Search PubMed⌕ Search

Biomedical subjects

John Clemens

Publications and source records attributed to John Clemens.

At least 19 recordsLinked to original sources

Trial participation and vaccine desirability for Vi polysaccharide typhoid fever vaccine in Hue City, Viet Nam.

OBJECTIVES: To identify demand for Vi typhoid fever vaccine for school-age children; obstacles and enabling factors for vaccine delivery; and socio-behavioural factors associated with trial participation and possible predictors of future vaccine acceptance, in Hue City, Viet Nam. METHODS: Pre- and post-trial surveys of randomly selected households with children aged 6-17 years. Simple multinomial logistic analyses for ratios of relative risks (RRR) and significance on trial participation by demographics and variables related to typhoid fever, vaccination, and pre-trial experiences with information and consents. Multiple logistic regressions to assess differences in participation based on child's characteristics. RESULTS: As many as 62.6% of households let all school age children participate, 10.2% let some participate, and 26.8% let none of their children participate in the trial. Factors associated with all children participating included past use of healthcare facilities (RRR, 0.45; 95% CI, 0.24-0.83), knowledge of vaccines (RRR, 0.17; 95% CI, 0.03-0.86), and perceived causes of typhoid fever (RRR, 0.90; 95% CI, 0.81-0.99). Factors associated with some children participating included utilization of healthcare facilities (RRR, 0.08; 95% CI, 0.01-0.66) and perceived severity of typhoid fever (RRR, 0.64; 95% CI 0.46-0.88). Participation was associated with satisfaction regarding pre-vaccination information and consent procedures. Children and adolescents were active decision-makers. Only 14 of 461 (2.2%) respondents would not use the Vi vaccine in the future for their child(ren). CONCLUSIONS: Inter-related factors contribute to participation in a clinical vaccine trial, which may differ from desire to participate in a public health campaign. Educational campaigns need to be targeted to children and adolescents, and consideration for assent procedures for minors. Obtaining informed consent may affect trial participation within a social and political system unaccustomed to these procedures.

Adolescent↗

Safety and immunogenicity of a reformulated Vietnamese bivalent killed, whole-cell, oral cholera vaccine in adults.

Vietnam currently produces an orally administered, bivalent (O1 and O139) killed whole-cell vaccine and is the only country in the world with endemic cholera to use an oral cholera vaccine in public health practice. In order to allow international use, the vaccine had to be reformulated to meet World Health Organization (WHO) requirements. We performed a randomized, placebo controlled, safety and immunogenicity studies of this reformulated vaccine among Vietnamese adults. One hundred and forty-four subjects received the two-dose regimen and 143 had two blood samples obtained for analysis. We found that this reformulated oral killed whole-cell cholera vaccine was safe, well tolerated and highly immunogenic.

Administration, Oral↗

Risk factors for shigellosis in Thailand.

OBJECTIVES: To assess the potential risk factors for shigellosis including housefly density. METHODS: A matched case-control study to investigate potential risk factors for shigellosis was conducted in a semi-urban area, Kaengkhoi District, Saraburi Province, central Thailand. Shigella cases were ascertained from a two-year population-based surveillance study detecting diarrhea and shigellosis in the area. The study evaluated a wide range of exposures, which were assessed by odds ratios (OR) adjusted for proxy markers of socioeconomic status: family income, and type of residence, using conditional logistic regression analysis. RESULTS: Hygiene behaviors such as regular hand washing (p<0.05), a clean environment surrounding the household (p<0.001), and the availability of water to flush the toilet (p=0.08) were associated with a reduced risk for shigellosis in the multivariate model. In contrast factors indicating a lower than average socioeconomic status, such as having to rent instead of owning one's housing (p<0.001) and a low family income (p<0.01) were associated with an increased risk for shigellosis. For children, breastfeeding showed a strong protective effect in reducing the risk of shigellosis (p<0.01). Prior to adjustment for environmental factors, fly density in the kitchen area was associated with an increased risk of shigellosis (p<0.01). CONCLUSIONS: We found a correlation between socioeconomic status and the risk for shigellosis. To reduce shigellosis in this setting, we recommend interventions focused on three aspects: improved water supply and sanitation (especially latrines and garbage disposal) including fly control, health education on hand washing, and the promotion of breastfeeding.

Animals↗

A multicentre study of Shigella diarrhoea in six Asian countries: disease burden, clinical manifestations, and microbiology.

BACKGROUND: The burden of shigellosis is greatest in resource-poor countries. Although this diarrheal disease has been thought to cause considerable morbidity and mortality in excess of 1,000,000 deaths globally per year, little recent data are available to guide intervention strategies in Asia. We conducted a prospective, population-based study in six Asian countries to gain a better understanding of the current disease burden, clinical manifestations, and microbiology of shigellosis in Asia. METHODS AND FINDINGS: Over 600,000 persons of all ages residing in Bangladesh, China, Pakistan, Indonesia, Vietnam, and Thailand were included in the surveillance. Shigella was isolated from 2,927 (5%) of 56,958 diarrhoea episodes detected between 2000 and 2004. The overall incidence of treated shigellosis was 2.1 episodes per 1,000 residents per year in all ages and 13.2/1,000/y in children under 60 months old. Shigellosis incidence increased after age 40 years. S. flexneri was the most frequently isolated Shigella species (1,976/2,927 [68%]) in all sites except in Thailand, where S. sonnei was most frequently detected (124/146 [85%]). S. flexneri serotypes were highly heterogeneous in their distribution from site to site, and even from year to year. PCR detected ipaH, the gene encoding invasion plasmid antigen H in 33% of a sample of culture-negative stool specimens. The majority of S. flexneri isolates in each site were resistant to amoxicillin and cotrimoxazole. Ciprofloxacin-resistant S. flexneri isolates were identified in China (18/305 [6%]), Pakistan (8/242 [3%]), and Vietnam (5/282 [2%]). CONCLUSIONS: Shigella appears to be more ubiquitous in Asian impoverished populations than previously thought, and antibiotic-resistant strains of different species and serotypes have emerged. Focusing on prevention of shigellosis could exert an immediate benefit first by substantially reducing the overall diarrhoea burden in the region and second by preventing the spread of panresistant Shigella strains. The heterogeneous distribution of Shigella species and serotypes suggest that multivalent or cross-protective Shigella vaccines will be needed to prevent shigellosis in Asia.

Adolescent↗

Estimating the burden of shigellosis in Thailand: 36-month population-based surveillance study.

OBJECTIVE: To estimate incidence of shigellosis in the Kaengkhoi district, Saraburi Province, Thailand. METHODS: Population-based surveillance of shigellosis based in treatment centres. The detected rates of treated shigellosis were corrected for the number of cases missed due to the low sensitivity of microbiological culture methods and participants' use of health-care providers not participating in the study. FINDINGS: The overall uncorrected incidence of shigellosis was 0.6/1000 population per year (95% confidence interval (CI) = 0.5-0.8). The unadjusted incidence of treated shigellosis was highest among children less than 5 years old (4/1000 children per year; 95% CI = 3-6) and significantly lower among people aged > 5 years (0.3/1000 population per year; 95% CI = 0.2-0.5; P < 0.001). Adjusting for cases likely to be missed as a result of culture and surveillance methods increased estimates approximately five times. The majority of Shigella isolates (122/146; 84%) were S. sonnei; the rest were S. flexneri. Of the 22 S. flexneri isolates, the three most frequently encountered serotypes were 2a (36%), 1b (23%) and 3b (28%). A total of 90-95% of S. sonnei and S. flexneri isolates were resistant to tetracycline and co-trimoxazole. In contrast to S. sonnei isolates, more than 90% of the S. flexneri isolates were also resistant to ampicillin and chloramphenicol (P < 0.0001). CONCLUSION: Estimates of incidence of Shigella infection in the community are 10-fold to 100-fold greater than those found from routine government surveillance. The high prevalence of Shigella strains resistant to multiple antibiotics adds urgency to the development of a vaccine to protect against shigellosis in this region of Thailand.

Child↗

Incidence of diarrhea caused by rotavirus infections in rural Zhengding, China: prospective, population-based surveillance.

Rotavirus is the pathogen most commonly associated with severe gastroenteritis in young children in the People's Republic of China, yet there are few population-based data on the incidence of rotavirus infection. The present study investigated the burden of rotavirus diarrhea and rotavirus infections in rural China, according to age. Population-based surveillance was used to study the incidence of rotavirus infection among children <5 years of age in 4 townships of Zhengding County, Hebei Province, China. The total population in the catchment area in 2002 was 75,630 individuals, including 2997 children aged <5 years. Stool samples were obtained and were tested for rotavirus antigen by use of an enzyme-linked immunosorbent assay. During 2002, a total of 2010 cases of diarrhea were detected among children <5 years of age. The incidence of treated cases of diarrhea was 671 cases/1000 children/year for children <5 years of age, and it was highest for children <12 months of age (1467 cases/1000 children/year). The estimated incidence of rotavirus infection was 151 cases/1000 children/year for children <5 years of age. The highest incidence of rotavirus infection was among children aged 1-2 years (340 cases/1000 children/year). Widespread immunization of children against rotavirus before 6 months of age should be considered for the control of rotavirus diarrhea.

Child, Preschool↗

Differences in perception of dysentery and enteric fever and willingness to receive vaccines among rural residents in China.

BACKGROUND: Enteric diseases including dysentery and enteric fever remain significant public health problems in China. While vaccines offer great potential in controlling these diseases, greater understanding of factors influencing acceptance of vaccines is needed to create effective enteric disease control programs in rural China. DESIGN: Cross-sectional quantitative study with randomly sampled households from two sites in China, one experiencing high rates of shigellosis (Zengding) and the other of typhoid/paratyphoid (Lingchuan). METHODS: Sociobehavioral survey data were collected through face-to-face interviews from 501 respondents (56% female) in Zhengding regarding dysentery and 624 in Lingchuan (51% female) regarding enteric fever. Vaccine acceptability was measured by expressed need for vaccination and willingness to pay. Comparative and associative analyses were conducted to assess disease perception, vaccination service satisfaction, likelihood of improvements in water and sanitation, and vaccine acceptability. RESULTS: Nearly all respondents in Lingchuan considered enteric fever to be prevalent in the community, while only one half of the respondents in Zhengding considered dysentery to be problematic (p < 0.01). Nevertheless, more respondents in Zhengding were fearful that a household member would acquire dysentery than were Lingchuan respondents worried that a household member would acquire enteric fever (p < 0.01). Perceived vulnerability of specific subgroups (odds ratios ranging from 1.6 to 8.1), knowing someone who died of the disease (odds ratio reached infinity) and satisfaction with past vaccination services (odds ratios reached infinity) were consistently associated with perceived need for vaccines of target populations of all age groups while the association between perception of sanitary improvement and vaccine need was limited. Perceived need for a vaccine was associated with willingness to pay for the vaccine. CONCLUSIONS: Perceptions of enhanced vulnerability of specific subgroups to a disease and satisfactory experiences with vaccination services may increase the perceived need for a vaccine, leading to increased willingness to pay for vaccine. Vaccines are not perceived as important for the elderly.

Adult↗

Willingness to be vaccinated against shigella and other forms of dysentery: a comparison of three regions in Asia.

We conducted a cross sectional survey of 3163 women and men in six Asian countries to examine willingness for children and adults to be vaccinated against shigellosis and other forms of dysentery. The six sites were clustered into three regions for ease of comparison. The regions are: Northeast Asia (China), Southeast Asia (Thailand, Vietnam, and Indonesia) and South Asia (Bangladesh and Pakistan). We used multiple logistic regression to identify region-specific models for vaccination willingness for both adults and children. A vaccine to protect against dysentery, if available would be very much in demand throughout the three Asian regions for children. For adults, the responses indicate that vaccine uptake by adults will vary. A large proportion of respondents in all regions, specifically in China, do not perceive themselves at risk yet still consider a shigellosis vaccine desirable.

Adult↗

Introducing new vaccines into developing countries: obstacles, opportunities and complexities.

Infectious diseases are thought to account for nearly 25% of all deaths worldwide, and extract a disproportionate toll in developing countries. Moreover, infectious diseases are now appreciated to be major causes of the poverty and economic underdevelopment that characterize the world's poorest countries. Development and deployment of new vaccines to prevent infectious diseases in developing countries have therefore become high priorities in the global health agenda.

Developing Countries↗

[Application of cluster randomization method on typhoid Vi vaccine trails].

OBJECTIVE: To describe the design and application of cluster randomized controlled method on typhoid Vi vaccine trial, and to assess the effect of implementation. METHODS: Simple size calculation of cluster-randomized trial was used to determine the sample size of the two groups and a vaccination campaign was conducted. The study group was given typhoid Vi vaccine and the control group was given meningococcal A vaccine. RESULTS: According to sample size calculation, a total sample of 96,121 participants was required and the study areas were divided into 108 clusters. In practice, 53 study clusters with 44,054 participants and 54 control clusters with 48,422 participants were stratified and matched according to size, location (urban or rural), characteristics (school, department, factory, demography) were randomized respectively. Confounding factors of two groups including age, sex, resident area, income, level of education were compared. It was found that the ratio of all confounding factors between the two groups were comparable and balanced. CONCLUSION: Confounding factors can be better controlled between study group and the control group by applying cluster-randomized method on vaccine trail which enabled the intervention to be more scientifically evaluated; The implementation of cluster randomization trial was simple and easy to be accepted.

Adolescent↗

Occurrence of shigellosis in the young and elderly in rural China: results of a 12-month population-based surveillance study.

In 2002, population- and treatment center-based surveillance was used to study the disease burden of shigellosis in rural Hebei Province in the People's Republic of China. A total of 10,105 children with diarrhea or dysentery were enrolled. Infants were treated most frequently for diarrhea (1,388/1,000/year) followed by children < or = 5 years old (618/1,000/year). Shigellosis was treated most often in children 3-4 years old (32/1,000/year) and people > 60 years of age (7/1,000/year). Fifty-six percent (184 of 331) Shigella isolates were detected in patients who had non-bloody diarrhea. Shigella flexneri was identified in 93% of 306 isolates. The most common S. flexneri serotypes were 1a (34%), X (33%), and 2a (28%). More than 90% of the Shigella isolates were resistant to cotrimoxazole and nalidixic acid, but remained susceptible to ciprofloxacin, norfloxacin, and gentamicin. Widespread resistance to antibiotics adds urgency to the development and use of vaccines to control shigellosis.

Adolescent↗

Mucosal adjuvants and anti-infection and anti-immunopathology vaccines based on cholera toxin, cholera toxin B subunit and CpG DNA.

Mucosal immunisation may be used both to protect the mucosal surfaces against infections and as a means for immunological treatment of peripheral immunopathological disorders through the induction of systemic antigen-specific tolerance ('oral tolerance'). The development of mucosal vaccines, whether for prevention of infectious diseases or for oral tolerance immunotherapy, requires efficient antigen delivery and adjuvant systems that can help to present the appropriate vaccine or immunotherapy antigens to the mucosal immune system. The most potent (but also toxic) mucosal adjuvants are cholera toxin (CT) and the closely related Escherichia coli heat-labile enterotoxin (LT), and much effort and significant progress have been made recently to generate toxicologically acceptable derivatives of these toxins with retained adjuvant activity. Among these are the non-toxic, recombinantly produced cholera toxin B-subunit (CTB). CTB is a specific protective antigen component of a widely registered oral cholera vaccine as well as a promising vector for either giving rise to mucosal anti-infective immunity or for inducing peripheral anti-inflammatory tolerance to chemically or genetically linked foreign antigens administered mucosally. CT and CTB have also recently been used as combined vectors and adjuvants for markedly promoting ex vivo dendritic cell (DC) vaccination with different antigens and also steering the immune response to the in vivo-reinfused DCs towards either broad Th1 + Th2 + CTL immunity (CT) or Th2 or tolerance (CTB). Another type of mucosal adjuvants is represented by bacterial DNA or synthetic oligodeoxynucleotides containing CpG-motifs, which especially when linked to CTB have been found to effectively stimulate both innate and adaptive mucosal immune responses. The properties and clinical potential of these different classes of adjuvants are being discussed.

Adjuvants, Immunologic↗

Development of pathogenicity-driven definitions of outcomes for a field trial of a killed oral vaccine against enterotoxigenic Escherichia coli in Egypt: application of an evidence-based method.

BACKGROUND: To design an efficacy trial of a killed oral vaccine against enterotoxigenic Escherichia coli (ETEC) diarrhea in Egyptian children, we derived for ETEC diarrhea an empirical definition that increased the probability that diarrhea associated with excretion of ETEC was caused by the detected ETEC. METHODS: We conducted a cohort study of 397 Egyptian children <24 months old and monitored them until they were 3 years old. Vaccine-preventable (VP) ETEC was defined as ETEC expressing >/=1 of the toxin- (heat-labile [LT] toxin) and colonization-factor antigens (CFA I, II, and IV) in the vaccine. RESULTS: Although fecal excretion of VP-ETEC was highly associated with diarrhea, excretion of LT-ETEC per se was not related to diarrhea (adjusted odds ratio [OR(A)], 1.16 [95% confidence interval [CI], 0.90-1.49]). The fecal excretion of antigenic types of VP-ETEC other than LT-ETEC (non-LT VP-ETEC) was highly associated with diarrheal symptoms (OR(A), 3.91 [95% CI, 2.78-5.49]; P<.001), and this association was greater for nonbloody than for bloody diarrhea. CONCLUSIONS: Because the vaccine had been anticipated to protect primarily against symptomatic ETEC diarrhea, these results indicate that the primary-outcome definition of ETEC diarrhea for the trial should be restricted to nonbloody diarrheal episodes associated with fecal excretion of non-LT VP-ETEC.

Bacterial Toxins↗

Flowering genes in Metrosideros fit a broad herbaceous model encompassing Arabidopsis and Antirrhinum.

Molecular studies were conducted on Metrosideros excelsa to determine if the current genetic models for flowering with regard to inflorescence and floral meristem identity genes in annual plants were applicable to a woody perennial. MEL, MESAP1 and METFL1, the fragments of LEAFY (LFY), APETALA1 (AP1) and TERMINAL FLOWER1 (TFL1) equivalents, respectively, were isolated from M. excelsa. Temporal expression patterns showed that MEL and MESAP1 exhibited a bimodal pattern of expression. Expression exhibited during early floral initiation in autumn was followed by down-regulation during winter, and up-regulation in spring as floral organogenesis occurred. Spatial expression patterns of MEL showed that it had greater similarity to FLORICAULA (FLO) than to LFY, whereas MESAP1 was more similar to AP1 than SQUAMOSA. The interaction between MEL and METFL1 was more similar to the interaction between FLO and CENTRORADIALIS than that between LFY and TFL1. Consequently, the three genes from M. excelsa fit a broader herbaceous model encompassing Antirrhinum as well as Arabidopsis, but with differences, such as the bimodal pattern of expression seen with MEL and MESAP1. In mid-winter, at the time when both MEL and MESAP1 were down-regulated, GA(1) was below the level of detection in M. excelsa buds. Even though application of gibberellin inhibits flowering in members of the Myrtaceae, MEL was responsive to gibberellin with expression in juvenile plants up-regulated by GA(3). However, MESAP1 was not up-regulated indicating that meristem competence was also probably required to promote flowering in M. excelsa.

Journal Article↗

Emergence and serovar transition of Vibrio parahaemolyticus pandemic strains isolated during a diarrhea outbreak in Vietnam between 1997 and 1999.

We characterized 523 Vibrio parahaemolyticus strains isolated during a survey of diarrhea patients in Khanh Hoa province, Vietnam between 1997 and 1999. Forty-nine percent of the strains were judged to belong to the pandemic strains that emerged around 1996 and spread to many countries. These strains were positive in the GS-PCR assay and carried the tdh gene. The ORF8 of the f237 phage genome, a possible marker of the pandemic clone, was absent in 10% of these strains. Eleven O: K serovars were detected among the pandemic strains and the strains representing all 11 serovars of pandemic strains were shown to be closely related regardless of the ORF8 genotype using arbitrarily primed PCR and pulsed field gel electrophoresis analyses. It was clear that a transition of major serovars occurred among the pandemic strains represented by the emergence of O3: K6 in 1997, O4: K68 in 1998, and O1: K25 in 1998 and 1999.

DNA Fingerprinting↗

A global perspective on vaccine safety and public health: the Global Advisory Committee on Vaccine Safety.

Established in 1999, the Global Advisory Committee on Vaccine Safety advises the World Health Organization (WHO) on vaccine-related safety issues and enables WHO to respond promptly, efficiently, and with scientific rigor to issues of vaccine safety with potential global importance. The committee also assesses the implications of vaccine safety for practice worldwide and for WHO policies. We describe the principles on which the committee was established, its modus operandi, and the scope of the work undertaken, both present and future. We highlight its recent recommendations on major issues, including the purported link between the measles-mumps-rubella vaccine and autism and the safety of the mumps, influenza, yellow fever, BCG, and smallpox vaccines as well as that of thiomersal-containing vaccines.

Advisory Committees↗

Mass psychogenic illness following oral cholera immunization in Ca Mau City, Vietnam.

INTRODUCTION: Targeted cholera immunization of high-risk populations in Vietnam is conducted based on routine surveillance data. Following mass immunization of schoolchildren in Ca Mau City using an oral bivalent killed cholera vaccine, adverse reactions were noted. METHODS: Salient data were collected in a systematic fashion including the review of medical records; interview of the school principal, teachers, students, parents and doctors; and review of the storage and handling of the vaccine. FINDINGS: On 18 December 2001, 234 children at a primary school in Ca Mau City received the cholera vaccine. Within 1h of immunization, three children in one of the classrooms complained of trembling, nausea and headache and were brought to the library and soon other children followed. Out of 234, 97 (42%) pupils were affected and brought to the Municipal Health Center or Ca Mau Provincial Hospital. Those who were affected were younger (mean age=9.6 years; 95% CI=9.4-9.7) compared to those who were not affected (mean age=10 years; 95% CI=9.7-10.3; t-test=-2.4; P-value=0.02). The proportion of affected females among those who had received the vaccine (49/114 or 43%) was similar to the proportion in males (48/120 or 40%; RR=1.07; 95% CI=0.79-1.46). The most frequent presenting complaint was cold extremities (60%) followed by headache (27%). All affected children recovered and were discharged in a few hours. None reported any sequelae or relapse. Once the situation was recognized, the cholera immunization campaign was continued. Laboratory tests of vaccine samples from the same batch detected no abnormality or contaminating agent. DISCUSSION: The findings suggest that the children at primary school number 1 suffered from a mass psychogenic illness. This incident was unusual in that a similar number of boys and girls were affected, in contrast to the frequently reported preponderance of female cases. Furthermore the underlying cause was very quickly diagnosed, medical interventions were kept to a minimum, and no relapse was observed. Future vaccination campaigns have to assure that the families are informed in advance.

Administration, Oral↗

Breastfeeding practices in a cohort of inner-city women: the role of contraindications.

BACKGROUND: Little is known about the role of breastfeeding contraindications in breastfeeding practices. Our objectives were to 1) identify predictors of breastfeeding initiation and duration among a cohort of predominantly low-income, inner-city women, and 2) evaluate the contribution of breastfeeding contraindications to breastfeeding practices. METHODS: Mother-infant dyads were systematically selected from 3 District of Columbia hospitals between 1995 and 1996. Breastfeeding contraindications and potential predictors of breastfeeding practices were identified through medical record reviews and interviews conducted after delivery (baseline). Interviews were conducted at 3-7 months postpartum and again at 7-12 months postpartum to determine breastfeeding initiation rates and duration. Multivariable logistic regression analysis was used to identify baseline factors associated with initiation of breastfeeding. Cox proportional hazards models were generated to identify baseline factors associated with duration of breastfeeding. RESULTS: Of 393 study participants, 201 (51%) initiated breastfeeding. A total of 61 women (16%) had at lease one documented contraindication to breastfeeding; 94% of these had a history of HIV infection and/or cocaine use. Of the 332 women with no documented contraindications, 58% initiated breastfeeding, vs. 13% of women with a contraindication. In adjusted analysis, factors most strongly associated with breastfeeding initiation were presence of a contraindication (adjusted odds ratio [AOR], 0.19; 95% confidence interval [CI], 0.08-0.47), and mother foreign-born (AOR, 4.90; 95% CI, 2.38-10.10). Twenty-five percent of study participants who did not initiate breastfeeding cited concern about passing dangerous things to their infants through breast milk. Factors associated with discontinuation of breastfeeding (all protective) included mother foreign-born (hazard ratio [HR], 0.55; 95% CI 0.39-0.77) increasing maternal age (HR for 5-year increments, 0.80; 95% CI, 0.69-0.92), and infant birth weight > or = 2500 grams (HR, 0.45; 95% CI, 0.26-0.80). CONCLUSIONS: Breastfeeding initiation rates and duration were suboptimal in this inner-city population. Many women who did not breastfeed had contraindications and/or were concerned about passing dangerous things to their infants through breast milk. It is important to consider the prevalence of contraindications to breastfeeding when evaluating breastfeeding practices in high-risk communities.

Adult↗