Velázquez F R, Matson D O, Calva J J, Guerrero L, Morrow A L, Carter-Campbell S, Glass R I, Estes M K, Pickering L K, Ruiz-Palacios G M
Department of Infectious Diseases, Instituto Nacional de la Nutrición, Mexico City, Mexico.
N Engl J Med. 1996 Oct 3;335(14):1022-8. doi: 10.1056/NEJM199610033351404.
Rotavirus is the leading cause of severe diarrhea in infants. To provide a base line for assessing the efficacy of rotavirus vaccines, we evaluated the protection that is conferred by natural rotavirus infection.
We monitored 200 Mexican infants from birth to two years of age by weekly home visits and stool collections. A physician assessed the severity of any episodes of diarrhea and collected additional stool specimens for testing by enzyme immunoassay and typing of strains. Serum collected during the first week of life and every four months thereafter was tested for antirotavirus IgA and IgG.
A total of 316 rotavirus infections were detected on the basis of the fecal excretion of virus (56 percent) or a serologic response (77 percent), of which 52 percent were first and 48 percent repeated infections. Children with one, two, or three previous infections had progressively lower risks of both subsequent rotavirus infection (adjusted relative risk, 0.62, 0.40, and 0.34, respectively) and diarrhea (adjusted relative risk, 0.23, 0.17, and 0.08) than children who had no previous infections. No child had moderate-to-severe diarrhea after two infections, whether symptomatic or asymptomatic. Subsequent infections were significantly less severe than first infections (P=0.024), and second infections were more likely to be caused by another G type (P=0.054).
In infants, natural rotavirus infection confers protection against subsequent infection. This protection increases with each new infection and reduces the severity of the diarrhea.
轮状病毒是婴儿严重腹泻的主要病因。为了为评估轮状病毒疫苗的疗效提供基线，我们评估了自然感染轮状病毒所提供的保护作用。
我们通过每周家访和采集粪便样本，对200名墨西哥婴儿从出生到两岁进行监测。医生评估任何腹泻发作的严重程度，并采集额外的粪便样本进行酶免疫测定和毒株分型检测。在出生后第一周及之后每四个月采集的血清，检测抗轮状病毒IgA和IgG。
基于病毒粪便排泄（56%）或血清学反应（77%）共检测到316例轮状病毒感染，其中52%为首次感染，48%为重复感染。与未感染过的儿童相比，曾有过一次、两次或三次感染的儿童随后发生轮状病毒感染（调整后的相对风险分别为0.62、0.40和0.34）和腹泻（调整后的相对风险分别为0.23、0.17和0.08）的风险逐渐降低。两次感染后，无论有无症状，没有儿童出现中度至重度腹泻。随后的感染明显不如首次感染严重（P = 0.024），第二次感染更可能由另一种G型引起（P = 0.054）。
在婴儿中，自然感染轮状病毒可对随后的感染提供保护。这种保护随着每次新感染而增强，并降低腹泻的严重程度。
