In this community based cross sectional study about 22.4% of the respondents were knowledgeable on PMTCT of HIV. This finding is less than the study conducted at Gondar (83.5%) [7], Hawasa referral hospital (82.3%) [8] and Southern Nigeria (91.4%) [9]. This discrepancy might be due to the study setting and source population difference.
Those women residing in urban areas were 2.5 times (AOR = 2.5, 95% CI 1.16–5.33) more likely to be knowledgeable when compared to the rural residents. This finding is in line with studies conducted at Hawassa referral hospital, Gondar and Tanzania [7, 8, 10]. It might be due to the urban location geographical accessibility and availability of nearby health services and greater media exposure compared with rural areas.
In this study education level of secondary and above were 5.4 times (AOR = 5.4, 95% CI 2.69–10.98) more likely to be knowledgeable on PMTCT of HIV than those with no formal education. This explanation is in line with the study done in, Addis Ababa, Hawassa and Tanzania [8, 11, 12]. This could be because when the women become educated their health seeking behavior and access to information might be increased. With this regard, they might have access to print media exposure for educated one.
Women who had history of ANC follow up were about 4.4times (AOR = 4.4, 95% CI 1.47–13.34) more likely to be knowledgeable on PMTCT of HIV/AIDS than those who hadn’t ANC followup. It could be due to women who had history of ANC follow up might get the chance to learn from health professionals and this information may enhance women’s knowledge about PMTCT. This finding is consistent with the study conducted at Hawassa referral hospital [8] despite the confidence interval in our study was found to be wide.
Women who had history of institutional delivery were more knowledgeable about PMTCT (AOR = 4.77, 95% CI 2.00–11.33) than those who had not. This finding is also consistent with the study conducted at Hawassa referral hospital [8]. This might be women who had history of institutional delivery might get the chance of PMTCT service at the health institution from health professionals.
Women who had comprehensive knowledge on HIV/AIDS were 1.7 times (AOR = 1.7, 95% CI 1.01–2.85) more likely to be knowledgeable on PMTCT of HIV than non-knowledgeable counter parts. This finding was consistent with a study conducted in Gondar and Assosa, Ethiopia [7, 13]. The possible interpretation for this positive association is that those women with comprehensive knowledge on HIV may appreciate the prevention strategies of mother to child transmission of HIV.
Women who were knowledgeable on MTCT of HIV were 2.2 times (AOR = 2.20, 95% CI 1.37–3.54) more knowledgeable on PMTCT of HIV than those who did not have. This finding is in agreement with previous study done at Assosa town, Ethiopia [13]. This might be due to women with knowledgeable on MTCT of HIV might have greater understanding on prevention possibilities.
Women who had discussions with their husband about HIV/AIDS, MTCT and its prevention were 2.7 times (AOR = 2.700, 95% CI 1.7, 4.4) more likely to be knowledgeable than those who had not. This finding is inline with the study done on Mekele and Southern Ethiopia [13,14,15]. This might be explained due to women having discussion with their husband regarding HIV/AIDS will help to share the information and increase her level of understanding which enhances her PMTCT knowledge.