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.
Objective: To investigate the validity and pattern of DSM-5-defined BQ use disorder (BUD) and its association with oral potentially malignant disorder (OPMD) among Asian populations.
Design, Setting, and Participants: In-person interviews were conducted from January 1, 2009, to February 28, 2010, among a random sample of 8922 noninstitutionalized adults from the Asian Betel-quid Consortium study, an Asian representative survey of 6 BQ-endemic populations. Statistical analysis was performed from January 1, 2015, to December 31, 2016.
Main Outcomes and Measures: Participants were evaluated for BUD using DSM-5 criteria for substance use disorder and for OPMD using a clinical oral examination. Current users of BQ with 0 to 1 symptoms were classified as having no BUD, those with 2 to 3 symptoms as having mild BUD, those with 4 to 5 symptoms as having moderate BUD, and those with 6 or more symptoms as having severe BUD.
Results: Among the 8922 participants (4564 women and 4358 men; mean [SD] age, 44.2 [0.2] years), DSM-5 symptoms showed sufficient unidimensionality to act as a valid measure for BUD. The 12-month prevalence of DSM-5-defined BUD in the 6 study populations was 18.0% (mild BUD, 3.2%; moderate BUD, 4.3%; and severe BUD, 10.5%). The 12-month proportion of DSM-5-defined BUD among current users of BQ was 86.0% (mild BUD, 15.5%; moderate BUD, 20.6%; and severe BUD, 50.0%). Sex, age, low educational level, smoking, and drinking were significantly associated with BUD. Among individuals who used BQ, family use, high frequency of use, and amount of BQ used were significantly linked to moderate to severe BUD. Compared with individuals who did not use BQ, those who used BQ and had no BUD showed a 22.0-fold (95% CI, 4.3-112.4) risk of OPMD (P
METHODS: Blood samples from 511 febrile patients were collected and a partial region of the 18 s ribosomal RNA (18 s rRNA) gene was amplified using nested PCR. From the 86 positive blood samples, 13 Plasmodium falciparum and 4 Plasmodium vivax were selected and underwent cloning and, subsequently, sequencing and the sequences were subjected to phylogenetic analysis using the neighbor-joining and maximum parsimony methods.
RESULTS: Malaria was detected by PCR in 86 samples (16.8%). The majority of the single infections were caused by P. falciparum (80.3%), followed by P. vivax (5.8%). Mixed infection rates of P. falciparum + P. vivax and P. falciparum + P. malariae were 11.6% and 2.3%, respectively. All P. falciparum isolates were grouped with the strain 3D7, while P. vivax isolates were grouped with the strain Salvador1. Phylogenetic trees based on 18 s rRNA placed the P. falciparum isolates into three sub-clusters and P. vivax into one cluster. Sequence alignment analysis showed 5-14.8% SNP in the partial sequences of the 18 s rRNA of P. falciparum.
CONCLUSIONS: Although P. falciparum is predominant, P. vivax, P. malariae and mixed infections are more prevalent than has been revealed by microscopy. This overlooked distribution should be considered by malaria control strategy makers. The genetic polymorphisms warrant further investigation.
PRINCIPAL FINDINGS: We performed whole genome sequencing and RT-qPCR analysis on the strains isolated during this study to gain further insights into their differences. We thus identified two types of resistance mechanisms in these clinical strains. The first one was an adaptive and transient mechanism that disappeared during the course of laboratory sub-cultures; the second was a mutation in the efflux pump regulator amrR, associated with the overexpression of the related transporter.
CONCLUSION: The development of such mechanisms may have a clinical impact on antibiotic treatment. Indeed, their transient nature could lead to an undiagnosed resistance. Efflux overexpression due to mutation leads to an important multiple resistance, reducing the effectiveness of antibiotics during treatment.