Insecticide susceptibility and detection of kdr-gene mutations in Aedes aegypti of Peshawar, Pakistan.

Dengue is an endemic disease in Peshawar, Pakistan and its primary vector is Aedes aegypti mosquito. Due to absence of vaccines and proper treatment for dengue, vector control becomes a necessary tool for disease management. Reported insecticide resistance in vectors is a serious threat to the control of dengue. This study presents the susceptibility status of Ae. aegypti to eight insecticides in district Peshawar along with one of the first attempts to screen mutations in the vector's knock down resistant gene (kdr). Local Ae. aegypti was found to be highly resistant to DDT and Deltamethrin while they were susceptible to Cyfluthrin and Bendiocarb. DNA sequencing of domains II and III of kdr-gene detected four SNPs in domain IIS6 at positions S989P and V1016G while two mutations were reported at position T1520I and F1534C in domain IIIS6. Lowest allele frequency was observed for S989P and V1016G positions while it was highest for F1534C. Among mutational combinations SSVVTICC (43%) was evidently the most predominant combination, where T1520I was heterozygous and F1534C was homozygous mutant. The study concludes instecticide resistance in local dengue population of Peshawar, Pakistan. The resistance observed is to some extent also corroborated in the molecular study of kdr gene. Findings herein can be utilized in designing dengue vector control strategies in Peshawar.

Malaria epidemiology and comparative reliability of diagnostic tools in Bannu; an endemic malaria focus in south of Khyber Pakhtunkhwa, Pakistan.

The present study was aimed at elucidation of malaria epidemiology and comparing performance of several diagnostic procedures in Bannu, a highly endemic district of Khyber Pakhtunkhwa, Pakistan. Dried blood spots were collected from patients suspected of malaria visiting a hospital and two private laboratories in district Bannu and processed for species-specific PCR (rRNA). Patients were also screened for malaria through microscopy and RDT. A well-structured questionnaire was used to collect patient information to assess risk factors for malaria. Of 2033 individuals recruited, 21.1% (N = 429) were positive for malaria by at least one method. Overall, positivity detected by PCR was 30.5% (95/311) followed by 17.7% by microscopy (359/2033) and 16.4% by RDT (266/1618). Plasmodium vivax (16.9%, N = 343) was detected as the dominant species followed by Plasmodium falciparum (2.3%, N = 47) and mixed infections (1.2%, N = 39). Microscopy and RDT (Cohen's kappa k = 0.968, p = <0.0001, McNemar test p = 0.069) displayed significant agreement with each other. Satisfactory health, sleeping indoors, presence of health-care facility in vicinity (at an accessible range from home), living in upper middle class and in concrete houses significantly reduced malaria risk; whereas, low literacy level, presence of domestic animals indoors and malaria diagnosis recommended by clinician increased the disease risk. Overall, findings from the study provide reasonable basis for use of RDT as a cost-effective screening tool in field and for clinicians who can proceed with timely treatment of malaria patients. Appropriate management of identified risk factors could contribute to reduction of malaria prevalence in Bannu and its peripheries.