Five-Year Community Surveillance Study for Acute Respiratory Infections Using Text Messaging: Findings From the MoSAIC Study.

BACKGROUND: Acute respiratory infections (ARI) are the most common infectious diseases globally. Community surveillance may provide a more comprehensive picture of disease burden than medically attended illness alone. METHODS: In this longitudinal study conducted from 2012 to 2017 in the Washington Heights/Inwood area of New York City, we enrolled 405 households with 1915 individuals. Households were sent research text messages twice weekly inquiring about ARI symptoms. Research staff confirmed symptoms by follow-up call. If ≥2 criteria for ARI were met (fever/feverish, cough, congestion, pharyngitis, myalgias), staff obtained a mid-turbinate nasal swab in participants' homes. Swabs were tested using the FilmArray reverse transcription polymerase chain reaction (RT-PCR) respiratory panel. RESULTS: Among participants, 43.9% were children, and 12.8% had a chronic respiratory condition. During the 5 years, 114 724 text messages were sent; the average response rate was 78.8% ± 6.8%. Swabs were collected for 91.4% (2756/3016) of confirmed ARI; 58.7% had a pathogen detected. Rhino/enteroviruses (51.9%), human coronaviruses (13.9%), and influenza (13.2%) were most commonly detected. The overall incidence was 0.62 ARI/person-year, highest (1.73) in <2 year-olds and lowest (0.46) in 18-49 year-olds. Approximately one-fourth of those with ARI sought healthcare; percents differed by pathogen, demographic factors, and presence of a chronic respiratory condition. CONCLUSIONS: Text messaging is a novel method for community-based surveillance that could be used both seasonally as well as during outbreaks, epidemics and pandemics. The importance of community surveillance to accurately estimate disease burden is underscored by the findings of low rates of care-seeking that varied by demographic factors and pathogens.

Household transmission of influenza A and B within a prospective cohort during the 2013-2014 and 2014-2015 seasons.

People living within the same household as someone ill with influenza are at increased risk of infection. Here, we use Markov chain Monte Carlo methods to partition the hazard of influenza illness within a cohort into the hazard from the community and the hazard from the household. During the 2013-2014 influenza season, 49 (4.7%) of the 1044 people enrolled in a community surveillance cohort had an acute respiratory illness (ARI) attributable to influenza. During the 2014-2015 influenza season, 50 (4.7%) of the 1063 people in the cohort had an ARI attributable to influenza. The secondary attack rate from a household member was 2.3% for influenza A (H1) during 2013-2014, 5.3% for influenza B during 2013-2014, and 7.6% for influenza A (H3) during 2014-2015. Living in a household with a person ill with influenza increased the risk of an ARI attributable to influenza up to 350%, depending on the season and the influenza virus circulating within the household.

Parental Notification Via Text Messaging for Infant Sickle Screening Programs: Exploration of Feasibility and Acceptability in Uganda.

Sickle cell disease (SCD) in Africa has high prevalence, morbidity, and early mortality. Difficulties in reaching parents following infant SCD screening dampen program effectiveness. Text messaging may support initial postscreening parental notification. We explored SCD awareness, and feasibility and acceptability of text messaging about screening follow-up among convenience samples of caretakers with children under 5 years (n=115) at 3 sites: a SCD family conference or 2 general pediatric clinics in urban or rural Uganda. Two thirds of the conference-based participants and 8% at clinic sites had affected children. At the clinics, 64% of caretakers were aware of SCD. In all, 87% claimed current possession of mobile phones; 89% previously had received messages. A sample text on the availability of screening results and need to bring their child to SCD clinic was at least partially understood by 82%. Overall, 52% preferred communication for initial follow-up by telephone over text message. Concerns about texting included phone access, privacy or cost, and readability of messages. Caretakers identified concerns about distance, cost, or preference for another clinic as additional barriers to SCD follow-up. Findings suggest that text messaging to caretakers may be feasible, but less acceptable compared with a telephone call about initial follow-up from newborn SCD screening.

Population pharmacokinetics of abacavir and lamivudine in severely malnourished human immunodeficiency virus-infected children in relation to treatment outcomes.

AIMS: Describe the pharmacokinetics (PK) of the antiretroviral drugs abacavir and lamivudine in malnourished paediatric patients and relate to viral load outcomes after 12 and 48 weeks of treatment. METHODS: Severely malnourished human immunodeficiency virus-infected children were randomized to early (within 14 days) or delayed (after nutritional recovery) initiation of antiretroviral treatment (ART) using World Health Organization weight-band dosages. Abacavir and lamivudine concentrations were measured as a secondary objective on day 1 and day 14 and patients were followed-up to week 48. Population PK of abacavir and lamivudine were described using NONMEM. RESULTS: In total, 623 abacavir and 627 lamivudine concentrations were collected from 75 paediatric patients aged 0.1-10.8 (median 1.4) years. Abacavir PK was described by a 2-compartment model, patients randomized to early ART showed increased bioavailability of 31%. Apparent clearance (CL/F, L/h/7 kg) of abacavir increased from day 1 to day 14 from 3.33 (95% confidence interval 2.71-4.12) to 5.86 (95% confidence interval 4.78-7.3). A 1-compartment model described lamivudine PK, variability on CL/F was explained by maturation with age, with age at half-matured CL/F being 4 months. For both drugs allometrically scaled total body weight was related to CL/F and apparent volume of distribution. PK exposure did not correlate with virological outcomes or death at 12 or 48 weeks. CONCLUSION: Increases in Abacavir's CL/F between day 1 to day 14, bioavailability and PK variability with early start of ART was found in this cohort of severely malnourished children; however, these changes did not influence virological outcomes. The study supports the use of weight-band dosage tables.

Burden of neurological and neurocognitive impairment in pediatric sickle cell anemia in Uganda (BRAIN SAFE): a cross-sectional study.

BACKGROUND: Children with sickle cell anemia (SCA) are highly susceptible to stroke and other manifestations of pediatric cerebral vasculopathy. Detailed evaluations in sub-Saharan Africa are limited. METHODS: We aimed to establish the frequency and types of pediatric brain injury in a cross-sectional study at a large SCA clinic in Kampala, Uganda in a randomly selected sample of 265 patients with HbSS ages 1-12 years. Brain injury was defined as one or more abnormality on standardized testing: neurocognitive impairment using an age-appropriate test battery, prior stroke by examination or transcranial Doppler (TCD) velocities associated with stroke risk in children with SCA (cerebral arterial time averaged mean maximum velocity ≥ 170 cm/second). RESULTS: Mean age was 5.5 ± 2.9 years; 52.3% were male. Mean hemoglobin was 7.3 ± 1.01 g/dl; 76.4% had hemoglobin < 8.0 g/dl. Using established international standards, 14.7% were malnourished, and was more common in children ages 5-12. Overall, 57 (21.5%) subjects had one to three abnormal primary testing. Neurocognitive dysfunction was found in 27, while prior stroke was detected in 15 (5.7%). The most frequent abnormality was elevated TCD velocity 43 (18.1%), of which five (2.1%) were in the highest velocity range of abnormal. Only impaired neurocognitive dysfunction increased with age (OR 1.44, 95%CI 1.23-1.68), p < 0.001). In univariate models, malnutrition defined as wasting (weight-for-height ≤ -2SD), but not sex or hemoglobin, was modestly related to elevated TCD (OR 1.37, 95%CI 1.01-1.86, p = 0.04). In adjusted models, neurocognitive dysfunction was strongly related to prior stroke (OR 6.88, 95%CI 1.95-24.3, p = .003) and to abnormal TCD (OR 4.37, 95%CI 1.30, p = 0.02). In a subset of 81 subjects who were enriched for other abnormal results, magnetic resonance imaging and angiography (MRI/MRA) detected infarcts and/or arterial stenosis in 52%. Thirteen subjects (25%) with abnormal imaging had no other abnormalities detected. CONCLUSIONS: The high frequency of neurocognitive impairment or other abnormal results describes a large burden of pediatric SCA brain disease in Uganda. Evaluation by any single modality would have underestimated the impact of SCA. Testing the impact of hydroxyurea or other available disease-modifying interventions for reducing or preventing SCA brain effects is warranted.

Paediatric immunisation and chemoprophylaxis in a Ugandan sickle cell disease clinic.

AIM: We aimed to assess the receipt of recommended care for young children with sickle cell disease (SCD) in a central SCD clinic in Kampala Uganda, focusing on standard vaccination and antibacterial and antimalarial prophylaxis. METHODS: A cross-sectional assessment of immunisation status and timeliness and prescribed antibacterial and antimalarial prophylaxis was performed in a sample with SCD aged ≤71 months in Mulago Hospital SCD Clinic. Government-issued immunisation cards and clinic-issued visit records for prescribed prophylaxis were reviewed. RESULTS: Vaccinations were documented by immunisation cards in 104 patients, mean age 31.7 months (range 3-70 months). Only 48 (46.2%) received all doses of each of the four recommended vaccine types, including pneumococcal 10-valent conjugate vaccine (pneumococcal conjugate vaccine (PCV)-10), which became available in 2014. Vaccination completion was associated with younger age and, for polio, maternal employment. PCV-10 series was completed in 54.8% of the sample and in 18.2% of those aged 48-71 months. Of children completing all vaccination types, an average 68.8% were immunised on time, defined as <60 days beyond the recommended age. Only 17 (13.5%) children were both fully and timely vaccinated. In an overlapping sample of 147 children, with a mean age of 38.4 months (4-70 months), 81.6% had ≥1 documented prescription for penicillin and/or antimalarial prophylaxis. CONCLUSIONS: Standardised vaccination and antibacterial and antimalarial protective measures for young children at this central SCD clinic were incomplete, especially PCV-10 for age ≥24 months, and often late. Child age, but not general maternal demographics, were associated with vaccination and chemoprophylaxis. Clinic-based oversight may improve timely uptake of these preventative measures.

Influenza Vaccination Beliefs and Practices in Elderly Primary Care Patients.

The majority of influenza related deaths and hospitalizations occur among individuals ≥65 years, yet the national influenza vaccination rate for this group is 63% and is lower in the Hispanic population. Previous studies have described negative predictors of vaccination; however, there is a knowledge gap of how influenza vaccine-specific beliefs affect vaccination rates. We examined the relationship between influenza vaccine health beliefs and vaccination behaviors in a cross sectional sample of 200 primarily Hispanic patients aged ≥65 years in an academic general internal medicine clinic. Participants were asked about perceptions of influenza vaccine effectiveness and safety. Interview responses regarding influenza vaccine concerns were evaluated qualitatively with conventional content analysis. Logistic regression evaluated associations between beliefs and self-reported vaccination the previous year, adjusted for age, gender, and language. Of those approached to complete the questionnaire, 88% participated. Self-reported influenza vaccination rate during the study year was 75%. Only 46.5% endorsed the belief that influenza vaccine is very effective and 47% that it is very safe. Many stated specific concerns about flu vaccine including that it causes side effects/adverse outcomes, is not effective, vaccine components are harmful, and vaccination is not necessary. Belief that the flu shot causes the flu and concern for variability of the flu shot were associated with reduced odds of vaccination (aOR 0.19, 95% CI [0.05, 0.83] and 0.06 [0.006, 0.63] respectively). The patient-perceived distinction between cold, flu, and other symptoms warrants further exploration. This information can be used to develop targeted communication to promote vaccination.

Influenza B virus infection and Stevens-Johnson syndrome.

A 2-year-old boy with influenza B infection and rapidly worsening targetoid skin lesions with mucosal involvement was diagnosed with Stevens-Johnson syndrome (SJS) and treated with oseltamivir and intravenous immunoglobulin, with resolution of illness. Subsequent quadrivalent inactivated influenza vaccine was well tolerated. This case highlights the rarity of SJS in the setting of influenza B infection and addresses the safety of administering subsequent influenza vaccines to such individuals.

Revisiting the genotyping scheme for varicella-zoster viruses based on whole-genome comparisons.

We report whole-genome sequences (WGSs) for four varicella-zoster virus (VZV) samples from a shingles study conducted by Kaiser Permanente of Southern California. Comparative genomics and phylogenetic analysis of all published VZV WGSs revealed that strain KY037798 is in clade IX, which shall henceforth be designated clade 9. Previously published single nucleotide polymorphisms (SNP)-based genotyping schemes fail to discriminate between clades 6 and VIII and employ positions that are not clade-specific. We provide an updated list of clade-specific positions that supersedes the list determined at the 2008 VZV nomenclature meeting. Finally, we propose a new targeted genotyping scheme that will discriminate the circulating VZV clades with at least a twofold redundancy. Genotyping strategies using a limited set of targeted SNPs will continue to provide an efficient 'first pass' method for VZV strain surveillance as vaccination programmes for varicella and zoster influence the dynamics of VZV transmission.

Referral of children seeking care at private health facilities in Uganda.

BACKGROUND: In Uganda, referral of sick children seeking care at public health facilities is poor and widely reported. However, studies focusing on the private health sector are scanty. The main objective of this study was to assess referral practices for sick children seeking care at private health facilities in order to explore ways of improving treatment and referral of sick children in this sector. METHODS: A survey was conducted from August to October 2014 in Mukono district, central Uganda. Data was collected using a structured questionnaire supplemented by Focus Group Discussions and Key Informant interviews with private providers and community members. RESULTS: A total of 241 private health facilities were surveyed; 170 (70.5%) were registered drug shops, 59 (24.5%) private clinics and 12 (5.0%) pharmacies. Overall, 104/241 (43.2%) of the private health facilities reported that they had referred sick children to higher levels of care in the two weeks prior to the survey. The main constraints to follow referral advice as perceived by caretakers were: not appreciating the importance of referral, gender-related decision-making and negotiations at household level, poor quality of care at referral facilities, inadequate finances at household level; while the perception that referral leads to loss of prestige and profit was a major constraint to private providers. CONCLUSION: In conclusion, the results show that referral of sick children at private health facilities faces many challenges at provider, caretaker, household and community levels. Thus, interventions to address constraints to referral of sick children are urgently needed.

Influenza Vaccine Effectiveness in a Low-Income, Urban Community Cohort.

In this community-based cohort study of 275 primarily low-income, urban households in New York City, overall 2013-2014 influenza vaccine effectiveness (VE) was 62.5% (95% confidence interval, 21.7%-82.0%). VE point estimates were highest against 2009 H1N1 and for those who were vaccinated in 2013-2014 but not in 2012-2013.

Treatment and prevention of malaria in pregnancy in the private health sector in Uganda: implications for patient safety.

BACKGROUND: Malaria in pregnancy is a major public health problem in Uganda; and it is the leading cause of anaemia among pregnant women and low birth weight in infants. Previous studies have noted poor quality of care in the private sector. Thus there is need to explore ways of improving quality of care in the private sector that provides almost a half of health services in Uganda. METHODS: A survey was conducted from August to October 2014 within 57 parishes in Mukono district, central Uganda. The selected parishes had a minimum of 200 households and at least one registered drug shop, pharmacy or private clinic. Data was collected using a structured questionnaire targeting one provider who was found on duty in each selected private health facility and consented to the study. The main variables were: provider characteristics, previous training received, type of drugs stocked, treatment and prevention practices for malaria among pregnant women. The main study outcome was the proportion of private health facilities who prescribe treatment of fever among pregnant women as recommended in the guidelines. RESULTS: A total of 241 private health facilities were surveyed; 70.5 % were registered drug shops, 24.5 % private clinics and 5.0 % pharmacies. Treatment of fever among pregnant women in accordance with the national treatment guidelines was poor: 40.7 % in private clinics, decreasing to 28.2 % in drug shops and 16.7 % at pharmacies. Anti-malarial monotherapies sulphadoxine-pyrimethamine and quinine were commonly prescribed, often without consideration of gestational age. The majority of providers (>75 %) at all private facilities prescribed SP for intermittent preventive treatment but artemisinin-based combination therapy was prescribed: 8.3, 6.9 and 8.3 % respectively at drug shops, private clinics and pharmacies for prevention of malaria in pregnancy. Few facilities had malaria treatment guidelines; (44.1 % of private clinics, 17.9 % of drug shops, and 41.7 % at pharmacies. Knowledge of people at risk of malaria, P = 0.02 and availability of malaria treatment guidelines, P = 0.03 were the factors that most influenced correct treatment of fever in pregnancy. CONCLUSION: Treatment of fever during pregnancy was poor in this study setting. These data highlight the need to develop interventions to improve patient safety and quality of care for pregnant women in the private health sector in Uganda.

Strengthening referral of sick children from the private health sector and its impact on referral uptake in Uganda: a cluster randomized controlled trial protocol.

BACKGROUND: Uganda's under-five mortality is high, currently estimated at 66/1000 live births. Poor referral of sick children that seek care from the private sector is one of the contributory factors. The proposed intervention aims to improve referral and uptake of referral advice for children that seek care from private facilities (registered drug shops/private clinics). METHODS/DESIGN: A cluster randomized design will be applied to test the intervention in Mukono District, central Uganda. A sample of study clusters will implement the intervention. The intervention will consist of three components: i) raising awareness in the community: village health teams will discuss the importance of referral and encourage households to save money, ii) training and supervision of providers in the private sector to diagnose, treat and refer sick children, iii) regular meetings between the public and private providers (convened by the district health team) to discuss the referral system. Twenty clusters will be included in the study, randomized in the ratio of 1:1. A minimum of 319 sick children per cluster and the total number of sick children to be recruited from all clusters will be 8910; adjusting for a 10 % loss to follow up and possible withdrawal of private outlets. DISCUSSION: The immediate sustainable impact will be appropriate treatment of sick children. The intervention is likely to impact on private sector practices since the scope of the services they provide will have expanded. The proposed study is also likely to have an impact on families as; i) they may appreciate the importance of timely referral on child illness management, ii) the cost savings related to reduced morbidity will be used by household to access other social services. The linkage between the private and public sectors will create a potential avenue for delivery of other public health interventions and improved working relations in the two sectors. Further, improved quality of services in the private sector will improve provider confidence and hopefully more clientelle to the private practices. TRIAL REGISTRATION: NCT02450630 Registration date: May/9th/2015.

Assessing the potential of rural and urban private facilities in implementing child health interventions in Mukono district, central Uganda-a cross sectional study.

BACKGROUND: Private facilities are the first place of care seeking for many sick children. Involving these facilities in child health interventions may provide opportunities to improve child welfare. The objective of this study was to assess the potential of rural and urban private facilities in diagnostic capabilities, operations and human resource in the management of malaria, pneumonia and diarrhoea. METHODS: A survey was conducted in pharmacies, private clinics and drug shops in Mukono district in October 2014. An assessment was done on availability of diagnostic equipment for malaria, record keeping, essential drugs for the treatment of malaria, pneumonia and diarrhoea; the sex, level of education, professional and in-service training of the persons found attending to patients in these facilities. A comparison was made between urban and rural facilities. Univariate and bivariate analysis was done. RESULTS: A total of 241 private facilities were assessed with only 47 (19.5 %) being in rural areas. Compared to urban areas, rural private facilities were more likely to be drug shops (OR 2.80; 95 % CI 1.23-7.11), less likely to be registered (OR 0.31; 95 % CI 0.16-0.60), not have trained clinicians, less likely to have people with tertiary education (OR 0.34; 95 % CI 0.17-0.66) and less likely to have zinc tablets (OR 0.38; 95 % CI 0.19-0.78). In both urban and rural areas, there was low usage of stock cards and patient registers. About half of the facilities in both rural and urban areas attended to at least one sick child in the week prior to the interview. CONCLUSION: There were big gaps between rural and urban private facilities with rural ones having less trained personnel and less zinc tablets' availability. In both rural and urban areas, record keeping was low. Child health interventions need to build capacity of private facilities with special focus on rural areas where child mortality is higher and capacity of facilities lower.

Disseminated, persistent, and fatal infection due to the vaccine strain of varicella-zoster virus in an adult following stem cell transplantation.

Live attenuated varicella vaccine is recommended for healthy individuals who are susceptible to varicella. Although the vaccine is safe, effective, and used worldwide, serious adverse events have been reported, mainly in immunocompromised patients who subsequently recovered. Here, we describe the fatality of an immunocompromised patient who received the varicella vaccine. His medical history provides a cautionary lens through which to view the decision of when vaccination is appropriate. A middle-aged man with non-Hodgkin lymphoma received chemotherapy and a stem cell transplant. He was vaccinated 4 years post-transplantation, despite diagnosis of a new low-grade lymphoma confined to the lymph nodes. Within 3 months of vaccination, he developed recurrent rashes with fever, malaise, weakness, hepatitis, weight loss, and renal failure. The syndrome was eventually determined to be associated with persistent disseminated zoster caused by the vaccine virus. This case illustrates a circumstance when a live viral vaccine should not be used.

Herpes zoster caused by vaccine-strain varicella zoster virus in an immunocompetent recipient of zoster vaccine.

We report the first laboratory-documented case of herpes zoster caused by the attenuated varicella zoster virus (VZV) contained in Zostavax in a 68-year-old immunocompetent adult with strong evidence of prior wild-type VZV infection. The complete genome sequence of the isolate revealed that the strain carried 15 of 42 (36%) recognized varicella vaccine-associated single-nucleotide polymorphisms, including all 5 of the fixed vaccine markers present in nearly all of the strains in the vaccine. The case of herpes zoster was relatively mild and resolved without complications.

MoSAIC: Mobile Surveillance for Acute Respiratory Infections and Influenza-Like Illness in the Community.

Surveillance for acute respiratory infection (ARI) and influenza-like illness (ILI) relies primarily on reports of medically attended illness. Community surveillance could mitigate delays in reporting, allow for timely collection of respiratory tract samples, and characterize cases of non­medically attended ILI representing substantial personal and economic burden. Text messaging could be utilized to perform longitudinal ILI surveillance in a community-based sample but has not been assessed. We recruited 161 households (789 people) in New York City for a study of mobile ARI/ILI surveillance, and selected reporters received text messages twice weekly inquiring whether anyone in the household was ill. Home visits were conducted to obtain nasal swabs from persons with ARI/ILI. Participants were primarily female, Latino, and publicly insured. During the 44-week period from December 2012 through September 2013, 11,282 text messages were sent. In responses to 8,250 (73.1%) messages, a household reported either that someone was ill or no one was ill; 88.9% of responses were received within 4 hours. Swabs were obtained for 361 of 363 reported ARI/ILI episodes. The median time from symptom onset to nasal swab was 2 days; 65.4% of samples were positive for a respiratory pathogen by reverse-transcriptase polymerase chain reaction. In summary, text messaging promoted rapid ARI/ILI reporting and specimen collection and could represent a promising approach to timely, community-based surveillance.

Infection prevention and control and related practices in African neonatal units: The Pan-African neonatal care assessment study (PANCAS).

BACKGROUND: The burden of neonatal mortality is primarily borne by low- and middle-income countries (LMICs), including deaths due to healthcare-associated infections (HAIs). Few studies have assessed infection prevention and control (IP&C) practices in African units caring for small and/or sick newborns aimed to reduce HAIs. METHODS: We performed a mixed-methods study composed of a survey and virtual tour to assess IP&C and related practices. We created a survey composed of multiple-choice and open-ended questions delivered to site respondents via Zoom or video equivalent. Respondents provided a virtual tour of their unit via video and the study team used a checklist to evaluate specific practices. RESULTS: We recruited 45 units caring for small and sick newborns in 20 African countries. Opportunities to optimize hand hygiene, Water, Sanitation and Hygiene (WASH) practices, Kangaroo Mother Care, and IP&C training were noted. The virtual tour offered further understanding of IP&C challenges unique to individual sites. All respondents expressed the need for additional space, equipment, supplies, education, and IP&C staff and emphasized that attention to maternal comfort was important to IP&C success. DISCUSSION: This study identified opportunities to improve IP&C practices using low-cost measures including further education and peer support through learning collaboratives. Virtual tours can be used to provide site-specific assessment and feedback from peers, IP&C specialists and environmental engineering experts.

Diagnosis, Treatment, and Prevention Resources for Infectious Diseases in Sub-Saharan African Hospitals Caring for Children.

Objective. The Children's Hospitals in Africa Mapping Project survey was developed and implemented to assess the readiness of hospitals in sub-Saharan African to respond to emergencies, epidemics, and pandemics affecting children. Methods. This sub-study analyzed 56 survey questions that characterized the hospitals and assessed resources for diagnosis, treatment, and prevention of community-acquired infections and healthcare-associated infections (HAIs). Results. Twenty-four sites were recruited and 20 (from 15 countries) completed the survey in 2018 to 2019. Overall, 90% to 100% of sites reported that diagnostic assays were available for malaria, tuberculosis, and HIV. Periodic shortages of antibiotics, antimalarial drugs, and vaccines were reported by 45%, 25%, and 20% of sites, respectively. Sites reported formal programs for infection prevention and control (79%), monitoring HAIs (17%), and antimicrobial stewardship (53%). Conclusions. Opportunities to improve care for hospitalized African children were identified. These included resources for HAI surveillance and antimicrobial stewardship which can facilitate epidemic and pandemic preparedness.

Effectiveness of 2 doses of varicella vaccine in children.

BACKGROUND: Because of ongoing outbreaks of varicella, a second dose of varicella vaccine was added to the routine immunization schedule for children in June 2006 by the Centers for Disease Control and Prevention. METHODS: We assessed the effectiveness of 2 doses of varicella vaccine in a case-control study by identifying children ≥4 years of age with varicella confirmed by polymerase chain reaction assay and up to 2 controls matched by age and pediatric practice. Effectiveness was calculated using exact conditional logistic regression. RESULTS: From July 2006 to January 2010, of the 71 case subjects and 140 matched controls enrolled, no cases (0%) vs 22 controls (15.7%) had received 2 doses of varicella vaccine, 66 cases (93.0%) vs 117 controls (83.6%) had received 1 dose, and 5 cases (7.0%) vs 1 control (0.7%) did not receive varicella vaccine (P < .001). The effectiveness of 2 doses of the vaccine was 98.3% (95% confidence level [CI]: 83.5%-100%; P < .001). The matched odds ratio for 2 doses vs 1 dose of the vaccine was 0.053 (95% CI: 0.002-0.320; P < .001). CONCLUSION: The effectiveness of 2 doses of varicella vaccine in the first 2.5 years after recommendation of a routine second dose of the vaccine for children is excellent. Odds of developing varicella were 95% lower for children who received 2 doses compared with 1 dose of varicella vaccine.