Pattern of exposure and measles mortality in Senegal

In a rural area of Senegal, 1500 cases of measles and 98 deaths (6.5%) were registered during a 4-year period (1983-1986). For children less than 5 years old, the acute case fatality ratio (CFR) was 9.6%. Compared with index cases who contracted measles in the village, secondary cases infected within the compound had a significantly higher mortality (odds ratio [OR], 2.9; 95% confidence interval [CI], 1.3-6.1). The CFR of secondary cases increased with the closeness of contact with the index cases; the ORs were 1.9 (CI, 0.6-6.0) for children living in the same compound but not the same household, 2.3 (CI, 1.0-5.7) for children living in the same household but not in the same hut, and 3.8 (CI, 1.7-8.4) for children living in the same hut. In large compounds with many cases, the CFR increased exponentially through the succession of generations; the ORs were 2.3 (CI, 1.0-5.2) in the second generation, 3.7 (CI, 1.1-3.0) in the third generation, 5.5 (CI, 1.7-18.1) in the fourth generation, and 16.1 (CI, 5.6-46.3) in the fifth or later generations. Postmeasles mortality through the year following measles infection was also significantly related to the intensity of exposure. Differences in exposure may be a major determinant of child survival, both at time of acute disease and for the long term impact of measles infection.     

Mortality among primary and secondary cases of measles in Bangladesh

Data were reviewed from an intensive 1975-1976 survey in two Bangladeshi villages that experienced a high incidence of measles. Mortality among secondary cases (four of 50, 8.0%) was significantly higher than that among primary cases (six of 290, 2.1%). In every case in which there was a death in a household with more than one case, it was the youngest patient who died. All children with secondary cases who died had a pre-illness weight-for-height status above the population mean. Measles mortality in Bangladesh appears to be determined by three factors: age, superinfections, and having a secondary case. The last two factors may be due to increased intrafamilial exposure to both the measles virus and the superinfecting pathogens.     

Non‐specific effects of diphtheria‐tetanus‐pertussis and measles vaccinations? An analysis of surveillance data from Navrongo,Ghana

Objectives Studies from low‐income countries have suggested that routine vaccinations may have non‐specific effects on child mortality; measles vaccine (MV) is associated with lower mortality and diphtheria‐tetanus‐pertussis (DTP) with relatively higher mortality. We used data from Navrongo, Ghana, to examine the impact of vaccinations on child mortality. Methods Vaccination status was assessed at the initiation of a trial of vitamin A supplementation and after 12 and 24 months of follow‐up. Within the placebo group, we compared the mortality over the first 4 months and the full 2 years of follow‐up for different vaccination status groups with different likelihoods of additional vaccinations during follow‐up. The frequency of additional vaccinations was assessed among children whose vaccination card was seen at 12 and 24 months of follow‐up. Results Among children with a vaccination card, more than 75% received missing DTP or MV during the first 12 months of follow‐up, whereas only 25% received these vaccines among children with no vaccination card at enrolment. Children without a card at enrolment had a significant threefold higher mortality over the 2‐year follow‐up period than those fully vaccinated. The small group of children with DTP3‐4 but no MV at enrolment had lower mortality than children without a card and had the same mortality as fully vaccinated children. In contrast, children with 1–2 DTP doses but no MV had a higher mortality during the first 4 months than children without a card [MRR = 1.65 (0.95, 2.87)]; compared with the fully vaccinated children, they had significantly higher mortality after 4 months [MRR = 2.38 (1.07, 5.30)] and after 2 years [MRR = 2.41 (1.41, 4.15)]. Children with 0–2 DTP doses at enrolment had higher mortality after 4 months (MRR = 1.67 (0.82, 3.43) and after 2 years [MRR = 1.85 (1.16, 2.95)] than children who had all three doses of DTP at enrolment. Conclusions As hypothesised, DTP vaccination was associated with higher child mortality than measles vaccination. To optimise vaccination policies, routine vaccinations need to be evaluated in randomised trials measuring the impact on survival.     

Patterns of transmission and severity of measles infection: a reanalysis of data from the Machakos area, Kenya

Data on measles from the project in the Machakos District, Kenya, 1974-1981, were reanalyzed. In families with several cases, secondary cases (children infected in the home) had a relative mortality risk of 3.00 (95% confidence interval [CI]: 1.55-5.80) compared with index cases who caught infection from someone outside the home. The case fatality rate (CFR) may be higher among secondary cases exposed to two or more index cases than among those exposed to only one index case (relative risk [RR] = 2.47; 95% CI: 0.93-6.56). The CFR was also higher among secondary cases exposed to a fatal index case than among those exposed to an index case who survived (RR = 4.69; 95% CI: 1.64-13.41). Children aged 12-23 months and those greater than or equal to 5 years were more likely than other age groups to have been infected by someone outside the home. During the course of the project the CFR in families with several cases was reduced from 8.8% to 2.7%. Though there is no general explanation for this tendency, it was observed that the proportion of secondary cases per index case was reduced during the last part of the project (odds ratio = 0.73; 95% CI: 0.56-0.95).     

Measles vaccination before nine months

Summary objective  To measure the protective effect of measles vaccine administered before 9 months of age and compare overall mortality of children vaccinated at 6–8 months and at 9–11 months.nsp;Non-concurrent cohort study involving all 13 134 children born between 16 January 1986 and 31st December 1991 in Kaniyambadi block near Vellore who had not left the area by six months of age. Main outcome measures were risk of disease and death among the under-five-year-olds according to age at measles immunization.ensp;Unimmunized children had a higher risk of developing measles compared to the immunized( P < 0.05). There was no significant difference in risk of measles among those vaccinated prior to and after nine months of age. Unvaccinated children were at significantly higher risk of death than vaccinated children ( P < 0.001). There was no difference in risk of death between infants vaccinated between 6 and 8 months and those vaccinated between 9 and 11 months. There was no difference in the risk of death between boys and girls vaccinated between 6 and 8 months with standard-titre Edmonston-Zagreb vaccine.p; Administration of standard-titre Edmonston-Zagreb measles vaccine at 6–8 months is an effective and safe preventive measure for measles, especially where the age-specific attack rate for childrenis high.     

Human monkeypox: a study of 2,510 contacts of 214 patients

A study of 2,510 contacts of 214 patients with human monkeypox was conducted in Zaire from 1980 to 1984. Among the contacts of 130 primary cases of human monkeypox, a further 22 co-primary and 62 secondary cases were detected, and an additional fourteen people who had no evidence of clinical disease had positive serological results. A majority of the clinical and subclinical cases of monkeypox occurred in children less than 10 years of age. Immunity in vaccinated persons now appears to be waning because 16 overt cases occurred in contacts who had been vaccinated. The overall attack rate for contacts without a vaccination scar (7.2%) differed significantly from the attack rate for those who had been vaccinated in the past (0.9%). The attack rate for household contacts was significantly higher than that for other contacts, among both unvaccinated (four times higher) and vaccinated (seven times higher) household contacts. Many unvaccinated contacts living in the same household as the index case under conditions of maximum exposure, however, escaped not only the disease but also infection.     

Malnutrition and overcrowding/intensive exposure in severe measles infection: review of community studies

Most hospital studies of measles mortality suggest that high case fatality ratios are associated with malnutrition. However, no community study has documented this association. On the contrary, several community studies from Africa and Asia have found no relation between nutritional status and risk of severe or fatal measles. Instead, overcrowding and intensive exposure may be more important determinants of measles mortality. Clustering of several cases in the family and/or intensive exposure were associated with high measles mortality in community studies in West Africa, Bangladesh, and England. Thus sociocultural factors that concentrate many susceptible children in the home may increase the case-fatality ratio in measles. Conversely, this ratio will be lower when measles cases are dispersed. Siblings in rural areas, where long intervals separate epidemics, run a higher risk of contracting measles simultaneously than do their urban counterparts. Measles vaccination increases herd immunity and diminishes the clustering of several cases in a family. Vaccination may therefore reduce mortality even among unvaccinated children who contract measles. Crowding and intensive exposure may partly explain regional and historical variations in measles mortality; community studies suggest that mortality is high when a high proportion of measles patients have secondary cases (acquired through exposure at home).     

Severe measles in Copenhagen, 1915-1925

Among the 2,208 cases of measles at the Infectious Disease Hospital of Copenhagen during the period 1915-1925, the case-fatality ratio was 13%. Mortality was significantly higher for secondary cases (those acquired at home) than for index cases; this difference in mortality was independent of family size. Moreover, mortality was higher for secondary cases than for cases acquired in institutions and hospitals. Children infected at day care institutions had the lowest mortality.     

Field epidemiology investigation on measles outbreak started from a junior high school at Kita Ibaraki City

We studied measles outbreak in Ibaraki Prefecture in spring 2002 as members of Field Epidemiology Training Program Japan (FETPJ). Of 84 cases diagnosed by not laboratory test but clinically, 67 (79.8%) were junior high school students, 9 (10.7%) were other students, and 8 (9.5%) were ordinary adult and infant citizens. Of the 84, 46 (54.8%) had been vaccinated. Most did not show typical Koplik spots. The city in which the school was located promoted vaccinations for infants and children aged 7.5 years old to grade 1 in High school. Questionnaire given to junior high students were detected 86 cases, of whom 57 (66.3%) were male. Overall, 4 peaks of clusters were observed in an epidemic curve, among which graduates' farewell parties and graduation ceremonies were the most common opportunities for measles virus exposure. The overall vaccination rate at school was 82.2%, vaccine efficacy extremely low at 72.5%, and vaccine failure high at 15.2%. Symptoms among those vaccinated were significantly milder than those not vaccinated. Immunity of those vaccinated as infants may have been decreased due to scarcity of measles cases in the last 10 years. In such situations--much less in typical measles among susceptible non affected and non vaccinated subjects--atypical or mild measles may be difficult to diagnose. These findings may keep clarify the need to introduce two-dose measles immunization in Japan.     

Measles incidence, vaccine efficacy, and mortality in two urban African areas with high vaccination coverage

Measles incidence, vaccine efficacy, and mortality were examined prospectively in two districts in Bissau where vaccine coverage for children aged 12-23 months was 81% (Bandim 1) and 61% (Bandim 2). There was little difference in cumulative measles incidence before 9 months of age (6.1% and 7.6%, respectively). Between 9 months and 2 years of age, however, 6.1% contracted measles in Bandim 1 and 13.7% in Bandim 2. Even adjusting for vaccination status, incidence was significantly higher in Bandim 2 (relative risk 1.6, P = .04). Even though 95% of the children had measles antibodies after vaccination, vaccine efficacy was not more than 68% (95% confidence interval [CI] 39%-84%) and was unrelated to age at vaccination. Unvaccinated children had a mortality hazard ratio of 3.0 compared with vaccinated children (P = .002), indicating a protective efficacy against death of 66% (CI 32%-83%) of measles vaccination. These data suggest that it will be necessary to vaccinate before age 9 months to control measles in hyperendemic urban African areas.     

Cross-sex transmission of infection and increased mortality due to measles

In an urban and a rural area of Guinea-Bissau, the incidence of and mortality due to measles were followed over four years. Significantly higher case-fatality ratios among secondary cases occurred when infection was transmitted across sexes than within the same sex. The case-fatality ratio was highest for girls infected by boys and lowest for girls infected by girls. Published reports of cases of fatal measles indicate a similar tendency. Apparently, no general background factor or difference in social interaction between children can explain this variation in severity of infection. It is therefore hypothesized that cross-sex transmission of measles virus produces infections of greater severity. These observations may suggest that measles virus incorporates host-specific cellular characteristics that interfere with the immune responses of persons infected by a member of the opposite sex.     

Two case studies of modified measles in vaccinated physicians exposed to primary measles cases: high risk of infection but low risk of transmission

In 2009, measles outbreaks in Pennsylvania and Virginia resulted in the exposure and apparent infection of 2 physicians, both of whom had a documented history of vaccination with >2 doses of measles-mumps-rubella vaccine. These physicians were suspected of having been infected with measles after treating patients who subsequently received a diagnosis of measles. The clinical presentation was nonclassical in regard to progression, duration, and severity. It is hypothesized that the 2 physicians mounted vigorous secondary immune responses typified by high avidity measles immunoglobulin G antibody and remarkably high neutralizing titers in response to intense and prolonged exposure to a primary measles case patient. Both of the physicians continued to see patients, because neither considered that they could have measles. Despite surveillance for cases among contacts, including unvaccinated persons, no additional cases were identified.     

Further community studies on the role of overcrowding and intensive exposure on measles mortality

Studies of measles mortality have continued for several years in an urban area of Guinea-Bissau. The case-fatality ratio has been as high as 15% despite a relatively good state of nutrition in the community. Mortality has been significantly higher for secondary cases in houses with several cases than for index cases. Of the deaths from measles, 85% have been the result of secondary cases. Sociocultural institutions such as multifamily dwellings, which foster close contact of many susceptible children, increase the risk of measles mortality.     

Short report: assessing field vaccine efficacy for measles in famine-affected rural Ethiopia

Measles is a major cause of mortality in complex emergencies. Both high vaccination coverage and vaccine efficacy are required to prevent major epidemics of measles in such situations. Evaluation of field vaccine efficacy is a critical but underutilized component of program monitoring in emergencies, and is particularly important in rural areas where the integrity of the cold chain is difficult to guarantee. In July 2000, we evaluated the field vaccine efficacy for measles vaccination by comparing the incidence of cases in vaccinated and unvaccinated groups during a two-stage cluster survey of 563 children in Ethiopia. Approximately 30% of the measles cases occurred in vaccinated children. Estimated field vaccine efficacy for measles was 66.9% in children 9-36 months old. The finding of a field vaccine efficacy for measles less than 80% warrants formal assessment of measles vaccine efficacy, particularly in famine emergencies where measles is associated with a high case fatality rate.     

Measles in suburban Khartoum: an epidemiological and clinical study

Clinical and epidemiological data were collected from 187 clinically diagnosed measles patients in Haj Yousif area, suburban Khartoum. Laboratory tests confirmed the diagnosis in 141 (75%) of the cases, but demonstrated that in 46 (25%) patients the clinical symptoms were not caused by an acute measles virus (MV) infection. According to their vaccination card, 59% of the laboratory-confirmed measles cases had been vaccinated for measles. Compared with non-measles rash disease cases, confirmed measles cases more often had severe illness (P < 0.0001), were dehydrated (P=0.01) at presentation and less likely to recover without complications [OR 0.19 (95% CI 0.09, 0.39)]. There was no difference in death rate (P=0.20). Underweight [weight-for-age Z score (WAZ) 相似文献   

Impact of mass measles campaigns among children less than 5 years old in Uganda

In 1999-2001, a national measles control strategy was implemented in Uganda, including routine immunization and mass vaccination campaigns for children aged 6 months to 5 years. This study assesses the impact of the campaigns on measles morbidity and mortality. Measles cases reported from 1992 through 2001 were obtained from the Health Management Information System, and measles admissions and deaths were assessed in six sentinel hospitals. Measles incidence declined by 39%, measles admissions by 60%, and measles deaths by 63% in the year following the campaigns, with impact lasting 15 to 22 months. Overall, 64% of measles cases were among children <5 years of age, and 93% were among children 相似文献   

The role of sex in the transmission of measles in a Gambian village

Data from the 1984-1985 epidemic of measles in Keneba, a Gambian village, have been reanalysed in order to test the effect of same sex vs. opposite sex transmission of measles on the severity of infection. A person infected by someone of the opposite sex was more likely to have severe infection with pulmonary complications than a person infected by someone of the same sex [RR (relative risk) = 2.8, 95% confidence interval (CI): 0.9-9.7]. A secondary case infected by someone of the opposite sex was significantly more likely to have a more severe illness relative to the primary case than a patient infected by someone of the same sex (P = 0.026, Fisher's exact test). There were slightly more female than male primary cases while male secondary cases had a higher risk than female cases of being infected by someone of the opposite sex (RR = 2.6, 95% CI: 0.9-6.9).     

Measles epidemic in the Netherlands, 1999-2000

In 1999-2000, a measles epidemic occurred in The Netherlands, with 3292 reported cases; 94% of the affected patients had not been vaccinated. Only 1 patient had received 2 doses of vaccine. Three patients died, and 16% had complications. For the unvaccinated population, the incidence per 1000 inhabitants 15 months to 14 years old increased from 83 (95% confidence interval [CI], 53-113), in municipalities with vaccine coverage rates < or =90%, to 200 (95% CI, 153-247), in municipalities with coverage rates >95%; for the vaccinated population, the incidence increased from 0.2 (95% CI, 0.1-0.4) to 1.4 (95% CI, 0.9-1.9). Unvaccinated individuals were 224 times (95% CI, 148-460 times) more likely to acquire measles than were vaccinated individuals; the relative risk increased with decreasing vaccine coverage. Herd immunity outside unvaccinated clusters was high enough to prevent further transmission. More case patients came from the vaccine-accepting population living among unvaccinated clusters than from individuals who declined vaccination and who lived among the vaccine-accepting population.     

Evaluation of urban measles mass campaigns for children aged 9-59 months in Mali

There are an estimated 234,000 cases of measles and 13,851 measles-related deaths per year in Mali. In 1998 and 1999, 548,309 children aged 9-59 months were vaccinated against measles during mass campaigns in urban centers across Mali. After the first campaign, measles incidence decreased by 95% in districts encompassing vaccinated urban centers and by 41% in nonvaccinated districts. There was no shift in the proportion of cases by age group in vaccinated centers. Measles in vaccinated districts after the campaign was likely related to persistent transmission in age groups not targeted for vaccination and among children living in nonvaccinated districts. The second campaign (1999) did not change the incidence of measles in vaccinated compared with nonvaccinated centers. Urban mass measles vaccination probably did not affect overall measles transmission in Mali. Mass vaccination of all children in Mali, targeting a larger age group, will be necessary to reach measles control objectives.     

Epidemic measles in young adults. Clinical, epidemiologic, and serologic studies.

An outbreak of measles at the University of California at Los Angeles provided the opportunity to study clinical, epidemiologic, and serologic characteristics of the disease in young adults in the present vaccine era. Of the 34 cases studied, 18 occurred in persons who thought they were immune. Fifteen of 19 seronegative students vaccinated during the epidemic responded with a secondary (IgG) antibody response. Antibody prevalence studies indicated that 91% of the student population had measles antibody at the onset of the outbreak, and history relating to measles correlated poorly with antibody prevalence. Of 212 adults vaccinated, 58% complained of one or more symptoms. Seventeen percent were confined to bed, and in three women vaccine-associated illness was notably severe. That measles will continue to be a problem in adults with our present national approach to immunization is predicted.