Longevity of serologic responses following a single dose of typhoid conjugate vaccine among children living with HIV in Pakistan: A prospective cohort study.

BACKGROUND: This study aimed to assess the longevity of serologic response and seroconversion rates at several time points following TCV vaccination among children living with HIV aged 6 months to 15 years in Pakistan. METHODS: From November 20, 2020, to January 2, 2021; 336 children were enrolled and followed up prospectively for 12 months. Blood samples were collected before the administration of TCV and at 4-6 weeks, 6 months, and 1 year after administration of a single dose (0.5 ml) of intramuscular Typbar TCV®. Samples were analyzed for anti-Vi-IgG antibodies using ELISA. Geometric mean titers (GMTs), seroconversion rates (fourfold rise in anti-Vi-IgG from baseline), and factors associated with sustained seroconversion at 1 year were evaluated using generalized linear mixed models. FINDINGS: The seroconversion rates were significantly lower in children aged 6 months to 5 years compared to children > 5 years; (127/216 (58·8%)) versus (81/111 (73·0%)) at 6 months and (110/217 (50·7%)) versus (78/109 (71·6%)) at 1 year, only two-third; 188/326 (57·7%) remained seroconverted at 1 year. The GMTs (95 % CI) were significantly lower in children aged 6 months to 5 years compared to children > 5 years, 9·6 (7·6, 12·0) versus 28·9 (20·2, 41·4) at 6 months, and 6·6 (5·4, 8·0) versus 23·1 (16·4, 32·5) at 1 year time point. The odds of sustained seroconversion significantly decreased with time (adjusted odds ratio (aOR): 0·232; 95 % CI: 0·136,0·396). The odds of sustained seroconversion following 1 year of TCV vaccination were significantly higher among children with non-severe HIV clinical disease (aOR: 10·6; 95 % CI: 1·5, 73·9) and children in elder age group (aOR: 7·45; 95 % CI: 11·2, 47·0). CONCLUSIONS: There was a decline in seroconversion after one year of TCV in children living with HIV. The decline was significant in children with severe or advanced HIV disease. A significant decrease in seroconversion rates was observed among children living with HIV following one year of TCV administration.

Factors associated with HIV infection among children in Larkana District, Pakistan: a matched case-control study.

BACKGROUND: In April, 2019, an HIV outbreak predominantly affecting children occurred in Larkana District, Sindh, Pakistan. By December, 2019, 881 (4·0%) of 21 962 children screened for HIV had tested positive. We aimed to assess factors associated with HIV infection in this outbreak. METHODS: In this individually matched case-control study, we sampled 406 cases (individuals aged <16 years who had registered for paediatric HIV care at the HIV Treatment Centre at Shaikh Zayed Children's Hospital in Larkana City, Pakistan) and 406 controls (individuals without HIV matched by age, sex, and neighbourhood residence, recruited through doorknocking at houses adjacent to case participants). An interviewer-administered questionnaire was used to collect data on possible risk factors for HIV acquisition and a blood sample was collected from all participants for hepatitis B and hepatitis C serology. Mothers of all participants underwent HIV testing. Odds ratios were estimated using conditional logistic regression to assess factors associated with HIV infection. FINDINGS: 406 case-control pairs were recruited between July 3 and Dec 26, 2019. Five pairs were excluded (three pairs had an age mismatch and two pairs were duplicate cases) and 401 were analysed. The prevalence of hepatitis B surface antigen was 18·2% (95% CI 14·5-22·3) among cases and 5·2% (3·3-7·9) among controls, and the prevalence of hepatitis C antibodies was 6·5% (95% CI 4·3-9·4) among cases and 1·0% (0·3-2·5) among controls. 28 (7%) of 397 mothers of cases for whom we had data, and no mothers of 394 controls, were HIV positive. In the 6 months before recruitment, 226 (56%) of 401 cases and 32 (8%) of 401 controls reported having more than ten injections, and 291 (73%) cases and 78 (19%) controls had received an intravenous infusion. At least one blood transfusion was reported in 56 (14%) cases and three (1%) controls in the past 2 years. HIV infection was associated with a history of more injections and infusions (adjusted odds ratio 1·63; 95% CI 1·30-2·04, p<0·0001), blood transfusion (336·75; 23·69-4787·01, p<0·0001), surgery (399·75, 13·99-11 419·39, p=0·0005), the child's mother being HIV positive or having died (3·13, 1·20-8·20, p=0·020), and increased frequency of private clinic (p<0·0001) and government hospital visits (p<0·0001), adjusting for confounders. INTERPRETATION: The predominant mode of HIV transmission in this outbreak was parenteral, probably due to unsafe injection practices and poor blood safety practices. General practitioners across Pakistan need training and systems support in reducing injection use, and in providing safe injections and transfusions only when necessary. FUNDING: Department of Pediatrics and Child Health, the Aga Khan University, Karachi, Pakistan.

Investigation of an extensive outbreak of HIV infection among children in Sindh, Pakistan: protocol for a matched case-control study.

INTRODUCTION: In April 2019, 14 children were diagnosed with HIV infection by a private healthcare provider in Larkana district, Sindh province, Pakistan. Over the next 3 months, 930 individuals were diagnosed with HIV, >80% below 16 years, the largest ever outbreak of HIV in children in Pakistan. In this protocol paper, we describe research methods for assessing likely modes of HIV transmission in this outbreak and investigate spatial and molecular epidemiology. METHODS AND ANALYSIS: A matched case-control study will be conducted with 406 cases recruited. Cases will be children aged below 16 years registered for care at the HIV treatment centre at Shaikh Zayed Children Hospital in Larkana City. Controls will be children who are HIV-uninfected (confirmed by a rapid HIV test) matched 1:1 by age (within 1 year), sex and neighbourhood. Following written informed consent from the guardian, a structured questionnaire will be administered to collect data on sociodemographic indices and exposure to risk factors for parenteral, vertical and sexual (only among those aged above 10 years) HIV transmission. A blood sample will be collected for hepatitis B and C serology (cases and controls) and HIV lineage studies (cases only). Mothers of participants will be tested for HIV to investigate the possibility of mother-to-child transmission. Conditional logistic regression will be used to investigate the association of a priori defined risk factors with HIV infection. Phylogenetic analyses will be conducted. Global positioning system coordinates of participants' addresses will be collected to investigate concordance between the genetic and spatial epidemiology. ETHICS AND DISSEMINATION: Ethical approval was granted by the Ethics Review Committee of the Aga Khan University, Karachi. Study results will be shared with Sindh and National AIDS Control Programs, relevant governmental and non-governmental organisations, presented at national and international research conferences and published in international peer-reviewed scientific journals.

Operability, Acceptability, and Usefulness of a Mobile App to Track Routine Immunization Performance in Rural Pakistan: Interview Study Among Vaccinators and Key Informants.

BACKGROUND: There has been a recent spate of mobile health (mHealth) app use for immunizations and other public health concerns in low- and middle-income countries. However, recent evidence has largely focused on app development or before-and-after effects on awareness or service coverage. There is little evidence on the factors that facilitate adoption of mHealth programs, which is critical to effectively embed digital technology into mainstream health systems. OBJECTIVE: This study aimed to provide the qualitative experiences of frontline health staff and district managers while engaging with real-time digital technology to improve the coverage of routine childhood immunization in an underserved rural district in Pakistan. METHODS: An Android-based app was iteratively developed and used for a 2-year period in 11 union councils of the Tando Muhammad Khan district, an underserved rural district with poor immunization coverage in Pakistan. We used iterative methods to examine the (1) acceptability and operability of the app, (2) validity of the collected data, and (3) use of the collected data. In addition, we collected the barriers and enablers for uptake of the mHealth app. Each of these topics was further explored related to changes in work as well as the enabling factors for and barriers to app use. In-depth interviews were conducted with the 26 vaccinators posted in the 11 union councils and 7 purposively selected key informants (government district managers) involved with the Expanded Program for Immunization. Findings were triangulated in line with the three broad research areas. RESULTS: Digital immunization tracking was considered acceptable by vaccinators and district managers. Real-time immunization data were used to monitor vaccination volume, track children with incomplete vaccinations, develop outreach visit plans, correct existing microplans, and disburse a fuel allowance for outreach sessions. The validity of the app data was perceived to be superior to that of data from manual records. Ease of operability, satisfaction with data, personal recognition, links to field support, and a sense of empowerment served as powerful enablers. Taking twice the time to complete both manual and digital entries and outdated phones over time were considered constraints. An unintended knock-on effect was improved coordination and strengthening of Expanded Program for Immunization review platforms across district stakeholders through digitalized data. CONCLUSIONS: Embedding digital technology into mainstream health systems relies on use by both end users and district stakeholders. Ease of operability, satisfaction with data reliability, personal recognition, links to field support, and empowerment are powerful enablers, whereas improved coordination as a result of easy, transparent data access can be an important by-product of digitalization. Findings are relevant not only for wide-scale implementation of immunization tracking apps in Pakistan but also for informing the use of digital technology for results-based delivery by frontline health workers.

HIV infection predominantly affecting children in Sindh, Pakistan, 2019: a cross-sectional study of an outbreak.

BACKGROUND: In April 2019, an HIV screening camp for all ages was established in response to a report of an unusually large number of paediatric HIV diagnoses in Larkana, Pakistan. We aimed to understand the clinical profile of the children who registered for HIV care. METHODS: In this cross-sectional study, we review the outbreak response from the government, academia, and UN agencies in Larkana, Sindh, Pakistan. We report age-stratified and sex-stratified HIV prevalence estimated among individuals screened. For children who registered for HIV care, clinical history of previous injections and blood transfusions, HIV disease stage, hepatitis B and hepatitis C status, and CD4 count was abstracted from clinical records from Sindh AIDS Control Program HIV Clinic (Shaikh Zayed Childrens Hospital, Larkana, Pakistan) and analysed using percentages, χ2 tests, and weight-for-age Z scores. We also analysed data for parents who were tested for HIV. FINDINGS: Between April 24, and July 15, 2019, 31 239 individuals underwent HIV testing, of whom 930 (3%) tested positive for HIV. Of these, 763 (82%) were younger than 16 years and 604 (79%) of these were aged 5 years and below. Estimated HIV prevalence was 3% overall; 7% (283 of 3803) in children aged 0-2 years, 6% (321 of 5412) in children aged 3-5 years, and 1% (148 of 11 251) in adults aged 16-49 years. Of the 591 children who registered for HIV care, 478 (81%) were 5 years or younger, 379 (64%) were boys, and 315 (53%) of 590 had a weight-for-age Z score of -3·2. Prevalence of hepatitis B surface antigen was 8% (48 of 574) and hepatitis C antibody positivity was 3% (15 of 574). Of children whose mothers tested for HIV, only 39 (11%) of 371 had HIV-positive mothers. Most children (404 [89%] of 453) reported multiple previous injections and 40 (9%) of 453 reported blood transfusions. INTERPRETATION: This HIV outbreak is unprecedented among children in Pakistan: a 54% increase in paediatric HIV diagnoses over the past 13 years. The outbreak was heavily skewed towards young children younger than 5 years, with a predominance of boys. Epidemiological and molecular studies are needed to understand the full extent of the outbreak and its drivers to guide HIV control strategies. FUNDING: None.