Trenton K. Ruebush

Effect of blood transfusion on survival among children in a Kenyan hospital

In Africa, blood transfusions are frequently given to treat severe paediatric anaemia. Because of the risk of HIV transmission, identification of when transfusion will reduce the risk of death for severely anaemic children has become increasingly important. For all children admitted to a Kenyan hospital from October, 1989, to October, 1990, we collected data on clinical presentation, haemoglobin (Hb), receipt of transfusion, and in-hospital survival. Of 2433 admissions, 29% (684) had severe anaemia (Hb less than 5.0 g/dl), and 20% (483) received blood transfusions. Based on laboratory criteria only, children with Hb less than 3.9 g/dl who were transfused had lower mortality than those with Hb less than 3.9 g/dl who were not transfused, but this finding applied only to children transfused on the day of admission (odds ratio [OR] 0.30; 95% Cl 0.14, 0.61) or the day after admission (OR 0.37; 95% Cl 0.14, 1.00). Based on a combination of laboratory and clinical criteria, children with clinical signs of respiratory distress and Hb less than 4.7 g/dl who were transfused had lower morality than those who were not (OR 0.19; 95% Cl 0.09, 0.41). Among children without respiratory distress, there was no association between receipt of transfusion and mortality, irrespective of admission Hb. The frequency of blood transfusion can be reduced and survival enhanced by targeting blood to those children with severe anaemia and clinical signs of respiratory distress, and by using transfusion early in the course of hospitalisation.

Human babesiosis on Nantucket Island. Evidence for self-limited and subclinical infections.

Between 1969 and 1975, seven patients infected with Babesia microti, a tick-borne intraerythrocytic protozoan parasite, were reported from Nantucket Island, Massachusetts.1 2 3 Although all seven p...

Human babesiosis on Nantucket Island. Clinical features.

Between 20 July and 15 Octoboer 1975, five cases of human infection with Babesia microti were diagnosed on Nantucket Island, Massachusetts. The illness was characterized by fever, drenching sweats, shaking chills, myalgia, arthralgia, extreme fatigue, and a mild-to-moderate hemolytic anemia. None of the patients had a history of splenetomy. Although all patients responded symptomatically to treatment with oral chloroquine phosphate, parasitemia and fatigue frequently persisted for several weeks to months.

Chloroquine in Africa : critical assessment and recommendations for monitoring and evaluating chloroquine therapy efficacy in sub-Saharan Africa

Chloroquine‐resistant malaria is a major public health threat in sub‐Saharan Africa. While a few countries have already replaced chloroquine as the first‐line therapy for uncomplicated malaria or are in the process of doing so, other countries are faced with the complicated task of assessing the current status of drug resistance, making national policy‐level decisions about whether to replace chloroquine or not, and initiating a monitoring system to track changes in the efficacy of malaria therapy. There is currently no standardized approach for collecting and interpreting data on therapy efficacy. There is also no agreement as to how much chloroquine resistance or treatment failure is acceptable and how much warrants a change in treatment policy. Using data collected in 10 sites in eastern and southern Africa between 1990 and 1996, we have assessed the therapeutic response to chloroquine and investigated predictors of clinical success or failure. Based on these experiences and analyses, a standardized protocol for in vivo studies of the efficacy of malaria therapy and for approaches to designing monitoring systems are proposed. The process of making policy‐level decisions based on data collected by these systems is also discussed.

Maintenance and sustained use of insecticide-treated bednets and curtains three years after a controlled trial in western Kenya*

Summary In large experimental trials throughout Africa, insecticide‐treated bednets and curtains have reduced child mortality in malaria‐endemic communities by 15%–30%. While few questions remain about the efficacy of this intervention, operational issues around how to implement and sustain insecticide‐treated materials (ITM) projects need attention. We revisited the site of a small‐scale ITM intervention trial, 3 years after the project ended, to assess how local attitudes and practices had changed. Qualitative and quantitative methods, including 16 focus group discussions and a household survey (n = 60), were employed to assess use, maintenance, retreatment and perceptions of ITM and the insecticide in former study communities. Families that had been issued bednets were more likely to have kept and maintained them and valued bednets more highly than those who had been issued curtains. While most households retained their original bednets, none had treated them with insecticide since the intervention trial was completed 3 years earlier. Most of those who had been issued bednets repaired them, but none acquired new or replacement nets. In contrast, households that had been issued insecticide‐treated curtains often removed them. Three (15%) of the households issued curtains had purchased one or more bednets since the study ended. In households where bednets had been issued, children 10 years of age and younger were a third as likely to sleep under a net as were adults (relative risk (RR) = 0.32; 95% confidence interval (95%CI) = 0.19, 0.53). Understanding how and why optimal ITM use declined following this small‐scale intervention trial can suggest measures that may improve the sustainability of current and future ITM efforts.

A systematic approach to the development of a rational malaria treatment policy in Zambia

Despite the spread of chloroquine‐resistant Plasmodium falciparum throughout sub‐Saharan Africa, chloroquine (CQ) remains the first‐line treatment for uncomplicated infection in most countries. To assess the efficacy of CQ and sulphadoxine‐pyrimethamine (SP) in Zambia, studies using a standardized 14‐day in vivo test were conducted at 6 geographically representative sites. Febrile children ≤ 5 years of age were treated with standard doses of CQ or SP and monitored for parasitological failure (using modified WHO criteria) and clinical failure (fever with parasitaemia after completion of therapy). RII/RIII (high to moderate level) parasitological failures were identified in 34% to 70% of CQ‐treated children (total N= 300) at the 6 sites and clinical failures in 31% to 48%. SP testing at 2 sites identified RII/RIII failures in 3% and 17% of children and only 1 clinical failure at each site. Because of the high levels of CQ resistance identified in these trials, the Ministry of Health of Zambia convened a national consensus meeting which recommended that Zambias national malaria treatment policy be modified to make SP available at all health facilities for use in persons who fail initial therapy with CQ. In addition, selected sites, staff, and the methodology from these studies were used to implement a sentinel surveillance system for antimalarial drug efficacy. This systematic approach to antimalarial drug efficacy testing could be easily replicated in other countries seeking to reassess their malaria treatment policies.

Anaemia, blood transfusion practices, HIV and mortality among women of reproductive age in western Kenya☆

Severe anaemia among women in sub-Saharan Africa is frequently treated with blood transfusions. The risk of transmission of human immunodeficiency virus (HIV) through blood products has led to a re-evaluation of the indications for transfusions. Prospective surveillance of women admitted to a district hospital in western Kenya was conducted from 1 December 1990 to 31 July 1991, for haemoglobin (Hb) transfusion status, and outcome. Of the 2986 enrolled women (mean Hb 10.4 g/dL, SD +/- 2.6, median age 24.4 years), 6% were severely anaemic (Hb < 6.0 g/dL). Severe anaemia was associated with a higher mortality rate (10.7% vs. 1.4%, odds ratio (OR) = 8.2, 95% confidence interval (CI) 2.6, 34.2) compared with women with Hb > or = 6.0 g/dL. Decreased mortality rates in hospital were observed with increasing Hb values (OR = 0.43, 95% CI 0.19, 0.98), but blood transfusions did not improve survival in hospital (OR = 1.56, 95% CI 0.22, 11.03). The attributable mortality due to HIV infection and severe anaemia was 75% and 31%, respectively. Maternal/child health care services must include prevention strategies for HIV transmission and the prevention, recognition, and treatment of severe anaemia.

Prevalence of malaria parasitemia and accuracy of microscopic diagnosis in Haiti, October 1995

In October 1995 the Ministry of Public Health and Population in Haiti surveyed 42 health facilities for the prevalence and distribution of malaria infection. They examined 1,803 peripheral blood smears from patients with suspected malaria; the overall slide positivity rate was 4.0% (range, 0.0% to 14.3%). The rate was lowest among 1- to 4-year-old children (1.6%) and highest among persons aged 15 and older (5.5%). Clinical and microscopic diagnoses of malaria were unreliable; the overall sensitivity of microscopic diagnosis was 83.6%, specificity was 88.6%, and the predictive value of a positive slide was 22.2%. Microscopic diagnoses need to be improved, and adequate surveillance must be reestablished to identify areas where transmission is most intense. The generally low level of malaria is encouraging and suggests that intensified control efforts targeted to the areas of highest prevalence could further diminish the effect of malaria in Haiti.

Methods for detecting Babesia microti infection in wild rodents.

We compared various methods for detecting Babesia microti infection in white-footed mice (Peromyscus leucopus) captured in enzootic regions of Massachusetts. The most sensitive method tested involved inoculating blood from wild rodents into hamsters. One month postinoculation proved to be the optimal time for microscopically examining blood of inoculated hamsters. With this method, as few as 300 organisms produced patent infection. Prior splenectomy of hamsters did not increase susceptibility to infection. For direct study of captured animals, a Giemsa-stained, thin blood-film prepared from the animals tail was the most convenient method tested. However, this method detected only 61% of infections identified by hamster inoculation.

Village-based diagnosis and treatment of malaria

Village-based volunteer workers have played an important role in malaria diagnosis and treatment in many different settings for more than 35 years. Two of these programs stand out in terms of their size and longevity: the Volunteer Collaborator Network of Latin America and the Village Voluntary Malaria Collaborator Program of Thailand. The success of these programs is based on a tradition of active community participation and sustained commitment and support from the national malaria control programs. As epidemiological conditions and program priorities change, these programs will have to be sufficiently flexible to keep pace. Perhaps the greatest challenge facing these single disease, vertical programs in the future is their integration into the general health services in a manner that will preserve their best features.