The association between salivary zinc levels and dysgeusia in COVID-19 patients

OBJECTIVE

Zinc insufficiency has been proposed to play a role in taste and smell impairment in Coronavirus disease 2019 (COVID-19) patients. Therefore, this study aimed at comparing salivary zinc levels in COVID-19 patients with and without dysgeusia.

PATIENTS AND METHODS

A total of 127 participants were recruited for this study. The patients were divided into three groups based on their COVID-19 test results and taste impairment. Groups I and II were COVID-19 positive with and without taste loss, respectively. Group III included the negative control participants. Salivary zinc levels were measured at baseline in all groups and three months after baseline in groups I and II. Wilcoxon signed-rank test was used to compare the zinc levels between baseline and three months after baseline within each group. Mann-Whitney U test was used to compare zinc levels between groups with different degrees of taste loss.

RESULTS

Salivary zinc levels were significantly lower in the COVID-19 positive group with taste loss compared to levels in the group without taste loss or the negative controls (p<0.005). Three months after baseline, salivary zinc levels were significantly elevated in both COVID-19 positive groups (p<0.001).

CONCLUSIONS

COVID-19 patients with dysgeusia had significantly lower levels of salivary zinc than positive and negative controls. Zinc levels were elevated after recovery, which may indicate that salivary zinc is directly associated with taste abnormalities and COVID-19 outcomes. This study showed that taste impairment is associated with lower salivary zinc levels in COVID-19 patients.

The impacts of dental filling materials on RapidArc treatment planning and dose delivery: challenges and solution

PURPOSE

The presence of high-density material in the oral cavity creates dose perturbation in both downstream and upstream directions at the surfaces of dental filling materials (DFM). In this study, the authors have investigated the effect of DFM on head and neck RapidArc treatment plans and delivery. Solutions are proposed to address (1) the issue of downstream dose perturbation, which might cause target under dosage, and (2) to reduce the upstream dose from DFM which may be the primary source of mucositis. In addition, an investigation of the clinical role of a custom-made plastic dental mold∕gutter (PDM) in sparing the oral mucosa and tongue reaction is outlined.

METHODS

The influence of the dental filling artifacts on dose distribution was investigated using a geometrically well-defined head and neck intensity modulated radiation therapy (IMRT) verification phantom (PTW, Freiberg, Germany) with DFM inserts called amalgam, which contained 50% mercury, 25% silver, 14% tin, 8% copper, and 3% other trace metals. Three RapidArc plans were generated in the Varian Eclipse System to treat the oral cavity using the same computer tomography (CT) dataset, including (1) a raw CT image, (2) a streaking artifacts region, which was replaced with a mask of 10 HU, and (3) a 2 cm-thick 6000 HU virtual filter [a volume created in treatment planning system to compensate for beam attenuation, where the thickness of this virtual filter is based on the measured percent depth dose (PDD) data and Eclipse calculation]. The dose delivery for the three plans was verified using Gafchromic-EBT2 film measurements. The custom-made PDM technique to reduce backscatter dose was clinically tested on four head and neck cancer patients (T3, N1, M0) with DFM, two patients with PDM and the other two patients without PDM. The thickness calculation of the PDM toward the mucosa and tongue was purely based on the measured upstream dose. Patients' with oral mucosal reaction was clinically examined initially and weekly during the course of radiotherapy.

RESULTS

For a RapidArc treatment technique, the backscatter dose from the DFM insert was measured to be 9.25±2.17 in the IMRT-verification-phantom. The measured backscatter upstream dose from DFM for a single-field was 22% higher than without the DFM, whereas the downstream dose was lower by 14%. The values of homogeneity index for the plans with and without the application of mask were 0.09 and 0.14, respectively. The calculated mean treatment planning volume (PTV) dose differed from the delivered dose by 13% and was reduced to 2% when using the mask and virtual filter together. A grade 3 mucosa reaction was observed in the control group after 22-24 fractions (44-48 Gy). In contrast, no grade 3 mucositis was observed in the patients wearing the PDM after 25-26 fractions (50-52 Gy).

CONCLUSIONS

The backscatter from the DFM for a single, parallel-opposed fields, and RapidArc treatment technique was found significant. The application of mask in replacing streaking artifacts can be useful in improving dose homogeneity in the PTV. The use of a virtual filter around the teeth during the planning phase reduces the target underdosage issue in the phantom. Furthermore, a reduction in mucositis is observed in the head and neck patients with the use of PDM.

Knowledge and attitudes towards AIDS among Saudi and non-Saudi bus drivers

We explored the AIDS knowledge and attitudes of long-distance (non-Saudi) and in-city (Saudi) bus drivers in Saudi Arabia. The 69 non-Saudi drivers tended to score higher on knowledge than the 40 Saudi drivers although there were several gaps in their knowledge. As regards attitude, more Saudis knew that chastity could protect against AIDS and both groups tended to think that they were not the kind of people to get AIDS. Intensive health education and follow up is highly recommended for this sector of workers.

Nosocomial infections and misuse of antibiotics in a provincial community hospital, Saudi Arabia

The incidence of nosocomial infection and prevalence of antibiotic misuse were studied in a 174-bed community hospital in Saudi Arabia over a six-month period. Of 2445 patients admitted, 8.5% developed nosocomial infection, the rates were highest for nursery (35.8%), intensive care (19.8%), gynaecological (16.2%) and surgical (11.7%) patients. Urinary tract (31.3%), wound (27.1%) and blood (14.9%) infections accounted for more than 70% of the infections. Staphylococcus aureus (23%) and Pseudomonas aeruginosa (11%), caused more than 90% of the infections. The majority of the bacterial pathogens (79%) were multi-drug resistant. Over 80% of patients were administered prophylactic and/or therapeutic antibiotics, with 53% receiving multiple antibiotics; 72% of the antibiotics were judged to be misused. Both prophylaxis and treatment were mostly misguided and clinically unwarranted. Host- and hospital-associated infection risk factors were identified. The minimum government cost estimates for the nosocomial infections and misused antibiotics were US $273 180 and $565 603, respectively. The findings emphasize the need for effective measures to reduce both the high infection rates and widespread antibiotic misusage in the hospital. Such measures should include institution of an effective infection control committee and a hospital antibiotic policy.

Therapeutic efficacy of chloroquine against uncomplicated, Plasmodium falciparum malaria in south-western Saudi Arabia

The results of annual random screening indicated that Plasmodium falciparum strains showing chloroquine (CQ) resistance in vitro became increasingly common in the Jazan region of south-western Saudi Arabia between 1986 and 1998 (chi(2) for trend = 50.027; P < 0.001). This worrying trend and the emergence of a micro-epidemic in 1997-1998 prompted an assessment of the therapeutic efficacy of CQ against uncomplicated, P. falciparum malaria in the area. The in-vivo testing of sensitivity to CQ was carried out in 291 clinically manifest, microscopically positive cases of P. falciparum malaria. Most of these patients (88%) were successfully treated with a single standard regimen of CQ therapy. The other 36 patients (12%) showed early treatment failure or a poor response to the CQ, although all of these were then successfully treated with a single standard dose of sulfadoxine-pyrimethamine (Fansidar), as a replacement therapy. Those unsuccessfully treated with CQ were generally younger (t = 2.625; P = 0.01) and tended to have higher body temperatures (t = -2.62; P = 0.012) and higher levels of parasitaemia at initial presentation (P > 0.000) than those who responded well to the drug. Although CQ remains a reasonably effective drug for the treatment of malaria in the Jazan region, and therefore will be kept as the first-line drug for the foreseeable future, failure of CQ efficacy must be carefully monitored in the area.

Is fine needle aspiration of the tonsil superior to a surface swab for isolating its core flora in recurrent tonsillitis?

This prospective study was designed to explore the possible role of fine needle aspiration of recurrently inflamed tonsils in determining their core flora. Seventy-seven patients undergoing tosillectomy for recurrent tonsillitis were included. Colonies grown from fine needle aspirate and surface swab were compared with tonsillar core culture obtained after tosillectomy. The pathogens isolated by fine needle aspiration culture were not greatly different from surface swab results in comparison to core isolates. The results of fine needle aspirate do not appear to confer any advantage over surface swab in representing core flora. These findings would seem to indicate no clinical use for fine needle aspiration in the management of recurrent tonsillitis.