Please select the eligibility criteria that correspond to the clinical trial below.
Title: Effects of Vitamin A Supplementation on Intestinal Parasitic Reinfections, Growth, Iron Status and Educational Achievement Among Orang Asli Schoolchildren in Pos Betau, Pahang, Malaysia
Brief Summary: Intestinal parasitic infections, malnutrition and iron deficiency anaemia (IDA) are still considered as public health problems in rural Malaysia especially among Orang Asli children. Despite intermittent control programmes, the prevalence of these problems is still high suggesting the need of other control and interventions measures. This randomized double-blind, placebo-controlled trial was carried out among Orang Asli schoolchildren from Sekolah Kebangsaan Betau in Pos Betau, Pahang (200 km northeast Kuala Lumpur) to investigate the effects of vitamin A supplementation on intestinal parasitic reinfections, growth, iron status and educational achievement.

HYPOTHESES

1. Vitamin A supplementation has a negative effect on intestinal parasitic reinfections and the worm burden of infections among Orang Asli schoolchildren in Pos Betau, Kuala Lipis, Pahang.
2. Vitamin A supplementation has a positive effect on growth (weight and height) among Orang Asli schoolchildren.
3. Vitamin A supplementation is effective in improving serum iron status among Orang Asli schoolchildren.
4. Vitamin A supplementation has a positive effect on cognitive function and educational achievement among Orang Asli schoolchildren.


Options:
A: Inclusion Criteria:

* Children should be infected with a minimum of 150 eggs/gram of any of the three species of STH (i.e. Ascaris or hookworms or Trichuris).

Exclusion Criteria:

* Not willing to participate
* Unable to give samples for follow up
* Severe intercurrent medical condition
* Diarrhoea at first sampling
B: Inclusion Criteria:

* presence of intestinal helminths eggs in the stool

Exclusion Criteria:

* allergy to imidazole derivate
* No intestinal helminths
C: Inclusion Criteria:

* Age 7-12 years (according to birth date in birth certificate).
* No evidence of concomitant severe and/or chronic illness such as acute respiratory tract infections, mental retardation and neurological deficits.
* Consent of parent to participate in the study.

Exclusion Criteria:

* history or evidence of underlying haematological-related diseases such as thalassaemia and ovalocytosis.
* menstruating females (age \>13)
D: Inclusion Criteria:

* Written informed consent signed by parents and/or caregiver; and oral assent by participant.
* Able and willing to be examined by a study physician at the beginning of the study.
* Able and willing to provide two stool samples at the beginning (baseline) and approximately three weeks after treatment (follow-up).
* Positive for hookworm eggs in the stool (≥ 100 EPG and at least two Kato-Katz thick smears slides with more than one hookworm egg).
* Absence of major systemic illnesses, e.g. diabetes, severe anemia (HB\<8.0 g/l) as assessed by a medical doctor at school, upon initial clinical assessment.
* No known or reported history of chronical illness as cancer, diabetes, chronic heart, liver or renal disease.
* No recent anthelminthic treatment (within past 4 weeks). No known allergy to study medications (mebendazole and albendazole).

Exclusion Criteria:

No written informed consent by parents and/or caregiver; no oral assent by participant.

* Menarche, based on self-report
* Presence of major systemic illnesses, e.g. diabetes, severe anemia (HB\<8.0 g/l) as assessed by a medical doctor, upon initial clinical assessment.
* History of acute or severe chronic disease.
* Recent use of anthelminthic drug (within past 4 weeks).
* Attending other clinical trials during the study.
* Negative diagnostic result for hookworm eggs in the stool (\< 100 EPG (total of the four slides) and/or only one Kato-Katz thick smear slide with more than one hookworm egg).

Answer: C