Pharmacokinetic characterization of favipiravir in patients with COVID-19

This prospective observational study describes the pharmacokinetic characteristics of favipiravir in adult patients hospitalized for mild to moderate COVID-19 with a positive RT-PCR test. Favipiravir was administered for 5 days, with a loading dose of 3200 mg and a maintenance dose of 1200 mg/day. Serial blood samples were collected on Day-2 and Day-4 of the therapy. Laboratory findings of the patients (n=21) and in-hospital mortality were recorded. Favipiravir concentrations exhibited substantial variability and a significant decrease during the treatment of COVID-19. The median favipiravir trough concentration (C_0-trough ) on Day-2 was 21.26 (IQR, 8.37-30.78) μg/mL whereas it decreased significantly to 1.61 (IQR, 0.00-6.41) μg/mL on Day-4, the area under the concentration versus time curve decreased by 68.5%. Day-2-C_0-trough of female patients was higher than male patients. Our findings indicate that favipiravir concentrations show significant variability during the treatment of COVID-19 and therapeutic drug monitoring may be necessary to maintain targeted concentrations.

First known COVID-19 case and contact tracing efforts in İstanbul, Turkey

Background/aim

COVID-19 has now become a global pandemic. Understanding the routes of transmission is vital in the mitigation and suppression of the disease. İstanbul has become one of the disease’s epicenters. This study aims to describe the first COVID-19 case and contact tracing efforts around it in İstanbul.

Materials and methods

The descriptive study was conducted in İstanbul, Turkey. The first COVID-19 cases and those associated with them were investigated with contact tracing, and primary and secondary cases were described.

Results

The source case was an individual who returned to Turkey from international travel at the beginning of March and tested PCR (–). The index case is the brother of the source case and is considered the first PCR (+) case diagnosed in İstanbul. Contact tracing revealed 23 PCR (+) cases, 14 of which resulted in hospitalization and three deaths.

Conclusions

This study described cases of the first COVID-19 cluster in İstanbul. Moreover, contact tracing was used in this first cluster. This contributed to contact tracing algorithms in Turkey.

The effects of irrigation volume to the heat generation during implant surgery

Background

To evaluate the effects of the amount of irrigation on heat generated during implant site preparation.

Material and Methods

Ten freshly dissected sheep mandibles were sectioned into 30 equal bone blocks and transferred into a heat-controlled water tank. Implant socket preparations were performed with four consecutive drills. Temperature measurements were performed with a thermocouple inserted into the bone immediately before the preparation and after the drilling using three different physiologic saline irrigation set-ups: 1- No irrigation, 2- 12 ml/min and 3- 30 ml/min irrigation volume. The temperature differences between three different irrigation set-ups for implant drills 1, 2, 3 and 4, and the temperature differences between the drills for three different irrigation set-ups were separately compared.

Results

The temperature difference of no irrigation group was significantly higher than 12 ml/min and 30 ml/min groups for all four drills (p<0.05), whereas no statistically significant difference was found between 12 ml/min and 30 ml/min irrigation groups. (P >0.05) The temperature difference of drill 1 is significantly higher than drills 2, 3 and 4 for no irrigation group. (P <0.05) The temperature differences of drill 1, 2 and 3 were significantly higher than the temperature difference of drill 4 for 12 ml/min irrigation group. (p<0.05).

Conclusions

The heat generated during drilling is not directly proportional to the coolant volume. Given that certain amount of irrigation is applied, implant sites can be prepared safely without the need for additional irrigation, which may result in reduced visibility of the surgical site and therefore a suboptimal surgery.

Key words:Dental implants, irrigation, heat generation, drilling.

Recurrent toxocariasis due to chronic urticaria and successful treatment with prolonged albendazole therapy

Toxocariasis is a worldwide human helminthiasis, especially seen in temperate and tropical climate regions around the world. The diagnosis of this disease is performed on the basis of clinical symptoms and laboratory findings. Albendazole is one of the treatment choices for toxocariasis, with a currently recommended regimen of 10 mg/kg/day in two doses (400 mg twice daily) for 5 days. However, there is no precise consensus about the duration of the treatment. In this article, we report a case of toxocariasis; the patient visited our infectious disease polyclinic with complaints of long-term itching and urticarial skin lesions that were resistant to routine treatment and that recurred. Then, recurrent disease was resolved and skin lesions were diminished after prolonged albendazole therapy.

[Tuberculosis and tularemia as part of the differential diagnosis in cervical lymphadenitis]

We have read with interest the recently published article entitled "Investigation of the presence of Mycobacterium tuberculosis in the lymph node aspirates of the suspected tularemia lymphadenitis cases" by Albayrak et al. published in Mikrobiyol Bul 2014; 48(1): 129-34. They concluded that tuberculous lymphadenitis (TCL) should be kept in mind in suspected tularemia cases and those patients should also be investigated simultaneously for the presence of TCL. With reference to data provided by the Ministry of Health in Turkey, the number of reported cases of pulmonary tuberculosis in comparison to previous years is currently on decline whereas a gradual increase in extra-pulmonary (specifically cervical TCL) cases has been observed. Besides, as one of the most common causes of cervical lymphadenitis, we are witnessing a marked increase in granulomatous infections which have been part of the evaluated cases of oropharyngeal tularemia in Turkey. In fact, differentiation of the two types of lymphadenitis can be confusing on the basis of clinical and histopathological findings. Thus, investigating the presence of M.tuberculosis in cervical lymph node aspirates of tularemia suspected cases is a vital contribution, specifically in a geographical region that is considered endemic for both diseases. We would therefore like to note the importance of this study and thank the authors for their comprehensive contribution. Contrary to what is noted in the study, cervical lymphadenitis due to acute tonsillopharyngitis unresponsive to penicillin and its derivatives, has been regarded as cervical TCL due to their histopathological appearance and have been treated unnecessarily with long-term antituberculous drugs. There are some publications from Turkey indicating the detection of Francisella tularensis antibodies and nucleic acids in the patients who were histologically diagnosed as TCL. In situations where the exact etiology of cervical lymphadenitis is not determined, treatment is delayed, disease duration is prolonged and patients are forced into visiting multiple physicians and hospitals. In this case uneccessary protocols such as lymph node excision and various surgical procedures are performed to rule out the presence of commonly encountered malignancies like lymphoma. On the other hand, lymph node suppuration is more commonly seen among these group of patients. As a conclusion, tularemia and TCL should be kept in mind as different endemic entities in widespread geographical regions such as Turkey. In particular, early serological and microbiological investigations should be performed for early diagnosis and appropriate treatment in such patients.

[Two imported and relapsed of Plasmodium vivax malaria cases and primaquine prophylaxis]

Malaria is a worldwide infection causing serious health and financial problems. Turkey is in the elimination phase, and malaria cases have been observed in patients who have come from abroad recently. In this study, 2 relapsed Plasmodium vivax (Pv) cases that returned from Afghanistan to our country at least 6 months ago were presented. The first case had received irregular chemoprophylaxis during travel, 6 months after returning to Turkey occurred malaria clinic. The second case had not received chemoprophlaxis during his travel, and he had experienced 2 previous episodes of malaria. He had used inappropriate anti-malarial drugs before returning to Turkey. Two separate incubation periods for P. vivax and P. ovale have been described. One of them is defined as late infection, or relapse, which is maturation of dormant bacilli in the liver, known as the hypnozoite stage. We thought that relapses of Pv infection could result from activation of hypnozoites in these cases. These 2 cases were treated with chloroquine and primaquine. The purpose of presenting these 2 cases is that primaquine should be considered for primer prophylaxis in short travels, especially after traveling to endemic areas, and the patient's relapse should be considered.

[Notice of first NDM-1 expressing isolates in Turkey and the use of modified Hodge test]

We read the article entitled "Investigation of the presence of New Delhi metallo- beta-lactamase-1 (NDM-1) by PCR in carbapenem-resistant gram-negative isolates" by Yanık et al. [Mikrobiyol Bul 2013; 47(2):382], with a great interest. Today, gram-negative enteric bacteria expressing NDM-1 are spreading rapidly all over the world and this is of great concern when increasing carbapenem resistance is considered. Yanık et al. reported that there were no NDM-1 positive isolates in their study involving a part of Turkey. It is well-known that the most sensitive indicator related to carbapenem resistance is ertapenem resistance [Perçin et al. Mikrobiyol Bul 2012; 46(4):546]. In their study Yanık et al. used imipenem, meropenem or doripenem instead of ertapenem resistance for screening carbapenem resistance. Thus, carbapenem-resistant strains might be unnoticed in their study. They also used Modified Hodge Test (MHT) for the investigation of carbapenem resistance in the second stage of their study. MHT is known to have a low sensitivity as a screening test for NDM-1 positive strains. To increase its sensitivity, ZnSO4 should be added to the culture medium [Girlich et al. J Clin Microbiol 2012; 50(2):477]. However, this issue was not specified in Yanık et al's study. Thus, this may be another possible cause of failure to detect NDM-1 expressing strains. Yanık et al. reported in their study that NDM-1-producing isolates were not detected in Turkey. However, very recently, four NDM-1 isolates which were not associated with importation from abroad, were reported in a study from Turkey [Alp et al. J Hosp Infect 2013; 84(2):178] and this was the first report of domestic NDM-1 secreting strains in Turkey. In conclusion, there is a need in our country to a carbapenem group antibiotic investigate the presence of NDM-1 positive strains. The use of ertapenem for screening carbapenem resistance and also adding ZnSO4 to MHT for the detection of NDM-1 strains are of great importance.

Boric acid inhibits alveolar bone loss in rats by affecting RANKL and osteoprotegerin expression

BACKGROUND AND OBJECTIVE

The goal of the present study was to evaluate the effects of systemic boric acid on the levels of expression of RANKL and osteoprotegerin (OPG) and on histopathologic and histometric changes in a rat periodontitis model.

MATERIAL AND METHODS

Twenty-four Wistar rats were divided into three groups of eight animals each: nonligated (NL); ligature only (LO); and ligature plus treatment with boric acid (BA) (3 mg/kg per day for 11 d). A 4/0 silk suture was placed in a subgingival position around the mandibular right first molars; after 11 d the rats were killed, and alveolar bone loss in the first molars was histometrically determined. Periodontal tissues were examined histopathologically to assess the differences among the study groups. RANKL and OPG were detected immunohistochemically.

RESULTS

Alveolar bone loss was significantly higher in the LO group than in the BA and NL groups (p < 0.05). The number of inflammatory infiltrate and osteoclasts in the LO group was significantly higher than that in the NL and BA groups (p < 0.05). The numbers of osteoblasts in LO and BA groups were significantly higher compared with NL group (p < 0.05). There were significantly more RANKL-positive cells in the LO group than in the BA and NL groups (p < 0.05). There was a higher number of OPG-positive cells in the BA group than in the LO and NL groups (p < 0.05).

CONCLUSION

The present study shows that systemic administration of boric acid may reduce alveolar bone loss by affecting the RANKL/OPG balance in periodontal disease in rats.