We analyzed data from our three GP offices in rural Germany between the onset of Covid-19 in our country on 27.01.2020 until 20.04.2020. The mean age of our patients was 47.03 years, which is quite young considering that mortality seems to increase in COVID-19 patients beyond 65 years; patients less than 65 with little predisposing factors may be at a low risk of severe disease(5). Although we also treat more elderly patients in our offices, this observation may mean that oligosymptomatic patients directly stay at home to reduce their physical contacts, or in case of progressing symptoms, directly report to the clinic.
Only five out of 80 tested patients were positive for COVID-19 (positives). Due to this low number and a potential reporting bias of symptoms, we refrained from using mean comparison tests and only depicted absolute values. However, we noticed that almost all patients in the positives suffered from a sore throat (4/5; 80%), while only 12% in the negatively tested group (negatives) showed this symptom (9/75). Furthermore, rhinitis was more prominent in the positives (60% vs. 26.67%). Although results have to be interpreted with caution, these two symptoms may be clinically particularly relevant to assess probability for COVID-19 positivity.
Known comorbidities, especially pre-existing lung and cardiovascular disease, in positives and negatives were quite low (see Table 3). The most common cardiovascular risk factor was arterial hypertension, which has already been published(5). SARS-Cov2 uses ACE-2 as a cellular entry point(24) and has raised concern about continuation of RAAS inhibitor intake in patients with chronic heart failure(25). However, recent data has shown that there is no evidence of increased disease severity or mortality in hospitalized patients on RAAS blockers(26). Additionally, pharamcological data suggests that ACE-2 expression is not increased in patients on RAAS blockers(27). Thus, current recommendations support continuation of RAAS blockers in patients with arterial hypertension and chronic heart failure(25). In our study two out of five positively tested patients were on RAAS blockers and did not display more severe symptoms than the others. Also in the negatives RAAS blockers were the most commonly prescribed antihypertensive drugs (15 out of 23 patients received RAAS blockers) showing no difference in clinical severity.
We constantly tried to apply the algorithm provided by the RKI(23) to decide which patient needed a smear. However, it seems quite problematic to handle patients with persistent symptoms (mainly unproductive cough), who have been isolated and treated conservatively and who report to the office several times. A rather liberal management of smear-taking could be applied in persistent symptoms refractory to conservative methods, such as inhalation, analgetics and antiphlogistics. Although we would wish for a nationwide testing to get maximal clarity on the real number of positive, oligo- or asymptomatic COVID-19 patients, this vision is still hampered by limited availability of tests, especially in rural areas. Additionally, since a median incubation period of 5 days was estimated(28), the general practitioner will have difficulties to retrieve a patient’s contacts in the asymptomatic phase, which makes restriction of viral spread even more difficult.
Due to a reliable recall system from our offices, the clinic with the smear centre and the health department, we were able to confirm that none of the patients negatively tested for COVID-19 progressed to COVID-19 positivity later on. Those five patients tested positive were kept in quarantine for at least two weeks. If symptoms had resided by then, patients were allowed to take part in public life again. In case of persisting symptoms quarantine was upheld and ambulatory medical services were sent to examine the patients whenever necessary. Moroever, due to regular communication with the local health department we can confirm that none of the patients who were sent home without a smear and treated conservatively, experienced symptom progression, which would have forced us to organize a smear. In summary, the communication between GP offices, hospitals with smear centres and the health department is satisfactory to ensure the best possible patient care, despite the limited smear capacity. In the future, wearables, such as smartwatches, may improve patient surveillance by constantly recording vitals and providing feedback about potential health deteriorations at home. For GPs this would be a great opportunity to improve patient care.
In Germany we have a health system based on solidarity, in which most people have health insurance and thus have easy access to health care. GP’s, usually as the first medical contacts, have to filter many patients directly in the office. The Center for Disease Control (CDC) has issued similar recommendations for the public as the RKI in Germany, namely (1) to cover mouth and nose with a cloth, (2) call the GP’s office first instead of showing up directly, (3) not to get in close physical contact to others and (4) engage in regular desinfection of hands and surfaces, (5) and self-monitor symptoms(29).
The death rate of SARS-Cov2 is currently 4.1%, almost 90% are over 70 years of age. The rate of infection in the high risk cohort of elderly (> 80) patients is still rising in Germany (approximately 300 per 100.000 inhabitants in the group 80–89 years and 475 in the group 90-99years, as per 23.04.2020)(30), but testing frequency is declining again (peak: 30.03–05.04.2020 > 400.000 tests in Germany, 13.04–19.04.2020: 320.000 tests)(30). This generates fear of a „second wave“ of infection. Similar to Germany, the CDC reported that 80% of deaths occurred in the age group > 65 years(29).
A fast incline of infection rates has occurred in Germany in February 2020, while in the US infections have risen in April (as per 21.04.2020: 802.583 total cases, 44.575 total deaths)(29) and GP’s in the States will be facing the same enormous logistic problems as in Germany earlier in the year. The paramount aim of medical personnel in this crisis is to maintain optimal medical care and personal health in a high-risk environment. Thus, stringent algorithms for GP’s and other medical specialties need to be introduced to achieve this goal. By segregating patients suggestive of respiratory infection and treating them under high standards of hygiene and protection, we believe that we have achieved this goal in a practicable and efficient manner. Until the date of submission, none of our employees called in sick, which may suggest that our stringent selection process prior to entering the office is a success. Our experience could now help colleagues in other countries with a later onset of COVID- 19 than Germany to organize their offices with the available resources. Transparency of strategies from different countries on how to deal with COVID-19 in inpatient and ambulatory settings is of paramount importance to optimize further patient care and improve educational measures(31).
Lung ultrasound seems to be a very promising tool to detect COVID-19, since it has been shown that B-lines are present in early stages of the disease. Later hyperechoic images, called „white lung“, and finally consolidation can be found in lung imaging(32). Although B-lines are not specific for COVID-19 they can easily be assessed by trained sonogrophaphers and can and should be be established in emergency departments and outpatient (GP) care.
Our data shows that it is not possible to accurately differentiate between oligosymptomatic COVID-19 patients and ordinary respiratory infection by analyzing symptoms alone. A few days ago, Arons et al. published the spread of COVID- 19 in a US nursing home, in which more than half of positively tested patients were asymptomatic(33, 34). This clearly demonstrates that strategies focusing only on symptoms fail to prevent further transmission. Since the capacity of testing is limited, we suggest the introduction of a new scoring system to stratify patients for COVID-19 that should be tested. This scoring system should embrace the established clinical signs of (unspecific) respiratory symptoms. The two symptoms sore throat and rhinitis clearly prevailing in positively tested patients should be used as essential symptomatic markers to stratify for obligatory testing. Known risk factors, such as arterial hypertension, chronic obstructive lung disease and immunosuppression should be additional selection criteria for essential testing. Contact to infected patients and working in high risk areas (such as the medical profession itself) and sonographic signs of lung damage (e.g. B-lines, consolidations) should also be essential components of the score.
We provide a combinatorial score to pre-clinically estimate the risk of SARS-Cov2 infection (Fig. 2). Given the recent observations that sonography is an easy and reliable method to assess suspicion of COVID19, we here add pulmonary sonography as an integral part in our proposed scorings system to stratify patients with unclear respiratory infections for obligatory Cov2 PCR testing.
We awarded 2 points each for sonographic signs of parenchymal or interstitial pulmonary infiltration, suggestive of pneumonia or edema/congestion. 65 years as a cut-off is arbitrary, but Wang et al. (2020) showed that severe COVID-19 infection is rare below 65, which may justify this value(5). We suggest that a total score > 5 points justifies to send patients to Cov2-PCR testing. This means that, theoretically, an asymptomatic patient could qualify for PCR, if there are enough risk factors (disease and environment); this was also demonstated by Arons et al.(34) We suggest to verify our 20 point-model in a larger cohort of suspected COVID-19 patients. The development and improvement of such a new combinatorial score as proposed here will help GP’s to better stratify patients for necessary testing than current suggestions.