New vectors that are early feeders for Plasmodium knowlesi and other simian malaria parasites in Sarawak, Malaysian Borneo

Plasmodium knowlesi is the main cause of malaria in Sarawak, where studies on vectors of P. knowlesi have been conducted in only two districts. Anopheles balabacensis and An. donaldi were incriminated as vectors in Lawas and An. latens in Kapit. We studied a third location in Sarawak, Betong, where of 2169 mosquitoes collected over 36 days using human-landing catches, 169 (7.8%) were Anopheles spp. PCR and phylogenetic analyses identified P. knowlesi and/or P. cynomolgi, P. fieldi, P. inui, P. coatneyi and possibly novel Plasmodium spp. in salivary glands of An. latens and An. introlatus from the Leucosphyrus Group and in An. collessi and An. roperi from the Umbrosus Group. Phylogenetic analyses of cytochrome oxidase subunit I sequences indicated three P. knowlesi-positive An. introlatus had been misidentified morphologically as An. latens, while An. collessi and An. roperi could not be delineated using the region sequenced. Almost all vectors from the Leucosphyrus Group were biting after 1800 h but those belonging to the Umbrosus Group were also biting between 0700 and 1100 h. Our study incriminated new vectors of knowlesi malaria in Sarawak and underscores the importance of including entomological studies during the daytime to obtain a comprehensive understanding of the transmission dynamics of malaria.

Identification of Anopheles Mosquito Species as Malaria Vector In Riau, Indonesia

Malaria merupakan penyakit infeksi yang sering terjadi di negara tropis dan sub tropis, termasuk Indonesia. Provinsi Riau termasuk dalam kategori insidensi rendah dimana 58% kabupaten telah menyandang status eliminasi malaria tahun 2016. Namun demikian daerah tersebut masih berpotensi menjadi daerah reseptif karena keberadaan vektor malaria yaitu nyamuk Anopheles yang terdiri dari beragam spesies. Penelitian ini bertujuan mengidentifikasi spesies nyamuk Anopheles dari 4 kabupaten di Provinsi Riau yaitu Kabupaten Indragiri Hilir, Rokan Hilir, Dumai dan Indragiri Hulu. Sampel diambil pada malam hari yang hinggap pada hewan maupun manusia yang dilanjutkan dengan identifikasi spesies secara morfologis. Observasi lingkungan dilakukan pada pagi hari. Terdapat tiga spesies Anopheles yang ditemukan yaitu dari sejumlah 219 ekor nyamuk terdapat 119 Anopheles sundaicus (54,34 %), 99 Anopheles subpictus (45,20%)and 1 Anopheles balabacensis (0,46 %). Terdapat dua lokasi yang menjadi tempat perindukan utama yaitu rawa dan genangan air.

New Vectors That Are Early Feeders for Plasmodium Knowlesi and Other Simian Malaria Parasites in the Betong Division of Sarawak, Malaysian Borneo.

Plasmodium knowlesi is the main cause of malaria in Sarawak, where studies on vectors of P. knowlesi have been conducted in only two districts. Anopheles balabacensis and An. donaldi were incriminated as vectors in Lawas and An. latens in Kapit. We studied a third location in Sarawak, Betong, where of 2,169 mosquitoes collected over 36 days using human-landing catches, 169 (7.8%) were Anopheles spp. PCR and phylogenetic analyses identified P. knowlesi and/or P. cynomolgi, P. fieldi, P. inui, P. coatneyi and novel Plasmodium spp. in salivary glands of An. latens and An. introlatus from the Leucosphyrus Group and in An. collessi and An. roperi from the Umbrosus Group. Phylogenetic analyses of cytochrome oxidase subunit I sequences indicated three P. knowlesi-positive An. introlatus had been misidentified morphologically as An. latens, while An. collessi and An. roperi could not be delineated using the region sequenced. Almost all vectors from the Leucosphyrus Group were biting after 1800 hr but those belonging to the Umbrosus Group were also biting between 0700-1100 hrs. Our study incriminated new vectors of knowlesi malaria in Sarawak and underscores the importance of including entomological studies during the daytime to obtain a comprehensive understanding of the transmission dynamics of malaria.

Identifikasi Anopheles Spp. sebagai Tersangka Vektor Malaria di Kabupaten Purworejo Tahun 2015

Purworejo District is a malaria endemic area in Central Java Province with Annual Parasite Incidence (API) value of 1.96 per 1,000 population. This figure is still above the Ministry of Health's Strategic Plan target for 2015 - 2019. Indigenous cases are still being reported in Purworejo District until 2017. Prevention of malaria transmission is carried out by controlling Anopheles spp. as a malaria vector. This study aims to identify the behavior and habitat where Anopheles spp. as a malaria vector suspect in Purworejo District. The method of catching mosquitoes is in the form of Human landing collection, animal bait, light traps which are carried out starting at 18.00 to 06.00 in the morning, resting in the morning both inside and outside the house. Data variables taken in the form of biting activity, the number of mosquitoes caught, and environmental conditions at the study site. The results of the study were: the species of Anopheles leucosphyrus , Anopheles maculatus, Anopheles vagus, Anopheles indefinitus, Anopheles barbirostris, Anopheles kochi, and Anopheles balabacensis. The peak activity of biting Anopheles spp. occur at 01.00 - 02.00 and 04.00 - 05.00 in the morning. Anopheles spp. most found in lagoon. Efforts to prevent mosquito bites are done using long-sleeved clothing or using repellents or household pesticides, avoiding doing activities outside the home at night and placing larva predators on lagoon. Abstrak Kabupaten Purworejo merupakan kabupaten endemis malaria di Provinsi Jawa Tengah dengan nilai Annual Parasite Incidence (API) mencapai 1,96 per 1.000 penduduk. Angka tersebut masih berada di atas target Rencana Strategis Kementerian Kesehatan Tahun 2015–2019. Kasus indigenous juga masih dilaporkan di Kabupaten Purworejo sampai dengan tahun 2017. Pencegahan penularan malaria dilakukan dengan pengendalian nyamuk Anopheles spp. sebagai vektor malaria. Penelitian ini bertujuan untuk mengidentifikasi perilaku dan habitat tempat ditemukannya nyamuk Anopheles spp. sebagai tersangka vektor malaria di Kabupaten Purworejo. Metode penangkapan nyamuk berupa human landing collection, umpan hewan, dan light trap yang dilakukan mulai pukul 18.00 – 06.00 pagi, resting pagi hari baik di dalam maupun di luar rumah. Variabel data yang diambil berupa aktivitas menggigit, jumlah nyamuk yang tertangkap, dan kondisi lingkungan di lokasi penelitian. Hasil penelitian berupa : spesies Anopheles yang tertangkap adalah Anopheles leucosphyrus, Anopheles maculatus, Anopheles vagus, Anopheles indefinitus, Anopheles barbirostris, Anopheles kochi, dan Anopheles balabacensis. Puncak aktivitas menggigit Anopheles spp. terjadi pada pukul 01.00 – 02.00 dan 04.00 – 05.00 dini hari. Nyamuk Anopheles spp. paling banyak ditemukan pada lagun/goba. Upaya pencegahan gigitan nyamuk dilakukan dengan menggunakan pakaian lengan panjang atau menggunakan repellent atau pestisida rumah tangga, menghindari melakukan aktivitas di luar rumah pada malam hari, dan menempatkan predator larva pada lagun/goba.

Confirmation of Anopheles balabacensis as natural vector of malaria caused by Plasmodium knowlesi inhabits forested areas in Kecamatan Balik Bukit, Western Lampung Regency

This study was conducted to confirm the Anopheles spp as malaria vector inhabits forested areas in Western Lampung Regency, Sumatra Island, Indonesia. Anopheles spp. were sampled using the human landing catch method at a remote forest habitat. Each caput and thorax of Anopheles balabacensis specimen was placed separately inside a sterilized mortar and the tissue homogenized using a sterile pestle. The total DNA was extracted from the tissues according to QIAamp DNA Mini Kit protocol. The presence of malaria parasites in the mosquitoes was detected using nested PCR by targeting the small subunit ribosomal RNA (SSU rRNA) gene of Plasmodium. A PCR primer pair, rPLU1, and rPLU5, was used in the first PCR reaction, while another pair (Pkr and Pkf) was used in the second PCR reaction for detecting Plasmodium knowlesi. There was only 1 Anopheles balabacensis mosquito caught in a remote forest habitat during this study. The results of the molecular analysis showed a positive result for Plasmodium knowlesi, which showed a similarity level of 99% with Plasmodium knowlesi isolates from JOHOR02.018S, and Plasmodium knowlesi clone H033H82 isolates from Serawak, and Plasmodium knowlesi genome isolates SWK113.2.18S. It is a confirmed natural vector of Plasmodium knowlesi namely Anopheles balabacensis in a remote forest habitat in Kecamatan Balik Bukit.

Vector compositions change across forested to deforested ecotones in emerging areas of zoonotic malaria transmission in Malaysia

In lowland areas of Malaysia, Plasmodium knowlesi infection is associated with land use change and high proportions of the vector Anopheles balabacensis. We conducted a 15-month study in two Malaysian villages to determine the effect of habitat on vector populations in understudied high-altitude, high-incidence districts. Anopheles mosquitoes were sampled in human settlements, plantations and forest edges, and screened for Plasmodium species by PCR. We report the first An. donaldi positive for P. knowlesi. This potential vector was associated with habitat fragmentation measured as disturbed forest edge:area ratio, while An. balabacensis was not, indicating fragmented land use could favour An. donaldi. Anopheline species richness and diversity decreased from forest edge, to plantation, to human settlement. Greater numbers of An. balabacensis and An. donaldi were found in forest edges compared to human settlements, suggesting exposure to vectors and associated zoonoses may be greater for people entering this habitat.