SARS-CoV-2 screening strategies for returning international travellers: Evaluation of a rapid antigen test approach.

BACKGROUND: International travel poses the risk of importing SARS-CoV-2 infections and introducing new viral variants into the country of destination. Established measures include mandatory quarantine with the opportunity to abbreviate it with a negative rapid antigen test (RAT). METHODS: A total of 1,488 returnees were tested for SARS-CoV-2 with both PCR and RAT no earlier than 5 days after arrival. We assessed the sensitivity and specificity of the RAT. Positive samples were evaluated for infectivity in vitro in a cell culture outgrowth assay. We tracked if participants who tested negative were reported positive within 2 weeks of the initial test. RESULTS: Potential infectiousness was determined based on symptom onset analysis, resulting in a sensitivity of the antigen test of 89% in terms of infectivity. The specificity was 100%. All positive outgrowth assays were preceded by a positive RAT, indicating that all participants with proven in vitro infectivity were correctly identified. None of the negative participants tested positive during the follow-up. CONCLUSIONS: RAT no earlier than the 5th day after arrival was a reliable method for detecting infectious travellers and can be recommended as an appropriate method for managing SARS-CoV-2 travel restrictions. Compliance to the regulations and a high standard of test quality must be ensured.

Two cases of airport-associated falciparum malaria in Frankfurt am Main, Germany, October 2019.

Two cases of presumably airport-acquired falciparum malaria were diagnosed in Frankfurt in October 2019. They were associated with occupation at the airport, and Plasmodium falciparum parasites from their blood showed genetically identical microsatellite and allele patterns. Both had severe malaria. It took more than a week before the diagnosis was made. If symptoms are indicative and there is a plausible exposure, malaria should be considered even if patients have not travelled to an endemic area.

Dynamic cerebral autoregulation in pregnancy and the risk of preeclampsia.

Preeclampsia may affect severely the cerebral circulation leading to impairment of cerebral autoregulation, edema, and ischemia. It is not known whether impaired autoregulation occurs before the clinical onset of preeclampsia, and whether this can predict the occurrence of preeclampsia. Seventy-two women at 25 to 28 weeks of gestation were studied. Control values were derived from 26 nonpregnant women. Dynamic properties of cerebral autoregulation (DCA) were measured in the middle and posterior cerebral artery using transcranial Doppler and transfer function analysis (phase and gain) of respiratory-induced 0.1 Hz hemodynamic oscillations. Uterine artery ultrasound was performed to search for a notch sign as an early marker of general endothelial dysfunction. All women were followed up until 6 weeks after delivery for the occurrence of preeclampsia. The autoregulation parameter gain did not differ between pregnant and nonpregnant women. Phase was slightly but significantly higher in pregnant women, indicating better DCA. Women with a notch sign did not show altered DCA. A history of preeclampsia during a previous pregnancy was associated with lower phase in middle cerebral artery and posterior cerebral artery (P<0.05 each). During follow-up, 9 women developed preeclampsia. None of the DCA parameters were associated with the occurrence of preeclampsia. In conclusion, DCA is well preserved during late midterm pregnancy, even in women with disturbed uterine blood flow. Yet, pregnant women with preeclampsia in a previous pregnancy seem to have poorer DCA. Although limited in statistical power, this study does not support DCA as a strong early risk marker of preeclampsia.

Cerebellar and cerebral autoregulation in migraine.

BACKGROUND AND PURPOSE: Silent ischemic brain lesions frequently occur in migraine with aura and are most often located in cerebellar border zones. This may imply an impairment of cerebellar blood flow autoregulation. This study investigated the characteristics of interictal cerebellar autoregulation in migraine with and without aura. METHODS: Thirty-four patients (n=17, migraine without aura; n=17, migraine with aura) and 35 age- and sex-matched controls were studied. Triple simultaneous transcranial Doppler monitoring of one posterior inferior cerebellar artery, right posterior cerebral artery, and left middle cerebral artery was performed. Autoregulation dynamics were assessed from spontaneous blood pressure fluctuations (correlation coefficient index Dx) and from respiratory-induced 0.1-Hz blood pressure oscillations (phase and gain). RESULTS: Compared with controls, the autoregulatory index Dx was higher (indicating less autoregulation) in the posterior inferior cerebellar artery (P=0.0062) and middle cerebral artery (P=0.0078) in migraine with aura, but not in migraine without aura. Phase and gain did not significantly differ between migraine patients and controls. No significant associations of autoregulation with clinical factors were found, including frequency of migraine attacks and orthostatic intolerance. CONCLUSIONS: This first-time analysis of cerebellar autoregulation in migraine did not show a specific cerebellar dysautoregulation in the interictal period. More static autoregulatory properties (index Dx) are, however, impaired in persons with migraine with aura both in the cerebellar and anterior circulation. The cerebellar predilection of ischemic lesions in migraine with aura might be a combination of altered autoregulation and additional factors, such as the end artery cerebellar angioarchitecture.