Fruits of Brucea javanica (L.) Merr. (“Ratchadad” in Thai) and roots of Eurycoma longifolia Jack (“Plalaipeag” in Thai) are used as traditional medicines for the treatment of malarial fever. Ethanol, methanol, ethyl acetate, ethyl alcohol and aqueous extracts were tested against the multidrug-resistant Plasmodium falciparum strain K1. Ethanol and methanol-ethanol extracts, together with methanol residue, from fruits of B. javanica (L.) Merr. showed the highest antiplasmodial activities with IC₅₀ values of 0.5 ± 0.3, 0.3 ± 0.1 and 0.3 ± 0.05 Μg⁄mL, respectively, comparable to the IC₅₀ values of chloroquine (0.17 ± 0.02 Μg⁄mL) and quinine (0.3 ± 0.1 Μg⁄mL). Similarly, ethanol and methanol-ethanol extracts of roots of E. longifolia Jack showed higher activities than those of the other solvent extracts, but their activities were about 10-fold lower than those of extracts from B. javanica (L.) Merr. fruit. In drug combination tests, B. javanica (L.) Merr. and E. longifolia Jack extracts did not appear to antagonize antiplasmodial activity of chloroquine and quinine. Not only well-known quassinoid glycosides but also coumarins and flavonoids identified by thin-layer chromatography in ethanol and methanol-ethanol extracts and in methanol residue of B. javanica (L.) Merr fruit and E. longifolia roots may be responsible for the antimalarial activity. Taken together, our extraction conditions provided extracts containing novel active compounds that did not antagonize the inhibitory effects of the two widely used antimalarials. This finding could lend support to the future discovery of active antimalaria compounds of Brucea javanica (L.) Merr. and Eurycoma longifolia Jack as drugs for the treatment of malaria that could be employed as drug combinations in order to delay the onset of parasite drug resistance.

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Some field trials have already demonstrated the high antischistosomal potential of combination therapies using Artesunate (ART) and current antimalarial drugs (Boulanger et al., 2007; Mohamed et al., 2009; Sissoko et al., 2009). The antischistosomal effects of these drugs are noteworthy, especially when they are used for the treatment of malaria in schistosomiasis endemic areas. However, the antischistosomal effects of Amodiaquine (AQ), Primaquine (PQ), Chloroquine (CQ) and Pyrimethamine (Py) have never been assessed by in vitro incubation. The objective of the present study is to assess the in vitro effects of current antimalarial drugs on the egg productivity of adult worm pairs of S. mansoni and their survival times. The effect of the current antimalarial drugs Mefloquine (MQ), quinine (QN), AQ, PQ, CQ, Sulfadiazine (Sf) and Py on the egg output of adult worm pairs of Schistosoma mansoni and their survival times during in vitro culture were assessed at a concentration of 10 Μg⁄ml. AQ, PQ, CQ and Py significantly inhibited the daily egg output of paired female worms at a concentration of 10 Μg⁄ml during the 1 or 2-day in vitro cultivation. However, QN and Sf did not significantly affect the daily egg output during the 8-day incubation. One-day exposure to MQ killed all paired male and female adult worms. AQ and PQ significantly decreased the survival of both paired male and female worms during the 14-day incubation, but QN, CQ, Py and Sf did not exert any similar effect. The present result is consistent with an assessment of the antischistosomal effects of artemisinin-based combination therapy in malaria and schistosomiasis co-endemic areas.

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Contamination of hands by soil-transmitted helminth eggs was investigated in a small village located in the suburbs of Hanoi, Vietnam. Thirty-three households, consisting of one to eight members, were selected in the village. In addition, 130 school children, including 80 pupils from primary school grade 1 and 50 students from secondary school grade 8, were selected for the survey. A total of 285 villagers were subjected to the collection of hand-wash samples either once or twice during the study. Parasite eggs were found in 37 (13.0%) samples from 21 males and 16 females aged between 2 and 72 years old. One person was positive in both the rainy and dry season. Eggs of seven parasite species were detected; Enterovius. vermicularis (8.4%), Ascaris sp. (2.1%), Trichuris sp. (1.1%), Ascaridia galli (0.7%), Taenia sp. (0.7%), Capillaria sp. (0.4%) and Toxocara sp. (0.4%). A total of 249 villagers were subjected to collection of nail samples either once or twice during the study. Parasite eggs were found in 10 (4.0%) samples from 5 males and 5 females aged between 6 and 46 years old. Six people were also positive on examination of hand-wash samples. Eggs of four parasite species were detected; E.vermicularis (2.0%), Ascaris sp. (0.8%), Trichuris sp.(0.8%) and Toxocara sp. (0.4%). The present study indicates that the infection route by hands plays an important role in the transmission of the soil-transmitted helminth.

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Although it is very important in view of public health to understand the mosquito breeding sites and key reservoirs existing around residential areas, such information is lacking in temporary housing sites constructed after the serious tsunami strikes on 26 December 2004 in Sri Lanka. This study clarified the situation regarding mosquito breeding 14 months after the tsunami in Sri Lanka by surveying temporary housing and non-damaged village areas, and also by examining people‘s knowledge related to mosquito breeding sites and mosquito-borne diseases. The relative frequency of mosquito larvae in wastewater pools was significantly higher in temporary housing than in village areas. The prevalence of storage containers at temporary housing and village areas was not significantly different. It was found that wastewater pools in temporary housing sites were the main breeding site of Culex quinquefasciatus Say, Cx. tritaeniorhynchus Giles, and Aedes albopictus Skuse whereas storage containers in village areas were the main breeding site of Cx. quinquefasciatus and Ae. albopictus. No mosquitoes bred in storage containers in the temporary housing but some Ae. albopictus did so in village areas. The questionnaires indicated a significant difference between residents of temporary housing and villages in response to the question: Do you know where mosquitoes breed? The proportion of the “wastewater pools” response was higher among temporary housing residents than among village residents. This knowledge among temporary housing residents may relate to the fact that wastewater pools are latent breeding sites for mosquitoes in temporary housing sites. Although residents in the temporary housing sites put salt and abluent into storage containers to prevent mosquitoes from breeding, wastewater pools receiving a constant supply of wastewater provided the best breeding site for mosquitoes.

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