11.   Hypogammaglobulinemia and depressed IgG to surface antigens of Giardia have been suggested as factors contributing to chronic infection.

12.   This study shows that chronic H pylori infection is accompanied by appreciably increased gastric acid output in both healthy volunteers and duodenal ulcer patients.

13.   H pylori is associated with gastritis and peptic ulcer and possibly with non-ulcer dyspepsia, so both patients may have had chronic infection.

14.   In chronic infections, which occur primarily in sheep, inappetence and emaciation with intermittent diarrhoea and anaemia are the main signs of oesophagostomiasis.

15.   In more chronic infections, the animal is usually underweight, the coat is poor, and there is loss of appetite and perhaps pica.

16.   The symptoms are those of a chronic respiratory infection, with coughing, sneezing, and nasal discharge associated with tachypnoea.

17.   -- Why do healthy animals and humans rarely suffer chronic infections of the tongue and skin although these and other tissues are constantly coated with large numbers of microbes?

18.   But they speculated that some chronic low-grade infections could occur when minor injuries to spinal disks let micro-organisms enter.

19.   Chronic infection of the middle ear can cause hearing impairment.

20.   Data are accumulating that the syndrome involves a chronic viral infection.