Human papillomavirus genotype distribution by cytological status and associated risk factors in the general population of Congolese women living in urban and rural areas: Implications for cervical cancer prevention.

INTRODUCTION: Cervical cancer related to high risk-human papillomavirus (HR-HPV) is the second female cancer in the Republic of Congo (Congo). We herein evaluated the molecular epidemiology of cervical HPV infection and associated risk factors in Congolese women living in urban (Brazzaville) and rural (Plateaux department) settings. PATIENTS AND METHODS: A population-based, cross-sectional survey was conducted to collect demographic and behavioral data among Congolese women, and to obtain endocervical swab samples for HPV DNA molecular detection (Anyplex II HPV28, Seegene, Seoul, South Korea). RESULTS: A total of 284 women (mean age: 37.8 years; HIV-1-positivity: 18.6%) were included. The prevalence of HPV DNA cervical shedding was 64.4% [HR-HPV: 80.9%, mainly HPV-16 (15.8%), and HPV-35 and HPV-52 (15.3%); multiple HPV infections: 60.6%; 9-valent HPV Gardasil-9® vaccine genotypes: 42.6%]. 91.6% and 100% of low-grade squamous intraepithelial neoplasia (LSIL) and cervical cancer, respectively, showed HR-HPV. HR-HPV prevalence was higher among students (aOR: 7.9) and HIV-infected women (aOR: 3.1) in Brazzaville, and among women aged between 21-30 years (aOR: 7.2) and HIV-infected women (aOR: 5.1) in the Plateaux department. CONCLUSION: Cervical HR-HPV infection is particularly frequent in young or HIV-infected Congolese women. Prophylactic HPV vaccination combined with primary molecular screening of HR-HPV infection in this country should be extended.

Molecular characterization of hepatitis B virus among chronic hepatitis B patients from Pointe Noire, Republic of Congo.

BACKGROUND: Chronic Hepatitis B infection is a major health problem in Republic of Congo therefore molecular analysis of HBV strains is important to detect the patients at high risk of disease progression. METHODS: Serum samples were obtained from 111 chronic HBV patients in Pointe Noire. HBsAg, HBeAg and HBeAb were detected. A fragment of the preS1 region of HBV was amplified and sequenced to determine genotypes, subgenotypes and to identify mutations. RESULTS: Of the 111 samples analyzed, 35 patients were asymptomatic carriers (ASC), 24 with a chronic active hepatitis (CAH), 33 with liver cirrhosis (LC) and 19 have a hepatocellular carcinoma (HCC). The mean age were 45 ± 13 year, 88 (79.3 %) were male and 23 (20.7 %) female. The prevalence of HBeAg was 15.3 % and 73 % of subjects were anti-HBe positive. The mean serum level of alanine aminotransferase transaminase (ALT) and aspartate transaminase (AST) was 25.1 ± 9 IU/L and 28.6 ± 10 IU/L respectively. Eighty two samples out of 111 (73.9 %) were genotyped by the analyzing of the S region of HBV, 58 (70.7 %) cases belonged to HBV genotype E and 24 (29.3 %) were genotype A with three subgenotypes; A3 (66.7 %), A4 (20.8 %) and A6 (12.5 %). Prevalence of genotype A was relatively high in CAH (33.3 %) and HCC (31.6 %) patients in comparison with other groups. The most prevalent amino acids substitutions were R38K found in 14 (17.1 %) sequences, following by H44L in 11 (13.4 %), K13E in 8 (9.8 %), N29K in 8 (9.8 %), A35E in 8 (9.8 %), V80I in 7 (8.5 %) and in 6 (7.3 %) sequences for S90T. Different substitutions located in the hepatocyte binding site were higher among patients with LC and HCC (p < 0.05). CONCLUSIONS: This study have shown that HBV genotype E and A were the most frequent strains circulating in Republic of Congo patients. HBV pres1 substitutions found in this study were associated with severe clinical forms of liver diseases. This data have shown the importance of implementing an effective program to fight HBV infection.

Human papillomavirus genotypes distribution by cervical cytologic status among women attending the General Hospital of Loandjili, Pointe-Noire, Southwest Congo (Brazzaville).

HPV infection is associated with cervical cancer, one of the major public health problems in developing countries. In the Republic of Congo, despite of the high age-standardized incidence rate estimated at 25.2 per 100,000 women, molecular epidemiology data on HPV infections are very limited. We investigated HPV genotypes distribution in cervical smears among patients attending the General Hospital of Loandjili, Southwest Congo. A cross-sectional hospital-based study was conducted on 321 women. Liquid-based cytology samples were collected for cytological diagnosis and HPV detection. Nested-PCR was performed using MY09/MY11 and GP5+/GP6+ primers with genotyping by direct sequencing. Type-specific PCR for HPV-6, -11, -16, -18, -31 and -33 was also used to assess multiple infections. Out of 321 women examined, 189 (58.8%) had normal cytology, 16 (5.0%) had ASCUS and 116 (36.1%) had cytological abnormalities. HPV-DNA was detected in 22 (11.6%), 6 (37.5%), and 104 (89.6%) normal cytology, ASCUS and cytological abnormalities respectively. HPV16 was the most prevalent genotype regardless of cytological status followed by HPV70 in women without lesions and HPV33 among those with lesions. HR-HPV prevalence varied significantly according to the cervical cytology (P = 0.000). Among women without lesions, two peaks of HPV infections were observed in age group less than 30 years (60.0%) and in age group 50-59 years (7.1%). Age, age of first sex, multiple sexual partners and pregnancies were the risk factors for HPV infection in women without lesions. Our findings could be used as evidence data base for future epidemiological monitoring in this region.

Genetic variability in E6 and E7 oncogenes of human papillomavirus Type 16 from Congolese cervical cancer isolates.

BACKGROUND: The molecular epidemiological studies showed that some variants of HPV-16, distributed geographically, would present a higher risk of causing cervical cancer. This study aimed to analyze nucleotide changes of HPV-16 E6 and E7 genomic regions from infected Southwestern Congolese women. METHODS: DNA of twenty HPV-16 isolates was analyzed by amplifying the E6 and E7 genes using type-specific primers PCR and direct sequencing. The sequences obtained were aligned with the HPV-16 GenBank reference sequences. RESULTS: Thirteen (65.0%) out of 20 DNA-samples were successfully amplified. Genetic analysis revealed 18 and 4 nucleotide changes in E6 and E7 genomic regions respectively. The most frequently observed nucleotide variations were the missense C143G, G145T and C335T in E6 (100%), leading to the non-synonymous amino acid variation Q14D and H78Y. E7 genomic region was found to be highly conserved with two most common T789C and T795G (100%) silent variations. All HPV-16 variants identified belonged to the African lineage: 7 (53.8%) belonged to Af-1 lineage and 6 (46.1%) to Af-2 lineage. The missense mutation G622A (D21N) in the E7 region seems to be described for the first time in this study. CONCLUSION: This study reported for the first time the distribution of HPV-16 E6 and E7 genetic variants in infected women from southwest Congo. The findings confirmed almost ascendancy of the African lineage in our study population.

Specific genotypes of human papillomavirus in 125 high-grade squamous lesions and invasive cervical cancer cases from Congolese women.

BACKGROUND: Knowledge on HPV prevalence and genotype distribution in HSIL and ICC is highly essential for the introduction of an effective vaccination program and appropriate epidemiological monitoring of viral ecology before and after vaccination in Congo. This study aimed to determine the specific-HPV genotypes in HSIL and ICC among women in southwestern Congo. METHODS: 125 archival paraffin-embedded biopsy collected between 2008 and 2012 and histologically diagnosed were investigated. DNA extraction was performed using the phenol/chloroform method. HPV search was performed by nested-PCR using MY09/MY11 and GP5+/GP6+ consensus primers followed by direct sequencing. RESULTS: The mean age of participants was 44.3 ± 8.2 years. Overall, HPV prevalence was 89.6% (112/125) with all high-risk genotypes. HPV-DNA was detected in 81.5% (53/65) of HSIL and 98.3% (59/60) of ICC. HPV 16 the most common genotype was detected in 47.1% (25/53) of HSIL and 52.5% (31/59) of ICC. Other types identified were: HPV 33 (22.6%), HPV 18 (15%), HPV 31 (11.3%) and HPV 69 (3.7%) in HSIL, and HPV 33 (28.8%), HPV 18 (11.8%), HPV 31 (5%) and HPV 35 (1.7%) in ICC. Knowing that the ADC accounted for 6.7% (4/60) of ICC cases, HPV 18 was identified in 25% (1/4) of these cases against 75% (3/4) for HPV 16. CONCLUSION: Our study showed that HPV 16, 33, 18 and 31 were the four most common genotypes in women with HSIL and ICC. These findings indicate that current vaccines against HPV could help to reduce the burden of cervical cancer in Congo.