For a study, researchers sought to understand that about 4 members of the genetically separate genera, Respirovirus (HPIV1&3) and Orthorubulavirus (HPIV2&4), make up the human parainfluenza virus (HPIV), which was a major cause of upper and lower respiratory tract infections worldwide, especially in children. They were commonly taken into account jointly or with HPIV4 completely ignored, despite the frequent molecular diagnosis. Therefore, investigators looked into the clinical and viral epidemiological variations of the relatively uncommon Orthorubulaviruses HPIV2 and HPIV4 at a regional UK hospital throughout 4 epidemic autumn/winter seasons. In addition to sequencing viral genome fragments in a representative fraction of samples, a retrospective review of the clinical characteristics of all HPIV2 or HPIV4 RT-PCR-positive patients identified between 1 September 2013 and 12 April 2017 was conducted. All age groups were infected; however, children under the age of 9 and adults over 40 were the most commonly affected, with nearly twice as many cases of HPIV4 than HPIV2 reported. More frequently observed in HPIV2 infections than in HPIV4 infections were fever, abnormal homology, increased C-reactive protein, and hospital admission. Each of the 4 seasonal maxima of either HPIV2, HPIV4, or both occurred in November and December and came before that of Influenza A, closely mirrored that of RSV. A portion of the viruses was only partially sequenced, showing co-circulation of numerous HPIV2 and 4 subtypes, but with slight variation between epidemic seasons or from the few available worldwide reference sequences. Their results showed that HPIV2 and HPIV4 might have different related diseases despite being the closest known genetic cousins, with more hospitalizations occurring in HPIV2 mono-infected patients but a higher overall number of HPIV4 cases.

Source: onlinelibrary.wiley.com/doi/10.1111/irv.13012