At the end of 2010, an estimated 34 million people were living with HIV. The number of people dying of AIDS-related causes was 1.8 million and there were 2.7 million new HIV infections. Sub-Saharan Africa remains the region most heavily affected by HIV. About 68% of all people living with HIV resided in sub-Saharan Africa which also accounted for 70% of new HIV infections. The epidemic was most severe in southern Africa, which has more people living with HIV (an estimated 5.6 million) than any other country in the world [1].

With an estimated 1.1 million people living with HIV, Ethiopia has one of the largest populations of HIV-infected people in the world in 2009. In the same year, an adult HIV prevalence was estimated to be 1.8% for males and 2.8% for females [2]. The estimated national incidence rates as inferred from prevalence data to be (1.7%) and (0.46%) for towns and rural areas respectively [3, 4].

In Jimma zone; Ethiopia study conducted in 2006 showed that, Out of a total 5648 registered VCT service utilized clients seven 742 (13.1%) were positive for HIV [5] and according to the zone Health department first quarter report, 2011, there were about 1221 peoples living with HIV/AIDS [6]. Furthermore, populations at higher risk of HIV infection were identified to be: sex workers, uniformed services, long-distance-trucker-drivers; refugees and displaced people, daily laborers, mobile/migrant laborers, including cross-border population, street children, high school and university students, out-of-school youth and indigenous populations in remote foreign tourist destinations involved transactional sex [2]. A study in South Africa on occupational hazard in health facilities on 721 health workers, found that 15.7% of them were living with HIV/AIDS [7].

Voluntary HIV counseling and testing has been introduced in many low-resource settings as it helps to create awareness of an individual’s HIV status and offers the opportunity for counseling on risk behavior modification being a cornerstone in the prevention of HIV/AIDS [8–10]. Among the general public in the fight against HIV/AIDS, the behavior of health professionals affects the public’ behaviors and the quality of services provided [10–12]. VCT use by health professionals has generally the following important aspects. First, like any other individuals it is a mechanism for protection of health workers from HIV infection. Second, from the behavior change perspective, health professionals should be role models in undertaking VCT so that it may increase VCT uptake by the general public. Third, due to accidental needle injury and other clinical practices they are vulnerable population for infection. Finally, protecting health workers in developing countries like Ethiopia where health institutions are highly understaffed is much important not to lose highly experienced and qualified health workers.

Hence, in order to promote VCT-uptake, it is imperative to understand HIV testing correlates and their theoretical underpinnings. Theory of planned behavior is a social cognition model (SCM) that constitutes a promising framework for understanding and predicting behaviors and behavioral intentions [13]. In an effort to identify factors associated with the utilization of VCT services, studies have applied theoretical models [14, 15] and the other studies have tested the applicability of the theory of planned behavior focusing on sexual behaviors such as intention to use a condom [16, 17], intention to refuse sexual debut [18] and intended use of contraception [19, 20] in Africa. Thus, theory based studies are used to construct effective and evidence based educational programs that can assist in the control and prevention of the HIV infection [13].

The TPB was applied to health professionals due to the following reasons. First, the HCWs decision making is the result of both intrapersonal and external factors, secondly, it will appears to be logical that the extent to which HCWs participate in the provision and utilization of VCT services is a function of conditions like services, programs, support from other workers. Finally, the normative issues concerning HIV/AIDS are not well established in developing countries like Ethiopia which may leads to stigma and discrimination.

It has been recommended that the TPB is open to the inclusion of other variables if they increase predictive utility of the model [13]. Consistent with this reasoning about the sufficiency of this theory, the current study extended the TPB by adding a measure of perceived risk and perceived severity. Past behavioral experience is also included in to the model because past behaviour often influences the future expressions of that behaviour and thus, increases predictive utility of the model [14–16]. Because of its content and use of repeatedly tested theory, this study is the first of its kind in Ethiopia which may indicate a need for special intervention on health professionals towards VCT. There for the aim of this study was to predict the intention VCT use and associated factors among health professionals in Jimma zone, Ethiopia using the theory of planned behavior.

The present study showed that have never been tested and there is high intention to use VCT services. Most health workers test their blood by themselves which may indicate the existence of fear of disclosure of HIV status and high perceived risk of HIV infection.

Like that of studies in Ethiopian and Tanzanian [6, 12, 22], this finding revealed no significant statistical association between socio-demographic factors and intention to use VCT. This finding has an implication that VCT services are accessible, available and affordable to the health professionals that the social determinants of health are not barriers for VCT use intention. The socio-demographic factors are not predictors since as part of primary health care, VCT services are provided in every health centers in the study area for free for everyone. VCT campaigns are also common that may increase accessibility of VCT services.

Findings of the present study suggested no statistical difference among the age group in requesting for VCT which contradicts with studies conducted in Tanzania and Ghana showing significant differences among age group with likely to be tested among teenagers due that high HIV prevalence among them and increasing tendency for young people to be tested before marriage [15, 17]. This difference might be due to that, most of the respondents in this study were married and the low Perceived risk to HIV in this age category might have hampered the association.

In line with the previous Nigerian study on medical students [23] the present study depicted insignificant difference among the two sexes in willingness to seek VCT services. But the current finding was not similar with other studies [24, 25]. It is conventional that the gender differences in seeking VCT are mainly due to factors like cultural, social and biological like male dominance, vulnerability to risk, social factors like rape especially in developing countries, that make female vulnerable to HIV infection.

In this study, the level of education might have influenced the socio-cultural factors positively that may leads to the differences among male and female, hence reducing the differences in seeking VCT services. Therefore, the insignificant gender differences in this aspect may be due to the social status of female HCWs is different from that of females in the general population.

The intention to use VCT services was primarily due to subjective norms and attitude while their perceived behavioral control was statistically insignificant predictor. Other studies also found similar results that subjective norms were more important predictors [24, 25]. However, other studies showed that perceived behavior control was the leading predictor of intention followed by attitude and subjective norm [23, 26]. In present study subjective norm was more important predictor than the other components of TPB which indicated that significant others have great role to play in the use VCT services. The possible reason for this variation could be due to variation across behavior, population and situation under which the behavior is occurring, according to the TPB perspective [13, 22]. Given the population for this study were HCWs they could have high perceived behavioral control on VCT. Unlike the general public, the HCWs are expected to have also the knowledge and skill related to HIV/AIDS including VCT.

In assessing the effect of past history of VCT use on the behavioral intention, the present study did not find a significant association after controlling for the effects of socio- demographic variables and components of TPB. This is contrary to previous studies [20, 27] and agrees with the assumption of the TPB [13, 22] which says past behavior experience affects the future expression of the behavior provided that it must be mediated by the proximal TPB components. The possible reason may be due to that the many HCWs have tested themselves for HIV which may not reflect the actual intention to VCT use.

In this study, none of the external to TPB variables significantly predicted intention to VCT. The finding of this study will goes with a study in Zimbabwean [28] in which the perceived risk was not associated with behavioral intention. The possible explanation related to this may be that HCWs are expected to have high knowledge about HIV/AIDS, unlike the other population group leads to the insignificant association to intention because motivation for VCT might be driven by knowledge and education of VCT itself rather than risk perception for this group. However, previous studies [29–31] claimed that high risk group tends to be less likely to participate in VCT services.

As suggested by the principle of the TPB [13, 22], there was positive correlation between the respective indirect and direct components of the theory of planned behavior. Hence, the indirect measures predicted the respective direct measures of attitude, subjective norm and perceived behavioral control. This implies that interventions can be designed on the salient beliefs identified during the elicitation study; so that, by influencing the direct measures of the TPB, intention to VCT use can be increased. The components of TPB explained intention to use VCT in a similar manner with studies of other public health topics in Ethiopia and other African countries [16–18, 29]. Since this study was conducted among the health care workers, there may be social desirability bias that could have affected not only the main study but also the elicitation study.

The study revealed that behavioral intention to use VCT was a function of attitude and perceived social pressure (SN). Demographic related social determinants were not barriers for VCT use intention. Most health workers test their blood by themselves which may indicate the existence of fear of disclosure of HIV status and high perceived risk of HIV infection. The belief based components (indirect measures) of the TPB can influence the direct measures of the TPB so that intention to use VCT will be increased. Strategies to empower health professionals on social pressure resistance and programs targeted at changing negative attitude on VCT use can enhance intention of health professionals to use VCT.