Low Efficacy of Single-Dose Albendazole and Mebendazole against Hookworm and Effect on Concomitant Helminth Infection in Lao PDR

Parasitic worms remain a public health problem in developing countries. Regular deworming with the drugs albendazole and mebendazole is the current global control strategy. We assessed the efficacies of a single tablet of albendazole (400 mg) and mebendazole (500 mg) against hookworm in children of southern Lao PDR. From each child, two stool samples were examined for the presence and number of hookworm eggs. Two hundred children were found to be infected. They were randomly assigned to albendazole (n = 100) or mebendazole (n = 100) treatment. Three weeks later, another two stool samples were analyzed for hookworm eggs. Thirty-two children who were given albendazole had no hookworm eggs anymore in their stool, while only 15 children who received mebendazole were found egg-negative. The total number of hookworm eggs was reduced by 85.3% in the albendazole and 74.5% in the mebendazole group. About one third of the children who were co-infected with the Asian liver fluke Opisthorchis viverrini were cleared from this infection following albendazole treatment and about one forth in the mebendazole group. Concluding, both albendazole and mebendazole showed disappointingly low cure rates against hookworm, with albendazole performing somewhat better. The effect of these two drugs against O. viverrini should be studied in greater detail

Helminth infection in southern Laos: high prevalence and low awareness

BACKGROUND: Helminthiasis is a public health concern in Lao People’s Democratic Republic (Lao PDR, Laos). This study aimed to understand helminth infection and associated risk factors in relation to existing local knowledge, attitudes and practices regarding worm infections in endemic communities. METHODS: A cross-sectional survey was conducted in 10 randomly selected villages in Saravane district, Southern Laos. Two stool samples obtained from 574 members (aged ≥2 years) of selected households were examined using the Kato Katz method. Household heads (n = 130) were interviewed. Eight focus group discussions (FGDs) and direct observations were performed. Uni- and multivariate logistic regression analyses were conducted to predict infection. Content analysis was conducted for qualitative data. RESULTS: The prevalence of Opisthorchis viverrini, hookworm, Trichuris trichiura, Ascaris lumbricoides and Taenia sp. was 88.7%, 86.6%, 32.9%, 9.8% and 11.5%, respectively. Most individuals were co-infected with O. viverrini and hookworm. More men had multiple helminth infections than did women. Only one-third of household heads had heard about liver fluke before, of which 59.2% associated it with eating raw fish dish. Among the soil-transmitted helminths, roundworm was the most well known (70.8%) but was attributed to raw food consumption (91.3%). Eating raw fish was a common practice (75.4%); few households possessed a latrine (16.1%); less than half of the study participants mentioned health benefits from latrine use and personal hygiene. Focus group discussion participants had a low level of awareness of worm infections; more men liked eating raw fish than did women; some disliked using latrines because they were not used to it and because of their bad smell. Poor personal and village hygiene practices were observed. CONCLUSIONS: This study highlights a high helminth infection rate and poor community awareness of worm and associated risk factors. Only a sound awareness of worm infection and the underlying risk factors may prevent infection and re-infection after treatment

Infection rate and cure rate of albendazole and mebendazole for hookworm co-infections.

a<p><i>OR 0.8 [95% CI (0.2–2.6; P = 0.71) comparison of treatment outcomes between mebendazole vs. albendazole</i>.</p>b<p> <i>ERRR n.a.</i></p>c<p><i>OR 0.8 [95% CI (0.3–1.9; P = 0.58)] comparison of treatment outcomes between mebendazole vs. albendazole</i>.</p>d<p><i>ERRR 0.7 [95% CI (0.3–1.2; P = 0.22)] comparison of treatment outcomes between mebendazole vs. albendazole</i>.</p>e<p><i>OR 0.7 [95% CI (0.3–1.9; P = 0.62)] comparison of treatment outcomes between mebendazole vs. albendazole</i>.</p>f<p><i>ERRR 0.8 [95% CI (0.2–3.9; P = 0.78)] comparison of treatment outcomes between mebendazole vs. albendazole</i>.</p><p><i>Note. Data are number; (%) of children, unless otherwise indicated (95% confident interval); GM, geometric mean; EPG, eggs per gram of stool; ERRR, egg reduction rate ratio; OR odds ratio; n.a. not applicable</i>.</p

Flow chart detailing the study participation and compliance.

<p>Children who completed two stool samples were included in the final analysis for assessing the efficacy of single-dose albendazole (400 mg) and single-dose mebendazole (500 mg) treatment against hookworm and concomitant helminth infections in Bachieng district, Champasack province, southern Lao PDR in February/March 2009.</p

Hookworm infection at baseline and follow-up and cure rate of albendazole and mebendazole (per-protocol analysis).

a<p> <i>OR 0.4 [95% CI (0.2–0.8; P = 0.01)] comparison of treatment outcomes between mebendazole vs. albendazole;</i></p>b<p> <i>P = 0.13;</i></p>c<p> <i>P = 0.04;</i></p>d<p> <i>P = 0.46;</i></p>e<p><i>ERRR 1.0 [95% CI (0.7–1.6; P = 0.90)] comparison of treatment outcomes between mebendazole vs. albendazole</i>.</p><p><i>Note. Data are number; (%) of children, unless otherwise indicated (95% confident interval); GM, geometric mean; EPG, eggs per gram of stool; ERRR egg reduction rate ratio; OR odds ratio; n.a. not applicable</i>.</p

Raw fish consumption in liver fluke endemic areas in rural southern Laos

Consumption of raw or insufficiently cooked fish is a major public health concern in Southeast Asia, and in Lao People's Democratic Republic (Lao PDR), in particular. We aimed to assess the knowledge, attitudes, perceptions and practices of villagers in liver fluke endemic areas related to raw fish preparation, consumption and its health consequences. In February 2010, eight focus group discussions (FGDs, 35 men and 37 women total) and direct observations were conducted in four randomly selected villages in Saravane District, Saravane Province (Lao PDR). FGDs distilled the knowledge, attitudes, perceptions and practices of adult community members on raw fish preparation, consumption and its consequences for health. Conversations were transcribed from notes and tape-recorders. MaxQDA software was used for content analysis. Knowledge regarding the health effects of raw fish consumption was heterogeneous. Some participants did not associate liver fluke infection with any ill health, while others linked it to digestive problems. Participants also associated vegetables and tree leave consumption with liver fluke infection. The majority of FGD participants considered fish flesh that had been prepared with weaver ant extract to be safe for consumption. Visual appearance, taste, smell and personal preference were given as reasons for consuming raw fish dishes. Moreover, participants considered it a traditional way of food preparation, practiced for generations in Laos. Ten different fish dishes that use raw or fermented fish were identified. All FGD participants reported consuming dishes with raw fish. This study reveals a low degree of knowledge among local people on the health risks related to frequent consumption of raw or insufficiently cooked fish. Fish dishes were considered to be 'well-prepared' (that is, 'cooked') even though the fish had not been heated. In future, successful health education campaigns will have to address the specific knowledge, attitudes, perceptions and practices of the concerned population

Baseline characteristics of 171 hookworm-infected school children, Bachieng district, Champasak province, Lao PDR, in February/March 2009.

a<p><i>According to guidelines put forth by WHO regarding definition of anemia </i><a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0001417#pntd.0001417-WHO5" target="_blank">[<i>42</i>]</a>.</p>b<p><i>According to guidelines put forth by WHO </i><a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0001417#pntd.0001417-WHO4" target="_blank">[<i>25</i>]</a><i>, based on Kato-Katz thick smear examination</i>.</p>c<p><i>According to Maleewong and colleagues </i><a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0001417#pntd.0001417-Maleewong1" target="_blank">[<i>24</i>]</a><i>, based on Kato-Katz thick smear examination</i>.</p><p><i>Data are no; (%) of subject, otherwise indicated (95% confidence interval); EPG, eggs per gram of stool; GM, geometric mean</i>.</p