ABSTRACT
India’s target of malaria elimination by 2030 may not be achieved solely by detecting Plasmodium falciparum and P. vivax, the two common Plasmodium species causing infections in humans. Sporadic reports have been documented on other Plasmodium species in the country, associated mostly with travel history. A febrile patient of Indian origin (Non-resident Indian (NRI)) was diagnosed with an infection of Plasmodium ovale curtisi malaria on his arrival from Sudan. A case report from Kerala was published in December 2020 and this is second report. Due to the inaccessibility of molecular techniques for routine diagnosis, this neglected non-falciparum malaria goes undetected. For an accurate diagnosis, suspected malaria cases should be tested using PCR and other advanced methods.
ABSTRACT
Background & objectives: Conventional insecticides are generally used as larvicides to control Culex quinquefasciatus, vector of lymphatic filariasis. This study was undertaken to evaluate the larvicidal activity of some potential larvicidal plants leaf extracts against Cx. quinquefasciatus larvae. Methods: The toxic effects of petroleum ether leaf extracts of plants viz., Argemone mexicana (Mexican prickly poppy), Clausena dentata (Dentate), Cipadessa baccifera (Rana bili), Dodonaea angustifolia (Hop bush) and Melia dubia (Pride of India) were evaluated under laboratory conditions in individual and in combination against 3rd - 4th instar larvae of Cx. quinquefasciatus. Results: The results indicated that among the selected plants, A. mexicana showed maximum larvicidal activity with an LC50 value of 48.89 ppm. Its toxicity was enhanced when the extract was mixed (1:1) with that of C. dentata as the LC50 value became 28.60 ppm indicating synergistic action of A. mexicana. Interpretation & conclusions: Our results showed high larvicidal potential in A. mexicana leaf extract, and it also showed additive effect when mixed with C. dentata extract.
Subject(s)
Animals , Clausena/chemistry , Culex/drug effects , Culex/parasitology , Elephantiasis, Filarial/parasitology , Elephantiasis, Filarial/prevention & control , Elephantiasis, Filarial/transmission , Insect Vectors/drug effects , Insect Vectors/parasitology , Larva/drug effects , Larva/parasitology , Plant Extracts/pharmacology , Plant Leaves/chemistryABSTRACT
Background & objectives: Field trials of lambda-cyhalothrin 10 CS (ICON 10 CS) in indoor residual spraying (IRS) with 25 mg a.i./m2 against Anopheles culicifacies was undertaken vs malathion IRS (25% WP–2 g a.i./ m2) in Tumkur district, Karnataka; vs deltamethrin IRS (2.5% WP–20 mg a.i./m2) in Dharmapuri district; and vs lambda-cyhalothrin (10 WP–25 mg a.i./m2) in Ramanathapuram district, Tamil Nadu, India. Methods: Spray operations in the experimental villages were done by the National Institute of Malaria Research (NIMR) and in the control villages by the respective State Health Department staff. Persistence of efficacy of insecticide sprayed in villages was assessed by contact bioassays against vector mosquitoes. Entomological indicators such as per structure density, parity rates of vector mosquitoes and sporozoite rates were measured in all the three study areas using standard procedures. Mass blood surveys and active fever case detections were carried out in experimental and control villages to study the impact of IRS on malaria transmission. Results: Persistence of effectiveness of ICON 10 CS was observed up to 2–3 months in all the three study areas. ICON 10 CS was found effective at par with or better than the insecticides used in the national programme in reducing the mosquito densities and in interrupting malaria transmission in the study villages. Vector density, parity rates and malaria cases considerably reduced in the ICON 10 CS-sprayed villages. Conclusion: Field trials at three sites have established that ICON 10 CS formulation was relatively more effective than malathion 25% WP, deltamethrin 2.5% WP and lambda-cyhalothrin 10% WP in some evaluation parameters like indoor resting mosquitoes, parity rates in vector mosquitoes and persistence of effectiveness. It can be used for IRS for malaria vector control with two rounds of spray at an interval of 3 months for curtailing the malaria transmission and an additional round is recommended in perennial malaria transmission areas.