Renata Báez-Saldaña

Partial protection of seasonal trivalent inactivated vaccine against novel pandemic influenza A/H1N1 2009: case-control study in Mexico City

Objective To evaluate the association of 2008-9 seasonal trivalent inactivated vaccine with cases of influenza A/H1N1 during the epidemic in Mexico. Design Frequency matched case-control study. Setting Specialty hospital in Mexico City, March to May 2009. Participants 60 patients with laboratory confirmed influenza A/H1N1 and 180 controls with other diseases (not influenza-like illness or pneumonia) living in Mexico City or the State of Mexico and matched for age and socioeconomic status. Main outcome measures Odds ratio and effectiveness of trivalent inactivated vaccine against influenza A/H1N1. Results Cases were more likely than controls to be admitted to hospital, undergo invasive mechanical ventilation, and die. Controls were more likely than cases to have chronic conditions that conferred a higher risk of influenza related complications. In the multivariate model, influenza A/H1N1 was independently associated with trivalent inactivated vaccine (odds ratio 0.27, 95% confidence interval 0.11 to 0.66) and underlying conditions (0.15, 0.08 to 0.30). Vaccine effectiveness was 73% (95% confidence interval 34% to 89%). None of the eight vaccinated cases died. Conclusions Preliminary evidence suggests some protection from the 2008-9 trivalent inactivated vaccine against pandemic influenza A/H1N1 2009, particularly severe forms of the disease, diagnosed in a specialty hospital during the influenza epidemic in Mexico City.

Association of diabetes and tuberculosis: impact on treatment and post-treatment outcomes

Objective To determine the clinical consequences of pulmonary tuberculosis (TB) among patients with diabetes mellitus (DM). Methods We conducted a prospective study of patients with TB in Southern Mexico. From 1995 to 2010, patients with acid-fast bacilli or Mycobacterium tuberculosis in sputum samples underwent epidemiological, clinical and microbiological evaluation. Annual follow-ups were performed to ascertain treatment outcome, recurrence, relapse and reinfection. Results The prevalence of DM among 1262 patients with pulmonary TB was 29.63% (n=374). Patients with DM and pulmonary TB had more severe clinical manifestations (cavities of any size on the chest x-ray, adjusted OR (aOR) 1.80, 95% CI 1.35 to 2.41), delayed sputum conversion (aOR 1.51, 95% CI 1.09 to 2.10), a higher probability of treatment failure (aOR 2.93, 95% CI 1.18 to 7.23), recurrence (adjusted HR (aHR) 1.76, 95% CI 1.11 to 2.79) and relapse (aHR 1.83, 95% CI 1.04 to 3.23). Most of the second episodes among patients with DM were caused by bacteria with the same genotype but, in 5/26 instances (19.23%), reinfection with a different strain occurred. Conclusions Given the growing epidemic of DM worldwide, it is necessary to add DM prevention and control strategies to TB control programmes and vice versa and to evaluate their effectiveness. The concurrence of both diseases potentially carries a risk of global spreading, with serious implications for TB control and the achievement of the United Nations Millennium Development Goals.

Tuberculosis in ageing: high rates, complex diagnosis and poor clinical outcomes

BACKGROUND worldwide, the frequency of tuberculosis among older people almost triples that observed among young adults. OBJECTIVE to describe clinical and epidemiological consequences of pulmonary tuberculosis among older people. METHODS we screened persons with a cough lasting more than 2 weeks in Southern Mexico from March 1995 to February 2007. We collected clinical and mycobacteriological information (isolation, identification, drug-susceptibility testing and IS6110-based genotyping and spoligotyping) from individuals with bacteriologically confirmed pulmonary tuberculosis. Patients were treated in accordance with official norms and followed to ascertain treatment outcomes, retreatment, and vital status. RESULTS eight hundred ninety-three tuberculosis patients were older than 15 years of age; of these, 147 (16.5%) were 65 years of age or older. Individuals ≥ 65 years had significantly higher rates of recently transmitted and reactivated tuberculosis. Older age was associated with treatment failure (OR=5.37; 95% CI: 1.06-27.23; P=0.042), and death due to tuberculosis (HR=3.52; 95% CI: 1.78-6.96; P<0.001) adjusting for sociodemographic and clinical variables. CONCLUSIONS community-dwelling older individuals participate in chains of transmission indicating that tuberculosis is not solely due to the reactivation of latent disease. Untimely and difficult diagnosis and a higher risk of poor outcomes even after treatment completion emphasise the need for specific strategies for this vulnerable group.

Use of a Novel Real-Time PCR Assay To Detect Oral Polio Vaccine Shedding and Reversion in Stool and Sewage Samples after a Mexican National Immunization Day

ABSTRACT During replication, oral polio vaccine (OPV) can revert to neurovirulence and cause paralytic poliomyelitis. In individual vaccinees, it can acquire specific revertant point mutations, leading to vaccine-associated paralytic poliomyelitis (VAPP). With longer replication, OPV can mutate into vaccine-derived poliovirus (VDPV), which causes poliomyelitis outbreaks similar to those caused by wild poliovirus. After wild poliovirus eradication, safely phasing out vaccination will likely require global use of inactivated polio vaccine (IPV) until cessation of OPV circulation. Mexico, where children receive routine IPV but where OPV is given biannually during national immunization days (NIDs), provides a natural setting to study the duration of OPV circulation in a population primarily vaccinated with IPV. We developed a real-time PCR assay to detect and distinguish revertant and nonrevertant OPV serotype 1 (OPV-1), OPV-2, and OPV-3 from RNA extracted directly from stool and sewage. Stool samples from 124 children and 8 1-liter sewage samples from Orizaba, Veracruz, Mexico, collected 6 to 13 weeks after a NID were analyzed. Revertant OPV-1 was found in stool at 7 and 9 weeks, and nonrevertant OPV-2 and OPV-3 were found in stool from two children 10 weeks after the NID. Revertant OPV-1 and nonrevertant OPV-2 and -3 were detected in sewage at 6 and 13 weeks after the NID. Our real-time PCR assay was able to detect small amounts of OPV in both stool and sewage and to distinguish nonrevertant and revertant serotypes and demonstrated that OPV continues to circulate at least 13 weeks after a NID in a Mexican population routinely immunized with IPV.

Association of Pulmonary Tuberculosis and Diabetes in Mexico: Analysis of the National Tuberculosis Registry 2000-2012

Background Tuberculosis (TB) remains a public health problem in Mexico while the incidence of diabetes mellitus type 2 (DM) has increased rapidly in recent years. Objective To describe the trends of incidence rates of pulmonary TB associated with DM and not associated with DM and to compare the results of treatment outcomes in patients with and without DM. Materials and Methods We analysed the National Tuberculosis Registry from 2000 to 2012 including patients with pulmonary TB among individuals older than 20 years of age. The association between DM and treatment failure was analysed using logistic regression, accounting for clustering due to regional distribution. Results In Mexico from 2000 to 2012, the incidence rates of pulmonary TB associated to DM increased by 82.64%, (p <0.001) in contrast to rates of pulmonary TB rate without DM, which decreased by 26.77%, (p <0.001). Patients with a prior diagnosis of DM had a greater likelihood of failing treatment (adjusted odds ratio, 1.34 (1.11–1.61) p <0.002) compared with patients who did not have DM. There was statistical evidence of interaction between DM and sex. The odds of treatment failure were increased in both sexes. Conclusion Our data suggest that the growing DM epidemic has an impact on the rates of pulmonary TB. In addition, patients who suffer from both diseases have a greater probability of treatment failure.

A systematic review of rubella vaccination strategies implemented in the Americas: impact on the incidence and seroprevalence rates of rubella and congenital rubella syndrome

OBJECTIVE To evaluate the impact of rubella vaccination strategies on the rates of acquired rubella and congenital rubella syndrome in the Americas. METHODS We conducted a systematic review of the literature (MEDLINE, PubMed, EMBASE, Cochrane Library, Artemisa Database, LILACS Database, Evidence Portal, VHL-PAHO Portal, Scielo, and Grey-Literature sources) that was published from 1969-2010. We included studies on rubella incidence and seroprevalence rates that were associated with rubella vaccination. The quality of the studies was evaluated according to international guidelines. RESULTS A total of 14 studies were identified: 2 clinical trials, 2 cohort studies, 3 transversal studies, 5 ecological studies, and 2 mathematical models. Childhood vaccination reduced the incidence of rubella by 23.6% to 99.6%, increased the occurrence of epidemic cycles in Argentina and in the United States, and shifted the illness to susceptible adults. Vaccination strategies that focused on women and children in Brazil were associated with a 5.5-fold greater incidence of rubella in men leading to new outbreaks and CRS. A combined vaccination strategy with a universal approach that included routine vaccination for boys, girls, women, and men in Mexico and in Costa Rica reduced the incidence of rubella by more than 98% and led to absence of CRS since 2008. A medium and a low risk of bias were found in 3 and 4 articles, respectively. CONCLUSION The results of this review demonstrate that the combined vaccination strategy with a universal approach was the most effective strategy as evidenced by a drastic reduction in the number of cases and the interruption of endemic transmission of rubella in the Americas.

Results of the Implementation of a Pilot Model for the Bidirectional Screening and Joint Management of Patients with Pulmonary Tuberculosis and Diabetes Mellitus in Mexico

Background Recently, the World Health Organisation and the International Union Against Tuberculosis and Lung Disease published a Collaborative Framework for the Care and Control of Tuberculosis (TB) and Diabetes (DM) (CFTB/DM) proposing bidirectional screening and joint management. Objective To evaluate the feasibility and effectiveness of the CFTB/DM in Mexico. Design. Prospective observational cohort. Setting. 15 primary care units in 5 states in Mexico. Participants: Patients aged ≥20 years diagnosed with DM or pulmonary TB who sought care at participating clinics. Intervention: The WHO/Union CFTB/DM was adapted and implemented according to official Mexican guidelines. We recruited participants from July 2012 to April 2013 and followed up until March 2014. Bidirectional screening was performed. Patients diagnosed with TB and DM were invited to receive TB treatment under joint management. Main outcome measures. Diagnoses of TB among DM, of DM among TB, and treatment outcomes among patients with DM and TB. Results Of 783 DM patients, 11 (1.4%) were unaware of their TB. Of 361 TB patients, 16 (4.4%) were unaware of their DM. 95 TB/DM patients accepted to be treated under joint management, of whom 85 (89.5%) successfully completed treatment. Multiple linear regression analysis with change in HbA1c and random capillary glucose as dependent variables revealed significant decrease with time (regression coefficients (β)  = −0.660, (95% confidence interval (CI), −0.96 to −0.35); and β = −1.889 (95% CI, −2.77 to −1.01, respectively)) adjusting by sex, age and having been treated for a previous TB episode. Patients treated under joint management were more likely to experience treatment success than patients treated under routine DM and TB programs as compared to historical (adjusted OR (aOR), 2.8, 95%CI 1.28–6.13) and same period (aOR 2.37, 95% CI 1.13–4.96) comparison groups. Conclusions Joint management of TB and DM is feasible and appears to improve clinical outcomes.

Impact of cigarette smoking on rates and clinical prognosis of pulmonary tuberculosis in Southern Mexico.

OBJECTIVES To examine the relationship between cigarette smoking and incidence and mortality rates of pulmonary tuberculosis (TB) and treatment outcomes. MATERIALS From 1995 to 2010, we analyzed data from 1062 patients with TB and from 2001 to 2004, 2951 contacts in Southern Mexico. Patients with acid-fast bacilli or Mycobacterium tuberculosis in sputum samples underwent epidemiological, clinical and mycobacteriological evaluation and received treatment by the local DOTS program. RESULTS Consumers of 1-10 (LS) or 11 or more (HS) cigarettes per day incidence (1.75 and 11.79) and mortality (HS, 17.74) smoker-non-smoker rate ratios were significantly higher for smokers. Smoker population was more likely to experience unfavorable treatment outcomes (HS, adjusted OR 2.36) and retreatment (LS and HS, adjusted hazard ratio (HR) 2.14 and 2.37). Contacts that smoked had a higher probability of developing active TB (HR 2.38) during follow up. CONCLUSIONS Results indicate the need of incorporating smoking prevention and cessation, especially among men, into international TB control strategies.

Community Circulation Patterns of Oral Polio Vaccine Serotypes 1, 2, and 3 After Mexican National Immunization Weeks

BACKGROUND With wild poliovirus nearing eradication, preventing circulating vaccine-derived poliovirus (cVDPV) by understanding oral polio vaccine (OPV) community circulation is increasingly important. Mexico, where OPV is given only during biannual national immunization weeks (NIWs) but where children receive inactivated polio vaccine (IPV) as part of their primary regimen, provides a natural setting to study OPV community circulation. METHODS In total, 216 children and household contacts in Veracruz, Mexico, were enrolled, and monthly stool samples and questionnaires collected for 1 year; 2501 stool samples underwent RNA extraction, reverse transcription, and real-time polymerase chain reaction (PCR) to detect OPV serotypes 1, 2, and 3. RESULTS OPV was detected up to 7 months after an NIW, but not at 8 months. In total, 35% of samples collected from children vaccinated the prior month, but only 4% of other samples, contained OPV. Although each serotype was detected in similar proportions among OPV strains shed as a result of direct vaccination, 87% of OPV acquired through community spread was serotype 2 (P < .0001). CONCLUSIONS Serotype 2 circulates longer and is transmitted more readily than serotypes 1 or 3 after NIWs in a Mexican community primarily vaccinated with IPV. This may be part of the reason why most isolated cVDPV has been serotype 2.

Association between Highly Active Antiretroviral Therapy and Type of Infectious Respiratory Disease and All-Cause In-Hospital Mortality in Patients with HIV/AIDS: A Case Series.

Background Respiratory manifestations of HIV disease differ globally due to differences in current availability of effective highly active antiretroviral therapy (HAART) programs and epidemiology of infectious diseases. Objective To describe the association between HAART and discharge diagnosis and all-cause in-hospital mortality among hospitalized patients with infectious respiratory disease and HIV/AIDS. Material and Methods We retrospectively reviewed the records of patients hospitalized at a specialty hospital for respiratory diseases in Mexico City between January 1st, 2010 and December 31st, 2011. We included patients whose discharge diagnosis included HIV or AIDS and at least one infectious respiratory diagnosis. The information source was the clinical chart. We analyzed the association between HAART for 180 days or more and type of respiratory disease using polytomous logistic regression and all-cause hospital mortality by multiple logistic regressions. Results We studied 308 patients, of whom 206 (66.9%) had been diagnosed with HIV infection before admission to the hospital. The CD4+ lymphocyte median count was 68 cells/mm3 [interquartile range (IQR): 30–150]. Seventy-five (24.4%) cases had received HAART for more than 180 days. Pneumocystis jirovecii pneumonia (PJP) (n = 142), tuberculosis (n = 63), and bacterial community-acquired pneumonia (n = 60) were the most frequent discharge diagnoses. Receiving HAART for more than 180 days was associated with a lower probability of PJP [Adjusted odd ratio (aOR): 0.245, 95% Confidence Interval (CI): 0.08–0.8, p = 0.02], adjusted for sociodemographic and clinical covariates. HAART was independently associated with reduced odds (aOR 0.214, 95% CI 0.06–0.75) of all-cause in-hospital mortality, adjusting for HIV diagnosis previous to hospitalization, age, access to social security, low socioeconomic level, CD4 cell count, viral load, and discharge diagnoses. Conclusions HAART for 180 days or more was associated with 79% decrease in all-cause in-hospital mortality and lower frequency of PJP as discharge diagnosis. The prevalence of poorly controlled HIV was high, regardless of whether HIV was diagnosed before or during admission. HIV diagnosis and treatment resources should be improved, and strengthening of HAART program needs to be promoted.