Influenza-like episodes in HIV-positive patients: the role of viral and 'atypical' infections.

OBJECTIVES

To document viral and 'atypical' infections in HIV-positive patients and association with influenza-like symptoms.

PATIENTS AND

METHODS

Monthly culture of urine, faeces and throat swabs in 63 HIV-positive patients (30 asymptomatic and 33 with AIDS-related complex/AIDS) over 5-27 months (with 1125 patient-months of follow-up), with further sample collections during influenza-like episodes. Standard viral detection methods were used. Throat swabs were assessed for Chlamydia sp. by culture and immunoblotting, and for Mycoplasma pneumoniae by polymerase chain reaction.

RESULTS

Viruses were detected in 15 (50%) and M. pneumoniae in nine (30%) out of 30 HIV-positive patients during an influenza-like illness. A close temporal relationship with symptoms was observed in 12 (40%) patients: cytomegalovirus in six (20%), M. pneumoniae in three (10%), herpes simplex virus in three (10%), and enterovirus in one (4%). Influenza-like symptoms were more frequent in asymptomatic HIV infection than in AIDS-related complex/AIDS patients (actuarial risk at 1 year, 63 versus 26%; P=0.002), particularly in those with CD4 cell counts >300 x 10(6)/l at enrolment (P=0.002). At least 44% (four out of nine) M. pneumoniae infections were asymptomatic and 78% (seven out of nine) were associated with prolonged excretion (2-17 months). Chlamydia sp. were not detected.

CONCLUSIONS

Influenza-like symptoms were more likely to be reported by HIV-positive patients at early stages of disease, possibly as a result of differences in immune responses to viral infection. There was a close association in 40% of cases between the development of symptoms and detection of cytomegalovirus, herpes simplex virus, enterovirus and M. pneumoniae (a previously unrecognized association).