METHODS: WHO resistance bioassays of mosquitoes with deltamethrin, permethrin and DDT were used in conjunction with TaqMan® SNP Genotyping Assays to characterize mutation profiles of Ae. aegypti.
RESULTS: Screening of the voltage-sensitive sodium channel (Vssc), the pyrethroid target site, revealed mutations at codons 989, 1016 and 1534 in Ae. aegypti from two districts of Jeddah. The triple mutant homozygote (1016G/1534C/989P) was confirmed from Al Safa and Al Rawabi. Bioassays with pyrethroids (Type I and II) and DDT showed that mosquitoes were resistant to each of these compounds based on WHO definitions. An association between Vssc mutations and resistance was established for the Type II pyrethroid, deltamethrin, with one genotype (989P/1016G/1534F) conferring a survival advantage over two others (989S/1016V/1534C and the triple heterozygote). An indication of synergism of Type I pyrethroid activity with piperonyl butoxide suggests that detoxification by cytochrome P450s accounts for some of the pyrethroid resistance response in Ae. aegypti populations from Jeddah.
CONCLUSIONS: The results provide a baseline for monitoring and management of resistance as well as knowledge of Vssc genotype frequencies required in Wolbachia release populations to ensure homogeneity with the target field population. Vssc mutation haplotypes observed show some similarity with those from Ae. aegypti in southeast Asia and the Indo-Pacific, but the presence of the triple mutant haplotype in three genotypes indicates that the species in this region may have a unique population history.
MATERIAL AND METHODS: This study included 472 CT scans (236 males and 236 females; age range, 18-72 years). The foramen magnum shapes were classified into 8 types: oval, egg, round, hexagonal, pentagonal, tetragonal, irregular (A) and irregular (B). The intraobserver and interobserver test was done to calculate the reliability of the measurement. Eight dimensions of the FM and occipital condyle were evaluated to determine the sexual dimorphism using an independent t-test. Sex determination was estimated using discriminate function analysis.
RESULTS: The commonest shape of FM was hexagonal and the tetragonal shape was the least common type. Coefficient of reliability (R) was high, ranging between 0.89 and 0.99, which indicates the measurements are reliable and sufficiently precise. All the eight measurements, the FM length and width, FM index, FM area, the width and length of right and left occipital condyles were significantly greater in males than the female. Univariate discriminant function showed an accuracy rate varying from 61% to 66.6% based on FM or occipital condyles measurements. The multivariate analysis of FM and occipital condyle measurements increased the overall accuracy rate of sex determination to 71.6%.
CONCLUSION: The univariate analysis of FM and occipital condyle measurements indicates, that the FM area (66.1%), FML (62.5%), FMW (62.5%) and ROCL (62.1%) could be reliable individual variables in sex determination. The multivariate analysis including all the eight variables of FM and occipital condyle increased the accuracy rate of sex determination to 71.6% in determining the sex as male (73.3%) or female (69.9%). The shape of the FM is not useful in sex estimation. The results obtained showed a low degree of sexual dimorphism in the basicranium, the use of this method in forensic anthropology could be helpful for assessment on highly fragmented skull bases.
METHODS: A 20-item questionnaire was distributed online to medical professors of a Saudi, Malaysian and a Pakistani medical school. The participants were instructed to select their responses on a 5-point Likert's scale and the collected data was analyzed for quantitative and qualitative results.
RESULTS: Of 161, 110 responded; response rate of 68.3%. About 35% professors spent 1-4 hours and 2% spent 19-25 hours per week for research. As many as 7% did not publish a single article and 29% had published 10 or more articles after attaining professor rank. During the last two years, 44% professors had published 5 or more research articles. Majority pointed out a lack of research support and funds, administrative burden and difficulty in data collection as the main obstacles to their research.
CONCLUSIONS: This research has identified time constraints and insufficient support for research as key barriers to medical professors' research productivity. Financial and technical support and lesser administrative work load are some suggested remedies to foster the professors' research output.
METHODS: A total of 151 P. falciparum isolates were collected between April 2018 and March 2019 from 12 of the governorates in Jazan region. Genomic DNA was extracted from dried blood spots and amplified using nested PCR. Polymorphisms in the propeller domain of the P. falciparum k13 (pfkelch13) gene and point mutations in the P. falciparum dihydrofolate reductase (pfdhfr) and dihydropteroate synthase (pfdhps) genes were identified by sequencing.
RESULTS: No mutations in the pfkelch13 propeller domain were found in any of the 151 isolates. However, point mutations in the pfdhfr and pfdhps genes were detected in 90.7% (137/151) of the isolates. The pfdhfr double mutations N51I + S108N (i.e. ACICNI haplotype) and triple mutations N51I + C59R + S108N (i.e. ACIRNI haplotype) were detected in 47% and 37.8% of the isolates, respectively. Moreover, the pfdhps single mutation at codon A437G and double mutations A437G + K540E (i.e. SGEAAI haplotype) were observed in 4.6% and 51.7% of the isolates, respectively. Interestingly, 23.8%, 25.1 and 12.6% of the isolates had quintuple, quadruple and triple mutated combined pfdhfr-pfdhps genotypes, respectively. Furthermore, significant associations were found between the prevalence of mutant haplotypes and the age, gender and nationality of the patients (P Saudi Arabia and the Arabian Peninsula. Despite the absence of the pfkelch13 mutation in the isolates examined, the pfdhfr and pfdhps mutations undermine the efficacy of SP partner drug, thereby threatening the main falciparum malaria treatment policy in Saudi Arabia, i.e. the use of AS + SP. Therefore, the continuous molecular and in-vivo monitoring of ACT efficacy in Jazan region is highly recommended.
METHODS: A cross-sectional study was carried out from 1 April 2018 to 31 January 2019 in Jazan region, southwestern Saudi Arabia, which targeted febrile individuals attending hospitals and primary healthcare centres. Participants' demographic data were collected, including age, gender, nationality, and residence. Moreover, association of climatic variables with the monthly autochthonous malaria cases reported during the period of 2010-2017 was retrospectively analysed.
RESULTS: A total of 1124 febrile subjects were found to be positive for malaria during the study period. Among them, 94.3 and 5.7% were infected with Plasmodium falciparum and Plasmodium vivax, respectively. In general, subjects aged 18-30 years and those aged over 50 years had the highest (42.7%) and lowest (5.9%) percentages of malaria cases. Similarly, the percentage of malaria-positive cases was higher among males than females (86.2 vs 13.8%), among non-Saudi compared to Saudi subjects (70.6 vs 29.4%), and among patients residing in rural rather than in urban areas (89.8 vs 10.2%). A total of 407 autochthonous malaria cases were reported in Jazan region between 2010 and 2017. Results of zero-inflated negative binomial regression analysis showed that monthly average temperature and relative humidity were the significant climatic determinants of autochthonous malaria in the region.
CONCLUSION: Malaria remains a public health problem in most governorates of Jazan region. The identification and monitoring of malaria transmission hotspots and predictors would enable control efforts to be intensified and focused on specific areas and therefore expedite the elimination of residual malaria from the whole region.