BackgroundMalaria still poses one of the major threats to human health. Development of effective antimalarial drugs has decreased this threat; however, the emergence of drug-resistant Plasmodium falciparum, a cause of Malaria, is disconcerting. The antimalarial drug chloroquine has been effectively used, but resistant parasites have spread worldwide. Interestingly, the withdrawal of the drug reportedly leads to an increased population of susceptible parasites in some cases. We examined the prevalence of genomic polymorphisms in a malaria parasite P. falciparum, associated with resistance to an antimalarial drug chloroquine, after the withdrawal of the drug from Indonesia.ResultsBlood samples were collected from 95 malaria patients in North Sulawesi, Indonesia, in 2010. Parasite DNA was extracted and analyzed by polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) for pfcrt and pfmdr1. In parallel, multiplex amplicon sequencing for the same genes was carried out with Illumina MiSeq. Of the 59 cases diagnosed as P. falciparum infection by microscopy, PCR–RFLP analysis clearly identified the genotype 76T in pfcrt in 44 cases. Sequencing analysis validated the identified genotypes in the 44 cases and demonstrated that the haplotype in the surrounding genomic region was exclusively SVMNT. Results of pfmdr1 were successfully obtained for 51 samples, where the genotyping results obtained by the two methods were completely consistent. In pfmdr1, the 86Y mutant genotype was observed in 45 cases (88.2%).ConclusionsOur results suggest that the prevalence of the mutated genotypes remained dominant even 6 years after the withdrawal of chloroquine from this region. Diversified haplotype of the resistance-related locus, potentially involved in fitness costs, unauthorized usage of chloroquine, and/or a short post-withdrawal period may account for the observed high persistence of prevalence.Electronic supplementary materialThe online version of this article (doi:10.1186/s13104-017-2468-1) contains supplementary material, which is available to authorized users.

Schistosomiasis is a chronic parasitic disease caused by blood worms (Trematodes) from Schistosoma genus. Schistosomiasis is a tropical disease that is the third most powerful in the world, after malaria and worms. And this is a major source of morbidity and mortality for developing countries. This study aims to describe the Schistosomiasis japonicum disease in terms of the distance between infected children homes with Lake Lindu. This research is a descriptive, by collecting data of stool examination results in children aged ≤ 18 years, after it did an interview using questionnaires. Based on the results of interviews using questionnaires showed that the distance between infected children homes with Lake Lindu did not affect the prevalence of Schistosomiasis japonicum. Key words: Schistosomiasis japonica, Distance between infected children homes with Lake Lindu.     Abstrak: Schistosomiasis adalah penyakit infeksi parasit kronis yang disebabkan oleh cacing darah (Trematoda) dari genus Schistosoma. Schistosomiasis termasuk dalam penyakit tropis yang paling dahsyat ketiga di dunia setelah malaria dan penyakit cacing Dan ini menjadi sumber utama morbiditas dan mortalitas bagi negara-negara yang sedang berkembang. Penelitian ini bertujuan untuk mengetahui gambaran penyakit Schistosomiasis japonicum yang  ditinjau dari jarak antara rumah anak yang terinfeksi dengan Danau Lindu. Penelitian ini merupakan penelitian yang bersifat deskriptif, yaitu dengan mengumpulkan data-data hasil pemeriksaan feses pada anak-anak yang berusia ≤ 18 tahun, setelah itu melakukan wawancara dengan menggunakan kuesioner. Berdasarkan hasil wawancara dengan menggunakan kuesioner menunjukkan bahwa jarak antara rumah anak yang terinfeksi dengan Danau Lindu tidak mempengaruhi angka kejadian Schistosomiasis japonicum. Kata Kunci: Schistosomiasis japonicum, Jarak antara rumah anak yang terinfeksi dengan Danau Lindu.