Since the first COVID-19 infected patient was identified in Spain in January 2020, the number of cases have rapidly increased with over 1,850,000 infected people as of December 20th [1]. Spain is a country with a high rate of migrants and consequently a significant number of non-natives have been affected by this disease [2]. Lower access to the health system and greater social vulnerability among other barriers have been linked with the differences in infection rates, need for hospitalization, and COVID-19-related death among migrants [3].
We aimed to evaluate if COVID-19 presentation and outcomes differed in migrants from those of Spanish natives. We characterize the first consecutive 486 migrant adult patients (defined as those citizens living in Spain but born in any other country) with confirmed SARS-CoV-2 infection hospitalized from February 25th (first cases admitted in our center) to April 19th, 2020 to La Paz University Hospital (Madrid), included in our previously described COVID19@HULP cohort [4]. The data were compared with those of 1740 Spanish natives admitted in the same time-period.
Among the 486 migrants, most were from South America (73.5%), mainly from Ecuador (27.7%), Peru (18.5%) and Colombia (14%). Median age was 47 years, 56.6% were female, and up to 65.4% had at least one comorbidity, mainly arterial hypertension (23.3%). Nearly 5% were admitted to ICU and 7% died during hospitalization (Table 1 ).
Table 1.
Area of origin of non-native COVID-19 infected patients and characteristics of native and non-native COVID-19 infected patients.
| Characteristics | All patients (n = 2226) | Native patients (n = 1740) | Non-Native patients (n = 486)b | P-value |
|---|---|---|---|---|
| Baseline and demographics | ||||
| Area of Origina, n (%c) | European regiond: 39 cases (1,7%); Romania (11), France (9), Bulgaria (5), Ukraine (4), Italy (3) and Germany Belgium, Poland, Portugal, United Kingdom, Russia, Switzerland (1 each) | |||
| Region of the Americas: 359 cases (16.1%); Ecuador (96), Peru (66), Colombia (50), Dominican Republic (31), Venezuela (23), Bolivia, Paraguay (21each), Honduras (13), Argentina (11), Chile (9), Cuba (7), Brazil (3), Mexico (2) and Canada, United States of America, Guatemala, Nicaragua, Panama, Uruguay (1 each) | ||||
| South-East Asia region: 5 cases (0.2%); Bangladesh (4), Vietnam (1) | ||||
| Eastern Mediterranean region: 17 cases (3.5%); Morocco (11), Syria (5), Pakistan (2) and Jordan, Occidental Sahara (1 each) | ||||
| Western Pacific region: 32 cases (1.4%); Philippines (29), China (3) | ||||
| African region: 3 cases (0.61%); Cameroon (2), Sudan (1) | ||||
| Age Median age, years [IQR] | 61 [46–78] | 68[52–81] | 47 [36–56] | <0.001 |
| Female, n (%) | 1151 (51.7) | 876 (50.3) | 275 (56.6) | n-s |
| Median time from disease onset to hospital admission, days [IQR] | 6 [3–9] | 6 [3–9] | 7 [4–10] | <0.001 |
| Comorbidities (at least one), n (%) | 1747 (78.5) | 1429 (82.1) | 318 (65.4) | <0.001 |
| Arterial hypertension | 920 (41.3) | 807 (46.4) | 113 (23.3) | <0.001 |
| Chronic heart disease | 429 (19.3) | 397 (22.8) | 32 (6.6) | <0.001 |
| Diabetes mellitus | 381 (17.1) | 316 (18.2) | 65 (13.4) | n-s |
| Obesitye | 242 (10.9) | 177 (10.2) | 65 (13.4) | n-s |
| Clinical presentation n (%) | ||||
| Fever | 1585 (71.2) | 1215 (69.8) | 370 (76.1) | n-s |
| Dry cough | 1373 (61.7) | 1025 (58.9) | 348 (71.6) | <0.001 |
| Headache | 427 (19.2) | 281 (16.1) | 146 (30.0) | <0.001 |
| Dyspnea | 1108 (49.8) | 831 (47.8) | 277 (57.0) | <0.001 |
| Anosmia | 284 (12.8) | 188 (10.8) | 96 (19.8) | <0.001 |
| Dysgeusia | 293 (13.2) | 187 (10.7) | 106 (21.8) | <0.001 |
| Respiratory status on admission | ||||
| Median SatO2% [IQR] | 95 [92–97] | 95 [92–97] | 96 [94–97] | <0.001 |
| SatO2 <90% n (%) | 234 (10.5) | 207 (11.9) | 27 (5.6) | <0.001 |
| Evolution | ||||
| Complications during hospitalization n (%) | ||||
| Kidney acute failure | 173 (7.8) | 157 (9.0) | 16 (3.3) | <0.001 |
| Any infection during admission | 119 (5.3) | 103 (5.9) | 16 (3.3) | n-s |
| Acute respiratory distress syndrome | 109 (4.9) | 91 (5.2) | 18 (3.7) | n-s |
| ICU admission n (%) | 75 (3.4) | 50 (2.9) | 25 (5.1) | n-s |
| Death n (%) | 460 (20.7) | 426 (24.5) | 34 (7.0) | <0.001 |
Abbreviations: ICU: Intensive care Unit; IQR: interquartile range; n-s: non-significant; SatO2, oxygen saturation.
Areas according to WHO Regions.
31 patients were classified as non-native, but no country of origin was documented.
Calculate on the basis of the total cohort of 2226.
Excluding people Spanish natives.
Obesity was defined as a body-mass index (the weight in kilograms divided by the square of the height in meters) of 30 or higher.
Compared to Spanish, infected migrants were younger and less likely to have comorbidities at presentation, were more likely to have dry cough, dyspnea, headache, ageusia and anosmia but less likely to have O2 saturation below 90% at admission, as. ICU admissions, although higher, didn't show statistical differences in both groups, whereas mortality was significantly lower in migrants. The multivariate analysis showed that being a migrant decreased the probability of dying (OR: 0.22; 95% CI 0.15–0.33; P < 0.001) after adjusting for sex, age and comorbidities. Of note, migrants represent 21.8% of all hospitalized patients in our cohort. This percentage far exceeds the proportion of non-native people living in the catchment area for our center, estimated in 15.1% [5]; those migrants frequently live in overcrowded households which facilitates transmission of SARS-CoV-2. It is necessary to study whether there are other specific factors predisposing migrants to be more vulnerable to this infection and its complications, as has been shown in other respiratory diseases [6].
We believe that, although the high rates of infection and consulting later than Spanish natives, being a younger and healthier population may have conditioned a more favorable outcome of the disease in this group. Despite these findings, the relatively small number of patients may lack sufficient statistical power to show differences between natives and non-natives. More diversity in the geographic origin of the migrants would contribute to the better characterization of the differences between the two groups.
Our study highlights the importance of studying the behavior of this disease in different populations to try to identify predictive factors that may impact on the clinical manifestations and evolution of the disease.
Funding
None.
Author contribution
- MDM designed the study, collected data, analyzed and interpreted data.
- ETE designed the study, collected data, analyzed and interpreted data.
- AMB designed the study, collected data, analyzed and interpreted data.
- MA designed the study, collected data.
- FdC designed the study, collected data.
- RMB designed the study, collected data.
- LM designed the study, collected data.
- JRA designed the study, collected data, analyzed and interpreted data.
- COVID@HULP Working Group designed the study, collected data.
Funding
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
Declaration of competing interest
None.
Acknowledgements
We want to thank María Jiménez González (UCICEC and FIBHULP of Hospital la Paz, Madrid), for statistical support.
References
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