Community Diarrhea Incidence Before and After Rotavirus Vaccine Introduction in Nicaragua

We estimated the incidence of watery diarrhea in the community before and after introduction of the pentavalent rotavirus vaccine in León, Nicaragua. A random sample of households was selected before and after rotavirus vaccine introduction. All children < 5 years of age in selected households were eligible for inclusion. Children were followed every 2 weeks for watery diarrhea episodes. The incidence rate was estimated as numbers of episodes per 100 child-years of exposure time. A mixed effects Poisson regression model was fit to compare incidence rates in the pre-vaccine and vaccine periods. The pre-vaccine cohort (N = 726) experienced 36 episodes per 100 child-years, and the vaccine cohort (N = 826) experienced 25 episodes per 100 child-years. The adjusted incidence rate ratio was 0.60 (95% confidence interval [CI] 0.40, 0.91) during the vaccine period versus the pre-vaccine period, indicating a lower incidence of watery diarrhea in the community during the vaccine period.     

Burden of Norovirus and Rotavirus in Children after Rotavirus Vaccine Introduction,Cochabamba, Bolivia

The effectiveness of rotavirus vaccine in the field may set the stage for a changing landscape of diarrheal illness affecting children worldwide. Norovirus and rotavirus are the two major viral enteropathogens of childhood. This study describes the prevalence of norovirus and rotavirus 2 years after widespread rotavirus vaccination in Cochabamba, Bolivia. Stool samples from hospitalized children with acute gastroenteritis (AGE) and outpatients aged 5–24 months without AGE were recruited from an urban hospital serving Bolivia''s third largest city. Both viruses were genotyped, and norovirus GII.4 was further sequenced. Norovirus was found much more frequently than rotavirus. Norovirus was detected in 69/201 (34.3%) of specimens from children with AGE and 13/71 (18.3%) of those without diarrhea. Rotavirus was detected in 38/201 (18.9%) of diarrheal specimens and 3/71 (4.2%) of non-diarrheal specimens. Norovirus GII was identified in 97.8% of norovirus-positive samples; GII.4 was the most common genotype (71.4% of typed specimens). Rotavirus G3P[8] was the most prevalent rotavirus genotype (44.0% of typed specimens) and G2P[4] was second most prevalent (16.0% of typed specimens). This community is likely part of a trend toward norovirus predominance over rotavirus in children after widespread vaccination against rotavirus.     

Impact of Traffic Flow on the Asthma Prevalence Among School Children in Lima,Peru

Objective. To estimate the impact of traffic flow on the prevalence of asthma among school children of 6 to7 and 13 to 14-years of age. Methods. A cross-sectional study consisting of 5,917 children selected in schools of the Cone Norte of Lima, Peru. Results. For the 6- to 7-year age group the prevalence of medical diagnosis of asthma according to the traffic flow index was 8.6% (CI: 6.8–10.8), 10.3% (CI: 8.4–12.4), and 15.3% (CI:13.3–17.5) at low, medium and high, respectively, and for the 13- to 14-year age group, 11.9% (CI: 9.4–14.6), 13.3% (CI: 11.6–15.2), and 17.1% (CI: 14.7–19.6). Conclusions. For both groups, the prevalence of asthma was significantly related to traffic flow density.     

Outbreak of cyclosporiasis at a naval base in Lima, Peru

Cyclospora cayetanensis is emerging as an important cause of food-borne diarrheal outbreaks, especially in developed regions like the United States and Europe. We describe an outbreak of cyclosporiasis in Peruvian naval recruits that we believe to be the first among a local population in a developing region.     

House dust mites in the city of Lima, Peru.

Since mites are the most common house dust allergens, knowledge about the species most prevalent in a region is important for diagnostic and specific immunotherapy purposes. In order to establish the prevalence of house dust mites in different city districts, 100 house dust samples were collected from different parts of Lima. Lima is a city of tropical climate located along the coast of the Pacific Ocean. The relative air humidity is 80-90% and the various districts studied are located at altitudes ranging from 37-355 meters. The mite Blomia tropicalis was the organism most frequently detected, being present in 59% of the house dust samples. Dermatophagoides pteronyssinus occupied second place (15.9%), followed by Chortoglyphus arcuatus and Tyrophagus putrescentiae. These four mites, taken together, represented more than 90% of the mites detected. No specimen of the species Dermatophagoides farinae was detected. We conclude that B. tropicalis and D. pteronyssinus are the most common house dust mites in Lima. Considering the high prevalence of B. tropicalis in Lima and the fact that its cross-reactivity with antigens of the mites of the family Pyroglyphidae is minimal, we conclude that sensitization to this mite should be investigated separately in allergic patients living in Lima.     

Defining the Recipe for an Optimal Rotavirus Vaccine Introduction in a High-Income Country in Europe

Observational data over 15 years of rotavirus vaccine introduction in Belgium have indicated that rotavirus hospitalisations in children aged <5 years plateaued at a higher level than expected, and was followed by biennial disease peaks. The research objective was to identify factors influencing these real-world vaccine impact data. We constructed mathematical models simulating rotavirus-related hospitalisations by age group and year for those children. Two periods were defined using different model constructs. First, the vaccine uptake period encompassed the years required to cover the whole at-risk population. Second, the post-uptake period covered the years in which a new infection/disease equilibrium was reached. The models were fitted to the observational data using optimisation programmes with regression and differential equations. Modifying parameter values identified factors affecting the pattern of hospitalisations. Results indicated that starting vaccination well before the peak disease season in the first year and rapidly achieving high coverage was critical in maximising early herd effect and minimising secondary sources of infection. This, in turn, would maximise the reduction in hospitalisations and minimise the size and frequency of subsequent disease peaks. The analysis and results identified key elements to consider for countries initiating an optimal rotavirus vaccine launch programme.     

Diagnosis of sputum-scarce HIV-associated pulmonary tuberculosis in Lima, Peru

Sputum induction, bronchoalveolar lavage, or gastric aspiration are often needed to produce adequate diagnostic respiratory samples from people with HIV in whom tuberculosis is suspected. Since these procedures are rarely appropriate in less-developed countries, we compared the performances of a simple string test and the gold-standard sputum induction. 160 HIV-positive adults under investigation for tuberculosis, and 52 asymptomatic HIV-positive control patients underwent the string test followed by sputum induction. The string test detected tuberculosis in 14 patients in whom this disease was suspected; sputum induction detected only eight of them (McNemar's test, p=0.03). These preliminary data suggest that the string test is safe and effective for retrieval of useful clinical specimens for diagnosis of pulmonary tuberculosis, and is at least as sensitive as sputum induction.     

秘鲁利马公共交通工作人员患结核病的风险

背景：对涂阳肺结核可疑症状者的诊断和治疗延迟可能会使其密切接触者成为新的患者。特别是在一些密闭的环境中,如在拥挤的公交车上,乘客和公交人员都处于感染肺结核的风险中。目的：了解研究地区结核病患者的发病率,以及公交人员中结核病和耐多药结核病患者的比例。方法：根据2007年1月1日至2008年6月30日期间内部卫生体系中所有结核病发病患者的病案资料,计算粗发病率和间接标化发病率。分析公交人员中结核病患者的比例以及在公交部门工作和耐多药结核病的相关性。结果：公交人员的结核病标化发病率比所有男性工作年龄组人群和研究地区全部人群的标化发病率高2．7～4．5倍。结核病、耐多药结核病和在公交部门工作的相关性较高（比值比分别为OR=3．06,95％CJ：2．2～4．2,OR=3．14,95％CJ：1．1～9．1）。结论：结果表明,日常乘坐公交车是感染结核病的一个危险因素,在与秘鲁相似国家中其也是感染结核病的一项职业危险因素。     

Use of commercially available oral rehydration solutions in Lima, Peru

Caregivers' practices concerning oral rehydration of young children during diarrheal illness were investigated in a periurban community of low socioeconomic level in Lima, Peru. Data of 330 caregivers of children aged 6-36 months were analyzed; 72.7% of all caregivers would give commercially available oral rehydration solutions (ORSs). However, only 58.6% of those caregivers with children that had experienced diarrhea during the previous week stated that they had used commercially available ORSs, a significantly lower percentage. The main reason for not using commercially available ORSs was that caregivers did not know about them. Of all recipes caregivers provided for homemade ORS, none contained the recommended concentrations of sugar and salt. Educating caregivers about availability, benefits, and use of commercially available ORSs as well as correct preparation of homemade ORS is urgently needed.     

A Foodborne Outbreak of Brucellosis at a Police Station Cafeteria,Lima, Peru

Brucella melitensis is highly infectious for humans and can be transmitted to humans in a number of epidemiological contexts. Within the context of an ongoing brucellosis surveillance project, an outbreak at a Peruvian police officer cafeteria was discovered, which led to active surveillance (serology, blood culture) for additional cases among 49 police officers who had also eaten there. The cohort was followed up to 18 months regardless of treatment or symptoms. Active surveillance estimated the attack rate at 26.5% (13 of 49). Blood cultures from four cases were positive; these isolates were indistinguishable using multiple locus variable number tandem repeat analysis. This investigation indicates the importance of case tracking and active surveillance for brucellosis in the context of potential common source exposure. These results provide rationale for public health investigations of brucellosis index cases including the bioterrorism-related dissemination of Brucella.     

Taeniasis and cysticercosis in housemaids working in affluent neighborhoods in Lima, Peru

Taenia solium taeniasis/cysticercosis is endemic in most developing countries, where it is an important cause of epileptic seizures and other neurologic symptoms. In industrialized countries, cysticercosis results from travel or immigration of tapeworm carriers from endemic areas. In both endemic and nonendemic countries, housemaids commonly immigrate from cysticercosis-endemic areas and can transmit the infection if they carry the adult tapeworm. Between July 2001 and July 2002, 1,178 housemaids (961 of them work in the top five most affluent districts of Lima, a metropolis of 8 million inhabitants considered nonendemic for cysticercosis) were evaluated for serum antibodies to Taenia solium and stool microscopy for taeniasis and cysticercosis. The serosurvey revealed a prevalence of cysticercosis-specific antibodies of 14.6% (95% CI: 12.6-16.6%), and stool microscopy detected 12 T. solium tapeworm carriers, for a prevalence of taeniasis of 1.2% (95% CI: 0.6-1.8%). A nonrandom sample of 26 seropositive housemaids was examined by brain CT and 50% of them had brain lesions compatible with neurocysticercosis, mainly calcifications. From the families who used a tapeworm-carrier housemaid, cysticercosis antibodies were detected in 6 (23%) of 26 persons who agreed to participate. One seropositive member of the employer families was symptomatic for seizures and had brain calcifications. The prevalence of tapeworm infections in this housemaid group is similar to levels in endemic areas, constituting a source of neurocysticercosis infection.     

Identification of 5 types of Cryptosporidium parasites in children in Lima, Peru

Cryptosporidium parvum is usually considered to be the pathogen responsible for human cryptosporidiosis. We genotyped Cryptosporidium in 132 stool specimens from 80 Peruvian children, representing 85 infection episodes, using techniques that differentiate Cryptosporidium species and C. parvum genotypes. Five types of Cryptosporidium were identified: C. parvum human (67), bovine (8), and dog (2) genotypes, C. meleagridis (7), and C. felis (1). Twenty-five (29%) of the 85 infection episodes were associated with diarrhea. There was no significant difference in age, antecedent stunting, percentage with diarrhea, or duration of diarrhea for episodes with human genotype, compared with those of zoonotic Cryptosporidium. Duration of oocyst shedding was longer for human genotype than for zoonotic Cryptosporidium (mean, 13.9 days and 6.4 days, respectively; P=.004). Serum samples from 8 children with C. meleagridis, C. felis, or C. parvum dog genotype were tested for anti-human immunodeficiency virus (HIV) type 1 antibodies; all were found to be negative. Contrary to common belief, novel Cryptosporidium species and C. parvum genotypes can infect HIV-negative children.     

Surveillance of bacterial pathogens associated with acute diarrhea in Lima, Peru.

OBJECTIVES: A study was conducted in Lima, Peru, from January to April 1995, to determine the bacterial pathogens associated with acute diarrhea in adults, their susceptibility to common antimicrobials, the risk factors involved in cholera transmission, and the best clinical predictors of cholera. METHODS: A random sample of adult patients with acute diarrhea was studied. Epidemiologic and clinical data and risk factors to acquire diarrheal diseases were evaluated. Identification of bacteria and susceptibility to antimicrobials were determined. RESULTS: The study included 336 patients. Vibrio cholerae O1 (52.7%), Shigella spp. (4. 8%), and Salmonella spp (2.7%) were the pathogens most commonly isolated. No resistance to antimicrobials was observed. Patients with cholera had less access to municipal water (P = 0.0018) and were less likely to have homes connected to a sewage system (P = 0. 0003) or to have indoor toilet facilities (P = 0.0001) than those without cholera. Liquid stools (odds ratio [OR] = 16.51; confidence interval [CI] = 13.71-19.02; P = 0.003), severe dehydration (OR = 2. 48; CI = 1.57-3.38; P = 0.0083), generalized cramps (OR = 4.63; CI = 3.10-6.17, P < 0.0001), and washerwoman's hands (OR = 2.45; CI = 1. 55-3.34; P = 0.017) were the best clinical predictors of cholera in this setting. CONCLUSIONS: Cholera is still prevalent in Lima, and people living in environments with low sanitary conditions are especially at risk. Clinical signs of severe dehydration and liquid stools were the best predictors of cholera.