You are looking at the HTML representation of the XML format.
HTML is good for debugging, but is unsuitable for application use.
Specify the format parameter to change the output format.
To see the non HTML representation of the XML format, set format=xml.
See the complete documentation, or API help for more information. 
<?xml version="1.0"?>
<api>
  <query-continue>
    <alllinks galcontinue="Bウイルス感染症|416" />
  </query-continue>
  <query>
    <pages>
      <page pageid="14" ns="12" title="ヘルプ:Categories/ja" />
      <page pageid="15" ns="12" title="ヘルプ:Images/ja" />
      <page pageid="30" ns="12" title="ヘルプ:Patrolled edits/ja" />
      <page pageid="68" ns="0" title="ウイルス性およびプリオンによる人獣共通感染症" />
      <page pageid="152" ns="14" title="カテゴリ:未作成薬物" />
      <page pageid="348" ns="0" title="培地" />
      <page pageid="353" ns="0" title="ウイルス病:牛" />
    </pages>
  </query>
</api>