Since 2005, artesunate (AS) plus sulfadoxine/pyrimethamine (SP) combination has been adopted as the first-line treatment for uncomplicated malaria in Yemen in response to the high level of Plasmodium falciparum resistance to chloroquine (CQ). Therefore, the aim of the present study was to determine the frequency distribution of molecular markers associated with resistance to CQ and AS plus SP combination among P. falciparum isolates from a malaria-endemic area in Taiz governorate, Yemen. Fifty P. falciparum isolates were collected during a cross-sectional study in Mawza district, Taiz, in the period from October 2013 to April 2014. The isolates were investigated for drug resistance-associated molecular markers in five genes, including P. falciparum CQ resistance transporter (pfcrt) 76T and P. falciparum multidrug resistance 1 (pfmdr1) 86Y as markers of resistance to CQ, mutations in the Kelch 13 (K13) propeller domain for resistance to AS, and P. falciparum dihydrofolate reductase (pfdhfr) and P. falciparum dihydropteroate synthase (pfdhps) genes for resistance to SP. Nested polymerase chain reaction was used to amplify target genes in DNA extracts of the isolates followed by restriction fragment length polymorphism for detecting 76T and 86Y mutations in pfcrt and pfmdr1, respectively, and by DNA sequencing for detecting mutations in K13, pfdhfr and pfdhps. All the investigated isolates from Mawza district were harboring the pfcrt 76T mutant and the pfmdr1 N86 wild-type alleles. The pfdhfr 51I/108N double mutant allele was found in 2.2% (1/45) of the isolates; however, no mutations were detected at codons 436, 437, 540, 581 and 613 of pfdhps. All P. falciparum isolates that were successfully sequenced (n=47) showed the K13 Y493, R539, I543 and C580 wild-type alleles. In conclusion, the pfcrt 76T mutant allele is fixed in the study area about six years after the official withdrawal of CQ, possibly indicating its over-the-counter availability and continued use as a self-medication in the study area. However, the almost predominant wild-type alleles of the genes associated with resistance to AS and SP among P. falciparum isolates in the present study indicates the sustained efficacy of the currently adopted first-line treatment of AS plus SP in the study area.
The epidemiology of giardiasis in rural villages in Peninsular Malaysia was examined in the context of the One Health triad that encompasses humans, animals and environment (i.e. river water). A cross-sectional study was carried out among five rural communities in Malaysia to determine the prevalence of Giardia duodenalis in humans, animals and river water. Fecal samples collected from humans and animals were examined by light microscopy. Water was sampled from the rivers adjacent to the target communities and investigated for the occurrence of Giardia cysts. The isolated cysts were further genotyped targeting the glutamate dehydrogenase and triosephosphate isomerase genes. The overall prevalence of G. duodenalis was 6.7% (18/269) and 4.7% (8/169) among humans and animals, respectively. Giardia cysts (mean concentration range: 0.10-5.97 cysts/L) were also found in adjacent rivers at four out of the five villages examined. At Kemensah and Kuala Pangsun, Giardia cysts were isolated from humans [rate: 3.7% each (of 54 each)], animals [rates: 6.3% (of 62) and 11.3% (of 16), respectively] and river water [average concentration of 9 samples each: 0.83±0.81 and 5.97±7.00, respectively]. For both villages at Pos Piah and Paya Lebar, 12.2% (of 98) and 6.1% (of 33) of collected human samples were infected, respectively whilst none of the collected animals samples in these villages were found to be positive. The river water samples of these two villages were also contaminated (average concentration: 0.20±0.35 (of 9) and 0.10±0.19 (of 3), respectively). In conclusion, Giardia cysts were simultaneously observed in the human-animal-environment (i.e., river water) interfaces in at least two of five studied communities highlighting a vital need to improve understanding on the interplay of transmission dynamics, the role of infected humans and animals in contaminating the water sources and the role of water as a vehicle of disease transmission in these communities. Indeed, this study illustrates the One Health approach which is to recognize that the optimal health of humans are interconnected with the well-being of animals and their environment.
The current war in Yemen has displaced millions of people from their homes into living in cramped shelters where the healthcare is limited. The breakdown of Yemen's healthcare and sanitation systems has facilitated the spread of infectious diseases including mosquito-borne diseases. The present study aimed to describe the prevalence of dengue virus (DENV) infection among the febrile patients of the Taiz governorate, Yemen as well as their knowledge, attitude and preventive practices (KAPs) regarding dengue fever (DF), and to investigate the factors associated with dengue preventive practices during the war. A total of 384 clinically dengue-suspected patients who sought health care in Taiz, Yemen during the period from July 2016 until October 2016 were recruited for the study. Serum samples were obtained and screened for the presence of DENV RNA and anti-DENV antibodies by reverse transcription-recombinase polymerase amplification (RT-RPA) and dengue IgM/IgG-capture ELISA, respectively. KAP questionnaires were obtained from all participants too. In the study, dengue was laboratory confirmed in approximately 49.3% (189/384) of the clinically suspected dengue patients. In general, 67.1% of the patients had low knowledge scores regarding DF. Low scores for knowledge about DF was significantly associated with those in the age groups of ≤20 years and 21-30 years, illiterates and patients with non-skilled jobs or jobless. The most common preventive practices reported by participants were covering stored water (78.6%) and putting a screen on the house's windows (65.3%). A low proportion of participants (6.7%) had 51-100% of good DF preventive practices. Low scores of positive attitudes toward DF was identified as a risk factor. The study participants showed poor knowledge about DF and their ways of dealing with the various aspects of DF prevention was quite limited, hence, preventive measures against the disease were less likely to be undertaken. Findings from the study highlight the peril of dengue in Taiz, Yemen, which is now comparable to that of endemic regions. The ongoing civil war with disruption in regular health services compounded by the low knowledge about DF as well as the limited DF preventive practices could result in entrenchment of dengue in Yemen.