According to a recent report by Sichanh et al. [
16], most women in Lao PDR do not know that HPV causes cervical cancer. In this study, we first reported the relationship between cytology and HPV genotype in Lao PDR, which has not yet established a cervical cancer prevention screening system. Previously, we reported on cervical cytology of healthy women in Vientiane in 2008 and 2010; cytological findings included PAP ≥ Class IIIa, which includes IIIa, IIIb, IV and V in the PAP classification system, in 3% of 200 volunteers in 2008 [
12] and ≥ASC-US in 5.7% of 1000 volunteers in 2010 [
14]. However, the present rate of cytologic findings ≥ASC-US was 9.3% in 1422 volunteers, which was higher than that seen in our previous trials. The reason for the higher rate may be due to the use of the LBC procedure after specimen collection with Kato’s device. In fact, several reports have shown better performance with LBC compared with conventional PAP method [
17,
18]. A cervical cancer prevention screening program in Okinawa, Japan, showed abnormal findings in 3.3% by LBC method in 2013 and 2014 but only 1.8% by a conventional PAP method in 2011 and 2012 [
19]. Furthermore, when the PAP detection rates for cervical cancer in neighboring countries were observed, the results showed abnormal findings with a conventional PAP method were 4.9% in Thailand and 3.9% in Vietnam [
20,
21]. Those data are similar to our previous findings using a conventional PAP method [
13]. Meanwhile, the detection rate was reported 8.0% in Myanmar [
22] when using a conventional PAP method, which is much higher than findings seen in this study in Lao PDR. Findings represented cytology of ≥ASC-US in 40% of cases in this study. In cases with ≥ASC-US, the positive rate of HR-HPV was 47.7% (63/132) and 92.9% (13/14) in HSIL and SCC cases, respectively. Cibas et al. also reported that the HR-HPV–positive rate for ASC-US ranged from 31.5% to 54.6% in abnormal cases [
23]. In addition, there appear to be some distribution differences of HPV genotypes among different regions such as Africa, Asia, Europe, and the Americas [
24,
25]. HPV genotypes 16, 18, 31, 52, and 58 are consistently found among the 10 most common types in all areas [
24,
25]. Genotypes 16 and 18 have been considered to cause 70% of cervical cancers and precancerous cervical lesions [
26]. Therefore, a 9-valent vaccine was recently developed in addition to a 2- or 4-valent vaccine for cervical cancer prevention [
27]. In this study, HPV examination by PCR technique identified seven important genotypes: 16 in 20.5% of findings, 58 in 9.1%, 52 in 4.5%, 18 in 3.8%, and 31, 33, and 35 in 1.5% in participants with cytologic findings ≥ASC-US. Phongsavan et al. [
10] also showed genotypes 33/52/58 in 4.3%, 16 in 3.1%, 18/45 in 1.5%, 56 in 1.4%, and 31 in 0.8% among their samples in Lao PDR. There seems to be high incidence of HPV58 in Lao PDR compared with other countries. Worldwide, it was reported that the most common HPV genotypes were 16, 18, and 52 [
25]. Kantathavorn et al. reported that in Thailand, a neighboring country of Lao PDR, genotype 52 was the most detectable HPV, followed by genotype 16 [
20]. In this study, we used a self-collecting device to collect cervical cytological material and did not perform histopathological examinations in volunteers with abnormal cytology and/or HR-HPV. We recognize that the accuracy of cytology collected by a gynecologist is better than that obtained through self-collection, and that it is necessary to do histopathological examinations for a precision management. However, Jeronimo et al. showed little difference in HPV test findings between clinician-collected and self-collected specimens [
28]. In addition, cervical cytology is not popular, and limited resources lead to a lack of cytology screening programs in Lao PDR. In our previous studies [
13,
14], we reported that 78% of participants preferred Kato’s device compared with collection by gynecologists. Yoshida et al. reported a similar preference by Lao women [
29]. Furthermore, it is not common to examine the cervical smear in gynecological patients, as there are many gynecologists in Lao PDR, but they mainly work as obstetricians because of many births throughout the country. Therefore, the use of self-collecting device for cervical cytology may have applications in Lao PDR.
In addition, the use of social media such as radio and television to join us as volunteers may have been effective to study women in developing counties, because even a short advertisement could reach approximately 1500 participants. It seemed to be interested in cervical cancer for Lao women but they did not got used usual cytology because there are not specialists for cytology in Lao PDR. It means that it is necessary to built up the histopathology and cytology education system for medical staff in future.