Table 1.
Characteristics of included studies
| First author | Year | Area | Age (in years) |
Gender (F/M) |
Case group (n) | Control group (n) | Microorganism type | Number of bacterial infections (n) |
Diagnostic method | Ref | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| case | control | case | control | case | control | ||||||||
| Wincup | 1996 | UK | 54 | 53.5 | NA | NA | 137 | 136 | H. pylori | 93 | 78 | ELISA | [15] |
| Cook | 1998 | UK | 67.9 | 56.5 | 73/103 | 674/844 | 176 | 1518 | C. pneumoniae | 81 | 280 | MIF | [60] |
| Rasura | 2000 | Italy | NA | NA | NA | NA | 101 | 101 | C. pneumoniae | 26 | 8 | ELISA | [65] |
| Elkind | 2000 | USA | 68.5 | 68.5 | 47/42 | 47/42 | 89 | 89 | C. pneumoniae | 72 | 74 | ELISA | [16] |
| Grau | 2001 | Germany | 62 | 59.5 | 36/73 | 27/55 | 109 | 82 | H. pylori | 57 | 34 | ELISA | [17] |
| Heuschmann | 2001 | Germany | 74.6 | 74.6 | 77/68 | 138/122 | 145 | 260 | H. pylori | 67 | 117 | ELISA | [61] |
| Ponzetto | 2002 | Italy | 56.7 | 57.4 | 22/58 | 88/232 | 80 | 320 | H. pylori | 64 | 190 | UBT | [18] |
| Pietroiusti | 2002 | Italy | 63.2 | 63.9 | 11/50 | 89/62 | 61 | 151 | H. pylori | 43 | 106 | PCR | [19] |
| Majka | 2002 | Germany | NA | NA | NA | NA | 80 | 80 | H. pylori | 69 | 54 | ELISA | [20] |
| Madre | 2002 | Spain | 70 | 70 | 46/45 | 53/59 | 91 | 112 | C. pneumoniae | 40 | 34 | IFI | [21] |
| Tarnacka | 2002 | Poland | 74 | 66 | 91/88 | 66/56 | 179 | 122 | C. pneumoniae | 6.00 (95% CI: 1.61-22.29) | ELISA | [22] | |
| Tanne | 2003 | Israel | 61 | 61 | 8/126 | 8/126 | 134 | 134 | C. pneumoniae | 115 | 110 | ELISA | [23] |
| Muller | 2003 | Denmark | 69 | 45 | 84/109 | 125/243 | 193 | 368 | C. pneumoniae | 20 | 29 | PCR | [24] |
| Kawamoto | 2003 | Japan | 75 | 74 | 17/23 | 48/37 | 40 | 85 | C. pneumoniae | 29 | 52 | ELISA | [25] |
| Moayyedi | 2003 | UK | 70.5 | 70.2 | 228/239 | 227/161 | 467 | 388 | H. pylori | 274 | 206 | ELISA | [27] |
| Voorend | 2004 | Netherlands | 43.9 | 39.4 | 22/19 | 31/24 | 41 | 55 | C. pneumoniae | 28 | 38 | ELISA | [29] |
| Ngeh | 2004 | UK | 80 | 80 | 59/41 | 57/25 | 100 | 82 | M. pneumoniae | 95 | 82 | ELISA | [30] |
| Gabrielli | 2004 | Italy | 68 | 66 | 56/49 | 66/64 | 105 | 130 | H. pylori | 75 | 81 | ELISA | [26] |
| Anzini | 2004 | Italy | 34.6 | 36.5 | 60/81 | 90/102 | 141 | 192 | C. pneumoniae | 2.9 (95% CI: 1.77-4.76) | ELISA | [31] | |
| Ngeh | 2005 | UK | NA | NA | 59/41 | 60/27 | 100 | 87 | C. pneumoniae | 71 | 57 | ELISA | [28] |
| Masoud | 2005 | Iran | 64.3 | 61.7 | 43/48 | 40/40 | 91 | 80 | H. pylori | 59 | 36 | ELISA | [32] |
| Kongoji | 2005 | Japan | 63.5 | 62.7 | 7/6 | 2/5 | 13 | 7 | C. pneumoniae | 5 | 0 | PCR | [33] |
| Wohlschlaeger | 2005 | Germany | 65.1 | 73.3 | 5/5 | 16/7 | 7 | 21 | C. pneumoniae | 4 | 1 | PCR | [34] |
| Sawayama | 2005 | Japan | 71.5 | 69 | 22/40 | 95/48 | 62 | 143 | H. pylori | 9.68 (95% CI: 3.56–33.08) | UBT | [35] | |
| Johnsen | 2005 | Denmark | 60.4 | 60.5 | 99/155 | 99/155 | 254 | 254 | C. pneumoniae | 1.28 (95% CI: 0.83–1.95) | ELISA | [36] | |
| Elkind | 2006 | USA | 72.3 | 72.3 | 125/121 | 219/38 | 246 | 474 | C. pneumoniae | 156 | 257 | ELISA | [37] |
| Park | 2006 | Korea | 66.7 | 66.8 | 62/63 | 62/63 | 125 | 125 | H. pylori | 100 | 75 | ELISA | [38] |
| Njamnshi | 2006 | Cameroon | NA | NA | 64/0 | 64/0 | 64 | 64 | C. pneumoniae | 41 | 35 | ELISA | [39] |
| Jozwiak | 2007 | Poland | 44 | 40 | 40/54 | 44/59 | 94 | 103 | C. pneumoniae | 63 | 15 | ELISA | [40] |
| Ashtari | 2008 | Iran | 65.4 | 60.2 | 43/38 | 24/19 | 81 | 43 | H. pylori | 57 | 29 | ELISA | [41] |
| Lin | 2008 | Taiwan | 64.2 | 63.2 | 202/248 | 198/252 | 450 | 450 | C. pneumoniae | 334 | 257 | ELISA | [42] |
| Bandaru | 2008 | India | 47.8 | 47.8 | 149/51 | 149/51 | 200 | 200 | C. pneumoniae | 72 | 35 | ELISA | [43] |
| Bastiani | 2008 | Italy | 76.6 | 76.5 | 51/55 | 51/55 | 106 | 106 | H. pylori | 67 | 57 | UBT | [44] |
| Bandaru | 2009 | India | 35.3 | 35.3 | 30/90 | 30/90 | 120 | 120 | C. pneumoniae | 35 | 15 | ELISA | [45] |
| Gagliardi | 2009 | Brazil | NA | NA | 25/40 | 37/22 | 65 | 59 | C. pneumoniae | 0 | 1 | PCR | [46] |
| Sheu | 2010 | Taiwan | 33.5 | 42.4 | 824/1459 | 2939/3910 | 2283 | 6849 | M. tuberculosis | 136 | 256 | Culture | [57] |
| Mousavi | 2011 | Iran | 65.6 | 62.9 | 46/50 | 36/57 | 96 | 93 | H. pylori | 44 | 39 | ELISA | [47] |
| Rai | 2011 | India | 53.6 | 38.6 | 16/35 | 14/34 | 51 | 48 | C. pneumoniae | 32 | 38 | ELISA | [48] |
| Ķēniņa | 2011 | Latvia | 65.8 | 64.3 | 41/61 | 22/26 | 102 | 48 | C. pneumoniae | 64 | 17 | ELISA | [49] |
| Hasan | 2011 | Iraq | 58.02 | 56.1 | 18/32 | 18/22 | 50 | 40 | C. pneumoniae | 36 | 21 | ELISA | [50] |
| Bandaru | 2012 | India | 74 | 71 | 30/70 | 32/68 | 100 | 100 | C. pneumoniae | 29 | 16 | ELISA | [51] |
| Hassanein | 2014 | Egypt | 53 | 52.6 | 35/55 | 25/35 | 90 | 60 | H. pylori | 70 | 32 | ELISA | [66] |
| Eini | 2014 | Iran | 68.9 | 66.9 | 60/81 | 60/81 | 141 | 141 | C. pneumoniae | 111 | 74 | ELISA | [54] |
| Ebrahimi-Rad | 2014 | Iran | NA | NA | NA | NA | 27 | 25 | C. pneumoniae | 20 | 13 | ELISA | [55] |
| Wu | 2014 | Taiwan | 53 | 53.2 | 1922/3882 | 1925/3879 | 5804 | 5804 | M. tuberculosis | 176 | 207 | Culture | [56] |
| Srivastava | 2014 | India | 43.6 | 43.2 | NA | NA | 80 | 80 | C. pneumoniae | 42 | 26 | ELISA | [58] |
| Sagar | 2016 | India | 47.8 | 46.6 | 14/25 | 8/22 | 39 | 30 | H. pylori | 26 | 12 | ELISA | [59] |
| Roham | 2016 | Iran | 69.1 | 67.2 | 61/36 | 51/46 | 97 | 97 | M. pneumoniae | 4 | 0 | ELISA | [62] |
| Salmasi | 2017 | Iran | 66.7 | 65.9 | 38/32 | 39/31 | 70 | 70 | H. pylori | 61 | 51 | ELISA | [63] |
| Mrđen | 2017 | Croatia | 72.8 | 72.8 | 34/32 | 34/32 | 82 | 93 | H. pylori | 21 | 32 | ELISA | [64] |