HIV, HPV, and oral health in Tanzania: a scoping review

Abstract

Background

People living with HIV (PLHIV) are at an increased risk of oral manifestations, including those linked to human papillomavirus (HPV). In Tanzania, the prevalence and impact of oral HPV among PLHIV remain unknown. This scoping review aimed to map evidence and identify gaps at the intersection of HIV, HPV, and oral health.

Methods

We conducted a scoping review of studies on oral health in relation to HIV or HPV. Studies involving HPV or oral health among PLHIV were included, while studies conducted outside Tanzania, lacked empirical data, or did not report relevant outcomes were excluded. Outcomes were prevalence of oral manifestations, HPV detection, HPV vaccination, and intervention effectiveness.

Results

Forty-four studies were included. One assessed HPV and oral health; none evaluated HPV vaccination effects on oral outcomes. Prevalence of oral manifestations among PLHIV increased from 10% to 34% over two decades. Antiretroviral therapy reduced oropharyngeal candidiasis but showed no effect on head and neck cancers.

Conclusions

Evidence on HPV-related oral lesions among PLHIV in Tanzania is scarce. Research is needed to define prevalence, risk factors, and barriers to care, which will inform policies to expand HPV vaccination, strengthen the oral workforce, and integrate oral health into HIV services.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13027-026-00760-9.

Introduction

At least two-thirds of the 39 million people living with HIV (PLHIV) globally reside in sub-Saharan Africa, with the highest reported AIDS-related mortality of 380,000 people annually [1]. HIV is also associated with the increased risk of infection by the human papillomavirus (HPV), and evidence suggests that in Tanzania, 12% of women living with HIV (WLHIV) and 26% of men living with HIV (MLHIV) have acquired high-risk HPV (hr-HPV) infection [2, 3]. The rate of hr-HPV infection is significantly higher among PLHIV compared with non-PLHIV [2].

The prevalence of HIV in Tanzania declined from 5.3% in 2011 to 4.5% in 2021, partly due to vigorous HIV/AIDS prevention programs. The country has achieved the 95-95-95 targets: at least 95% of PLHIV have been diagnosed with HIV, 95% of those diagnosed are on antiretroviral therapy (ART), and 95% of those on therapy have attained viral load suppression [4]. This has led to an improved life expectancy for PLHIV. However, longer-term survivorship of PLHIV has also made cancer prevention increasingly imperative, as malignancies have emerged as competing causes of mortality for this population [5].

Along with the well-established links between HPV and cervical and other anogenital cancers, growing attention has been given to HPV’s association with head and neck cancer globally [6]. In addition to head and neck cancer, HPV is also associated with oropharyngeal candidiasis [7]. These two HPV-related conditions are significantly more common in individuals with a history of HIV [5]. However, the association of PLHIV and HPV-related oral manifestations remains largely unexplored in sub-Saharan Africa.

Due to the high burden of morbidity and mortality associated with cervical cancer, Tanzania introduced a national HPV vaccination campaign for 14-year-old girls in 2018 [8]. The current vaccination campaign covers young girls only, resulting in potential gaps for other vulnerable individuals, including PLHIV and others outside of this country-specific age of eligibility. The current campaign’s coverage is in contrast with the Centers for Disease and Control (CDC), recommending the vaccination of males and females aged 11 to 26 years, and a recent expansion of the age of eligibility in the United States to 27–45 years, based on a patient-physician shared decision-making model [9]. This underscores a need to improve the coverage of the HPV vaccination protocol in Tanzania and across sub-Saharan Africa.

Given the limited resources available in Tanzania and other low- and middle-income countries in sub-Saharan Africa, it is critical to explore the complex interplay between HIV, HPV, and oral health. Individuals with HIV have 2–3 times higher odds of contracting oral HPV infections than non-PLHIV [5]. PLHIV were more likely to have a hr-HPV genotype and persistent uncleared infection [10]. Furthermore, they had an increased risk of acquiring HPV-associated and unassociated head and neck cancer [5, 10]. The link between HIV and HPV-associated head and neck cancers has not been thoroughly explored in sub-Saharan Africa. While sub-Saharan Africa has studies on HPV vaccination, none have explored its connection to oral manifestations. Understanding the interplay of HIV, HPV and oral health in Tanzania is important for measuring the burden, defining the barriers, and formulating interventions. This study aimed to fill this gap by conducting a scoping review of the intersection of HIV, HPV, and oral health in Tanzania.

Methods

Research question

The primary research questions for this study were: What is known about the HPV-related oral manifestations among PLHIV in Tanzania, and what gaps exist in the literature? Given this area is understudied, a scoping review was considered the most ideal approach to map existing research and identify knowledge gaps.

Search strategy

The search was developed and conducted by a professional medical librarian (E.B.) in consultation with the author team (K.G. and N.O.P.) and included a mix of keywords and subject headings representing oral health concerns, HPV, HIV and Tanzania. The searches were independently peer reviewed by another librarian using a modified PRESS Checklist [11].

Searches were conducted in MEDLINE via PubMed, Embase via Elsevier, Web of Science via Clarivate, and Global Index Medicus via the World Health Organization, and CABI Global Health via EBSCOhost. The searches were executed on February 9, 2024 and found 423 unique citations. Because of scarcity of available literature, no citation was excluded based on publication date. Complete reproducible search strategies, including search filters, for all databases are detailed in the Supplementary Materials. All citations were imported into Covidence, a systematic review screening software, which also de-duplicated the citations.

Criteria for inclusion

To be included in the study, papers had to document an intersection between oral health and either HIV or HPV. Additionally, it was required that study populations were based in Tanzania only and studies were eligible regardless of their date of publication.

Criteria for exclusion

Authors excluded papers that fell in the wrong geographic region (outside of Tanzania) or were of mixed settings (included Tanzania but also included other regions). The authors also excluded papers that did not contain empirical data, did not explore the intersection of oral health and either HIV or HPV, or were of the wrong study type. Specifically, systematic reviews, scoping reviews, abstracts, case reports, and editorials were excluded. Additionally, papers that were not published in English were excluded from the study and the authors note that this is a limitation of the current project. However, English is widely used as the primary language of academic publication in Tanzania. It is unlikely that the exclusion of non-English studies substantially affected the results, though there is room for further study.

Two coauthors (K.G. and J.M.) reviewed extracted literature, and all disagreements were resolved by N.O.P. The PRISMA extension for scoping reviews was followed. This review was exempt from institutional review board approval as it did not involve human subjects.

Study selection

A total of 840 records were identified from database searches, and 423 titles and abstracts were screened after duplicates were identified and removed. Following selection criteria, 44 studies from Tanzania were included in our final analysis (see Fig. 1). Most of the studies were cross-sectional or cohort studies; however, there were also a few randomized controlled trials, and one qualitative study included (see Table 1). No studies examined the intersection of all HIV, HPV, and oral health areas in Tanzania (see Fig. 2).

Fig. 1.

Study flow chart showing inclusion and exclusion criteria

Table 1.

Characteristics and findings of the 44 articles

Surname, year	Aim of study	Study design	Population description	Related findings of the intersection
Houlihan 2019 [12]	To describe the HPV DNA prevalence in genital and non-genital sites and in the bathroom of unvaccinated adolescent girls, and examine genotype concordance between sites	Cross sectional study	65 Unvaccinated girls aged 16–18 years in Mwanza, who reported ever having had sex	6% of the 63 adequate oral samples had detectable HPV.
Zuckerman 2015 [36]	To evaluate longitudinal oral Herpes Simplex Virus (HSV) reactivation in HIV-positive and negative children.	Cohort study	20 HIV positive ART-naive and 10 HIV negative aged 3–12 years	There was no difference in HSV detection between uncompromised HIV-infected and HIV-uninfected children. HIV-infected children who reported having oral sores have a high rate of HSV detection.
Villamor 2005 [29]	To examine the effect of vitamin supplements on wasting in HIV-infected women and to assess the effects of sociodemographic characteristics, morbidity events, and immunologic progression on the risk of wasting.	Randomised controlled trial	1078 HIV infected women in Tanzania	Oral ulcers and thrush were significantly related to the increased risk of wasting.
Tillekeratne 2009 [33]	To identify the components of an effective Community Home-Based Care (CHBC) program	Cohort study	257 HIV infected adults	Oral thrush and dysphagia were associated with HIV mortality in 2 years.
Sudfeld 2013 [31]	To assess associations of body mass index (BMI in) at antiretroviral therapy (ART) initiation and weight change after 1 month of treatment with mortality, morbidity, and CD4 T-cell reconstitution	Cohort study	3389 Tanzanian adults initiating ART enrolled in a multivitamin trial	Weight loss of HIV patients at 1 month of ART was associated with oral thrush.
Sudfeld 2015 [69]	To prospectively assess the association of vitamin D status with mortality, morbidity, and growth during the first 2 years of life.	Cohort study	53 HIV-infected and 948 HIV-exposed Tanzanian infants	Among HIV-exposed infants, lower concentrations (< 10 ng/mL) of vitamin D were associated with oral candidiasis and wasting. There was no statistically significant association between lower concentrations of vitamin D and HIV mortality.
Ngasala 2016 [16]	To determine the prevalence of oral candida infection in HIV positive patients and investigate the relationship between oral manifestations and the level of immunosuppression.	Cross sectional study	314 HIV patients on ARV and attending hospital for care and treatment	The prevalence of oral candida was 42·0% in HIV individuals, more than half being in the age group 6–17 years. A significantly higher prevalence of candida infection (66·7%) was observed among patients with < 200 cells/µl than in those with 200–500 cells/µl or > 500 cells/µl. The prevalence of oral candida infection was significantly higher in patients with CD4 cell counts of less than 200 cells/µl.
Mwangosi 2011 [17]	To assess the magnitude of and extent of awareness on oral manifestations among People Living With HIV/AIDS (PLWHA) attending counseling and treatment centers in Iringa Municipality in south-western Tanzania.	Cross sectional study	200 PLWHA	23·5% of the PLWHA had at least one oral manifestation, with statistically significant differences across age groups. Clinical manifestations observed were mucosal ulcerations with or without severe periodontal lesions (7·0%), angular cheilitis (7·0%), oral thrush (6·5%), Kaposi’s sarcoma (1·5%), and hairy leukoplakia (1·0%). The majority (89·5%) of PLWHA had sound awareness of clinical oral manifestations with a significant statistical difference by educational status.
Mwangosi 2012 [38]	To assess the prevalences and patterns of oral lesions occurring in HIV and AIDS	Cross sectional study	200 HIV subjects	58·5% were aware of predispositions towards the occurrence of oral lesions such as oral candidiasis (60·0%) in HIV/ AIDS an 72·0% were aware that the lesions are treatable. Some participants reported occurrences of oral thrush (22·5%) and lip ulcerations (28·5%), although only 47·0% of these had sought medical advice. 29·0% of participants had at least one oral lesion associated with HIV/AIDS: 11·5% for herpes simplex, 7·5% for oral candidiasis, 4·0% for oral hairy leukoplakia, 3·5% for Kaposi’s sarcoma; 1·5% for dry mouth; 0·5% for angular cheilitis, and 0·5% for acute necrotizing ulcerative gingivitis. Herpes simplex and Kaposi’s sarcoma were more frequently observed in males (56·5% and 71·4%, respectively), whereas oral candidiasis and dry mouth were observed more often in females (86·7% and 66·7%, respectively).
Mushi 2016 [25]	To compare the oral colonization of non-albicans candida spp. between PLHIV and non-PLHIV in Mwanza, Tanzania.	Cross sectional study	351 PLHIV and 639 non-PLHIV in Mwanza without clinical signs of oral candidiasis	Candida albicans was the commonest spp. detected in both groups 119 (n = 351, 33·90%) of HIV-infected and 146 (n = 639, 22·9%) of non-HIV infected population (p = 0·023). NAC spp. carriage was detected in 64 (n = 990, 6·46%) of the study participants. Of HIV-infected patients, 36/351 (10·3%) carried NAC spp., as compared to only 28/639 (4·4%) among non-HIV infected (P = 0·0003). Only one HIV infected participant was colonized by two NAC spp. The median CD4 cell count among HIV-infected patients colonized by non-albicans Candida spp. was 251 (IQR 170–380) cells/ml, while for those not colonized by NAC spp. was 473 (IQR 304–673·5) cells/ml, P < 0·001. Of 191 HIV-infected individuals without history of antibiotic use, 15 (7·85%) were colonized by NAC spp., as compared to 26 (4·3%) of 606 HIV-uninfected individuals without a history of antibiotic use p = 0·026
Mugusi 2012 [30]	To describe risk factors for mortality and clinical characteristics of HIV-infected patients with and without TB coinfection	Cohort study	255 HIV infected patients without active TB and 231 HIV infected patients with active TB, all with CD4 less than 200	There was no difference between oral candidiasis infectivity among those with or without TB. Oral candidiasis is a predictor of mortality of HIV patients (regardless of the status of TB).
Mugusi 2009 [32]	To investigate factors associated with mortality, including patients’ HIV serostatus, CD4 cell count, laboratory, nutritional and demographic characteristics in Acid- Fast Bacilli smear positive pulmonary TB patients.	Randomized controlled trial	887 TB positive patients aged 18–65 receiving 8 months anti-TB treatment	Oral thrush was associated with mortality of HIV-infected patients. The association still exists after 8 months of treatment of TB. Causes of death could be due to other conditions apart from TB, likely HIV-related causes.
Miller 1995 [70]	To directly compare previously proposed modifications of the original WHO clinical case definition among medical inpatients in a large urban teaching hospital in Tanzania	Cross sectional study	223 inpatients in Muhimbili aged 16 and above	Oral candidiasis and lymphadenopathy as best HIV predictor.
Mehta 2011 [71]	To examine the relationship between low vitamin D status and HIV-related complications	Randomized controlled trial	884 HIV infected women in Tanzania	Low vitamin D is associated with the complication of oral thrush and reported mouth/throat ulcers.
Matee 2000 [18]	To determine the association, if any, between the presence of oral lesions and clinical and immunological status of untreated HIV-infected adults in Tanzania.	Cross sectional study	192 HIV-infected individuals not receiving treatment and 156 individuals confirmed to be HIV-seronegative acted as a control group	Intra-oral lesions were seen among 7·7% of the HIV-seronegative, 10·4% of the HIV-seropositive, and 36·8% of the AIDS groups, respectively. Enlarged parotid glands were seen in 20% of the AIDS patients, 11·9% of the HIV-seropositive, and 5·1% of the HIV seronegative. Enlargement of submandibular salivary glands was seen in 29·6% of the AIDS patients, 31·3% of the HIV-seropositive compared with 14·7% among the HIV-seronegative. The association of oral lesions with the clinical stage of HIV infection and to a lesser extent peripheral CD4 T cell count does suggest that these lesions could be used as additional markers of immunosuppression and AIDS. (OR higher among seropositive, then decreasing CD4 counts, and total lymphocyte counts) Intra-oral lesions occurred in 36·8% of the AIDS patients, which is approximately 3·5 times the frequency among the HIV-seropositive (10·4%) and 4·8 times the frequency among the HIV-seronegative individuals (7·7%). Oral candidiasis and hairy leukoplakia were the most frequent lesion. Carcinoma only seen in AIDS patients 2(1·6%) of 125.
Masoza 2022 [21]	To determine the prevalence, clinical characteristics and outcome of HIV-infected children admitted at Bugando Medical Centre after active provision of Provider Initiated Testing and Counseling services.	Cross sectional study	525 inpatient children	Factors independently associated with oral thrush (OR 20·06). 61·2% of HIV infected had oral thrush while 3·6% of uninfected had oral thrush.
Kinabo 2013 [37]	To estimate the prevalence of nasopharyngeal bacterial colonization (NPBC) patterns in young Tanzanian HIV-exposed infants and to analyze the influence of maternal NPBC and of the infant’s HIV status on the NPBC pattern.	Cohort study	338 HIV exposed infants	In HIV-uninfected infants, colonization with S. pneumoniae was more frequent at 6 weeks, 3 and 6 months of age, than in HIV-infected infants while colonization with S. aureus diminished over time and was more common in HIV-infected infants. Co-colonization of S. pneumoniae with H. influenzae or M. catarrhalis was mostly noticed in HIV- infected infants. Maternal S. aureus colonization was a risk factor for colonization in HIV-infected infants.
Kapiga 1994 [22]	To identify risk factors for HIV infection among women not known to be members of high-risk groups in Dar es Salaam, Tanzania and assess associations between contraceptive use and HIV infection	Cross sectional study	2285 women, not in key and vulnerable groups	Candidiasis found in 15% of HIV-infected women.
Kahabuka 2007 [40]	To investigate the awareness of the oral manifestations of HIV/AIDS and general issues about HIV and AIDS among PLHIV in Dar es Salaam, Tanzania	Cross sectional study	187 PLHIV in Dar es Salaam	13·4% of the participants were completely unaware of the oral manifestations of HIV/AIDS. Participants were relatively well aware of the different types of oral manifestations (e.g., oral ulcers 87%, oral candidiasis 84%) while their knowledge of the management of specific oral manifestations and the problems associated with oral manifestations was more limited.
Hamza 2006 [13]	To compare the prevalence and types of HIV-related oral lesions between children and adult Tanzanian patients on HAART with those not on HAART and to relate the occurrence of the lesions with anti-HIV drug regimen, clinical stage of HIV disease and CD4 cell count	Cross sectional study	532 HIV infected patients, 51 children and 481 adults, 165 males and 367 females Children were aged 2 to 17 years and adults 18 to 67 years	HIV-associated oral lesions were observed in 39·5% of patients. Oral candidiasis was the most common (23·5%), followed by mucosal hyperpigmentation (4·7%), parotid enlargement (3·9%), and oral Kaposi’s sarcoma (3·2%). In children, parotid enlargement (19·6%) was more common than oral candidiasis 11·8%. There was a significant difference in the occurrence of oral candidiasis and parotid enlargement between children and adults. Adult patients on HAART had a significantly lower risk of oral lesions, oral candidiasis, and oral hairy leukoplakia. There was no significant reduction in the occurrence of oral lesions in children on HAART. There was also a significant association between the presence of oral lesions and CD4 + cell count < 200 cell/mm3 and with WHO clinical stage. Oral lesions were also associated with tobacco smoking.
Hamza 2008 [52]	To determine the species distribution of Candida isolates obtained from Tanzanian HIV infected patients with primary and recurrent OPC	Cross sectional study	292 HIV infected patients with oropharyngeal candidiasis at Muhimbili National Hospital	No statistical difference between primary and recurrent oropharyngeal candidiasis. Recurrent oropharyngeal candidiasis and previous antifungal therapy significantly correlated with reduced susceptibility to azoles antifungal agents. C. albicans most frequently isolated species from oropharyngeal candidiasis. Oral yeast from Tanzania had a high level of susceptibility to antifungal agents.
Fawzi 2004 [72]	To examine the effects of daily supplements of vitamin A (preformed vitamin A and beta carotene), multivitamins (Vitamins B, C, and E), or both on progression of HIV disease, using survival models	Randomized controlled trial	1078 pregnant women infected with HIV	Supplementation with multivitamins reduced the incidence of oral thrush, oral ulcers, difficulty in swallowing, and esophageal candidiasis. Micronutrients may protect the integrity of oral and gastrointestinal epithelia and enhance local and systemic immunity.
Faini 2015 [73]	To determine the incidence and prevalence of fungal infections in Tanzania	Other		Oral candidiasis was the most common clinical presentation of ART-naive immunosuppressed HIV pts. About 50% of newly diagnosed HIV pts have oral candidiasis. Esophageal candidiasis among advanced HIV pts, not limited to those ART-naive.
Fabian 2009 [15]	To determine the prevalence of various oral and peri-oral manifestations in PLWHA in Tanzania	Cross sectional study	187 HIV infected	45% of participants had at least one oral condition. 32·5% had 2–4 conditions. The conditions in order of frequency: Candidiasis 28·9% (lips/ mucosa 22·5%, tongue 18·7%, palate 11·8%, gingiva 10·2%), non-tender lymphadenopathy 11·8%, oral ulcers 12·0%, angular cheilitis 5·3%, dry mouth 3·7%, oral hairy leukoplakia 3·7%, herpes zoster 3·2%, necrotizing ulcerative gingivitis/ periodontitis 3·2%, Kaposi’s sarcoma 0·5%. Malnutrition and low BMI was linked to candidiasis.
Idindili 2011 [26]	To share lessons learnt from upscaling ART services	Cross sectional study	611 HIV care and 284 ART patients	Parotid enlargement not associated with increasing CD4 counts. Esophageal candidiasis was present in 13·1% of subjects. It was more prevalent in low CD4 counts: 61(16·9%) for those with CD4 < 100, 16(6·9%) for those with CD4 100–200, and 16 (5·1%) for CD4 > 200.
Bles 2015 [35]	To determine antibiotic susceptibility of colonizing pneumococcal serotypes in HIV-exposed infants before the introduction of the 13-valent pneumococcal conjugate vaccine (PCV13), because HIV-exposed infants are at increased risk of invasive pneumococcal infections	Cross sectional study	104 pneumococcal isolates	There were no differences in antibiotic susceptibility between vaccine and non-vaccine serotypes. Reduced susceptibility of colonizing pneumococcal isolates for commonly used antibiotics is common in HIV-exposed Tanzanian infants.
Anthony 2012 [34]	To assess the prevalence of, and risk factors for, pneumococcal carriage in HIV-positive children aged < 15 years.	Cross sectional study	142 HIV-positive children aged < 15 years	81% of the HIV children had pneumonia in nasopharyngeal swabs.
Shija 2020 [14]	To identify the magnitude of ENT manifestations among HIV-infected patients attended HIV clinics at KCMC based on age, sex, and CD4 count.	Cross sectional study	HIV-infected patients who attended HIV clinics	Sixty-eight (34%) of 200 HIV-infected patients had ENT manifestations. The most affected age group was 0–9 years. Those with CD4 count less than 200cells/µL also it was a high prevalence (56·3%). 13/68 had rhinosinusitis, 11/68 had tonsilitis, 6/68 had esophageal candidiasis, 6/68 had cervical lymphadenopathy, 3/68 had oral candidiasis. We therefore recommend that all clients seeking care at HIV-clinics, particularly those with CD4 counts below 500 cells/µL be screened for ENT conditions. These conditions in this study were not their presenting complaints and were uncovered after screening.
Schiødt 1990 [19]	To report a detailed study on oral lesions and their association with AIDS criteria and serologic signs of HIV infection in Tanzania	Cross sectional study	39 hospitalized suspected AIDS patients, 44 internal medicine unsuspected patients, 53 dental outpatients, and 50 patients with sexually transmitted diseases.	Oral lesions were found in 54% of those with AIDS criteria and 52% of HIV-infected patients, as compared to 3% and 6% of the patients without AIDS criteria and HIV infection, respectively. Among patients with AIDS atrophic candidiasis occurred in 21% pseudomembranous candidiasis in 23%. hairy leukoplakia in 36%, herpetic stomatitis in 2%, Kaposi’s sarcoma in 4%, and nonspecific ulcer in 4%. The presence of oral lesions had a high predictive value for presence of AIDS criteria as well as for presence of HIV infection in this hospital setting. All patients should have a thorough oral examination, and the presence of the oral lesions should lead to testing for HIV infection.
Scheutz 1997 [24]	To determine whether there is an association between carriage of oral yeasts, malnutrition and HIV-1 infection among Tanzanian children.	Case control study	882 children between 1·5-5yrs	The presence of HIV predisposes the carriage of oral yeasts in the tongue and buccal regions.
Plantinga 2010 [23]	To investigate whether genetic variations in the innate immune genes DECTIN-1, TLR2, TLR4, TIRAP, and CASPASE-12 are associated with the presence of OPC in HIV-infected subjects from East Africa.	Cross sectional study	225 HIV patients	No statistical differences of the polymorphism frequencies in most genes of HIV subjects. There may be a immunomodulatory effect of the I223S SNP on dectin-1 function and possibly the susceptibility to OPC in HIV patients
Panya 2009 [20]	To determine the prevalence and pattern of mucocutaneous disorders among HIV infected children attending public pediatric Care and Treatment Centres (CTC) in Dar es Salaam.	Cross sectional study	To determine the prevalence and pattern of mucocutaneous disorders among HIV infected children attending public pediatric CTC in Dar es Salaam.	4% oral candidiasis in HIV children.
Kisangau 2007 [74]	To present the first detailed account of the status and use of traditional medicines in the management of HIV/AIDS opportunistic infections in Tanzania.	Cross sectional study	30 herbal practitioners	25% of plant species are used to treat candidiasis.
Kibonde 2018 [49]	To identify medicinal plant species used to manage HIV/AIDS opportunistic infections by the communities in Rungwe District, Tanzania	Cross sectional study	193 PLHIV	Oral candidiasis utilized 35% of the species (known medicinal plants) in the treatment
Hamza 2008 [52]	To compare the clinical and mycological responses, relapse rates, and safety of a single 750-mg dose and a 14-day course of treatment with fluconazole	Randomized controlled trial	220 HIV-infected patients with clinical and mycological evidence of oropharyngeal candidiasis.	Single-dose and 14-day course fluconazole were both effective in achieving clinical and mycological cure of oropharyngeal candidiasis among HIV patients.
Marealle 2021 [50]	To document medicinal plants used in the management of HIV and AIDS-related conditions in Mbulu District.	Qualitative research	6 traditional health professionals and 37 species	66·7% reported encountering oral thrush. 24% of the herbal medicines reported to treat oral candidiasis.
Tuominen 1992 [39]	To evaluate possible changes in the knowledge of HIV infection and AIDS in Tanzanian dental staff after 1 year	Cross sectional study	89 dental officers, assistant dental officers, and dental assistants	Dental officers and other members of the operating team were not well aware of the oral manifestations of HIV. Some could not mention a single oral symptom.
Simon 2001 [42]	To investigate the types and magnitude of post-extraction complication	Cross sectional study	Dental patients who had their teeth extracted at the Muhimbili Medical Centre dental outpatient clinic	Post-extraction complications are few, mostly minor, self-limiting, and easily treatable. The study does not support routine antibiotic prophylaxis or special pre-extraction procedures, even in this patient population with poor oral hygiene and high HIV seroprevalence.
Scheutz 1997 [41]	To study the natural association between periodontal condition and HIV infection and the stage of infection	Randomized controlled trial	119 HIV-infected adults, 73 individuals with AIDS and 156 control HIV negative	No significance in bleeding on probing, pocket formation or attachment loss among the three groups. No significance of the groups to CD4 counts.
Matee 1999 [28]	To determine the frequency of HIV infection among dental patients attending the three dental facilities at Muhimbili Medical Centre in Dar-es-Salaam, Tanzania, and to compare the dental treatment demands and needs of the patients found to be HIV-infected with those of their HIV-seronegative counterpart	Cross sectional study	460 dental patients	Dental demands/conditions not different between HIV and non-HIV. The high frequency of HIV infection calls for the institution of infection control measures in the dental clinics.
Mwakigonja 2007 [27]	To elucidate viral and cell biological aspects of oral Kaposi Sarcoma (KS) to allow formulation of preventive and therapeutic strategies	Cohort study	74 of 78 subjects were HIV infected	78 (11%) oral cases out of 700 KS registered, where 69·7% were HIV positive and 112 were unknown. Oral Kaposi Sarcoma is highly associated with HIV and advanced/nodular histological stage. HHV-8 lesional content (LANA immunoreactivity) is higher in nodular oral AIDS-related KS (AKS) lesions of males than females and of children than adults. Males appeared to have more tumor burden (multicentricity and systemization) although OKS frequency among females is seemingly higher. 31/78 showed very low CD4 counts. Cell counts of available for (31) oral KS in HIV patient blood showed that 25 (80·7%) had CD4 values of less than 50cells/ µL. Concordantly, most patients (24/31) (77·4%) had a CD4/CD8 ratio < 0·1 implying severe immune deficiency.
Gilyoma 2015 [48]	To describe the clinicopathological profile of HNC in our local setting and highlights the challenges in the management of this disease.	Cohort study	346 confirmed cases of histologically confirmed HNC	No statistical significance between HAART and HNC.
Campbell 2016 [46]	To gain further understanding of Tanzania’s changing cancer burden	Cross sectional study	1127 patients diagnosed/treated in 2010–2014 plus all ORCI patients diagnosed/treated for lung, liver, and HNC 2002–2014  = 2067	7·5% of all head and neck cancer cases were HIV-positive. 81·5% of HIV patients with NADC had head and neck cancer. Of these 81·5, 44.4% of HIV-positive patients were diagnosed with cancer of the oral cavity/oropharynx, 27·2% had cancer of the nasal cavity/ paranasal sinuses, and 9·9% had cancer of the hypopharynx/ larynx/ trachea. Lastly, over half the patients (HIV plus HNC) diagnosed with these NADCs during 2010–2014 presented to ORCI at advanced stages of malignancy.
Koski 2015 [47]	To examine the trend and possible changes in annual proportions of K.S. in relation to all cancers over a 10-year period (2002–2011) that correlated with increased access to ARTs and examine the sociodemographic, clinical, and treatment characteristics of patients with K.S. during the study period.	Cross sectional study	1504 KS from ORCI, of which 72·5% were HIV positive	ART duration showed a protective effect with oral lesions (OR = 0·55, CI: 0·33, 0·91).

Fig. 2.

Venn diagram highlighting the intersection of the 44 studies

Results

Our analysis showed several themes related to HIV infection and oral health in Tanzania. Most of the studies focused on oral manifestations linked to HIV infection and their relationship to immunity and disease development. Other themes explored in the studies included the effect of treatment and nutritional factors, and awareness of oral symptoms among PLHIV. Only one study examined oral HPV detection, but none have investigated the full interaction between HIV status, HPV infection, and oral health outcomes. This highlights a major gap in the literature [12].

This section will explore the themes identified in the studies.

High burden of HIV-related oral conditions in Tanzania

Across ten studies, oral conditions were commonly reported among PLHIV in Tanzania [13–22]. These conditions included oral candidiasis, oral ulcers, hairy leukoplakia, and Kaposi’s sarcoma (KS). For example, Hamza et al. observed HIV-associated oral lesions in 39.5% of patients, with oral candidiasis being the most common manifestation [13]. Similarly, Fabian et al. reported that 45% of participants had at least one oral condition, while Ngasala et al. found a 42% prevalence of oral Candida infection among HIV-positive patients attending clinics [15, 16]. Older studies conducted in the 90s reported oral lesions in AIDS patients and candidiasis in 15% of women patients with HIV [19, 20]. Collectively, these findings demonstrate that oral diseases are highly prevalent among PLHIV and represent a significant component of HIV-related morbidity in Tanzania.

Oral conditions as indicators of immunosuppression

Eight studies showed a strong association between oral conditions and markers of HIV-related immunosuppression [13, 16, 18, 23–27]. Some studies found that oral candidiasis was a common occurrence among HIV patients with lower CD4 counts. Ngasala et al. found that Candida infection was much higher among patients with CD4 counts below 200 cells/µL compared to those with higher counts [16]. Similarly, Hamza et al. and Matee et al. found that patients with CD4 counts below 200 cells/µL and at advanced stages were likely to have oral lesions [13, 28].

Other studies found markers of immunosuppression by HIV among patients with low CD4 counts included oral colonization of non-Candida albicans species and oral Kaposi sarcoma [25, 27]. These findings collectively indicate that oral manifestations may serve as important clinical indicators of immune deterioration in PLHIV.

Oral conditions as predictors of HIV morbidity and mortality

Five studies found that oral conditions are not only indicators of immunosuppression but may also predict adverse clinical outcomes among PLHIV [29–33]. Villamor and colleagues found that among WLHIV, oral ulcers and thrush were highly associated with a higher risk of wasting away [29]. Sudfeld et al. found that after patients began using ART, weight loss and oral thrush developed, suggesting an association between the two [31]. One study found that oral thrush and dysphagia were factors associated with deaths among PLHIV participating in community home-based care programs [33]. Two studies, examining HIV-related deaths among patients who were also infected with tuberculosis, found that oral candidiasis was a significant predictor of mortality [30, 32]. These findings suggest that oral conditions may serve as early clinical indicators of worsening health and increased risk of death among individuals living with HIV.

Microbial colonization

Six studies explored the microbial colonization and opportunistic infections that affected the oral cavity and respiratory tract of HIV-infected individuals [24, 25, 34–37]. Candida was the most identified pathogen. One study found that Candida albicans was the most commonly occurring species in HIV infected patients [25]. The same study found that also non-Candida albicans species were more common among PLHIV than non-PLHIV.

There were also notable differences in microbial colonization between children with and without HIV. An older study conducted in 1997 by Scheutz and colleagues found that children living with HIV were more likely to have oral yeasts [34]. Another study found that Herpes Simplex Virus was associated with oral sores among children with HIV [36]. Two studies found that infants with HIV were more likely to have co-colonization of S. pneumoniae with H. influenzae or M. catarrhalis.[34, 37].

Health-seeking behavior and awareness

Only four studies explored awareness of oral conditions associated with HIV infections and subsequent health-seeking behavior [15, 17, 38, 39].

Mwangosi and colleagues found that most of the study participants were aware of the oral manifestations associated with HIV infection [38]. However, this awareness largely varied by educational level and that despite being aware of the oral conditions, many did not seek medical care [38]. Kahabuka et al. similarly found high levels of awareness but low knowledge of how to manage conditions [40].

Limited knowledge was not only a preserve for the patients. A study by Tuominen and colleagues found that dental health care professionals had limited knowledge about oral symptoms associated with HIV infection [39]. Some care providers could not identify any oral conditions associated with HIV infection [39].

These findings suggest that while there is high awareness of oral conditions associated with HIV among PLHIV, there are gaps in health care professionals’ management and patients’ care seeking.

Three studies identified no difference in dental caries, safety, or post-extraction complications between PLHIV and non-PHIV in dental care [28, 41, 42]. Other studies elsewhere pointed out that dental caries were more prevalent in PLHIV, with 42% to 83%, unlike in Tanzania [43]. An old study in 1992 shared findings that dental workers were unfamiliar with oral manifestations of PLHIV [39]. No follow-up study has been conducted since. Furthermore, studies elsewhere explored continued stigma for PLHIV, rapid testing willingness, and varied barriers in dental settings [44, 45]. More studies are needed to explore different facets of dental care among PLHIV.

HIV-related oral malignancies

Only four studies examined the malignancies among PLHIV in Tanzania [27, 46–48]. Oral KS is one of the most frequently documented malignancies associated with HIV infection. Mwakigonja et al. reported that the majority of oral KS cases occurred among HIV-infected individuals with severe immunosuppression [27].

Koski and colleagues examined the trends in KS incidence in relation to ART coverage [47]. They found that longer duration of ART was associated with a reduced likelihood of oral KS lesions. A study examining broader cancer patterns in Tanzania found that a notable proportion of head and neck cancer cases occurred among HIV-positive individuals, with many presenting at advanced stages of disease [46]. These findings underscore the importance of monitoring oral malignancies as part of HIV care and cancer surveillance programs.

Traditional and pharmaceutical antifungal treatments

This review found studies examining Candida treatment in oral health among PLHIV in Tanzania. Among medicinal plants used in traditional medicine, about a quarter were identified by herbal practitioners as treatment for candidiasis, and 35% of the known medicinal plants were effective [49, 50]. There underlines a great need to document these indigenous practices and evaluate indigenous therapeutic practices for potential clinical application.

Candida in Tanzania has a high susceptibility to antifungal agents with minimal resistance [51]. Another study in 2008 revealed similar effectiveness of a single dose vs. 2-week fluconazole administration for oropharyngeal candidiasis [52]. The single dose was considered cost-effective in resource-constrained settings and may improve treatment adherence [52]. More studies are warranted to determine the effectiveness and adherence of a single-dose treatment before its adoption to clinical treatment guidelines.

Discussion

This scoping review identified a major knowledge gap on the intersection of HPV, HIV and oral health in Tanzania. The absence of published studies on this topic likely reflects broader structural and research system factors rather than the absence of disease burden. While there is a doubled prevalence of HPV oral manifestations among PLHIV in developed countries, there is no data to compare in sub-Saharan Africa [5]. Without immediate action to determine the burden of HPV oral malignancies in Tanzania, health systems will be left unprepared and overwhelmed to manage them. Furthermore, several factors may explain the absence of published evidence such as limited diagnostic capacity for oral HPV detection, research and funding priorities focused on cervical cancer programs, and lack of integrated oral screening programs in HIV care [45, 53, 54].

While no studies in Tanzania identified the risk factors contributing to oral HPV among PLHIV, oral sex is a known primary predictor of hr-HPV oral detection and cancer, especially in men [55]. The practice is common in developed countries, but it is increasingly growing (47%) among university students and adults in sub-Saharan Africa [56, 57]. While there is limited data on oral sex practices in Tanzania, neighboring countries hint at an upward trend. This risk factor may likely lead to the increase of HPV oral transmission for both sexes. Since men are more prone to acquiring oral HPV and are unprotected by the national HPV vaccination guidelines, they are at an even greater risk of malignancy [8, 58]. Another risk factor is HIV-related immunosuppression, which promotes persistent HPV infection and raises the risk of malignant transformation by weakening viral clearance and increasing chronic inflammation [59]. It is paramount to understand these risk factors and prevent the progression to oral malignancy.

Regarding HPV prevention, WHO and the CDC recommend vaccinating young people of both sexes, PLHIV, MSM, and the remaining population, when feasible [9, 60]. Since Tanzania currently vaccinates only girls up to the age of 14, policymakers should extend HPV vaccination coverage to PLHIV and male youth [8]. In addition, HPV vaccination programs should be integrated into schools, health facilities, and outreach programs while accompanied by community-level awareness initiatives to enhance acceptability [8, 61].

Furthermore, an alarming 2023 study reported that WLHIV in Tanzania had a 6-fold higher prevalence of HPV52 than non-WLHIV [2]. This hr-HPV genotype is not covered by the quadrivalent vaccine offered in Tanzania because of its high cost [62]. Urgent attention is needed to further evaluate HPV genotype distribution in Tanzania and assess the potential adoption of broader-coverage HPV vaccines.

Health system gaps contribute to the under-appreciation of HPV-associated oral disease. Tanzania has a marked shortage of oral health workforce and lack of integrated HIV-oral health services, which contributes to the late detection of oral lesions [63, 64]. Incorporating routine oral care into HIV clinics and training dental providers will improve early detection and management of oral lesions.

It is worth noting that our study had limitations. Our study included papers with study designs of empirical evidence, excluding reviews and case reports. This limited the exploration of the subject matter. The review also excluded studies that were not geographically bound solely to Tanzania. The intention was to minimize the lack of generalization of our data. Furthermore, the review included recent and older evidence, regardless of the publication date, for their valuable insights. Because of the long-time range, some findings might not reflect the country’s current situation. It also excluded a few studies without full articles despite the efforts for retrieval. This may have led to selection bias and affected the findings. Lastly, the quality of the included studies differed in methodological approaches and flaws. This may have introduced bias and affected the conclusions.

Global health implications of the study

This scoping review identified an important gap in the intersection of HIV, HPV and oral health, as we found no studies throughout the Tanzanian literature. This limitation, or paucity of data that interlinks oral health, HIV and HPV is also evident throughout the sub-Saharan Africa region, where HIV is endemic, and with an increasing burden of HPV-associated malignancies. In contrast, data indicate that 23% of PLHIV in the U.S. have oral HPV infection, more than double the prevalence of non-PLHIV. MLHIV had a higher prevalence than WLHIV, and oral HPV among PLHIV was linked to oral sex partners and immunodeficiency [65]. The U.S. has an increasing trend of HPV-associated oropharyngeal cancer in PLHIV from 6.8 to 11.44 cases per 100,000 years from 1996 to 2009 [66]. Due to the epidemiologic shift of increasing non-communicable disease burden, there will be an increase in the burden of HPV-associated malignancies in Tanzania in the future [67]. However, the incidence of such cases is unknown. Another U.S. study revealed that PLHIV with HPV-oropharyngeal tumors had a worse prognosis and lower survival. However, it was a small-scale study and presented contrasting evidence from previous studies [68]. While HPV-related HNSCC (head and neck squamous cell carcinoma) tends to have more favorable prognoses than non-HPV HNSCC, the phenomenon is unclear among PLHIV and warrants further studies [68].

Given the burden of disease, the fact that there is little or no data linking HIV, HPV and oral health in Tanzania suggests that there is a critical need for more research and research capacity building in this area.

Conclusions

There are no studies exploring the intersection of HIV, HPV and oral health in Tanzania. It is paramount to determine the prevalence and barriers of HPV-related oral manifestations among PLHIV. These insights will inform stakeholders to develop evidence-based protocols, including expanding HPV vaccination coverage, strengthening oral health workforce, and integrating HIV-oral care services. Further research in this area will also fill the knowledge gaps both in sub-Saharan Africa and globally.

Electronic Supplementary Material

Below is the link to the electronic supplementary material.

Author contributions

All authors contributed equally for Conceptualization, Data Curation, Formal analysis, Investigation, Methodology, Project administration, Resources, Supervision, Writing – original draft, Writing – review & editing.

Funding

No source of funding.

Data availability

Not applicable.

Declarations

Ethics, consent to participate, and consent to publish

Not applicable.

Competing interests

Dr. Osazuwa-Peters received consultation fees from Navigating Cancer and Merck.