MHIRT Poster Session 2019

Background: Particulate Matter 2.5 (PM2.5) has been attributed to more health consequences compared to the prevalent concentrations of Particulate Matter 10 (PM10). Bangkok is known to have a high level of PM2.5 during dry seasonal haze episodes. Its prevalence had been further observed along PM10 and a smaller particulate matter, particulate matter 1 (PM1). Studies regarding the prevalence of PM2.5 during non-haze episodes are not available. The extent of various chemical molecules such as Nitrogen Dioxide (NO2) and Volatile Organic Compound (VOC) as the triggering factor of PM2.5 are also unknown.

Objective: To identify the PM concentrations and prevalence in the environment and to determine the chemical molecules concentration as the triggering factor of PM2.5 in Bangkok, Thailand during dry seasonal non-haze episodes.

Methods and Materials: PM2.5, PM10, and PM1 concentrations were measured using AirBeam 2 and Aslung. Additionally, NO2, VOC, and PM2.5 concentrations were measured using Plume. Samples were collected in Bangkok during wet season from different locations and using various modes of transportation. AirBeam 2 and Aslung measured PM by direction, and modes of transportation were analyzed via descriptive statistics and illustrated with a bar graph to compare PM concentrations. Plume measurements were analyzed using linear correlation to determine the significance of NO2 and VOC to PM2.5.

Results: Overall, NO2 and VOC were significant to the formation of PM2.5 with the correlation of 0.255 and 0.114 respectively (n=882). In the moving ferry-boat (Khlong Sansaep), surrounded by water, there is a higher prevalence of PM2.5. However, PM10 is still more prevalent in the moving ferry-boat (Khlong Sansaep) compared to PM2.5 and PM1.; average= 52 μ/m3 and 20 μ/m3, respectively.

Conclusions: NO2 and VOC trigger the high concentration of PM2.5 in ferry-boat located in the west (Khlong Sansaep). We found lesser prevalence of PM2.5 than PM10 throughout Bangkok. Determining areas with the highest concentration of PM2.5 allows for monitoring increases in air pollution and ways to mitigate the occurrence of haze episodes. These data can be used as the baseline information for the comparison of haze episodes during dry season.

Background: Human papillomavirus (HPV) is the most common sexually transmitted virus. Low-risk HPV can cause warts, and the virus often clears on its own. High-risk HPV can persist and can cause cervical, anogenital, and head and neck cancer, primarily of the oropharynx. Not all oral cancers are caused by HPV alone. Additional independent risk factors include alcohol, smoking, and smokeless tobacco consumption. Tobacco use, including cigarette smoking and tobacco chewing, is the primary cause of oral cancer worldwide. India has high prevalence of tobacco consumption and 60% of smokeless tobacco users are women. Tobacco users have a fifteen-fold increased risk of oral cancer compared to non-tobacco users. There may be interactions between smokeless tobacco use, oral HPV infection and oral cancer.

Objective: The goal of this project is to examine the prevalence of oral HPV among women who are chronic tobacco users, and determine factors associated with HPV infection. The long-term objective is to inform oral cancer prevention strategies such as tobacco cessation and HPV vaccination within these communities.

Materials and Methods: In June and July 2019, 50 chronic smokeless tobacco users and 50 non-users from rural areas of Mysore were consented to participate in this study. Interviewer administered questionnaires were used to assess demographic and socioeconomic characteristics, tobacco and alcohol use history, and oral health behaviors. Oral samples were collected using an all-collection swab to collect oral cells of the center of tongue, below the tongue, hard palate, buccal mucosa, and upper front gums and placed into a sterile Qiagen collection tube. The brush in the collection kit was used on these regions and placed in the same collection tube as the swab. Lastly, 10 mL saline was given to participants to gargle before spitting out into a separate sample container. The samples were tested with the digeneHC2 High Risk HPV DNA test kit (Qiagen) using microplate chemiluminescence for the qualitative detection of 13 high-risk types of HPV DNA.

Results: The results show that the prevalence of high-risk oral HPV within these communities was very low (2%).

Conclusions: This study shows that the prevalence of oral-HPV among chronic smokeless tobacco using women of the rural/tribal community in Mysore, India, is similar to the prevalence of oral-HPV for women in the United States.

Background: HIV is transmitted by body fluids. As of 2017, 36.9 million people worldwide live with HIV. In Thailand, about 440,000 people live with HIV, accounting for 9% of the region’s total population of people living with HIV. Thus Thailand has high HIV prevalence in the Asia Pacific region. Prevention strategies are effective in the transmission and acquisition of HIV. Oral pre-exposure prophylaxis (PrEP) is the most effective HIV prevention option with an HIV prevention efficacy of 92% when the virus is detected in the blood. When taken in tandem with condoms and adherence to the PrEP regimen, these preventive measures can result in 100% efficacy of preventing the transmission and acquisition of HIV, and sexually transmitted infections (STI). PrEP is offered to anyone who is at risk of HIV infection such as men who have sex with men (MSM), sex workers, transgender women (TGW), and people who inject drugs (PWID). More than half of new HIV infections occur in MSM and TGW in Thailand. In order to provide prevention assistance for these key populations, PrEP is offered to them free of charge through the Princess PrEP Program.

Objective: To assess reasons behind discontinuation of PrEP offered free of charge among high-risk populations in Bangkok, Thailand.

Materials and Methods: The reasons for discontinuation was explored using a behavior and risk factor survey to better explore why clients discontinue PrEP. Surveys were sent through online messenger, email, and mail, in which 120 surveys were returned.

Results: 92 out of 120 respondents (70%) discontinued PrEP. Among TGW and MSM, the main reason for discontinuing PrEP was the fact that clients felt that they were no longer at risk. Over 30% respondents reported that they were no longer at risk, and 60% said they would restart PrEP when their risk increases. Self reported risk behaviors were that of the clients who reported to not be at risk, 43% may not be using condoms, and more than 50% did not return for testing.

Conclusion: At-risk clients misperceive their HIV risk. These results will help in further promoting PrEP services to provide knowledge and discussions for clients about HIV risks, and how to lower risk.

Project Title: Evaluation of the correlation between herpes simplex virus-2 infection and adverse birth outcomes among rural pregnant women in Mysore district, India.

Background: Herpes simplex virus type 2 (HSV-2) is one of the most common sexually transmitted infections worldwide and the main cause of genital ulcers. Although HSV-2 prevalence varies among countries and population, it is more prevalent in developing countries rather than developed countries. HSV-2 can be transmitted sexually, when ulcers or lesions are present, or when skin is broken. HSV-2 is a lifelong asymptomatic infection, however, antivirals can be used to suppress the virus shedding. People with HSV-2 infection are at increased risk for HIV acquisition and transmission, thus the increase in risk of perinatal transmission. Infants exposed to HSV-2 during vaginal delivery can have severe disabilities and malformations. Objective: The objective of this project is to evaluate the prevalence of HSV-2 among pregnant women during childbirth and the correlation HSV-2 has with adverse birth outcomes.

Materials and Methods: Blood samples were collected from pregnant women from Mysore subdistrict, India, in a previously completed project that Public Health Research Institute of India (PHRII) conducted in 2011-2014 called Saving Children Improving Lives (SCIL). All women were administered informed consent prior to the blood draw. Pregnancy outcomes were documented immediately after birth, 3 months and 6 months after delivery. From the SCIL study, 306 random serum samples were analyzed based on their adverse birth outcomes. HerpeSelect 2 ELISA IgG kit (Focus Diagnostics, USA) was used to test the serum samples for HSV-2 specific antibodies. An HSV-2 IgG/IgM Rapid Test kit was also used to retest the ELISA positive serum samples.

Results: Out of the 306 serum samples tested using ELISA there were 17 (5.5%) positive samples with nine (2.9%) high positive (> 3.5 Index Value) and eight (2.6%) low positive (1.10 – 3.5 Index Value), two equivocal and the remaining serum samples were negative. The HSV-2 IgG/IgM Rapid test detected nine samples positive for HSV-2 IgG antibodies; eight from the high positive and one from the low positive serum samples.

Conclusion: Of the 306 serum samples tested from women during childbirth, 5.6% were positive for HSV-2. Data analysis to evaluate the correlation between positive serum samples and the birth outcomes is ongoing.

Background: HIV infection has been a global health issue for past three decades. Around 2 million new cases of HIV are reported every year, and if left untreated will result in AIDS. Currently, there are no vaccines available to prevent acquisition and transmission of HIV. However, preventative measures in the form of pre-exposure prophylaxis (PrEP) have provided an approach to reduce the sexual transmission of the virus. Currently, several clinical trials are ongoing to evaluate the efficacy of local (vaginal or rectal) delivery of anti-HIV drugs for reducing the sexual transmission of HIV infection. Adefovir dipivoxil (ADV) is an FDA-approved nucleotide reverse transcriptase inhibitor used for the treatment of chronic HBV infection. However, recent studies have demonstrated that ADV also has significant activity against HIV-1.

Objective: To develop vaginal films containing ADV for the prevention of HIV infection.

Materials and Methods: Various polymers were evaluated for the development of the placebo vaginal film. The placebo films were prepared using a solvent casting technique. The films were then cut into the desired dimensions. After optimizing the placebo film formulation, films containing ADV were prepared. Finally, an in vitro release test using a Franz diffusion cell was used to measure cumulative drug release from the optimized film formulation with ADV.

Results: The films prepared with the polymer HPMC K100 LV (3%) and PVP K-30 (1%) as well as the HPMC K100 LV (3%) and ethylcellulose 7 cps (0.5%) showed acceptable organoleptic and physical properties. The films containing 5 mg of ADV/7.5 cm2 area exhibited good physicochemical and in vitro drug release.

Conclusion: Vaginal films impregnated with ADV films may be used as a vaginal microbicide product that could effectively provide pre-exposure prophylaxis against sexual transmission of HIV.

Background: Among the 21 species in the genera Angiostrongylus, only one has been confirmed to cause disease in humans. A. cantonensis is a parasitic nematode of rodents whose life-cycle involves a maturation phase in the central nervous system. Infected humans often develop eosinophilic meningitis, and when the infection is confirmed, the condition is called neuroangiostrongyliasis. The two most commonly found species of Angiostrongylus in Thailand are A. cantonensis and A. malaysiensis. Both species exhibit a very similar life-cycle, but only A. cantonensis is considered a human pathogen. Recent molecular studies revealed that A. cantonensis and A. malaysiensis have an overlapping distribution in many parts of Thailand which might indicate that A. malaysiensis is also causing human disease. The two species have similar morphologies, which results in misidentification.

Objective: Compare the morphological identification of the two species with their corresponding molecular analysis.

Materials and Methods: Polymerase chain reaction (PCR) was used to amplify the mitochondrial cytochrome c oxidase subunit 1 (COX1) gene. Fourteen adult worms were obtained from Phayao province, located in Northern Thailand. All fourteen adult worms were morphologically identified and compared with the corresponding PCR results.

Results: Analysis of the data showed a 28.6% mismatch between the two assays.

Conclusion: Further refinement and research are needed to achieve a 0% mismatch to unequivocally differentiate the two species. Understanding the epidemiology and clinical implications of these species is essential for infection control and patient management.