Sexually transmitted infections among pregnant women attending antenatal clinics in Mongolia: potential impact on the Mongolian HIV epidemic

We conducted Mongolia's first nation-wide cross-sectional survey of sexually transmitted infections (STIs) among pregnant women attending prenatal care. Among our 2000 participants, 386 (19.3%) were infected with Chlamydia trachomatis, 133 (6.7%) with Trichomonas vaginalis, 121 (6.1%) with Neisseria gonorrhoeae, and 128 (6.4%) were seropositive for Treponemal antibodies. None of our participants were seropositive for HIV infection. Additionally, 605 (30.3%) of the women had at least one STI, 133 (6.7%) had a double infection, and 15 (0.8%) had a triple infection. Our results suggest that STIs are a serious problem in Mongolia. Pregnant women represent a lower-risk general population; these high STI rates suggest that at this nascent stage, the identification, treatment, and prevention of STIs as risk factors for HIV transmission are crucial in the prevention of the emerging Mongolian HIV epidemic.     

Histopathological, Serological, and Molecular Confirmation of Indigenous Alveolar Echinococcosis Cases in Mongolia

The combined efficacy of a long-lasting insecticidal net (LLIN) and a carbamate-treated plastic sheeting (CTPS) or indoor residual spraying (IRS) for control of insecticide-resistant mosquitoes was evaluated in experimental huts in Burkina Faso. Anopheles gambiae from the area is resistant to pyrethroids and to a lesser extent, carbamates. Relatively low mortality rates were observed with the LLIN (44%), IRS (42%), and CTPS (52%), whereas both combinations killed significantly more mosquitoes (~70% for LLIN + CTPS and LLIN + IRS). Blood feeding by An. gambiae was uninhibited by IRS and CTPS compared with LLIN (43%), LLIN + CTPS (58%), and LLIN + IRS (56%). No evidence for selection of the kdr and ace-1^R alleles was observed with the combinations, whereas a survival advantage of mosquitoes bearing the ace-1^R mutation was observed with IRS and CTPS. The results suggest that the combination of the two interventions constitutes a potential tool for vector-resistance management.     

Mitochondrial genomes of the human broad tapeworms <Emphasis Type="Italic">Diphyllobothrium latum</Emphasis> and <Emphasis Type="Italic">Diphyllobothrium nihonkaiense</Emphasis> (Cestoda: Diphyllobothriidae)

Mitochondrial DNA (mtDNA) sequences of the human broad tapeworms Diphyllobothrium latum and Diphyllobothrium nihonkaiense have been totally determined. Both of them are closed circular molecules (total length, 13,720 bp in D. latum and 13,747 bp in D. nihonkaiense) containing genes for 12 proteins, 22 transfer RNAs, and two ribosomal RNAs. All the genes are coded on T-rich strand. The gene order of Diphyllobothrium mtDNAs is completely identical with that of Taenia and Echinococcus mtDNAs. The overall A + T contents of the genomes are 68.3% in D. latum and 67.8% in D. nihonkaiense. The pairwise divergence values of nucleotide sequences between these tapeworms ranged from 0.069 to 0.152 in protein-coding genes, demonstrating that D. nihonkaiense is a distinct species. The sequences determined in this study may provide useful marker systems for diagnostic, epidemiological, and phylogeographical studies of human diphyllobothriasis.     

Molecular Characterization of Giardia duodenalis and Cryptosporidium parvum in Fecal Samples of Individuals in Mongolia

The Giardia and Cryptosporidium species are widespread and frequent diarrhea-related parasites affecting humans and other mammalian species. The prevalence of these parasites in Mongolia is currently unknown. Therefore, we performed molecular analyses of G. duodenalis and C. parvum in stool samples from 138 patients hospitalized with diarrhea in Mongolia using nested polymerase chain reaction (PCR). A total of 5 (3.62%) and 7 (5.07%) fecal samples were positive for G. duodenalis and C. parvum, respectively. Giardia duodenalis and C. parvum infections were prevalent in children < 9 years of age. The assemblage-specific fragment patterns for the β-giardin gene of G. duodenalis revealed that all five samples testing positive belonged to Assemblage A by the PCR-restriction fragment polymorphism method. For sequencing and phylogenetic analysis of the 18S rDNA and HSP70 genes of all seven patients testing positive the genes were further identified to be of the C. parvum bovine genotype. This study is the first to report the prevalence of G. duodenalis and C. parvum and its molecular characterization of fecal samples from individuals with diarrhea in Mongolia.     

Taeniasis in Mongolia, 2002-2006

Survey on secondary data of taeniasis/cysticercosis was carried out in Mongolia in 2002-2006. A total of 118 taeniid proglottids, a diphyllobothriid segment, and 59 serum samples from 118 taeniasis cases were collected at National Center for Communicable Diseases, Ulaanbaatar, Mongolia. In 2006, 14 serum samples were collected from local people who had histories of epileptic seizures in Selenge Province where pig husbandry was the main business. The 118 proglottids were confirmed to be Taenia saginata by mitochondrial DNA analysis using cytochrome c oxidase subunit 1 and cytochrome b genes. T. saginata taeniasis was widely distributed at least in 10 of 21 provinces. No variation in the nucleotide sequences of the two genes was observed among T. saginata isolates from Mongolia. There was no evidence of Taenia solium taeniasis/cysticercosis or Taenia asiatica taeniasis. A diphyllobothriid segment was confirmed to be Diphyllobothrium latum by mitochondrial DNA analysis.     

Prevalence of sexually transmitted infections (Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis and human papillomavirus) in female attendees of a sexually transmitted diseases clinic in Ulaanbaatar, Mongolia

BACKGROUND: Epidemiological data suggest that the prevalence of syphilis, gonorrhea and trichomoniasis has increased in both urban and rural areas of Mongolia. These data are primarily substantiated by notifications of cases of clinically apparent disease in both rural and urban areas, plus laboratory diagnoses from the AIDS/STD Reference Center, Ulaanbaatar. In the past 5 years, however, there has been a marked decline in the total number of patients being screened for sexually transmitted infections (STIs). An assessment of true prevalence of STIs in a female population attending an urban sexually transmitted diseases (STD) clinic was therefore commenced. METHODS: Consecutive women attending an STD clinic in Ulaanbaatar had genital samples collected by the insertion and immediate removal of a tampon, which was then tested for the presence of Neisseria gonorrhoeae, Chlamydia trachomatis, human papillomavirus (HPV) and Trichomonas vaginalis, using polymerase chain reaction (PCR) amplification. RESULTS: A total of 110 women were studied (mean age 26.7 years). Overall, 58 (53%) patients had one or more pathogens identified; 43 (39%) had a single pathogen, while 15 (14%) had mixed pathogens. C. trachomatis was found in 15 (14%), N. gonorrhoeae in 12 (11%), T. vaginalis in nine (8%) and HPV in 39 (36%). Among the 39 HPV-positive patients, oncogenicgenotypes (16, 18, 31, 33, 35, 39, 45, 51, 52) were found in 17(44%) patients. CONCLUSIONS: Sexually transmitted infections as defined by PCR were common, and found in 53% of female attendees of an urban STD clinic in Mongolia. As infections with conventional STIs increase the risk of human immunodeficiency virus (HIV) transmission, it is imperative that strategies be introduced to reduce the prevalence of STIs. Furthermore, detection of oncogenic HPV was common, indicating that it is vital that a strategy to reduce cervical cancer such as a pre-cancer cervical cytology screening program also be introduced.     

Mesothelioma in Mongolia: case report

Background:

More than 80% of cases of mesothelioma worldwide have a history of asbestos exposure. In Mongolia, workers in coal burning thermal power plants (TPP) have widely utilized asbestos as an insulation material.

Methods:

We describe the case of a 47-year-old woman diagnosed with a malignant pleural mesothelioma. She worked in a TPP in Ulaanbaatar, Mongolia for 28 years.

Results:

A computer tomography (CT) scan showed a circumferential ring around her left lung, and tissues’ samples had a biphasic variant of mesothelioma with epithelioid and sarcomatoid components.

Discussion:

This is the first reported case of mesothelioma in Mongolia. We expect additional cases of mesothelioma, as well as other asbestos related diseases, will be identified in the future. In order to properly track asbestos related diseases in the country, we recommend the creation of an asbestos related disease registry.     

Human papillomavirus infection in Ulaanbaatar, Mongolia: a population-based study.

Data on human papillomavirus (HPV) and cervical cancer burden in Central Asia are scarce. To investigate HPV infection in Ulaanbaatar, the capital of Mongolia, we obtained cervical cell specimens from a population of 969 women ages 15 to 59 years. DNA of 44 HPV types was detected using a GP5+/6+ PCR-based assay. Seropositivity for L1 proteins of HPV 16, 18, 31, 33, 45, 52, and 58 was assessed using multiplex HPV serology. Cytologic abnormalities were detected in 127 women (13.1%), among whom 6 cervical intraepithelial neoplasia grade 3 and 2 invasive cervical cancers were diagnosed. Overall HPV DNA prevalence was 35.0%, being highest (48.5%) in women ages <25 years. High-risk types were detected in 24.5% of women. HPV DNA prevalence declined with age but remained >25% in all age groups. HPV seroprevalence was also very high (38.0%) and increased steadily from 33.2% to 48.9% in women ages <25 and 50 to 59 years, respectively. However, the proportion of women positive for both HPV markers of any individual HPV type was low. HPV16 was the most frequently detected type by PCR (6.1%), serology (23.0%), or both (2.1%). Lifetime number of sexual partners and induced abortions were shown to be directly associated with HPV DNA and/or seroprevalence. HPV prevalence in Ulaanbaatar was higher than that detected by similar HPV testing protocols in other populations in Asia or elsewhere and would suggest an important, yet unquantified, cervical cancer burden. Improving cervical cancer prevention, through screening and HPV vaccination, is an important public health issue for Mongolia.