Table 1 Summary of characteristics of included 64 studies
From: Evaluation of viral infection as an etiology of ME/CFS: a systematic review and meta-analysis
Items | N. of study | N. ME/CFS case | N. Control |
|---|---|---|---|
(Healthy or 10 Diseases) | |||
Number of participants | 64 | 4971 (77.6 ± 61.8) | 5564 (87.2 ± 106.9) |
Male/femalea | Â | 807/1974 | 1165/1503 |
Enveloped virus | |||
 DNA virus | |||
  HHV familyb | 24 | 1694 | 1318 (5) |
  HHV-6 | 24 | 1694 | 1318 (5) |
  HSV-1 | 3 | 422 | 184 (2) |
  HSV-2 | 2 | 522 | 168 (2) |
  EBV | 14 | 1301 | 1108 (5) |
  CMV | 7 | 974 | 606 (4) |
  VZV | 2 | 272 | 178 (2) |
 RNA virus | |||
  BDV | 3 | 321 | 338 (2) |
  Hepatitis C virus | 1 | 36 | 14 (1) |
 Retrovirus | |||
  XMRV | 25 | 1579 | 2335 (9) |
  Retrovirus | 8 | 240 | 363 (2) |
Non-enveloped virus | |||
 DNA virus | |||
  Parvovirus B19 | 6 | 553 | 439 (1) |
  JC virus | 1 | 22 | 22 (1) |
  BK virus | 1 | 22 | 22 (1) |
 RNA virus | |||
  Enterovirus | 5 | 533 | 264 (3) |
  Coxsackie B virus | 1 | 290 | 500 (1) |
Detection methodc | |||
 DNA detection (PCR) | 42 | 3035 | 4863 |
 RNA detection (PCR) | 10 | 800 | 913 |
 Antibody detection | 33 | 2755 | 5916 |
 Antigen detection | 5 | 414 | 281 |
CFS criteriad | |||
 Fukuda | 40 | 3559 | – |
 Holmes | 10 | 342 | – |
 Canadian | 8 | 745 | – |
 Oxford | 3 | 137 | – |
 2015 IOM | 1 | 166 | – |
 Others | 5 | 359 | – |
 Unknown | 3 | 362 | – |
Publication year | |||
 1988–1999 | 23 | 1451 | 1668 |
 2000–2009 | 11 | 636 | 477 |
 2010–2022 | 30 | 2884 | 3440 |
Continent (N) | Â | Â | Â |
 Europe | 28 | 2804 | 2802 |
 North America | 27 | 1688 | 1653 |
 Asia | 9 | 479 | 1109 |
Country (N) | |||
 United States | 25 | 1613 | 1588 |
 United Kingdom | 12 | 1654 | 1712 |
 Japan | 8 | 414 | 1014 |
 Latvia | 4 | 409 | 246 |
 Sweden | 3 | 312 | 317 |
 Germany | 3 | 114 | 199 |
 The Netherland | 2 | 108 | 119 |
 Italy | 2 | 101 | 124 |
 Canada | 2 | 75 | 65 |
 China | 1 | 65 | 85 |
 Bulgaria | 1 | 58 | 50 |
 Belgium | 1 | 48 | 35 |