Illness tracking in SARS-CoV-2 tested persons using a smartphone app: a non-interventional, prospective, cohort study

There are few data on the range and severity of symptoms of SARS-CoV-2 infection or the impact on life quality in infected, previously healthy, young adults such as Swiss Armed Forces personnel. It is also unclear if an app can be used to remotely monitor symptoms in persons who test positive. Using a smartphone app called ITITP (Illness Tracking in Tested Persons) and weekly pop-up questionnaires, we aimed to evaluate the spectrum, duration, and impact of symptoms reported after a positive SARS-CoV-2 test according to sex, age, location, and comorbidities, and to compare these to responses from persons who tested negative. We followed up 502 participants (57% active participation), including 68 (13.5%) positive tested persons. Hospitalisation was reported by 6% of the positive tested participants. We found that positives reported significantly more symptoms that are typical of COVID-19 compared to negatives. These symptoms with odds ratio (OR > 1) were having difficulty breathing (OR 3.35; 95% CI: 1.16, 9.65; p = 0.03), having a reduced sense of taste (OR 5.45; 95% CI: 1.22, 24.34; p = 0.03) and a reduced sense of smell (OR 18.24; 95% CI: 4.23, 78.69; p < 0.001). Using a random forest model, we showed that tiredness was the single symptom that was rated as having a significant impact on daily activities, whereas the other symptoms, although frequent, had less impact. The study showed that the use of an app was feasible to remotely monitor symptoms in persons infected with SARS-CoV-2 and could be adapted for other settings and new pandemic phases such as the current Omicron wave.

Infectious diseases among travellers and migrants in Europe, EuroTravNet 2010

To investigate trends in travel-associated morbidity with particular emphasis on emerging infections with the potential for introduction into Europe, diagnoses of 7,408 returning travellers presenting to 16 EuroTravNet sites in 2010 were compared with 2008 and 2009. A significant increase in reported Plasmodium falciparum malaria (n=393 (6% of all travel-related morbidity) vs. n=267 (4%) and 296 (5%); p<0.001), P. vivax malaria (n=53 (1%) vs. n=31 (0.5%) and 39 (1%); p=0.038) and dengue fever (n=327 (5%) vs. n=131 (2%) and 172 (2%); p<0.001) was observed. Giardia lamblia was identified in 16% of patients with acute diarrhoea, with no significant annual variation. The proportion of acute diarrhoea due to Campylobacter increased from 7% in 2008 to 12% in 2010 (p=0.002). We recorded 121 patients with pulmonary tuberculosis in 2010, a three-fold increase in the proportionate morbidity from 2008 to 2010. In 2010, 60 (0.8%) cases of chronic Chagas disease, 151 (2%) cases of schistosomiasis and 112 (2%) cases of cutaneous larva migrans were reported. Illness patterns in sentinel travellers, captured by EuroTravnet, continue to highlight the potential role of travellers in the emergence of infectious diseases of public health concern in Europe and the relevance of offering medical travel advice and enforcing specific and adequate prophylaxis.*

Infectious diseases among travellers and migrants in Europe, EuroTravNet 2010

To investigate trends in travel-associated morbidity with particular emphasis on emerging infections with the potential for introduction into Europe, diagnoses of 7,408 returning travellers presenting to 16 EuroTravNet sites in 2010 were compared with 2008 and 2009. A significant increase in reported Plasmodium falciparum malaria (n=361 (6% of all travel-related morbidity) vs. n=254 (4%) and 260 (5%); p<0.001), P. vivax malaria (n=51 (1%) vs. n=31 (0.5%) and 38 (1%); p=0.027) and dengue fever (n=299 (5%) vs. n=127 (2%) and 127 (2%); p<0.001) was observed. Giardia lamblia was identified in 16% of patients with acute diarrhoea, with no significant annual variation. The proportion of acute diarrhoea due to Campylobacter increased from 7% in 2008 to 12% in 2010 (p=0.001). We recorded 121 patients with pulmonary tuberculosis in 2010, a threefold increase in the proportionate morbidity from 2008 to 2010. In 2010, 60 (0.8%) cases of chronic Chagas disease, 151 (2%) cases of schistosomiasis and 112 (2%) cases of cutaneous larva migrans were reported. Illness patterns in sentinel travellers, captured by EuroTravnet, continue to highlight the potential role of travellers in the emergence of infectious diseases of public health concern in Europe and the relevance of offering medical travel advice and enforcing specific and adequate prophylaxis.

Travel-related imported infections in Europe, EuroTravNet 2009

The aim of this study was to investigate travel-associated morbidity in European travellers in 2009 in comparison with 2008, with a particular emphasis on emerging infectious diseases with the potential for introduction into Europe. Diagnoses with demographic, clinical and travel-related predictors of disease from ill returning travelers presenting to 12 core EuroTravNet sites from January to December 2009 were analysed. A total of 6392 patients were seen at EuroTravNet core sites in 2009, as compared with 6957 in 2008. As compared with 2008, there was a marked increase in the number of travellers exposed in North America and western Europe. Respiratory illnesses, in particular pandemic A(H1N1) influenza, influenza-like syndromes, and tuberculosis, were also observed more frequently. A significant increase in reported dengue cases in 2009 as compared with 2008 was observed (n = 172, 2.7% vs. n = 131, 1.90%) (p 0.002). The numbers of malaria and chikungunya cases were also increasing, although not significantly. Two deaths were recorded: visceral leishmaniasis and sepsis in a Sudanese migrant, and Acinetobacter sp. pneumonia in a patient who had visited Spain. This is the most comprehensive study of travel-related illness in Europe in 2009 as compared with 2008. A significant increase in travel-related respiratory and vector-borne infections was observed, highlighting the potential risk for introduction of these diseases into Europe, where competent vectors are present. The number of traveller deaths is probably underestimated. The possible role of the travellers in the emergence of infectious diseases of public health concern is highlighted.

The practice of travel medicine in Europe

Europe, because of its geographical location, strategic position on trade routes, and colonial past, has a long history of caring for travellers' health. Within Europe, there is great diversity in the practice of travel medicine. Some countries have travel medicine societies and provisions for a periodic distribution of recommendations, but many countries have no national pre-travel guidelines and follow international recommendations such as those provided by the WHO. Providers of travel medicine include tropical medicine specialists, general practice nurses and physicians, specialist 'travel clinics', occupational physicians, and pharmacists. One of the core functions of the European Centre for Disease Prevention and Control-funded network of travel and tropical medicine professionals, EuroTravNet, is to document the status quo of travel medicine in Europe. A three-pronged approach is used, with a real-time online questionnaire, a structured interview with experts in each country, and web searching.

Imported human African trypanosomiasis in Europe, 2005-2009

Physicians in Europe are likely to see more African trypanosomiasis cases because of the increasing popularity of travel to Africa. In this paper the literature on imported cases in Europe, since 2005 is reviewed. Because of the high mortality risk associated with acute Rhodesian trypanosomiasis, travellers should be informed about preventive measures and the early disease manifestations.

Imported human African trypanosomiasis in Europe, 2005-2009

Physicians in Europe are likely to see more African trypanosomiasis cases because of the increasing popularity of travel to Africa. In this paper the literature on imported cases in Europe, since 2005 is reviewed. Because of the high mortality risk associated with acute Rhodesian trypanosomiasis, travellers should be informed about preventive measures and the early disease manifestations.

Effectiveness and tolerability of melatonin and zolpidem for the alleviation of jet lag

BACKGROUND

The aim of this study was to compare the effectiveness and tolerability of a chronobiotic (melatonin) with a hypnotic (zolpidem) and the combination of both substances to alleviate jet lag symptoms associated with eastward travel.

METHODS

This double-blind, randomized, placebo-controlled study is based on 137 volunteers flying from Switzerland to the American continent and back (6-9 time zones). The participants either received melatonin 5 mg (n = 35), zolpidem 10 mg (n = 34), a combination thereof (n = 29) or placebo (n = 39) on the eastbound flight back to Switzerland and once daily at bedtime on 4 consecutive days after the flight. The test battery included daily sleep logs, symptoms questionnaires, and the Profile of Mood States (POMS). Also, on the last treatment day, Visual Analog Scales (VAS) were completed to assess overall jet lag ratings and treatment effectiveness. Baseline data were collected on 4 consecutive days 2 wk after the flight. During post-flight treatment and baseline, motor activity was assessed in a subgroup of 49 subjects using wrist-worn ambulatory monitors.

RESULTS

The self-rated sleep quality was significantly improved by zolpidem, especially during the night flight. Subjects taking zolpidem reported significantly less jet lag and zolpidem was rated as the most effective jet lag medication. However, zolpidem and the combination melatonin/zolpidem were less well tolerated than melatonin alone; adverse event reports included nausea, vomiting, amnesia and somnambulia to the point of incapacitation. Confusion, morning sleepiness and nausea were highest in the combination group.

CONCLUSIONS

All active treatments led to a decrease of jet lag severity with zolpidem being the most effective treatment, particularly in facilitating sleep on night flights. Potential individual adverse reactions to this hypnotic have to be considered.

[Malaria--chemoprophylaxis 2001]

An estimated 20,000 to 30,000 cases of imported malaria are annually diagnosed in industrialised countries. Some 700 of them concern Swiss travellers and foreign guests. Exposure prophylaxis and chemoprophylaxis for high risk destinations lower the risk of malarial disease. The latter is defined as regular intake of antimalarial drugs in subtherapeutic dosage in order to suppress the development of clinical disease. Drugs are usually taken from one week before travel until four weeks after return from an endemic area. Mefloquine, doxycycline, chloroquine plus proguanil, and presumably soon also atovaquone plus proguanil are available in Switzerland for chemoprophylaxis.

Mefloquine for malaria chemoprophylaxis 1992-1998: a review

Mefloquine is an orally administered blood schizontocide for the chemoprophylaxis of malaria in nonimmune travelers. New pharmacokinetic data has shown that food increases the bioavailability of mefloquine. Steady-state pharmacokinetics of weekly prophylaxis in long term travelers have shown that toxic accumulation does not occur and that weekly dosing is associated with protective levels of the drug. The pharmacokinetics of mefloquine are highly stereospecific and all pharmacokinetic parameters, except tmax are significantly different for the (+) and (-) enantiomers. Mefloquine and its metabolite are not appreciably removed by hemodialysis. Steady-state levels of mefloquine can be attained in a reduced time frame of 4 days compared to 7-9 weeks using a loading dose strategy of 250 mg mefloquine daily for 3 days followed thereafter by weekly mefloquine dosage. This strategy, is however, associated with a higher incidence of an adverse event (AE). Cumulative evidence suggests a high protective efficacy of mefloquine (>91%) in nonimmune travelers to areas of chloroquine resistant Plasmodium falciparum (CRPF) except for clearly defined regions of multi-drug resistance. Reports from sub-Saharan Africa indicate a low but increasing level of resistance to this drug. Mefloquine resistance is associated with halofantrine and quinine resistance but not with chloroquine resistance. Penfluridol has been shown to reverse P. falciparum mefloquine resistance in vitro. There is some controversy regarding the tolerabilty of mefloquine for malaria chemoprophylaxis. A review of the studies conducted during 1992-1998 shows that in the reporting of any AE the incidence lies in the range (12-90%) and where there is a comparator, is equivalent to the incidence reported for almost all alternative regimens. When some measure of subjective severity is applied to the rating of AE, it appears that 11-17% of travelers are, to some extent, incapacitated by AE. Major studies and worldwide monitoring have shown that serious events are rare. A recent meta-analysis showed that rates of withdrawal and overall incidence of AE with mefloquine were not significantly higher than those observed with comparator regimens except that mefloquine was more likely to cause insomnia and fatigue. Withdrawals in mefloquine arms were higher than in placebo arms. No performance deficit or functional impairment was observed in five clinical toxicity studies of mefloquine prophylaxis, including a study of driving performance. There is limited data regarding use of mefloquine in pregnancy. Early animal studies have documented teratogenic and embryotoxic effects associated with the use of high dose mefloquine. Two studies have shown a relatively high incidence of spontaneous abortions in mefloquine users. Cumulative evidence, however, is reassuring and has led the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC) to sanction the use of mefloquine in pregnant women during the second and third trimesters. In conclusion, mefloquine prophylaxis is recommended for travelers to high risk areas of chloroquine resistant Plasmodium falciparum. The risk of malarial infection and the proven efficacy of mefloquine to prevent malaria should be weighed against the risk of drug associated adverse events.

Feasibility of a rapid dipstick antigen-capture assay for self-testing of travellers' malaria

This open comparative study sought to determine whether, and with what level of instruction, travellers can successfully use and interpret the rapid whole blood malaria diagnostic test, ParaSight F. 160 visitors to the Zürich University Travel Clinic took part in the study. One group received written instructions only, while another group was given combined oral and written instructions on how to test their own blood for malaria infection and interpret a series of 5 prepared test strips. Each volunteer also completed a questionnaire targeted at assessing performance in using the diagnostic, interpretation of the results and acceptability of the concept of self-testing for malaria infection. The main outcome measures were successful performance of the test, correct interpretation of prepared test strips and acceptability of the test. In the group which received only written instructions, 60/80 (75%) were successful, whilst in the group which received written and oral instructions, 72/80 (90%) successfully performed the test (P < 0.02). Overall, 565 (70.6%) test strips were correctly and 165 (20.6%) incorrectly interpreted with 113 (14.1%) false negative interpretations. No prepared test strip was interpreted as false positive. Seventy (8.8%) test strips were not interpreted. Some 91. 9% of all candidates would use such a test if it were available. While it is possible for lay persons to successfully perform the test, interpretation of results poses a problem. In particular, the proportion of false negative interpretations is unacceptable. A combination of written and oral instructions leads to a significantly higher level of successful test performance. If such a test is to be made available to the general public, written instructions must be made concise and foolproof and the test endpoint clearly defined, as the currently available test is more suitable for trained laboratory personnel. In the meantime other candidate diagnostics have become available and these should now be assessed for their suitability in the context of travellers' malaria.

MalaQuick versus ParaSight F as a diagnostic aid in travellers' malaria

In this study we assessed whether travellers can perform malaria rapid tests, following the provided information leaflet, and correctly interpret performed and pre-prepared test strips. Two Plasmodium falciparum testing systems, namely MalaQuick (ICT) and ParaSight F were used. Test performance and test interpretation of pre-prepared tests were compared. There was no significant difference in test performance between the 2 tests. Interpretation of prepared test strips in both test systems was very reliable in blood parasite densities between 0.1% and 2%, but major problems were encountered at low parasitaemia (< 0.1% blood parasites) and also in ParaSight F test strips showing high parasitaemia (> 2% blood parasites). Low parasitaemia ParaSight F test strips were correctly interpreted by 52.1% compared with 10.8% correct interpretations with MalaQuick (P < 0.0001). Correct interpretation of highly positive (> 2% blood parasites) pre-prepared test strips was higher with MalaQuick (96.8%) than with ParaSight F (33.8%), P < 0.0001. Both tests were associated with high levels of false-negative interpretations which render them unsuitable as self-diagnostic kits. Efforts must be made to assist lay individuals in test performance by technical test improvement, by equiping the test strips with an additional reading aid for interpretation, and by providing instruction by a skilled person.

Imported malaria (1985-95): trends and perspectives

Malaria is frequently imported into nonendemic industrialized areas. In this study we collated data on the reported malaria cases in industrialized countries during the period 1985-95, with the object of identifying trends and promising strategies. The main outcome measures were incidence, case-fatality rates (CFRs), and attack rates in tourists returning from Kenya. Our survey showed gross underreporting and marked heterogeneity in the type and availability of national data. The total incidence or reported numbers of malaria infections in Europe increased from 6840 in 1985 to 7244 in 1995, with a peak of 8438 in 1989. The principal importing countries were France, Germany, Italy, and the United Kingdom. In the former USSR, the reported annual incidence dropped from 1145 in 1989 to 356 in 1990 after cessation of activities in Afghanistan. Among the imported species of malaria parasite, Plasmodium falciparum was identified in an increasing proportion, the CFR ranging from 0% to 3.6%, with consistently high rates in Germany. The attack rates among travellers to Kenya in 1990-95 were high, ranging from 18 to 207 per 100,000 travellers. Our findings indicate that in industrialized countries malaria is associated with a high CFR and remains a public health problem. Irregular surveillance and lack of homogeneity in the collected data hinder the assessment of incidences, risk groups, and the efficacy of chemoprophylaxis.

Comparative study to determine the optimal melatonin dosage form for the alleviation of jet lag

To compare the impact of various dosage forms of melatonin and placebo on jet lag symptoms, 320 volunteers who had flights over 6 to 8 time zones were recruited for a double-blind, randomized, placebo-controlled study. The volunteers received either melatonin 0.5-mg fast-release (FR) formulation, melatonin 5-mg FR formulation, melatonin 2-mg controlled-release (CR) formulation, or placebo. The study medication was taken once daily at bedtime during 4 days after an eastward flight. The volunteers completed the Profile of Mood States (POMS), sleep log, and symptoms questionnaires once daily and the Karolinska Sleepiness Scale (KSS) three times daily prior to departure and during the 4 days of medication intake postflight. A total of 234 (73.1%) participants were compliant and completed the study. The FR melatonin formulations were more effective than the slow-release formulation. The 5-mg FR formulation significantly improved the self-rated sleep quality (p < .05), shortened sleep latency (p < .05), and reduced fatigue and daytime sleepiness (p < .05) after intercontinental flight. The lower physiological dose of 0.5 mg was almost as effective as the pharmacological dose of 5.0 mg. Only the hypnotic properties of melatonin, sleep quality and sleep latency, were significantly greater with the 5.0-mg dose.

Impact of melatonin on driving performance

BACKGROUND

Because millions of people are self-prescribing melatonin for various indications, the safety aspects of this substance have become very important. The aim of our study was to determine whether or not melatonin impairs driving-related performance.

METHODS

Twenty healthy men and women aged 21-57 years volunteered for this randomized, placebo-controlled, double-blind, crossover study. The crossover arms were separated by an interval of at least 4 weeks. On each testing day, melatonin 5 mg or placebo was taken at 1630 h; 60 minutes later a test series was performed, consisting of a medical examination, body sway measurement, and a standardized driving computer test battery to assess attention, reaction time, power of concentration, and sensomotor coordination. Subjective sleepiness was measured on three occasions during the test session using the Stanford Sleepiness Scale questionnaire.

RESULTS

Just one of the 16 main variables of the driving computer test battery, the selective attention tested by signal-detection, was significantly affected by melatonin (p &lt; .05). However, even those values were still within the normal range. Subjective sleepiness was increased by melatonin, although the result was significant only after the prolonged concentration task (p &lt; .05). Neither the clinical examination nor the body sway test showed signs of any drug influence.

CONCLUSIONS

The overall result of the computer test battery showed no objective adverse impact of melatonin on driving performance. However, due to the increased subjective sleepiness after administration of this hormone, caution should be exercised when driving under the influence of melatonin.

Tolerance of mefloquine by SwissAir trainee pilots

Due to presumed adverse performance impact, a World Health Organization clause currently restricts the use of mefloquine malaria chemoprophylaxis in individuals requiring fine coordination and spatial discrimination. We conducted a double-blind, placebo-controlled, cross-over study to quantitatively assess the effects of mefloquine at steady state on performance in 23 trainee airline pilots. Flying performance was assessed using a flight simulator, psychomotor function was evaluated, sleep and wake cycles were monitored, and symptoms and moods were assessed using standardized questionnaires. A simplified postural sway meter recorded sway in three test positions. In the mefloquine loading dose phase, there was one withdrawal due to dizziness, diarrhea, and flu-like symptoms, and three volunteers reported nonserious, sleep-related adverse events. There was no significant difference in flying performance, psychomotor functions, or mean sway for any test position. Nonsignificant reductions in mean total nocturnal sleep (mefloquine = 450 min versus placebo = 484 min) and poorer sleep quality were detected in the mefloquine phases. The mood findings indicated a predominance of positive states, with vigor the predominant mood in all phases. No significant performance deficit was documented under laboratory conditions during use of mefloquine at steady state.

Mefloquine tolerability during chemoprophylaxis: focus on adverse event assessments, stereochemistry and compliance

This longitudinal study of travellers to Africa taking mefloquine (MQ) chemoprophylaxis aimed to quantify and assess non-serious adverse events (AE) occurring during short-term prophylaxis and relate these to concentrations of racemic MQ, its enantiomers and metabolite. A total of 420 volunteers (52% F) participated. AEs with some impact on activities were reported by 11.2% of participants including 7.9% of neurological/psychiatric symptoms. Women were more likely to report AEs (P = 0.02). The standardized questionnaires used showed more pathological indicators in travellers who reported subjective AE with significantly more dizziness, distress, sleep disturbances and a high total mood disturbance (TMD) in the AE group. There was, however, no significant performance deficit in computerized psychomotor tests in those experiencing AE. Furthermore, no significant differences were observed in enantiomer ratios, metabolite concentrations, or racemic MQ levels in participants with or without AEs suggesting that these factors are not the main predictors of mefloquine intolerability.

Behavioural aspects of travellers in their use of malaria presumptive treatment

The use of stand-by treatment for malaria by travellers depends on their knowledge, attitudes and behaviour. We examined the behavioural aspects of a cohort of travellers from Switzerland to low-risk malarial areas who, on recruitment, were provided with a kit containing medication for stand-by treatment, guidelines on the diagnosis of malaria, and materials for collection of blood samples for later confirmation of malaria. All subjects were urged to seek medical advice at the first signs of possible malarial symptoms. Illness (fever as the main indicator) was reported by 123 of the 1187 participants, often accompanied by shivering/chills (36.6%), headache (35.0%), gastrointestinal symptoms (69.9%), and myalgia and/or arthralgia (41.5%). Two-thirds of those ill failed to seek medical attention despite their symptoms and pretravel advice. Only 9 (7.3%) were actually beyond the reach of medical attention. The stand-by treatment was self-administered by 6 travellers, only one of whom had confirmed malaria. Two non-serious adverse events were reported. All users consulted a physician after administering the presumptive treatment. This stand-by approach is limited by inappropriate behaviour and poor malaria awareness among travellers. These negative factors can be mitigated by development of an improved kit containing a simple test for self-diagnosis.

Stand-by treatment of malaria in travellers: a review

Stand-by treatment is the use of anti-malaria drugs carried for self-administration when fever and flu-like symptoms occur and prompt medical attention is not available. This paper aims to review the rationale for the stand-by therapy concept, the range of options available, the factors influencing the choice of therapy and the efficacy and toxicity of the various agents available in the light of ever increasing resistance to conventional drugs. The use of chloroquine as a possible stand-by treatment is limited because of widespread chloroquine resistance and the problem is further compounded by the increasing prevalence of parasites resistant to antifolate/sulpha drug combinations, particularly in South-East Asia and South America. Mefloquine is a promising agent for presumptive malarial treatment with limited foci of drug resistance, notably in Thailand. Mefloquine therapy has been associated with adverse events, mostly minor but with occasional neuropsychiatric events. The use of halofantrine, hitherto often recommended as a stand-by treatment, has been curtailed after recent research reports demonstrated that the drug may cause prolongation of the QTc interval. Current experience with stand-by therapy is limited and studies are in progress to elucidate the exact circumstances under which travellers actually use their emergency medication. Stand-by treatment is an option for clearly defined situations while prophylaxis remains the safest choice for travellers to areas of high transmission.

Mefloquine compared with other malaria chemoprophylactic regimens in tourists visiting east Africa

There is much confusion over which malaria chemoprophylaxis should be used in areas such as East Africa. We did two consecutive studies between 1985 and 1991 to assess the efficacy and side-effects of malaria chemoprophylaxis in short-term travellers to East Africa. All passengers returning from Kenya to Europe received an in-flight questionnaire and a second one three months later. Any report of documented malaria or of admission to hospital for possible side-effects was verified with the physician. 145 003 travellers completed questionnaires. Among the 139 164 who stayed in East Africa for less than one year, 296 cases of confirmed malaria were reported (275 due to P falciparum). In people who used no chemoprophylaxis, the incidence of falciparum malaria was 1.2% per month. Prophylactic effectiveness was 91% (95% Cl 85 to 94) for mefloquine, 82% (71 to 89) for pyrimethamine and sulfadoxine, 72% (56 to 82) for chloroquine plus proguanil, and 10 to 42% for chloroquine at various doses. Rates of side-effects, which were usually mild, were 18.8% for mefloquine users, 17.1% and 18.6% for chloroquine 300 mg and 600 mg base per week, respectively, 30.1% for chloroquine plus proguanil, and 11.7% for sulfadoxine and pyrimethamine. Mefloquine is significantly more effective than chloroquine plus proguanil for malaria prophylaxis in short-term tourists visiting East Africa and has a tolerance similar to that of chloroquine used alone.