Parainfluenza Virus Infection Among Human Immunodeficiency Virus (HIV)-Infected and HIV-Uninfected Children and Adults Hospitalized for Severe Acute Respiratory Illness in South Africa, 2009–2014

Cohen, Adam L.; Sahr, Philip K.; Treurnicht, Florette; Walaza, Sibongile; Groome, Michelle J.; Kahn, Kathleen; Dawood, Halima; Variava, Ebrahim; Tempia, Stefano; Pretorius, Marthi; Moyes, Jocelyn; Olorunju, Steven A. S.; Malope-Kgokong, Babatyi; Kuonza, Lazarus; Wolter, Nicole; von Gottberg, Anne; Madhi, Shabir A.; Venter, Marietjie; Cohen, Cheryl

The seasonality of PIV in South Africa is similar to that seen in other temperate countries such as the United States, where PIV circulates during the northern hemisphere spring and winter seasons [28] . In contrast, in tropical and subtropical countries in Africa, such as Cameroon, Ghana, and Kenya, PIV does not appear to have distinct seasonality [6, 7, 29] . This is one of few studies that describe the epidemiology of PIV in both children and adults over a long period and in the context of controls. However, there were some limitations to our study. Not all children were tested for HIV, and we did not analyze PIV in cases of milder outpatient influenza-like illness, which includes common presentations of PIV illness such as croup. Although it is uncommon and uncommonly tested for, we did not test for PIV type 4, so our incidence estimates would be a minimum estimate. We also did not test for all viral respiratory pathogens, such as coronavirus and bocavirus. The large number of patients from CHBAH (70%) may bias results toward the epidemiology at that one site. Our calculation of incidence was for only 1 site and the calculation of AF was conducted at 2, so these analyses may not be representative of all regions in South Africa. The incidence may be an underestimate if patients did not seek medical care for their illness or sought care at a hospital other than CHBAH or died before reaching the hospital. The increased incidence of hospitalization among individuals infected with HIV may be due to a lower threshold for hospitalization compared with HIV-uninfected individuals. Lastly, we did not have data on steroid use, which is a common treatment for croup in children, and for patients with HIV infection, we did not have information on ART nor CD4 cell count.