The true infective impact of any environmental infection is difficult to model as it will depend on the distribution of the bacteria and the grazing habits of the animals [ 22, 23].
"A single egg simply tells us that the particular person was infected with schistosomiasis; so, drawing any major conclusions regarding route of infection is difficult.
Chronic hepatitis B virus (HBV) infection is difficult to cure due to the presence of covalently closed circular DNA (cccDNA).
Because clinical symptoms of hMPV resemble those caused by respiratory syncytial virus (RSV), clinical diagnosis of hMPV infection is difficult.
Whether the study's findings reflect higher rates of H.I.V. infection is difficult to say because some cases are not diagnosed immediately.
The infection is difficult to diagnose because it often produces no symptoms, but at its worst chlamydia can cause infertility in women.
Chronic infection is difficult to overcome because of exhaustion or depletion of cytotoxic effector CD8+ T cells (cytotoxic T lymphoytes (CTLs)).
Pseudomonas aeruginosa infection is difficult to treat because of its drug resistance, but how it develops drug resistance remains largely unknown.
Infection is difficult to diagnose when systemic inflammation is present for multiple potential reasons.
The diagnosis of an active infection is difficult to establish, as confirmatory testing can be unreliable or unavailable.
But it's important to specify that information about local signs of infection is difficult to collect in a retrospective study.
