Prevalence Of Risk Factors For Infection Research Articles

Prevalence, incidence and correlates of low risk HPV infection and anogenital warts in a cohort of women living with HIV in Burkina Faso and South Africa.

ObjectiveTo report the prevalence and incidence of low-risk human papillomavirus infection (LR-HPV) and anogenital warts (AGW) among women living with HIV (WLHIV) in Burkina Faso (BF) and South Africa (SA), and to explore HIV-related factors associated with these outcomes.MethodsWe enrolled 1238 WLHIV (BF = 615; SA = 623) aged 25–50 years and followed them at three time points (6, 12 and 16 months) after enrolment. Presence of AGW was assessed during gynaecological examination. Cervico-vaginal swabs for enrolment and month 16 follow-up visits were tested for HPV infection by Inno-LiPA® genotyping. Logistic regression was used to assess risk factors for prevalent infection or AGW. Cox regression was used to assess risk factors for incident AGW.ResultsWomen in SA were more likely than those in BF to have prevalent LR-HPV infection (BF: 27.1% vs. SA: 40.9%; p<0.001) and incident LR-HPV infection (BF: 25.8% vs. SA: 31.6%, p = 0.05). Prevalence of persistent LR-HPV was similar in the two countries (BF: 33.3% vs. SA: 30.4%; p = 0.54), as were prevalence and incidence of AGW (Prevalence: BF: 7.5% vs. SA: 5.7%; p = 0.21; Incidence: BF: 2.47 vs. SA: 2.33 per 100 person-years; p = 0.41). HPV6 was associated with incident AGW (BF: adjusted Hazard Ratio (aHR) = 4.88; 95%CI: 1.36–17.45; SA: aHR = 5.02; 95%CI: 1.40–17.99). Prevalent LR-HPV (BF: adjusted Odds Ratio [aOR = 1.86]; 95%CI: 1.01–3.41; SA: aOR = 1.75; 95%CI: 0.88–3.48); persistent LR-HPV (BF: aOR = 1.92; 95%CI: 0.44–8.44; SA: aOR = 2.81; 95%CI: 1.07–7.41) and prevalent AGW (BF: aOR = 1.53; 95%CI: 0.61–3.87; SA: aOR = 4.11; 95%CI: 1.20–14.10) were each associated with low CD4+ counts (i.e. <200 vs. >500 cells/μL). Duration of ART and HIV plasma viral load were not associated with any LR-HPV infection or AGW outcomes.ConclusionLR-HPV infection and AGW are common in WLHIV in sub-Saharan Africa. Type-specific HPV vaccines and effective ART with immunological reconstitution could reduce the burden of AGW in this population.

Risk Factors for Prevalent and Incident Trichomonas vaginalis Among Women Attending Three Sexually Transmitted Disease Clinics

Trichomonas vaginalis is the most common nonviral sexually transmitted infection in the United States and may be associated with adverse birth outcomes and may also increase susceptibility to or transmissibility of human immunodeficiency virus. The purpose of this analysis is to describe the epidemiology of T. vaginalis in Sexually Transmitted Disease clinics and characterize the risk factors associated with prevalent and incident T. vaginalis within the same population. We analyzed data from visits occurring during February 1999-December 2001 from 3 sexually transmitted disease clinics in Newark, NJ; Long Beach, CA; and Denver, CO. Data were analyzed from 1462 women aged 15 to 39 years who were tested by culture at their initial visit for T. vaginalis, and for 1269 women with at least 1 follow-up visit. Risk factors for prevalent infections at baseline and incident infections among treated or previously uninfected women were assessed. At baseline, 13.0% of the women had a prevalent infection; risk factors included the following: older age (> or =20 years), black race, having less than 12 years of education, and having a concurrent chlamydial infection. At follow-up, 4.6% of women had an incident infection; risk factors included the following: older age (35-39 years), black race, having a concurrent chlamydial infection, having had multiple sexual partners in the 3 months before incident infection, and having had T. vaginalis at the visit before their incident infection. T. vaginalis incidence is high in women. Risk factors for prevalent and incident infection are similar. T. vaginalis was associated with older age in women, unlike other sexually transmitted infections.

Case–control study of canine infection by a newly recognised Babesia microti-like piroplasm

We did a case–control study to identify risk factors for prevalent infection of dogs by a newly recognised Babesia microti-like piroplasm. Clinical manifestations and haematology of infected dogs also were described. Forty-three laboratory-based cases and 86 individually matched controls were studied. Information on clinical signs and on risk factors was collected by a questionnaire and telephone interviews. Haematology was carried out for all the dogs. Variables were screened in a bivariable conditional logistic regression and checked for colinearity. The final multivariable model was selected by backward stepwise elimination. The odds of a case having ticks when examined at the clinic was 4 times that of a control and the odds of a case being a hunting or a house-guarding dog were, respectively, 24.2 and 2.7 times those of a control. The most consistently reported clinical signs were weakness (79%), tachycardia (43%) and haemoglobinuria (42%). Mean red-blood-cell count, haemoglobin concentration, platelet count, and mean platelet volume of infected dogs were lower than the reference values and those of non-infected dogs—but leukocyte count, mean corpuscular volume and red-blood-cell distribution width were higher.

Risk factors for infection with verocytotoxigenic Escherichia coli in cattle on Ontario dairy farms

Risk factors for prevalent infection with verocytotoxigenic Escherichia coli (VTEC) were studied in a random sample of 886 cows and 592 calves under 3 months of age on 80 randomly selected dairy farms in southern Ontario. Fecal-culture supernatants from each animal were screened for verocytotoxicity using a Vero cell assay (VCA) and for verocytotoxin (VT) genes by a polymerase chain reaction (PCR) procedure. Up to 20 E. coli isolates from positive samples were tested for VT production using VCA and PCR. VTEC isolates were serotyped. Farm managers were interviewed using a standardized questionnaire to obtain information on farm- and individual animal-level management practices and characteristics. There was a significant ( P<0.001) positive association between age of calves and their VTEC infection status, and calves were significantly more likely to be infected than cows. The proportion of calves infected on the farm was positively associated with both the use of regular pails for feeding calves (as opposed to nipple bottles or nipple pails) and bringing new animals into the herd in the previous year.

Risk factors for bovine infection with verocytotoxigenic Escherichia coli in Ontario, Canada

Risk factors for prevalent infection with verocytotoxigenic Escherichia coli (VTEC) were studied in a random sample of 1131 cows and 659 calves < 3 months of age on 100 dairy farms in southern Ontario. Faecal-culture supernatants from each animal were screened for verocytotoxicity using a Vero cell assay. Five E. coli isolates from positive samples were tested for verocytotoxin production using a test sequence consisting of (1) hybridization with DNA probes for Shiga-like toxin I (SLT-I) and SLT-II sequences, (2) neutralization of verocytotoxicity by a mixture of anti-SLT-I and anti-SLT-IIv antisera, and (3) amplification of SLT genes by a polymerase chain reaction procedure. Neutralization assays were performed on positive faecal-culture supernatants from which no positive isolates were obtained. Farm managers were interviewed using a standardized questionnaire to obtain information on farm and individual animal-level characteristics and management practices. Calves > 2 weeks of age were at significantly greater risk of infection than those under 2 weeks (OR = 2.0). Farm-level calf infection was negatively associated with herd size, the use of nipple bottles for feeding calves, the use of traditional tie-stall housing as opposed to loose housing or other methods, and the maintenance of a closed herd. Farm-level cow infection was negatively associated with herd size, the use of loose housing, the maintenance of a relatively open herd, and the use of milking parlours or pipelines as opposed to bucket-type milking machines. These variables provide potential markers for the VTEC infection status of dairy herds in the target population, but the causal mechanisms underlying these observed associations are unknown.