Household drug-resistant TB contact tracing in Tajikistan

BACKGROUND: Tajikistan has a high burden of rifampicin-resistant TB (RR-TB), with 2,700 new cases estimated for 2021 (28/100,000 population). TB is spread among household members through close interaction and children exposed through household contact progress to disease rapidly and frequently.METHODS: We retrospectively analysed programmatic data from household contact tracing in Dushanbe over 50 months. We calculated person-years of follow-up, contact tracing yield, number needed to screen (NNS) and number needed to test (NNT) to find one new case, and time to diagnosis.RESULTS: We screened 6,654 household contacts of 830 RR-TB index cases; 47 new RR-TB cases were detected, 43 in Year 1 and 4 in Years 2 or 3. Ten were aged <5 years; 46/47 had TB symptoms, 34/45 had chest radiographs consistent with TB, 11/35 were Xpert Ultra-positive, 29/32 were tuberculin skin test-positive and 28/47 had positive TB culture and phenotypic drug susceptibility results. The NNS to find one RR-TB case was 141.57 and the NNT was 34.49. The yields for different types of contacts were as follows: 0.7% for screened contacts, 2.9% for tested contacts, 17.0% for symptomatic contacts and 12.1% for symptomatic contacts aged below 5 years.CONCLUSION: RR-TB household contact tracing was feasible and productive in Tajikistan, a low middle-income country with an inefficient healthcare delivery system.

Primary bedaquiline resistance in Karakalpakstan, Uzbekistan

BACKGROUND: Bedaquiline (BDQ) is widely used in the treatment of rifampicin-resistant TB (RR-TB). However, resistance to BDQ is now emerging. There are no standardised regimens for BDQ-resistant TB. This study aims to share experience in managing primary BDQ-resistant TB.METHODS: We performed a retrospective study of patients treated for RR-TB in Karakalpakstan, Uzbekistan, from January 2017 to March 2022. We identified patients with resistance to BDQ with no history of BDQ exposure. We describe baseline characteristics, treatment and follow-up of these patients.RESULTS: Twelve of the 1,930 patients (0.6%) had baseline samples resistant to BDQ with no history of BDQ exposure, 75% (9/12) of whom had been previously treated for TB. Ten (83.3%) were resistant to fluoroquinolones; respectively 66% and 50% had culture conversion by Month 3 and Month 6. The interim treatment outcomes were as follows: unfavourable treatment outcomes (3/12, 25%), favourable outcomes (2/12, 17%); the remaining seven (58%) were continuing treatment.CONCLUSIONS: A large proportion of the cases had previously been treated for TB and had TB resistant to quinolone. Both patients who had not experienced culture conversion by Month 3 had an unfavourable treatment outcome. Therefore, we recommend monthly monitoring of culture status for patients on treatment regimens for BDQ resistance.

Epidemiology of chlamydial infection: are we losing ground?

Are we losing ground in our efforts to control sexually transmitted Chlamydia trachomatis infection? Before we can answer this question, we must first consider recent trends in Chlamydia from around the world to establish a baseline for understanding the possible explanations underlying these data.

Incorporating a social networking approach to enhance contact tracing in a heterosexual outbreak of syphilis

OBJECTIVE

This report describes the outcomes of a social networking approach (SNA) in a heterosexually transmitted syphilis epidemic by street nurses in British Columbia, Canada.

METHODS

Street nurses used SNA interviewing cues, environmental observation, peer outreach, serial interviewing, conducted blood tests, and offered treatment on the street. Rates of cases of syphilis identified by outreach nurses and cases linked to another case were compared before and after adoption of an SNA.

RESULTS

SNA resulted in a significantly increased proportion of cases identified by the street nurses (p = 0.01) and increased the percentage of cases linked to a previous case (p = 0.03).

CONCLUSION

This preliminary study confirms that SNA can increase the number of cases and contacts identified in an epidemic of a sexually transmitted disease in a vulnerable, hard to reach population.

Heterosexual outbreak of infectious syphilis: epidemiological and ethnographic analysis and implications for control

This study describes the epidemiology and ethnography of an outbreak of infectious syphilis in Vancouver, British Columbia. Between 1996 and 1999, British Columbias's rate of infectious syphilis rose from 0.5 to 3.4 per 100,000, with a dense concentration of cases among sex trade workers, their clients, and street-involved people in the downtown eastside area of Vancouver. Sexual networks were imported cases with secondary spread (dyads and triads), large densely connected dendritic networks of sex trade workers and clients, or occasional starburst networks among gay men. Only 232 of 429 partners were documented as having been treated (54% of those named, or 0.9 per case). The geographical and demographic concentration of this outbreak led to consideration of a programme of focused mass treatment with single dose azithromycin.

Sex in the city: sexual behaviour, societal change, and STDs in Saigon

HIV infection is increasing among sex workers and injection drug users in southern Vietnam. Vietnamese sex workers returning from Cambodia are an important factor. This phase I growth stage is being accelerated by widespread prostitution and escalating heroin use. Sexually transmitted disease (STD) rates are significant in sex workers but low in the general population. STD epidemics in developing countries may not follow the dynamic topology that is common in developed countries. Vietnam has the potential for significant HIV and STD epidemics but also the capacity to respond to these threats.

Incidence of hepatitis C virus infection among injection drug users during an outbreak of HIV infection

BACKGROUND

Beginning in 1994, Vancouver experienced an explosive outbreak of HIV infection among injection drug users (IDUs). The objectives of this study were to measure the prevalence and incidence of hepatitis C virus (HCV) infection in this context and to examine factors associated with HCV seroconversion among IDUs.

METHODS

IDUs recruited through a study site and street outreach completed interviewer-administered questionnaires covering subjects' characteristics, behaviour, health status and service utilization and underwent serologic testing for HIV and HCV at baseline and semiannually thereafter. A Cox proportional hazards model was used to identify independent correlates of HCV seroconversion.

RESULTS

As of Nov. 30, 1999, 1345 subjects had been recruited into the study cohort. The prevalence of anti-HCV antibodies was 81.6% (95% confidence interval [CI] 79.6% to 83.6%) at enrollment. Sixty-two HCV seroconversions occurred among 155 IDUs who were initially HCV negative and who returned for follow-up, for an overall incidence density rate of 29.1 per 100 person-years (95% CI 22.3 to 37.3). The HCV incidence remained above 16 per 100 person-years over 3 years of observation (December 1996 to November 1999), whereas HIV incidence declined from more than 19 to less than 5 per 100 person-years. Independent correlates of HCV seroconversion included female sex, cocaine use, injecting at least daily and frequent attendance at a needle exchange program.

INTERPRETATION

Because of high transmissibility of HCV among those injecting frequently and using cocaine, the harm reduction initiatives deployed in Vancouver during the study period proved insufficient to eliminate hepatitis C transmission in this population.

Antenatal seroprevalence of herpes simplex virus type 2 (HSV-2) in Canadian women: HSV-2 prevalence increases throughout the reproductive years

BACKGROUND

This study sought to provide the first population estimates of herpes simplex type 2 (HSV-2) seroprevalence in Canada.

GOAL

To measure the antenatal seroprevalence of HSV-2 antibodies in reproductive age women.

STUDY DESIGN

An anonymous unlinked seroprevalence study used stored sera collected from pregnant women in British Columbia during 1999. Randomized sampling within age strata selected a total of 1215 subjects, ages 15 to 44 years. Serologic testing used the Gull Meridian Test. Overall prevalence was directly standardized to the 1999 Canadian female population.

RESULTS

The age-adjusted prevalence for HSV-2 was 17.3% (95% CI, 15.2-19.4). Prevalence ranged from 7.1% (ages, 15-19 years) to 28.1% (ages, 40-44 years), with the largest increases after the age of 24 years.

CONCLUSIONS

The HSV-2 seroprevalence among pregnant women in British Columbia is similar to that in the United States and other countries. Seroprevalence continues to rise through the later reproductive years. This observation may relate to continued transmission, an age cohort effect, or both.

Non-nominal HIV surveillance: preserving privacy while tracking an epidemic

OBJECTIVE

To enhance HIV surveillance within a non-nominal provincial testing system.

METHODS

Confirmatory HIV tests from a provincial laboratory were analyzed during 1995 and 1996. Enhancements included elimination of repeat positive tests for the same individual using automated matching of non-nominal identifiers and nurse call-back of health care providers, completion of missing information through call-back and connection of providers with resources for patient care.

RESULTS

Forty-seven percent of 2,683 reactive HIV tests were identified as duplicates for the same individual, meaning that 1,401 people tested positive for the first time. From laboratory test data to enhanced unduplicated data after call-back, the proportion of tests for which risk and ethnic information was unknown dropped from 37% to 11% and from 64% to 18% respectively (p < 0.0001).

CONCLUSIONS

Enhanced non-nominal surveillance for HIV is a practical means of marrying the needs of public health for epidemiological information and the rights of patients to privacy.

Do needle exchange programmes increase the spread of HIV among injection drug users?: an investigation of the Vancouver outbreak

OBJECTIVE

An association between needle exchange attendance and higher HIV prevalence rates among injecting drug users (IDU) in Vancouver has been interpreted by some to suggest that needle exchange programmes (NEP) may exacerbate HIV spread. We investigated this observed association to determine whether needle exchange was causally associated with the spread of HIV.

DESIGN AND METHOD

Prospective cohort study of 694 IDU recruited in the downtown eastside of Vancouver. Subjects were HIV-negative at the time of recruitment and had injected illicit drugs within the previous month.

RESULTS

Of 694 subjects, the 15-month cumulative HIV incidence was significantly elevated in frequent NEP attendees (11.8+/-1.7 versus 6.2+/-1.5%; log-rank P = 0.012). Frequent attendees (one or more visits per week) were younger and were more likely to report: unstable housing and hotel living, the downtown eastside as their primary injecting site, frequent cocaine injection, sex trade involvement, injecting in 'shooting galleries', and incarceration within the previous 6 months. The Cox regression model predicted 48 seroconversions among frequent attendees; 47 were observed. Although significant proportions of subjects reported obtaining needles, swabs, water and bleach from the NEP, only five (0.7%) reported meeting new friends or people there. When asked where subjects had met their new sharing partners, only one out of 498 respondents cited the needle exchange. Paired analysis of risk variables at baseline and the first follow-up visit did not reveal any increase in risk behaviours among frequent attendees, regardless of whether they had initiated drug injection after establishment of the NEP.

CONCLUSIONS

We found no evidence that this NEP is causally associated with HIV transmission. The observed association should not be cited as evidence that NEP may promote the spread of HIV. By attracting higher risk users, NEP may furnish a valuable opportunity to provide additional preventive/support services to these difficult-to-reach individuals.

Routine prenatal screening for HIV in a low-prevalence setting

BACKGROUND

The objectives of this study were to assess the effect of British Columbia's June 1994 guidelines for prenatal HIV screening on the rate of maternal-fetal HIV transmission and to estimate the cost-effectiveness of such screening.

METHODS

The authors conducted a retrospective review of pregnancy and delivery statistics, HIV screening practices, laboratory testing volume, prenatal and labour management decisions of HIV-positive women, maternal-fetal transmission rates and associated costs.

RESULTS

Over 1995 and 1996, 135,681 women were pregnant and 92,645 carried to term. The rate of HIV testing increased from 55% to 76% of pregnancies on chart review at one hospital between November 1995 and November 1996. On the basis of seroprevalence studies, an estimated 50.2 pregnancies and 34.3 (95% confidence interval 17.6 to 51.0) live births to HIV-positive women were expected. Of 42 identified mother-infant pairs with an estimated date of delivery during 1995 or 1996, 25 were known only through screening. Of these 25 cases, there were 10 terminations, 1 spontaneous abortion and 14 cases in which the woman elected to carry the pregnancy to term with antiretroviral therapy. There was one stillbirth. One instance of maternal-fetal HIV transmission occurred among the 13 live births. The net savings attributable to prevented infections among babies carried to term were $165,586, with a saving per prevented case of $75,266.

INTERPRETATION

A routine offer of pregnancy screening for HIV in a low-prevalence setting reduces the rate of maternal-fetal HIV transmission and may rival other widely accepted health care expenditures in terms of cost-effectiveness.

Factors associated with frequent needle exchange program attendance in injection drug users in Vancouver, Canada

The objective of this study was to identify factors associated with frequent needle exchange program (NEP) attendance by injection drug users (IDUs) in Vancouver, Canada. Data were examined from a case control study of recent HIV infection. IDUs with documented HIV seroconversion after January 1, 1994 (n = 89) and seronegative controls with two documented HIV-negative test results in the same period (n = 192) were asked about demographic and social information, drug injection and sexual behavior, and NEP attendance. Logistic regression was used to examine the effect of multiple variables on NEP attendance while adjusting for HIV status and other potential confounders. Frequent (> 1 time/week) versus nonfrequent (< or = 1 time/week) NEP attenders did not differ with respect to gender, age, ethnicity, education, or HIV serostatus. For men, multivariate analysis showed that frequent cocaine injection was the only variable independently associated with NEP attendance (adjusted odds ratio [AOR] = 3.9; 95% confidence interval [CI] = 1.8-8.3); for women, independently associated variables were frequency of any drug injection (AOR = 5.5; 95% CI = 1.7-17), shooting gallery attendance (AOR = 11.5; 95% CI = 2.2-66), and having a nonlegal source of income (AOR = 3.4; 95% CI = 1.0-12). Borrowing used needles was associated with frequent NEP attendance in the univariate analysis. The NEP in Vancouver attracts IDUs who are frequent injectors (especially men using cocaine) and who have high-risk behaviors or an unstable lifestyle. This finding reinforces the role of NEPs as potential focal points for intervention in this hard-to-reach population.

Determinants of HIV seroconversion in injection drug users during a period of rising prevalence in Vancouver

To identify determinants of HIV seroconversion among injection drug users (IDUs) during a period of rising prevalence, a case-control investigation was conducted. Cases were IDUs with a new positive test after 1 January 1994, and a negative test within the prior 18 months. Controls required 2 negative tests during the same period. Subjects completed a questionnaire on demographic, psychosocial, and behavioural factors. Eighty-nine cases and 192 controls were similar with respect to gender, age, ethnicity and inter-test interval. Multivariate analyses of events during the inter-test interval showed borrowing syringes (adj. OR = 2.96; P < 0.006), unstable housing (adj. OR = 2.01; P = 0.03) and injecting > or = 4 times daily (adj. OR = 1.71; P = 0.06) to be independently associated with seroconversion. Protective associations were demonstrated for sex with opposite gender (adj. OR = 0.36; P = 0.001) and tetrahydrocannabinol use (adj. OR = 0.41; P = 0.001). There is a need to evaluate programmes dealing with addiction, housing and the social underpinnings of risk behaviours in this population.

Needle exchange is not enough: lessons from the Vancouver injecting drug use study

OBJECTIVE

To describe prevalence and incidence of HIV-1, hepatitis C virus (HCV) and risk behaviours in a prospective cohort of injecting drugs users (IDU).

SETTING

Vancouver, which introduced a needle exchange programme (NEP) in 1988, and currently exchanges over 2 million needles per year.

DESIGN

IDU who had injected illicit drugs within the previous month were recruited through street outreach. At baseline and semi-annually, subjects underwent serology for HIV-1 and HCV, and questionnaires on demographics, behaviours and NEP attendance were completed. Logistic regression analysis was used to identify determinants of HIV prevalence.

RESULTS

Of 1006 IDU, 65% were men, and either white (65%) or Native (27%). Prevalence rates of HIV-1 and HCV were 23 and 88%, respectively. The majority (92%) had attended Vancouver's NEP, which was the most important syringe source for 78%. Identical proportions of known HIV-positive and HIV-negative IDU reported lending used syringes (40%). Of HIV-negative IDU, 39% borrowed used needles within the previous 6 months. Relative to HIV-negative IDU, HIV-positive IDU were more likely to frequently inject cocaine (72 versus 62%; P < 0.001). Independent predictors of HIV-positive serostatus were low education, unstable housing, commercial sex, borrowing needles, being an established IDU, injecting with others, and frequent NEP attendance. Based on 24 seroconversions among 257 follow-up visits, estimated HIV incidence was 18.6 per 100 person-years (95% confidence interval, 11.1-26.0).

CONCLUSIONS

Despite having the largest NEP in North America, Vancouver has been experiencing an ongoing HIV epidemic. Whereas NEP are crucial for sterile syringe provision, they should be considered one component of a comprehensive programme including counselling, support and education.

HIV transmission through donor artificial insemination

OBJECTIVE

To investigate and report cases of human immunodeficiency virus (HIV) transmission through donor artificial insemination (AI) before 1986 at five infertility clinics.

DESIGN

Two types of look-back studies were performed: (1) identification of an HIV-infected woman who reported previous AI, followed by identification of the infected donor(s) and contact tracing of women who were inseminated with his semen, and (2) identification of an HIV-infected donor and subsequent examination of women receiving AI procedures using his semen.

SETTING

Five infertility clinics in Los Angeles County, California; San Diego County, California; Arizona; and Vancouver, British Columbia.

PATIENTS

A total of 230 women were inseminated with semen from any one of the five identified HIV-infected donors; 199 (87%) consented to HIV testing.

MAIN OUTCOME MEASURE

Seropositivity for HIV among AI recipients.

RESULTS

Seven (3.52%) of the 199 women (95% confidence interval, 1.55% to 7.41%) who were artificially inseminated with semen from any of five HIV-infected donors and consented to HIV testing tested HIV-seropositive. Information on HIV risk was available for three of the five donors; all three reported a history of having sex with men. Four HIV-infected women were identified through uncommon circumstances, rather than through routine look-back studies of donors.

CONCLUSION

Infection with HIV through donor AI performed before routine HIV screening of semen donors represents a potentially serious threat to women who underwent AI procedures. Public health policies requiring retrospective identification of HIV-infected semen donors and patients receiving AI before 1986, especially in acquired immunodeficiency syndrome (AIDS)-prevalent areas, should be considered routine. Women diagnosed with AIDS or HIV infection, in whom no identified risk of HIV acquisition is established, should be questioned about previous AI procedures.

Unsatisfactory performance of the leukocyte esterase test of first voided urine for rapid diagnosis of urethritis

BACKGROUND AND OBJECTIVES

The objective of this study was to determine the performance characteristics of a dipstick test for leukocyte esterase (LE), (Chemstrip 2LN, Boehringer Mannheim) in predicting the presence of urethritis and urethral pathogens in men presenting to a busy sexually transmitted disease clinic and to street outreach facilities.

METHODS

Urethral swabs for polymorphonuclear (pmn) cell count, gonorrhoea culture and chlamydia enzyme immunoassay (EIA) as well as 15 ml of first voided urine (FVU) were collected from 737 symptomatic and 726 asymptomatic men. Gonorrhoea cultures and pmn counts were processed according to standard methods. Either Abbott Chlamydiazyme EIA (confirmed) or Syva Microtrak EIA (confirmed) test was employed to detect C trachomatis. The LE test was immediately dipped in FVU, read after 60-120 seconds by the clinician and considered positive if trace, 1+ or 2+.

RESULTS

Microscopic evidence of urethritis (> or = = 4 pmn cells per 1000 x field) was found on urethral smear of 782 (53.5%) patients. Chlamydia, gonorrhoea or both were present in 104 (7.1%) patients. Performance characteristics of the LE test were as follows: (table below)

CONCLUSION

The LE test did not have adequate sensitivity to be considered a reliable rapid diagnostic test for urethritis or urethral pathogens, particularly in the asymptomatic portion of this STD clinic population.

Randomized, double-blind, placebo-controlled, patient-initiated study of topical high- and low-dose interferon-alpha with nonoxynol-9 in the treatment of recurrent genital herpes

To explore further topical antiviral therapy for recurrent genital herpes, 188 culture-proven patients were randomized to receive treatment with topical interferon-alpha in high-dose (10(6) IU/g with 1% nonoxynol-9 in 3.5% methylcellulose) or low-dose (10(3) IU/g with 0.1% nonoxynol-9 in 3.5% methylcellulose) treatments or placebo (3.5% methylcellulose, alone), applied three times daily for 5 days. Of these, 105 experienced prodromal symptoms within the study period and applied the medication, of whom 99 could be evaluated for efficacy. Patients were followed with daily clinical assessments and cultures until reepithelialization. The median time to negative virus culture in high-dose recipients was 2.5 days compared with 3.9 days for placebo recipients (P = .023), and a significant dose response was observed (P = .016). Antiviral effects were more prominent in men than women. High-dose recipients also had reduced median duration of symptoms to 2.7 days from 3.7 days for placebo recipients (P = .03), with a significant dose-response relationship (P = .047). Effects on duration of symptoms were more prominent in women. Times to complete reepithelialization in those who applied the drug during the prodromal phase were 5.8 days for high-dose recipients compared with 6.5 days for placebo recipients (P = .053). A multivariate ranked linear model analysis of four efficacy variables (crusting, healing, virus shedding, symptom duration) also favored the high-dose gel (P = .015). High-dose topical interferon-alpha preparation is effective for patients with recurrent genital herpes. Applied early in the course of a recurrent episode, this treatment is safe and may provide a topical alternative to other types of therapy in the future.