Tropical and geographical medicine最新文献

Two annual follow-up measures of incidence, reinfection after treatment and reversion rates were estimated in a large prospective study of Schistosoma mansoni located in the northern Nile Delta of Kafr El Sheikh. Rates were estimated in a cohort established from a probability sample of the entire rural area of Kafr El Sheikh. Infection was determined by the examination of two Kato stool slides. The weighted first and second annual overall incidence rates were 20.4%, SE +/- 1.4 and 15.9%, SE +/- 1.4, respectively. Geometric mean egg counts in incident cases were 35.6 epg, SE +/- 1.2 and 31.0, SE +/- 1.6 in the first and second follow-ups. Incidence was strongly associated with first round prevalence (r2 = 0.34). Reinfection rates were higher: 33.4%, SE +/- 3.1 and 31.0%, SE +/- 2.1. Reinfection was associated with incidence (r2 = 0.32). Reversion rates were highest in children 0 to 4 years old (61.2%, SE +/- 18.1 and 78.5%, SE +/- 7.0, respectively) and increased from the first to second follow-up: 37.2%, SE +/- 3.4 and 47.0%, SE +/- 3.7, respectively. Patterns of these rates by village community, age and sex are also given over both follow-up examinations and comparison with limited data on rates of S. mansoni infection from previous studies, suggests a stable pattern of transmission over time in the Nile Delta.

A repeat survey for schistosomiasis japonica was carried out in Sisan community 1 year after chemotherapy with praziquantel was stopped. Prevalence of infection had fallen from 43.7 to 10.2%, intensity (population geometric mean) had dropped from 6.3 to 0.6 eggs per gram of stool and morbidity decreased significantly.

Twenty-five confirmed cases of human immunodeficiency virus type 1 (HIV-1) infection due to blood transfusion have been documented at King Fahad Hospital (KFH) in Al-Baha, southwestern Saudi Arabia since 1986, but complete follow-up was only possible on 19 of these cases and their contacts. Seventeen cases were diagnosed as having acquired immunodeficiency syndrome (AIDS) or AIDS-related complex (ARC) after admission to the hospital due to the deterioration of their health status. Two cases were found to be anti-HIV-1 positive on routine screening for blood donation. This cluster of HIV-1 infected patients through blood transfusion allowed us to study the efficiency of sexual transmission of HIV-1 infection between spouses, the rate of perinatal transmission of HIV-1 infection, and to see whether intrafamilial transmission is a possible route of spread of the virus. Firstly, the present results confirm our earlier observation that transmission of HIV-1 infection was more efficient from the infected husband to his wife(s) in contrast to the inefficient transmission of the infection from the infected wife to her husband. Secondly, by the age of 16 months, all nine newborns to HIV-1 infected mothers became HIV-1 infected. This highlights the importance of medical advice to those mothers regarding conception and/or breast-feeding, particularly as breast-feeding up to 2 years is not an uncommon practice among Saudi women. Finally, none of the household contacts of the 19 cases was infected until now, indicating that intrafamilial spread of HIV-1 did not occur among the population studied.

As part of a study of surgical operations in a rural African district, different quantitative output rates were explored. The aim was to develop methods facilitating major surgery output comparison between different hospitals or districts and between different points in time at any given hospital or district. All major surgical operations performed at hospitals in a Kenyan district during 12 months in 1990-1991 were listed on record forms including age, sex, and home address of patients, and type of operation. Totally 3,415 major operations were recorded. We discuss, from a health planning perspective, four possible methods of quantifying the major surgery output: a) the annual number of major operations per 100 hospital beds; b) the number per 1,000 in-patient admissions; c) the number per 10,000 new out-patient consultations; and d) the number per 100,000 catchment area population. The mean number per 100 beds was 310 (range 452-140); the mean number per 1,000 admissions was 69 (range 88-31), the number per 10,000 new out-patient visits was 90 (range 182-55), and the mean number per 100,000 catchment area population was 263 for the entire district with a range from 383 to 119 among the five hospitals. We conclude that option a) and b) are useful and implementable, c) is less useful but implementable, and option d) is potentially very useful but not easily implementable until a catchment area population definition is agreed and applied.

[NANP]19-5.1 is a recombinant Plasmodium falciparum vaccine consisting of 19 repeats of the sporozoite surface protein [NANP] and the schizont export antigen 5.1. In a previous study, an experimentally infected subject (with a history of malaria exposure and an elevated pre-immunization lymphocyte stimulation index to antigen 5.1) showed parasitaemia but no signs of clinical malaria. In an attempt to find a comparable partially immune population, we tested the vaccine in 194 schoolchildren (6 to 12 years, vaccine and placebo groups of equal size), who already possessed a certain degree of immunity. It was hoped that this immunity would be boosted by the vaccine. During the 12 weeks of observation, no child developed clinical malaria. Analysis of serum taken before and after immunization revealed that, except for eight children, all had considerable levels of antibodies to both antigens. We conclude that the trial should be repeated in younger children who are still vulnerable to clinical malaria.

The effect of nylon-netting wall-curtains impregnated with 0.5 g permethrin/m2 upon the biting rate of malaria vectors (Anopheles gambiae s.l. and An. funestus) and on the Plasmodium falciparum parasite rate, and morbidity due to malaria in children under five and between five and fourteen years was tested in the Maputo area. The curtains significantly lowered biting rates of both vector species inside curtained houses, but reduced inside resting and outside biting only in An. funestus. The percentage of children with falciparum parasitaemia fell significantly in curtained houses, and among their neighbours. However, parasite load and malaria morbidity in under fives was unaffected but malaria morbidity fell throughout the experimental area in 5 to 14-year-olds. This led to the speculation that malaria vectors inhibited from feeding in the vicinity of the curtains might have gone to feed in the adjacent control area.

High caesarean birth rates are an issue of international public health concern. Determinants of caesarean birth are reviewed in order to formulate strategies to reduce these high rates. A strong independent profession of highly qualified midwives, who care for women with low-risk pregnancies, may contribute to a relatively low caesarean birth rate. Different clinical policies which influence the intervention rate, are discussed for the most frequent reasons to perform caesarean section: dystocia, repeat caesarean birth, breech delivery and foetal distress. The risks and safety of caesarean birth differ from place to place in this world. As the relative safety of the procedure is an important factor contributing to the rise of caesarean birth, the fact that this has only been achieved in some parts of the world should restrict the indications to perform the operation in the best interests of pregnant women.

Liquid crystal thermometer (LCT) readings of skin temperatures were compared with mercury thermometer (MT) rectal temperature readings to assess the reliability of LCTs. Temperatures of 498 children were measured at two points in time. LCT skin temperature readings of children 0 to 52 months were on average 0.50 degrees C and 1.97 degrees C lower than MT rectal temperature readings. A strong correlation between temperature differences and LCT readings indicated that the greatest differences occurred at the lower LCT readings. These conclusions indicate LCT skin readings undermeasure temperature. Some of these differences were due to MTs not measuring temperatures below 35 degrees C. Children under 1 year of age had significantly greater differences than any other age group. Their LCT readings were, on average, 1.65 degrees C lower than their MT readings. Using MTs as a standard, LCTs were 100% sensitive and 92% specific for detecting children with hypothermia. LCTs were 38.5% sensitive and 100% specific for detecting fevers. These results suggest that LCTs leave undetected a large proportion of children who have fevers. However, they are sensitive for identifying children with hypothermia. A knowledge, attitude and practice (KAP) study indicated that local mothers can be identified who understand principles and procedures of LCTs, and accept them for health care of their child.