Table 1.

The characteristics of the included studies.

Rows	Author (references)	Period of participants' recruitment	Region of recruitment	City/area	Study design	Population type	Mean or median age	No. of participants with triplex infection	Sample size	Prevalence (%)
1	Adesina et al. 2010 [16]	Jan 2006 to December 2007	South-West	Ibadan	Retrospective cross sectional	HIV infected	28.86 ± 5.85 years	1	721	0.14
2	Ezechi et al. 2014 [17]	January 2006 to December 2011	South-West	Lagos	Cross sectional	HIV infected	29.5 ± 4.4 years	2	2391	0.08
3	Ikeako et al. 2014 [18]	May 2006 to April 2008	South-East	Enugu	Retrospective cross sectional	General obstetrics	30.1 ± 2.1 years	0	1239	0.0
4	Oga et al. 2018 [19]	February 2015-January 2016	North-Central	Jos	Cohort	HIV infected	Not stated	0	150	0.0
5	Okeke et al. 2012 [20]	January 2007 to December 2009	South-East	Enugu	Retrospective cross-sectional	HIV infected	Not stated	1	401	0.3
6	Omatola et al. 2019 [21]	September 2017 to November 2017	North-Central	Anyigba	Cross sectional	HIV infected	Not stated	0	200	0.0
7	Opaleye et al. 2016 [22]	Not stated, but assumed to be after 2011 since the accepted author version of the manuscript was posted online on 16 April 2015	South-West	Oshogbo	Cross sectional	General obstetrics	Not stated	0	182	0.0
8	Ya'aba et al. 2019 [23]	January 2015 to December 2018	North-Central	Abuja	Cross sectional	General obstetrics	Not stated	0	330	0.0

HIV = human immunodeficiency virus.