Characterization of species B adenoviruses isolated from fecal specimens taken from poliomyelitis-suspected cases.

Background: Human adenoviruses are classified into six species, A-F, and 51 serotypes are recognized. Adenoviruses can cause a broad range of diseases. Serotypes 3, 7 and 21 are most commonly associated with CNS disease. Serotype 21 (specie B) was isolated from brain tissue and CSF of patients with acute flaccid paralysis (AFP) in Malaysia.

Objectives: Characterize, by molecular methods, species B adenoviruses isolated from poliomyelitis-suspected cases and investigate the possible etiological role of adenoviruses in acute flaccid paralysis (AFP).

Study Design: 622 virus isolates, including Sabin-related polioviruses, non-polio enteroviruses (NPEV) and adenoviruses, were recovered from fecal specimens in our laboratory during the period of 1997-2002 from AFP cases occurring in Brazil, Peru and Bolivia. Negative controls consisted of 528 fecal specimens collected from healthy children <==5 of age. Of these, 478 were contacts of AFP negative cases and 50 were from a day-care center.

Results: Sixty-four adenovirus strains isolated in HEp2 (human laryngeal tumor cells) cells were confirmed as such by an adenovirus-group specific PCR. Nucleotide sequencing identified the following adenovirus species: A (3 isolates), B (20 isolates), C (38 isolates), D (2 isolates) and E (1 isolate). The following serotypes belonging to the species B were identified: Ad3 (1 strain), Ad7 (17 strains) and, Ad16 (2 strains).

Conclusion: Other viral agents became more recognized in association with CNS diseases in areas where wild polioviruses have been eradicated. The possible role of species B adenoviruses in the etiology of AFP cases similar to that caused by wild poliovirus is discussed.