Household Contact Tracing Research Articles

Cost-effectiveness of public health strategies for COVID-19 epidemic control in South Africa: a microsimulation modelling study

BackgroundHealth-care resource constraints in low-income and middle-income countries necessitate the identification of cost-effective public health interventions to address COVID-19. We aimed to develop a dynamic COVID-19 microsimulation model to assess clinical and economic outcomes and cost-effectiveness of epidemic control strategies in KwaZulu-Natal province, South Africa.MethodsWe compared different combinations of five public health interventions: health-care testing alone, where diagnostic testing is done only for individuals presenting to health-care centres; contact tracing in households of cases; isolation centres, for cases not requiring hospital admission; mass symptom screening and molecular testing for symptomatic individuals by community health-care workers; and quarantine centres, for household contacts who test negative. We calibrated infection transmission rates to match effective reproduction number (Re) estimates reported in South Africa. We assessed two main epidemic scenarios for a period of 360 days, with an Re of 1·5 and 1·2. Strategies with incremental cost-effectiveness ratio (ICER) of less than US$3250 per year of life saved were considered cost-effective. We also did sensitivity analyses by varying key parameters (Re values, molecular testing sensitivity, and efficacies and costs of interventions) to determine the effect on clinical and cost projections.FindingsWhen Re was 1·5, health-care testing alone resulted in the highest number of COVID-19 deaths during the 360-day period. Compared with health-care testing alone, a combination of health-care testing, contact tracing, use of isolation centres, mass symptom screening, and use of quarantine centres reduced mortality by 94%, increased health-care costs by 33%, and was cost-effective (ICER $340 per year of life saved). In settings where quarantine centres were not feasible, a combination of health-care testing, contact tracing, use of isolation centres, and mass symptom screening was cost-effective compared with health-care testing alone (ICER $590 per year of life saved). When Re was 1·2, health-care testing, contact tracing, use of isolation centres, and use of quarantine centres was the least costly strategy, and no other strategies were cost-effective. In sensitivity analyses, a combination of health-care testing, contact tracing, use of isolation centres, mass symptom screening, and use of quarantine centres was generally cost-effective, with the exception of scenarios in which Re was 2·6 and when efficacies of isolation centres and quarantine centres for transmission reduction were reduced.InterpretationIn South Africa, strategies involving household contact tracing, isolation, mass symptom screening, and quarantining household contacts who test negative would substantially reduce COVID-19 mortality and would be cost-effective. The optimal combination of interventions depends on epidemic growth characteristics and practical implementation considerations.FundingUS National Institutes of Health, Royal Society, Wellcome Trust.

COVID-19 in children: current evidence and key questions.

SARS-CoV-2 infection in children has been less well characterized than in adults, primarily due to a significantly milder clinical phenotype meaning many cases have gone undocumented by health professionals or researchers. This review outlines the current evidence of the epidemiology of infection in children, the clinical manifestations of disease, the role of children in transmission of the virus and the recently described hyperinflammatory syndrome observed later during the first phase of the pandemic. International seroprevalence studies have found younger children to have lower prevalence of antibodies to SARS-CoV-2, indicating they have not been infected as much as adults. This may be due to shielding by school closures, or by a reduced susceptibility to infection, as indicated by a significantly lower attack rate in children than adults in household contact tracing studies. The most well recognized symptoms in adults of cough, fever, anosmia and ageusia are less frequent in children, who may often present with mild and nonspecific symptoms, or with gastrointestinal symptoms alone. Risk factors for severe disease in children include chronic lung, cardiac or neurological disease, and malignancy. However, the absolute risk still appears very low for these cohorts. A new hyperinflammatory syndrome has emerged with an apparent immune cause. Important questions remain unanswered regarding why children have mild disease compared with adults; how children of different ages contribute to asymptomatic community transmission of the virus; and the pathophysiology of and most appropriate investigation and treatment strategies for the novel hyperinflammatory syndrome.

Using community health workers for facility and community based TB case finding: An evaluation in central Mozambique.

Mozambique has one of the highest incidence rates of both TB and HIV in the world and an estimated tuberculosis (TB) treatment coverage of only 57% in 2018. Numerous approaches are being tested to reduce existing gaps in coverage and the estimated number of missing cases. Thirty Community Healthcare Workers (CHWs) were tasked with increasing TB notifications by performing verbal facility-based TB screening of all people presenting for care and TB contact tracing in the community. Using routine National TB Program data, we analyzed trends in TB notifications in five intervention districts and seven control districts in Manica province the year before this project and during a one-year intervention period. In the four quarters before the study, the intervention districts notified 5,219 individuals with all forms of TB, and the control districts notified 2,248 TB cases. During the study 5,982 all forms of people with TB were notified in the intervention area, an increase of 763 (14.6%) over the baseline, whereas the control districts notified 1,877 persons with TB, a decrease of -371 (-16.5%). The CHW screening activities yielded 1,502 notified and treated individuals with TB. Employing CHWs to promote facility-based TB screening and household contact tracing may lead to an overall increase in TB notification.

Weekly COVID-19 testing with household quarantine and contact tracing is feasible and would probably end the epidemic.

The COVID-19 epidemic can probably be ended and normal life restored, perhaps quite quickly, by weekly SARS-CoV-2 RNA testing together with household quarantine and systematic contact tracing. Isolated outbreaks could then be contained by contact tracing, supplemented if necessary by temporary local reintroduction of population testing or lockdown. Leading public health experts have recommended that this should be tried in a demonstration project in which a medium-sized city introduces weekly testing and lifts lockdown completely. The idea was not considered by the groups whose predictions have guided UK policy, so we have examined the statistical case for such a study. The combination of regular testing with strict household quarantine, which was not analysed in their models, has remarkable power to reduce transmission to the community from other household members as well as providing earlier diagnosis and facilitating rapid contact tracing.

Yield of Systematic Longitudinal Screening of Household Contacts of Pre-Extensively Drug Resistant (PreXDR) and Extensively Drug Resistant (XDR) Tuberculosis Patients in Mumbai, India.

While risk of tuberculosis (TB) is high among household contacts (HHCs) of pre-extensively drug resistant (pre-XDR) TB and XDR-TB, data on yield of systematic longitudinal screening are lacking. We aim to describe the yield of systematic longitudinal TB contact tracing among HHCs of patients with pre-XDR-TB and XDR-TB. At the Médecins Sans Frontières (MSF) clinic, Mumbai, India a cohort comprising 518 HHCs of 109 pre-XDR and XDR index cases was enrolled between January 2016 and June 2018. Regular HHC follow-ups were done till one year post treatment of index cases. Of 518 HHCs, 23 had TB (21 on TB treatment and two newly diagnosed) at the time of first visit. Of the rest, 19% HHCs had no follow-ups. Fourteen (3.5%) TB cases were identified among 400 HHCs; incidence rate: 2072/100,000 person-years (95% CI: 1227–3499). The overall yield of household contact tracing was 3% (16/518). Of 14 who were diagnosed with TB during follow-up, six had drug susceptible TB (DSTB); six had pre-XDR-TB and one had XDR-TB. Five of fourteen cases had resistance patterns concordant with their index case. In view of the high incidence of TB among HHCs of pre-XDR and XDR-TB cases, follow-up of HHCs for at least the duration of index cases’ treatment should be considered.

Exploration of barriers and facilitators to household contact tracing of index tuberculosis cases in Anlemo district, Hadiya zone, Southern Ethiopia: Qualitative study.

BackgroundTuberculosis [TB] is the second leading cause of death from an infectious disease in the world. Intensifying tuberculosis screening and contact investigation strategy is recommended to ensure early diagnosis among household contacts of TB patients. Studies showed that there is low TB contact tracing. There was limited evidence on barriers and facilitators of household contact tracing. Therefore, this study was aimed at exploring barriers and facilitators for household contact tracing of index TB cases.MethodsA descriptive qualitative study was conducted at Anlemo district, Hadiya zone, Ethiopia from March 12-April 9, 2019. Purposive sampling technique was used to recruit study participants. A total of 16 participants were involved in the study which included health extension workers [HEWs], index TB patients, household contacts of TB patients, health center TB focal and district TB coordinator. Data were collected through in-depth interviews using a semi-structured guide, transcribed verbatim and translated into English. Inductive thematic analysis was employed using ATLAS.ti7.1 software and the findings were presented on major themes, categories, and quotations.ResultsThis study found low TB contact tracing and investigation, and explored barriers and facilitators such as monitoring and supervision, training of health workers, logistics and infrastructure, waiting time and institutional readiness, referral, feedback and linkage, human resource, charge for some laboratory, transportation, budget, knowledge, commitment and motivation, workload, distance, social support, economic constrain, and stigma and discrimination for household contact tracing of index TB cases under four themes.ConclusionsFrom this study, it was understood that there was a gap in addressing all household contacts. Also, the study explored a wide range of possible barriers and facilitators for it. Explored barriers outweigh the facilitators which might have an implication facilitating the dissemination of TB silently within the community. This underscores the importance of taking action to avert those barriers by developing different strategies to increase TB contact tracing. Therefore, health care providers should have to improve the implementation of contact tracing by designing and developing appropriate strategies that should fit the local context.

Electronic data capture for large scale typhoid surveillance, household contact tracing, and health utilisation survey: Strategic Typhoid Alliance across Africa and Asia.

Electronic data capture systems (EDCs) have the potential to achieve efficiency and quality in collection of multisite data. We quantify the volume, time, accuracy and costs of an EDC using large-scale census data from the STRATAA consortium, a comprehensive programme assessing population dynamics and epidemiology of typhoid fever in Malawi, Nepal and Bangladesh to inform vaccine and public health interventions. A census form was developed through a structured iterative process and implemented using Open Data Kit Collect running on Android-based tablets. Data were uploaded to Open Data Kit Aggregate, then auto-synced to MySQL-defined database nightly. Data were backed-up daily from three sites centrally, and auto-reported weekly. Pre-census materials' costs were estimated. Demographics of 308,348 individuals from 80,851 households were recorded within an average of 14.7 weeks range (13-16) using 65 fieldworkers. Overall, 21.7 errors (95% confidence interval: 21.4, 22.0) per 10,000 data points were found: 13.0 (95% confidence interval: 12.6, 13.5) and 24.5 (95% confidence interval: 24.1, 24.9) errors on numeric and text fields respectively. These values meet standard quality threshold of 50 errors per 10,000 data points. The EDC's total variable cost was estimated at US$13,791.82 per site. In conclusion, the EDC is robust, allowing for timely and high-volume accurate data collection, and could be adopted in similar epidemiological settings.

Intensified household contact tracing, prevention and treatment support versus enhanced standard of care for contacts of tuberculosis cases in South Africa: study protocol for a household cluster-randomised trial

BackgroundHousehold contact tracing of index TB cases has been advocated as a key part of TB control for many years, but has not been widely implemented in many low-resource setting because of the current dearth of high quality evidence for effectiveness. Innovative strategies for earlier, more effective treatment are particularly important in contexts with hyper-endemic levels of HIV, where levels of TB infection remain extremely high.MethodsWe present the design of a household cluster-randomised controlled trial of interventions aimed at improving TB-free survival and reducing childhood prevalence of Mycobacterium tuberculosis infection among household contacts of index TB cases diagnosed in two provinces of South Africa. Households of index TB cases will be randomly allocated in a 1:1 ratio to receive either an intensified home screening and linkage for TB and HIV intervention, or enhanced standard of care. The primary outcome will compare between groups the TB-free survival of household contacts over 15 months. All participants, or their next-of-kin, will provide written informed consent to participate.DiscussionEvidence from randomised trials is required to identify cost-effective approaches to TB case-finding that can be applied at scale in sub-Saharan Africa.Trial registrationISRCTN16006202 (01/02/2017: retrospectively registered) and NHREC4399 (11/04/2016: prospectively registered). Protocol version: 4.0 (date: 18th January 2018).

Yield of household contact tracing for tuberculosis in rural South Africa

BackgroundEfficient and effective strategies for identifying cases of active tuberculosis (TB) in rural sub-Saharan Africa are lacking. Household contact tracing offers a potential approach to diagnose more TB cases, and to do so earlier in the disease course.MethodsAdults newly diagnosed with active TB were recruited from public clinics in Vhembe District, South Africa. Study staff visited index case households and collected sputum specimens for TB testing via smear microscopy and culture. We calculated the yield and the number of households needed to screen (NHNS) to find one additional case. Predictors of new TB among household contacts were evaluated using multilevel logistic regression.ResultsWe recruited 130 index cases and 282 household contacts. We identified 11 previously undiagnosed cases of bacteriologically-confirmed TB, giving a prevalence of 3.9% (95% CI: 2.0–6.9%) among contacts, a yield of 8.5 per 100 (95% CI: 4.2–15.1) index cases traced, and NHNS of 12 (95% CI: 7–24). The majority of new TB cases (10/11, 90.9%) were smear negative, culture positive. The presence of TB symptoms was not associated with an increased odds of active TB (aOR: 0.3, 95% CI: 0.1–1.4).ConclusionsHousehold contacts of recently diagnosed TB patients in rural South Africa have high prevalence of TB and can be feasibly detected through contact tracing, but more sensitive tests than sputum smear are required. Symptom screening among household contacts had low sensitivity and specificity for active TB in this study.

Minimum requirements and optimal testing strategies of a diagnostic test for leprosy as a tool towards zero transmission: A modeling study.

BackgroundThe availability of a diagnostic test to detect subclinical leprosy cases is crucial to interrupt the transmission of M. leprae. In this study we assessed the minimum sensitivity level of such a (hypothetical) diagnostic test and the optimal testing strategy in order to effectively reduce the new case detection rate (NCDR) of leprosy.Methods and findingsWe used the individual-based model SIMCOLEP, and based it on previous quantification using COLEP data, a cohort study of leprosy cases in Bangladesh. The baseline consisted of treatment with Multidrug therapy of clinically diagnosed leprosy cases, passive case detection and household contact tracing. We examined the use of a leprosy diagnostic test for subclinical leprosy in four strategies: testing in 1) household contacts, 2) household contacts with a 3-year follow-up, 3) a population survey with coverage 50%, and 4) a population survey (100%). For each strategy, we varied the test sensitivity between 50% and 100%. All analyses were conducted for a high, medium, and low (i.e. 25, 5 and 1 per 100,000) endemic setting over a period of 50 years.In all strategies, the use of a diagnostic test further reduces the NCDR of leprosy compared to the no test strategy. A substantial reduction could already be achieved at a test sensitivity as low as 50%. In a high endemic setting, a NCDR of 10 per 100,000 could be reached within 8–10 years in household contact testing, and 2–6 years in a population testing. Testing in a population survey could also yield the highest number of prevented new cases, but requires a large number needed to test and treat. In contrast, household contact testing has a smaller impact on the NCDR but requires a substantially lower number needed to test and treat.ConclusionsA diagnostic test for subclinical leprosy with a sensitivity of at least 50% could substantially reduce M. leprae transmission. To effectively reduce NCDR in the short run, a population survey is preferred over household contact tracing. However, this is only favorable in high endemic settings.

Household point of care CD4 testing and isoniazid preventive therapy initiation in a household TB contact tracing programme in two districts of South Africa.

BackgroundIn South Africa, TB household contact tracing provides an opportunity for increased TB and HIV case finding. We aimed to determine the effect of two new potential interventions for TB contact tracing programmes: Point of Care CD4 (PoC CD4) on HIV linkage to care and household Isoniazid Preventive Therapy (IPT) provision on uptake and retention of IPT.MethodsA pragmatic, three-arm, cluster-randomized trial was undertaken. TB Household contacts were randomised to 3 arms: 1) Standard of Care TB and HIV testing (SOC); 2) SOC with POC CD4 for those testing HIV positive; 3) SOC with POC CD4 and IPT for eligible household members. Linkage to care within 90 days was assessed either through patient visits (at 10 weeks and 6 months) or via telephonic contact.Results2,243 index TB patients and 3,012 contacts (64,3% female, median age 30 years) were enrolled. On self-report, 26(1.2%) were currently receiving TB treatment and 1816 (60.3%) reported a prior HIV test. HIV testing uptake was 34.7% in the SoC arm, 40.2% in the PoC CD4 arm (RR1.16, CI 0.99–1.36, p-value = 0.060) and 39.9% in the PoC CD4 + HH-IPT arm (RR = 1.15, CI 0.99–1.35, p-value = 0.075). Linkage to care within 3 months was 30.8% in the SoC arm and 42.1% in the POC CD4 arms (RR 1.37; CI: 0.68–2.76, p-value = 0.382). 20/21 contacts (95.2%) initiated IPT in the PoC CD4 + HH-IPT arm, compared to 3/20 (15.0%) in the PoC CD4 arm (p = 0.004; p-value from Fisher’s exact test < 0.001). Among 3,008 contacts screened for tuberculosis, 15 (3.4%) had bacteriologically confirmed TB with an overall yield of TB of 0.5% (95% CI: 0.3%, 0.8%).ConclusionsHousehold PoC CD4 testing and IPT initiation is feasible. There was only weak evidence that PoCCD4 led to a small increase in HCT uptake and no evidence for an increase in linkage-to-care. IPT initiation and completion was increased by the household intervention. Although feasible, these interventions had low impact due to the low uptake of HIV testing in households.

Leveraging tuberculosis case relative locations to enhance case detection and linkage to care in Swaziland

BackgroundIn Swaziland, as in many high HIV/TB burden settings, there is not information available regarding the household location of TB cases for identifying areas of increased TB incidence, limiting the development of targeted interventions. Data from “Butimba”, a TB REACH active case finding project, was re-analyzed to provide insight into the location of TB cases surrounding Mbabane, Swaziland.ObjectiveThe project aimed to identify geographical areas with high TB burdens to inform active case finding efforts.MethodsButimba implemented household contact tracing; obtaining landmark based, informal directions, to index case homes, defined here as relative locations. The relative locations were matched to census enumeration areas (known location reference areas) using the Microsoft Excel Fuzzy Lookup function. Of 403 relative locations, an enumeration area reference was detected in 388 (96%). TB cases in each census enumeration area and the active case finders in each Tinkhundla, a local governmental region, were mapped using the geographic information system, QGIS 2.16.ResultsUrban Tinkhundla predictably accounted for most cases; however, after adjusting for population, the highest density of cases was found in rural Tinkhundla. There was no correlation between the number of active case finders currently assigned to the 7 Tinkhundla surrounding Mbabane and the total number of TB cases (Spearman rho = −0.57, p = 0.17) or the population adjusted TB cases (Spearman rho = 0.14, p = 0.75) per Tinkhundla.DiscussionReducing TB incidence in high-burden settings demands novel analytic approaches to study TB case locations. We demonstrated the feasibility of linking relative locations to more precise geographical areas, enabling data-driven guidance for National Tuberculosis Programs’ resource allocation. In collaboration with the Swazi National Tuberculosis Control Program, this analysis highlighted opportunities to better align the active case finding national strategy with the TB disease burden.

Targeted Treatment of Yaws With Household Contact Tracing: How Much Do We Miss?

Yaws is a disabling bacterial infection found primarily in warm and humid tropical areas. The World Health Organization strategy mandates an initial round of total community treatment (TCT) with single-dose azithromycin followed either by further TCT or active case-finding and treatment of cases and their contacts (the Morges strategy). We sought to investigate the effectiveness of the Morges strategy. We employed a stochastic household model to study the transmission of infection using data collected from a pre-TCT survey conducted in the Solomon Islands. We used this model to assess the proportion of asymptomatic infections that occurred in households without active cases. This analysis indicated that targeted treatment of cases and their household contacts would miss a large fraction of asymptomatic infections (65%–100%). This fraction was actually higher at lower prevalences. Even assuming that all active cases and their households were successfully treated, our analysis demonstrated that at all prevalences present in the data set, up to 90% of (active and asymptomatic) infections would not be treated under household-based contact tracing. Mapping was undertaken as part of the study “Epidemiology of Yaws in the Solomon Islands and the Impact of a Trachoma Control Programme,” in September–October 2013.

Recent household transmission of tuberculosis in England, 2010\u20132012: retrospective national cohort study combining epidemiological and molecular strain typing data

BackgroundWe estimate the proportion of tuberculosis (TB) in England due to recent household transmission, identify factors associated with being a household transmitter, and investigate the impact that identification of a case has on time to treatment of subsequent cases.MethodsTB cases notified between 2010 and 2012 in England in the same household as another case were identified; 24 locus MIRU-VNTR strain typing (ST) was used to identify household cases with likely recent transmission. Treatment delay in index and subsequent cases was compared. Risk factors for being a household transmitter were identified in univariable and multivariable analyses.ResultsOverall, 7.7% (1849/24,060) of TB cases lived in a household with another case. We estimate that 3.9% were due to recent household transmission. ST data was unavailable for 67% (1242) of household pairs. For those with ST data, 64% (386) had confirmed, 11% probable (66) and 25% (155) refuted household transmission. The median treatment delay was 65 days for index cases and 37 days for subsequent asymptomatic cases. Risk factors for being a household transmitter included being under 25 years old, UK-born with Black African, Indian or Pakistani ethnicity, or born in Somalia or Romania.ConclusionsThis study has a number of implications for household TB contact tracing in low incidence countries, including the potential to reduce the diagnostic delay for subsequent household cases and the benefit of using ST to identify when to conduct source contact tracing outside the household. As 25% of TB cases in households had discordant strains, households with multiple TB cases do not necessarily represent household transmission. The additional fact that 25% of index cases within households only had extra-pulmonary TB demonstrates that, if household contact tracing is limited to pulmonary TB cases (as recently recommended in UK guidelines), additional cases of active TB in households will be missed. Our finding that no lineage of TB was associated with recent household transmission and with no increased transmissibility in the Beijing lineage compared to others, suggests that the lineage need not impact contact tracing efforts. Improvements in contact tracing have the potential to reduce transmission of TB in low incidence countries.

BUTIMBA: Intensifying the Hunt for Child TB in Swaziland through Household Contact Tracing.

BackgroundLimited data exists to inform contact tracing guidelines in children and HIV-affected populations. We evaluated the yield and additionality of household contact and source case investigations in Swaziland, a TB/HIV high-burden setting, while prioritizing identification of childhood TB.MethodsIn partnership with 7 local TB clinics, we implemented standardized contact tracing of index cases (IC) receiving TB treatment. Prioritizing child contacts and HIV-affected households, screening officers screened contacts for TB symptoms and to identify risk factors associated with TB. We ascertained factors moderating the yield of contact tracing and measured the impact of our program by additional notifications.ResultsFrom March 2013 to November 2015, 3,258 ICs (54% bacteriologically confirmed; 70% HIV-infected; 85% adults) were enrolled leading to evaluation of 12,175 contacts (median age 18 years, IQR 24–42; 45% children; 9% HIV-infected). Among contacts, 196 TB cases (56% bacteriologically confirmed) were diagnosed resulting in a program yield of 1.6% for all forms of TB. The number needed to screen (NNS) to identify a bacteriologically confirmed TB case or all forms TB case traced from a child IC <5 years was respectively 62% and 40% greater than the NNS for tracing from an adult IC. In year one, we demonstrated a 32% increase in detection of bacteriologically confirmed child TB. Contacts were more likely to have TB if <5 years (OR = 2.0), HIV-infected (OR = 4.9), reporting ≥1 TB symptoms (OR = 7.7), and sharing a bed (OR = 1.7) or home (OR = 1.4) with the IC. There was a 1.4 fold increased chance of detecting a TB case in households known to be HIV-affected.ConclusionContact tracing prioritizing children is not only feasible in a TB/HIV high-burden setting but contributes to overall case detection. Our findings support WHO guidelines prioritizing contact tracing among children and HIV-infected populations while highlighting potential to integrate TB and HIV case finding.

Household Contact Tracing of Adult Pulmonary Tuberculosis (TB) Patients in India: Prevalence of TB disease and Infection

Household Contact Tracing of Adult Pulmonary Tuberculosis (TB) Patients in India: Prevalence of TB disease and Infection

Household HIV Testing Uptake among Contacts of TB Patients in South Africa.

BackgroundIn high HIV prevalence settings, offering HIV testing may be a reasonable part of contact tracing of index tuberculosis (TB) patients. We evaluated the uptake of HIV counselling and testing (HCT) among household contacts of index TB patients and the proportion of newly diagnosed HIV-infected persons linked into care as part of a household TB contact tracing study.MethodsWe recruited index TB patients at public health clinics in two South African provinces to obtain consent for household contact tracing. During scheduled household visits we offered TB symptom screening to all household members and HCT to individuals ≥14years of age. Factors associated with HCT uptake were investigated using a random effects logistic regression model.Results & DiscussionOut of 1,887 listed household members ≥14 years old, 984 (52%) were available during a household visit and offered HCT of which 108 (11%) self-reported being HIV infected and did not undergo HCT. Of the remaining 876, a total of 304 agreed to HCT (35%); 26 (8.6%) were newly diagnosed as HIV positive. In multivariable analysis, factors associated with uptake of HCT were prior testing (odds ratio 1.6; 95% confidence interval [CI]: 1.1–2.3) and another member in the household testing (odds ratio 2.4; 95% CI: 1.7–3.4). Within 3 months of testing HIV-positive, 35% reported initiating HIV care.ConclusionHCT as a component of household TB contact tracing reached individuals without prior HIV testing, however uptake of HIV testing was poor. Strategies to improve HIV testing in household contacts should be evaluated.

PWE-118 Hepatitis b testing practice: how widespread is household contact tracing?

<h3>Introduction</h3> Contact tracing in hepatitis B (HBV) is nationally and internationally advocated. Acute HBV is managed by Public Health England (PHE). However, the expectation and responsibility for contact tracing in chronic HBV lies predominately with primary care, with no formal implementation strategy or monitoring system in place. <h3>Method</h3> The Surrey Pathology Partnership serves over 1 million individuals in South East England. We collected laboratory data from the past 10 years on all Hepatitis B Surface Antigen (HBsAg), and Core Antibody (total HBcAb) testing requests, to assess the uptake and efficacy of contact-tracing amongst those with HBV. We identified address and postcode data from hospital and community-based testing requests (excluding anonymised GUM data) to identify those individuals who had undergone household contact-testing for HBV. <h3>Results</h3> In total, 119,873 HBV (HBcAb +/- HBsAg) tests were undertaken between Jan 2005 and Jan 2015; 69,256 HBsAg tests (+/- cAb) were subsequently identified with appropriate address and postcode information. HBsAg was detected (positive) in 851/69,256 laboratory requests (0.01%); median age 36 years, Female 55%, with 661 individual patients diagnosed with HBV in this period (HBcAb+ 77%). Clinical indications for testing and the requesting speciality were poorly documented, but antenatal HBV testing was the predominant indication/specialty with 23,719 requests. 159/661(24%) of HBsAg-positive cases were detected in primary care, 395/661 (60%) in Hospital outpatients (Gastro/Hepatology); 10/661 (1.5%) in Antenatal services and 3/661 (0.45%) in Prisons. 814 unique patient addresses were identified for 661 HBV positive patients; 54 HBV positive patients shared the same address (26 households, range 2–3/household), with an additional 203 negative HBsAg requests made in the remaining household contacts, with HBcAb evident in 18% of these individuals. <h3>Conclusion</h3> NICE public health recommendations were issued in late 2012 to guide HBV testing practice, but its uptake is thought to be poor, and our data highlights the deficits that exist in contact-tracing, with close to 70% of household-contacts not offered testing. Although there are data-deficits to using recorded laboratory data, it provides a readily available and reproducible format to identify and monitor regional contact-testing practice. We hope to use this format to guide and monitor regional testing strategies. <h3>Disclosure of interest</h3> None Declared.

Timing of Tuberculosis Transmission and the Impact of Household Contact Tracing. An Agent-based Simulation Model

Household contact tracing has recently been endorsed for global tuberculosis (TB) control, but its potential population-level impact remains uncertain. To project the maximum impact of household contact tracing for TB in a moderate-burden setting. We developed a stochastic, agent-based simulation model of a simplified TB epidemic, calibrated to a setting of moderate TB incidence. We used data from the literature to generate "community-driven" and "household-driven" scenarios in which 22 and 50% of TB transmission occurred within the household, respectively. In each scenario, we simulated an intervention in which the household members are screened and treated for TB at the time of an index patient's active TB diagnosis. By the time of TB diagnosis, 75 to 95% of initial household infections had already occurred, but only 1.5 to 3.0% of contacts had sufficient time to progress to active TB. With 100% sensitive tracing of all contacts for 5 consecutive years, TB incidence declined by 10 to 15%, with a mean year-over-year decline of 2% per year. Effects were sustained for many years after stopping the intervention. Providing preventive therapy with contact tracing nearly doubled this impact (17-27% decline in incidence). Impact was proportional to sensitivity and coverage; thus, if 50% of contacts were screened with a 50% sensitive test, TB incidence declined by only 0.5% per year. Household contact tracing is unlikely to transform TB epidemiology in isolation but has the potential, especially with provision of preventive therapy, to augment a comprehensive package of interventions that could substantially reduce the population-level burden of TB.

Development and testing of models of tuberculosis contact tracing in rural southern Africa.

A regional hospital in rural Swaziland. To evaluate a hospital-based contact screening programme and test approaches to improve its effectiveness. An evaluation and quality improvement study of tuberculosis (TB) contact tracing services. Hospital-based TB contact tracing led to screening of 157 (24%) of 658 contacts; of these, 4 (2.5%) were diagnosed with TB. Of 68 contacts eligible for human immunodeficiency virus (HIV) testing and counselling, 45 (66%) were tested and 7/45 (16%) were identified as HIV-positive. Twelve (50%) of 24 screened contacts aged <5 years were provided isoniazid prophylaxis. Three enhanced models of TB contact tracing were piloted to screen contacts in the community. Although some enhanced models screened large numbers of contacts, no contacts were diagnosed with TB. Contact tracing of household members conducted in TB clinics within hospital settings is effective in high-burden, low-income settings, and can be provided using current resources. Enhanced household contact tracing models that followed up contacts in the community were not found to be effective. Additional resources would be required to provide household TB contact tracing in the community.