Piet A. Kager

A simple and economical direct agglutination test for serodiagnosis and sero-epidemiological studies of visceral leishmaniasis

A simple and economical direct agglutination test for the detection of visceral leishmaniasis is described. Trypsin-treated, Coomassie Brilliant Blue-stained, formalin-preserved promastigotes were used as antigen in re-usable V-well microtitre plates. In 21 patients with recent kala-azar, titres of 1:51200 or higher were found. Cured kala-azar patients treated 4 to 14 months before testing, showed titres in the range of 1:3,200 to greater than 1:51,200. Healthy and diseased controls had titres below 1:1,600 with the exception of African trypanosomiasis patients who showed titres of 1:200 to 1:12,800, overlapping with the titres of cured kala-azar patients. Where trypanosomiasis is not a consideration, a titre of 1:1,600 could be considered indicative of visceral leishmaniasis, the sensitivity and specificity were then 100%. The test was applied to sera of 280 inhabitants of Baringo District, a known focus of visceral leishmaniasis in Kenya. When treated cases were included, the test showed a sensitivity of 100% and specificity of 99.3%. This test could be used in district hospitals and health centres in endemic areas as an aid in diagnosis of kala-azar and in the field for sero-epidemiological studies.

Kala-azar: a comparative study of parasitological methods and the direct agglutination test in diagnosis

In a comparative study 88 patients were diagnosed as suffering from kala-azar (visceral leishmaniasis) using 3 parasitological methods simultaneously. Splenomegaly was absent in 4 cases. In 84 patients with splenomegaly, splenic aspiration appeared to be the most sensitive method (96.4%), followed by bone marrow aspiration (70.2%) and lymph node aspiration (58.3%). There was no relation between titres in the direct agglutination test and parasite load as determined by the number of parasitological methods which were positive or parasite density in splenic aspirates. Splenic aspiration and bone marrow aspiration were compared as an assessment of cure in kala-azar. In 6 (13%) of 46 patients tested, parasites were found, all by splenic aspiration. Bone marrow showed parasites in one of these. The literature with regard to parasitological investigations before and after treatment is reviewed.

Abnormal blood flow and red blood cell deformability in severe malaria

Obstruction of the microcirculation plays a central role in the pathophysiology of severe malaria. Here, Arjen Dondorp and colleagues describe the various contributors to impaired microcirculatory flow in falciparum malaria: sequestration, rosetting and recent findings regarding impaired red blood cell deformability. The correlation with clinical findings and possible therapeutic consequences are discussed.

Effectiveness of intermittent preventive treatment with sulphadoxine‐pyrimethamine for control of malaria in pregnancy in western Kenya: a hospital‐based study

Objective  To monitor the effectiveness of intermittent preventive treatment (IPT) with sulphadoxine‐pyrimethamine (SP) for the control of malaria in pregnancy at delivery in the Provincial Hospital in Kisumu, Kenya, and to assess the effect of IPT in participants in a cohort study.

Evaluation of a newly developed direct agglutination test (DAT) for serodiagnosis and sero-epidemiological studies of visceral leishmaniasis: comparison with IFAT and ELISA

A newly developed direct agglutination test (DAT) for visceral leishmaniasis, IFAT and ELISA were applied to sera of patients with visceral leishmaniasis, African and American trypanosomiasis, other parasitic infections and healthy controls. The sensitivities of the 3 tests were comparable (96.3% to 100%); excluding patients with African and American trypanosomiasis, the specificities of DAT and IFAT were 100% and ELISA 87.3%. When trypanosomiasis sera were included, the specificities were 72.6%, 94.3% and 79.4% in DAT, IFAT and ELISA respectively. In 273 sera from a leishmaniasis endemic area (Baringo District, Kenya), the sensitivity was 80% in DAT and IFAT and 60% in ELISA, specificities being 99.6% (DAT), 98.5% (IFAT) and 62.5% (ELISA). As the new DAT is economical and easy to perform, it is recommended for sero-epidemiological field work on visceral leishmaniasis.

Incidence and risk factors of probable dengue virus infection among Dutch travellers to Asia

We studied the incidence of dengue virus (DEN) infections in a cohort of Dutch short‐term travellers to endemic areas in Asia during 1991–92. Sera were collected before and after travel. All post‐travel sera were tested for DEN immunoglobulin M (IgM) [IgM capture (MAC)‐enzyme‐linked immunosorbent assay (ELISA)] and IgG (indirect ELISA). Probable DEN infection was defined as IgM seroconversion or a fourfold rise in IgG ratio in the absence of cross‐reaction with antibody to Japanese encephalitis virus (JEV). Infections were considered clinically apparent in case of febrile illness (> 24 H) with headache, myalgia, arthralgia or rash. Probable DEN infection was found in 13 of 447 travellers (incidence rate 30/1000 person‐months, 95% CI 17.4–51.6). One infection was considered secondary; no haemorrhagic fever occurred. The clinical‐to‐subclinical infection rate was 1 : 3.3. The risk of infection showed marked seasonal variation. DEN infections are frequent in travellers to endemic areas in Asia; most remain subclinical.

Antenatal and delivery care in rural western Kenya: the effect of training health care workers to provide "focused antenatal care"

BackgroundMaternal mortality remains high in developing countries and data to monitor indicators of progress in maternal care is needed. We examined the status of maternal care before and after health care worker (HCW) training in WHO recommended Focused Antenatal Care.MethodsAn initial cross-sectional survey was conducted in 2002 in Asembo and Gem in western Kenya among a representative sample of women with a recent birth. HCW training was performed in 2003 in Asembo, and a repeat survey was conducted in 2005 in both areas.ResultsAntenatal clinic (ANC) attendance was similar in both areas (86%) in 2005 and not significantly different from 2002 (90%). There was no difference in place of delivery between the areas or over time. However, in 2005, more women in Asembo were delivered by a skilled assistant compared to Gem (30% vs.23%, P = 0.04), and this proportion increased compared to 2002 (17.6% and 16.1%, respectively). Provision of iron (82.4%), folic acid (72.0%), sulfadoxine-pyrimethamine (61.7%), and anthelminths (12.7%) had increased in Asembo compared to 2002 (2002: 53.3%, 52.8%, 20.3%, and 4.6%, respectively), and was significantly higher than in Gem in 2005 (Gem 2005: 69.7%, 47.8%, 19.8%, and 4.1%, respectively) (P < 0.05 for all). Offering of tests for sexually transmitted diseases and providing information related to maternal health was overall low (<20%) and did not differ by area. In 2005, more women rated the quality of the antenatal service in Asembo as very satisfactory compared to Gem (17% vs. 6.5%, P < 0.05).ConclusionsWe observed improvements in some ANC services in the area where HCWs were trained. However, since our evaluation was carried out 2 years after three-day training, we consider any significant, sustained improvement to be remarkable.

Is molecular biology the best alternative for diagnosis of malaria to microscopy? A comparison between microscopy, antigen detection and molecular tests in rural Kenya and urban Tanzania.

Objective  To assess the agreement of different diagnostic methods for the diagnosis and confirmation of the clinical suspicion of Plasmodium infection in children in Tanzania and Kenya.

Dengue as a cause of acute undifferentiated fever in Vietnam

BackgroundDengue is a common cause of fever in the tropics but its contribution to the total burden of febrile illnesses that is presented to primary health facilities in endemic regions such as Vietnam, is largely unknown. We aimed to report the frequency of dengue as a cause of fever in Binh Thuan Province, to describe the characteristics of dengue patients, and analyze the diagnostic accuracy of the health care workers and the determinants of the diagnostic process.MethodsAll patients presenting with acute undifferentiated fever at twelve community health posts and one clinic at the provincial malaria station, Binh Thuan Province, a dengue endemic province in southern Vietnam, were included. Record forms were used to fill in patient and diseases characteristics, pre-referral treatment, signs and symptoms, provisional diagnosis and prescribed treatment, referral and final outcome. Serum samples were collected at first presentation and after 3 weeks for serologic diagnosis.Results2096 patients were included from April 2001 to March 2002. All 697 patients with paired serum samples were tested for dengue virus IgM and IgG. Acute dengue was found in 33.6% cases and past dengue virus infections were found in 57.1% cases. Acute primary infections were more common among children under 15 years old than among adults (7.7% vs. 3.5%, p value < 0.001). Younger age significantly predicted acute dengue (RR per increasing year of age (95 % CI): 0.986 (0.975–0.997, p value = 0.014). 48.9% of cases with clinical diagnosis of acute dengue were serologically confirmed and 32.5% of cases without clinical diagnosis of acute dengue were positive by serology after all (OR = 1.981, p value 0.025, 95% CI: 1.079 – 3.635). Tourniquet test was not a predictor for dengue diagnosis.ConclusionDengue is responsible for one third of the fevers presented to the public primary health services in Binh Thuan, southern Vietnam. It presents as a highly unspecific illness and is hardly recognized as a clinical entity by primary physicians.

Prevalence and severity of malnutrition and age at menarche; cross-sectional studies in adolescent schoolgirls in western Kenya.

Objective: Nutritional status is an important marker of overall health and linear growth retardation has serious long-term physiological and economic consequences. Approximately 35 and 29% of preschool children in sub-Saharan Africa are stunted and underweight, respectively. There is relatively little information available about the nutritional status in adolescents, the age group with the highest growth velocity after infancy. We conducted a series of cross-sectional surveys to determine the prevalence and main risk groups for malnutrition and to describe the associations between age, sexual maturation and nutritional status in adolescent schoolgirls in western Kenya.Design: Three cross-sectional surveys; one in Mumias, using random sampling in all schools, and two surveys in Asembo, using a multi-stage random sample design.Setting: Public primary schools in two different rural malaria endemic areas in western Kenya with high levels of malnutrition in preschool children.Subjects: In all, 928 randomly selected adolescent schoolgirls aged 12–18 y.Results: Overall prevalence of stunting and thinness was 12.1 and 15.6%, respectively. Of the total, 2% were severely stunted. Menarche and start of puberty were delayed by approximately 1.5–2 y compared to a US reference population. The prevalence of stunting and thinness decreased with age and mean height for age z-scores converged towards the median of the US reference curve. Girls who had not yet started menstruating were more likely to be stunted than the girls of the same age who were post-menarche.Conclusions: Stunting and thinness are common in young adolescent schoolgirls in these poor rural settings in western Kenya, but the prevalence decreases with age, providing observational support that children catch up on incomplete growth attained earlier in life due to a maturational delay of 1.5–2 y allowing prolonged growth.Sponsorship: This study was supported by a grant from The Netherlands Foundation for the Advancement of Tropical Research (WOTRO), the Netherlands.