of Odisha has adopted the WHO recommendation of biannual VAS.\[[@ref19]\] The VAS coverage in Odisha has increased from 61% in 2006 to 97% in 2011 though we suspect that it has not reached the most vulnerable population uniformly\[[@ref20]\] and this includes the Rayagada district.\[[@ref21]\] Normally, one has to conduct a massive drive to search these localities where children with VAD live. This is expensive in terms of time and other resources. While the traditional method should continue, tracking to these habitats through the lead provided by the children in the school was another modality, both opportunistic and cost-saving.

The cut-off to define VAD as a public health problem in a community is the prevalence of Bitot\'s spot at ≥0.5%.\[[@ref22]\] The prevalence of Bitot\'s spot \[3.5%; [Table 2](#T2){ref-type="table"}\] in this study exceeded this limit. Thus, VAD in Rayagada (Odisha, India) is a public health problem. The large prospective study involving a million preschool children in north India has shown that the prevalence of Bitot\'s spot halved over the 5-year study period using the DEVTA strategy of combined deworming and VAS.\[[@ref6]\] In the absence of a case--control study, one could attribute the reasons for this high prevalence to poor neonatal care, home delivery, questionable VAS, inadequate diet, poverty, and poor sanitation. While continuing with the biannual VAS program recommended by the WHO and others,\[[@ref2][@ref23][@ref24]\] special efforts are required to improve education, mother\'s nutrition, and household sanitation.\[[@ref11]\]

This study has several limitations: (1) the Rayagada SSP was not inherently designed to detect VAD. The study team only performed an opportunistic screening of reaching those habitats from where certain students were found to have clinical features of VAD. (2) All children in this tribal community may not be attending the school; it is likely that we missed visiting some habitats. (3) The SSP was not designed to identify the risk factors leading to VAD.

The strength of the study lies in the fact that the lead was obtained from a large pool of over 153,000 school-going students and the use of the opportunistic screening in the children\'s home and habitat. This reemphasizes our belief that the school screening should be beyond the detection of refractive error only. This kind of opportunistic screening is cost-effective in areas where the VAS forms part of the public policy. A future study could be planned to screen all preschool children and pregnant women to detect the VAD burden and identify the risk factors of VAD in this district so that the local health authorities could design a tailored plan of care. In addition, adopting the WHO and United Nations International Children Emergency Fund recommendation of the Integrated Management of Childhood Illness\[[@ref25]\] and delivering the child care through primary eye care\[[@ref26]\] at the district level will help reduce the VAD disease.

Conclusion {#sec1-5}
==========

The results of our study suggest that an opportunistic screening for detection of VAD through a SSP could be cost-effective and complement the existing strategy.

Financial support and sponsorship {#sec2-1}
---------------------------------

Nil.

Conflicts of interest {#sec2-2}
---------------------

There are no conflicts of interest.
