High Spleen Rate Research Articles

Child malaria treatment practices among mothers in the district of Yanfolila, Sikasso region, Mali.

We studied child malaria treatment practices among mothers living in the District of Yanfolila in southern Mali. For sampling, we first chose five of 13 health areas with probability proportional to size. Then villages, compounds and mothers with at least one child aged 1-5 years were randomly chosen. We assessed the spleen size of one 1-5 year-old child of each mother, collected a thick blood film and recorded the body temperature of every child whose mother thought he/she was sick. 399 mothers in 28 villages were interviewed with a structured questionnaire divided into two parts. If the child had had soumaya (a term previously associated with uncomplicated malaria) during the past rainy season, we asked about signs and symptoms, health-seeking behaviour (who the mother consulted first) and treatment. If not, information about knowledge of the disease and treatment to be given was collected. 86% of the mothers interviewed stated that their child had been sick and almost half of them had had soumaya. All mothers named at least one sign by which they recognized the disease. Vomiting, fever and dark urine/yellow eyes/jaundice were the three most common signs mentioned. 75.8% managed their child's disease at home and used both traditional and modern treatment. The most common anti-malarial drug was chloroquine, often given at inappropriate dosage. The sensitivity and specificity of the mothers' diagnosis was poor, although this might be explained by the large percentage of children who had already been treated at the time of the interview. The results of our survey call for prompt educational action for the correct treatment of uncomplicated malaria/soumaya, particularly for mothers and possibly for shopkeepers. The high spleen rate (58.1%) among randomly selected children confirms that malaria is a common disease in this area. Improved case-management at home could only be beneficial.

Diethylcarbamazine in the control of splenomegaly associated with Bancroftian filariasis in the Ok Tedi area of Papua New Guinea

Bancroftian filariasis is highly endemic in the Ok Tedi region of Papua New Guinea, with a reported mean rate of 39% before the implementation of a single-dose diethylcarbamazine (DEC) treatment programme in 1986. This was followed by a 72% decline in the rate of detectable microfilaraemia and a 40% reduction in pre- and post-treatment splenomegaly. No significant difference was observed when spleen enlargement was compared to the presence of patent malaria. A significant difference in splenomegaly was observed between DEC-treated villagers and their untreated counterparts. Significant differences were reported in the rate of detectable microfilariae of Wuchereria bancrofti, but not of malaria, between the 2 groups. The number of DEC administrations and the period of time since the first treatment played a significant role immunologically. Significant differences were observed in immunoglobulin (Ig) M and IgG levels and in the extent of splenomegaly between DEC-treated and untreated areas. Filarial infection associated with malaria resulted in higher spleen rates and size. W. bancrofti is a major contributor to splenomegaly in the Ok Tedi region, and splenomegaly associated with bancroftian filariasis can be reduced or controlled by low, well-spaced doses of DEC.

The relationship between splenomegaly and antibody to the circumsporozoite protein of Plasmodium falciparum in two groups of women with high and low enlarged spleen rates in Madang, Papua New Guinea

The objective of this study was to determine the prevalence of antibodies recognizing the circumsporozoite (CS) protein of Plasmodium by an enzyme-linked immunosorbent assay, in 2 subpopulations of women with significantly different enlarged spleen rates but similar exposure to malaria, on the north coast of Papua New Guinea. Antibody levels of immunoglobulin G (IgG) antibody to CS protein in the high and low spleen rate groups were similar (56·2% and 55·1%) but there was a significant difference in IgM (29·6% and 16·7%). In neither group did antibodies increase with parity (age). In both groups a high level of either IgG or IgM antibody to CS protein was associated with a high spleen rate and women with hyper-reactive malarious splenomegaly were more likely to be positive for both. Lower parasite rates were associated only with increased IgM antibody titres. High levels of antibody to blood-stage parasites were also present in the high spleen rate group, suggesting that antibodies to the CS protein were not protective. It is considered that cell-mediated immunity may be deficient in women with persistent splenomegaly.

Two populations of women with high and low spleen rates living in the same area of Madang, Papua New Guinea, demonstrate different immune responses to malaria

Specific malaria and total IgM antibody responses were measured in 2 linguistically distinct coastal Papua New Guinean populations living in the same endemic malarious area, but exhibiting different adult female spleen rates (51% and 30%), in order to establish whether the higher spleen rates in the former group were due to hyper-reactive malarious splenomegaly (HMS). Malaria parasite rates were comparable, and geometric mean titres of IgG malaria anitbody were the same, in both groups, indicating comparable exposure to malaria. A higher mean total IgM was observed in the high spleen (HS) rate group (6·07 g/litre, compared with 4·62 g/litre), a higher proportion was seropositive for IgM antibody to Plasmodium falciparum (63% compared with 54%), and HMS was found rather more frequently (4·7% compared with 2·6%). In both groups total IgM concentrations increased significantly with rising parity, and the mean level of 5·27 g/litre in young nulliparous women from the HS group suggested that IgM levels in this group at least were elevated from childhood. In both groups a rise in total IgM was associated with higher P. falciparum IgM geometric mean titres of antibody activity, a fall in parasite rates (HS group: 30% to 15%, P = 0·02; LS group: 24% to 0%, P = 0·034), and higher spleen rates (HS group: 38% to 65%, P = 0·001; LS group: 20% to 67%, P = 0·00012). It is concluded that the difference in spleen rates between the 2 groups was the result of differing degrees of acquired immunity to malaria, probably due to genetic differences in immune responses. This is the first study to distinguish 2 coastal Papua New Guinean populations living under the same conditions of malarial endemicity, but with different immune responses to malaria.

High and low spleen rates distinguish two populations of women living under the same malaria endemic conditions in Madang, Papua New Guinea

In a malariometric survey of 594 non-pregnant women living in 17 villages in Madang Province, Papua New Guinea, village groups were identified with average spleen rates of <35%, 40–49% and ⩾50%, with no difference in parasite rates between groups. Most villages where a non-Austronesian language was spoken had high spleen rates, but the association was not consistent. Some women were not indigenous to the study area and to control for the effects of migration on spleen rates, women were grouped according to their area of origin. This analysis, which cuts across village groups, identified 2 subpopulations, one with a high, and the other with a low spleen rate (relative risk 2·23; P < 0·0001). Persistent splenomegaly was observed more frequently in the high spleen rate population ( P < 0·025) which also showed a significantly increased spleen size ( P < 0·01). The existence of 2 subpopulations living under the same conditions of malaria endemicity, but with different splenic responses to malaria, suggests an altered host immune response to malaria in the high spleen rate group. The absence of intermarriage between these two subpopulations indicates genetic differences distinguish them.

Immunoglobulin levels in the Kaiapit and upper Watut areas of New Guinea: with special reference to the tropical splenomegaly syndrome

Serum concentrations of IgA, IgG and IgM were estimated for 2,000 inhabitants of 2 malarious areas of New Guinea—Kaiapit, where spleen rates are high in children but splenomegaly occurs infrequently in adults and is never gross, and the Upper Watut Valley, where the tropical splenomegaly syndrome is particularly common, and 80% of adults and children have palpable spleens. Kaiapit adults had significantly higher IgM levels than children: IgM levels tended to increase throughout life, were higher in women than in men and in adults with splenomegaly. IgG and IgA levels showed no significant relation to increasing age above 10 years, to sex or to the presence or absence of splenomegaly. The youngest Watut children had higher IgM levels than Kaiapit subjects. IgM concentrations rose more rapidly with age, particularly in the first 20 years of life, so that the mean Watut adult level was more than twice that of Kaiapit adults. In Watut children splenomegaly was associated with significantly higher levels of all 3 immunoglobulin fractions, whereas adults with splenomegaly showed markedly higher levels of IgM, but significantly lower IgA concentrations than did subjects with impalpable spleens. The change in the pattern of immunoglobulin levels in association with splenomegaly occurred between the ages of 6 and 20 years, indicating that the transition from simple malarious splenomegaly to tropical splenomegaly syndrome probably occurs at this age. Subjects living near the valley floor had higher spleen rates than those living in high villages; IgM concentrations were also affected by altitude. The reason for this remains obscure, but it is suggested that both observations may be related to differences in intensity of operation of the factors responsible for the development of the tropical splenomegaly syndrome.

Malaria in the Kirkuk division of Northern Mesopotamia during 1923

The following are the main features which have been noticed during 1923 with regard to malaria in the Kirkuk Division of Northern Mesopotamia in dealing with indigenous natives. Treatment and preventive measures are not touched upon. There were two malaria seasons, the main one in the summer and a lesser one in the late autumn. The summer malaria season lasted roughly from the beginning of June to the middle of August. It was caused by the malignant tertian, and to a less extent by the benign tertian, parasite. The autumn malaria season occurred in late October and November, being most marked in the first half of the latter month. It was due to the malignant tertian parasite. Malaria in 1923 showed certain features which were the outcome of malaria in the preceding summer, when it was prevalent in epidemic form. The chief feature was the marked prevalence and predominance of residual quartan malaria, which existed during the first five months of the year until the starting of the malaria season. It is judged that normally quartan malaria is a comparatively common infection, and that a fuller explanation of the marked quartan predominance referred to is that it was due to residual infections from an epidemic year occurring in an area where quartan is peculiarly common. Quartan malaria was not confined to any one part of the division but was equally prevalent everywhere. Malignant tertian was the main cause of the summer and autumn malaria seasons. Infections started somewhat later than the benign form (roughly fifteen days) and rapidly disappeared with the passing of the malaria season. Crescent infections were comparatively not common. The main clinical manifestation was a quotidian fever of no great severity. Pernicious forms were absent. Benign tertian was the earliest infection to appear in any number with the opening of the malaria season. This parasite seemed to depart markedly from its usual rôle as a cause of relapses, its behaviour as regards disappearance of infection at the end of the malaria season closely resembling that of malignant tertian. There was no evidence that benign tertian was a factor in the autumn malaria season. Quartan malaria. Presumably its season of infectivity coincided with the summer malaria season. This, however, could not be proved, fresh cases being obscured by the mass of already existing quartan malaria. Triple infections were comparatively common, especially in the early months. Double infections not common. Quartan malaria, as met with, has quite sustained its reputation as the cause of an extremely chronic infection. Nomadic Arabs on the whole suffer very little from malaria. Its occurrence can be explained by their habits. During both the summer and autumn malaria season they are in fixed camping grounds, and according to the malarious nature of these grounds so will malaria among them vary. Malaria was most seen in small sections which camped alongside the fringe of villages on the edge of the desert, to the west of Kirkuk and Taza Khurmatu. The Quaraghan — Kifri — Tuz — Tauk — Taza — Kirkuk — Alton Keupri road serves as a rough line of division of malarial endemicity. On the east, or hilly side, malaria is hyperendemic and shows very high spleen rates. The area to the west or desert side shows medium spleen rates, passing to low or nil the further one goes into the desert. Malaria in the Kirkuk Division seems to be associated with— A higher degree of splenic enlargement than that usually recorded. Very high spleen rates among the children and often a comparatively high spleen rate in adults. A surprisingly low parasite rate in children and adults considering the high spleen rate. The theory is advanced that (a) is due to the prevalence of quartan malaria. It is possible that this fact also contributes to (b) and (c). Each malaria season was preceded by a marked increase of mosquito breeding, including Anopheles. A feature of the main malaria season was the fact that it lasted throughout the hottest and dryest month of the year, when the 8 a.m. mean temperature was about 90°F. and the mean relative humidity was below 30 per cent. Humidity, within limits, appeared to be a factor of comparatively little importance in influencing malarial prevalence.