Prevalence of intestinal parasitic infections and associated risk factors for hookworm infections among primary schoolchildren in rural areas of Nakhon Si Thammarat, southern Thailand.

BACKGROUND: Soil-transmitted helminth (STH) infections are among the most common type of infections worldwide and are widely distributed in tropical areas. In rural areas of southern Thailand where most land is used for agriculture, children are at risk of acquiring parasites, especially STHs. Assessing the current situation regarding parasitic infection in these areas is a prerequisite for developing appropriate control measures. This study is aimed at determining the prevalence of intestinal parasitic infections, the intensity of STH infections and the associated risk factors among primary schoolchildren in Nopphitam District, Nakhon Si Thammarat Province, Thailand. METHODS: A cross-sectional study involving 299 schoolchildren between 7 and 12 years of age was conducted between January and March 2016. A questionnaire administered by direct interviews was used to collect sociodemographic information and data on associated risk factors. Stool samples were processed using direct wet smears, formalin-ethyl acetate sedimentation concentration, and the modified Kato-Katz technique. RESULTS: The overall prevalence of intestinal parasites among the 299 children was 16% (48 of 299), with 32 children infected with hookworms (10.7%), 10 with Blastocystis hominis (3.3%), seven with Giardia intestinalis (1.6%), one with Enterobius vermicularis (0.3%), and one with Trichuris trichiura (0.3%). The hookworm infection intensity, measured by the median eggs per gram (EPG) of stool, was 1200 EPG (Interquartile range (IQR): 360-3200). Most children had light-intensity hookworm infections, but two had heavy-intensity infections. When participants included in the sample were classified by age, children 10-12 years old demonstrated higher intestinal parasite prevalence than those aged 7-9 years (adjusted odds ratio (AOR) = 2.3, 95% CI: 1.1-4.9, P = 0.030). Inadequate handwashing before meals was statistically associated with hookworm infections (AOR = 2.3; 95% CI: 1.1-4.8, P = 0.037). CONCLUSIONS: This study highlights that hookworms are the most prevalent STH infection in the study area. Older age group (10-12 years) and inadequate handwashing before meals were statistically associated with hookworm infections. Accordingly, appropriate strategies and education on personal and environmental hygiene should be implemented. Moreover, the cost-effectiveness of mass drug administration in this area should be further investigated.

Prevalence of intestinal parasitic infection and associated risk factors among village health volunteers in rural communities of southern Thailand.

BACKGROUND: Intestinal parasitic infections remain prevalent and constitute a public health problem in certain rural areas of Thailand. Village health volunteers (VHVs), who are members of a Thai healthcare alliance, function as key providers of health prevention measures, disease control, and health education and share national health promotion campaigns with community members. This study is aimed at evaluating the prevalence, intensity, and risk factors for intestinal parasitic infection in VHVs in order to design community awareness and health education campaigns for the target population. METHODS: This cross-sectional study was conducted between January to April 2016 among village health volunteers (VHVs) from four sub-districts of Nopphitam District, Nakhon Si Thammarat Province, southern Thailand. Subjects for the study were selected using a simple random sampling method. Socio-demographic variables and risk factors were collected by a structured questionnaire. Stool specimens were collected and processed using direct wet mount and formol-ether concentration techniques to determine the presence of parasites and modified Kato-Katz thick smear to determine the intensity of infection. RESULTS: A total of 324 VHVs were enrolled. The overall prevalence of intestinal helminths was 9.3% (95% confidence interval [CI]: 6.3-13.0). The prevalence of hookworm, Strongyloides stercoralis, and Trichuris trichiura were 8.0% (95% CI: 5.3-11.5), 0.9% (95% CI: 0.2-2.7), and 0.3% (95% CI: 0-1.7), respectively. Mean intensity of hookworm infection was 1732 eggs per gram of stool. The prevalence was lower for protozoan infection than for helminth infection. Blastocystis hominis accounted for the highest percentage of intestinal protozoan infections 4.0% (95% CI: 2.2-6.8), followed by Giardia intestinalis 0.6% (95% CI: 0-2.2). No statistically significant difference was observed in the prevalence of intestinal parasitic infection among sub-districts (p > 0.05). Having dogs at home was associated with soil-transmitted helminth (STH) infection in study participants (Crude prevalence ratio [CPR]: 2.3; 95% CI: 1.0-5.2). CONCLUSIONS: This study is the first to describe the prevalence of intestinal parasitic infection VHVs from southern Thailand. Hookworm infection is more prevalent than other types of STH infection. The development of community awareness campaigns and appropriate control measures should be considered to reduce the prevalence of hookworm infection, especially among VHVs who are the key persons providing health education to the community.