Factors associated with the severity and complication of patients with malaria hospitalized between 2009 and 2013 in three municipalities of Colombia, case control study

Background

Malaria worldwide annual reported cases range between 250 and 500 million and nearly half a million deaths are reported every year. Colombia has a vast expanse of territory with environmental and social conditions conducive to malaria transmission, which is the reason why it has second place in Latin America for the number of cases of malaria.

Methods

This is a retrospective, paired, case–control study that compares patients with severe malaria and malaria patients without mention of complication. Medical records of patients with confirmed malaria diagnosis were reviewed. The objective of this study was to identify factors associated with complicated malaria in three municipalities of Colombia during the period 2009–2013.

Results

A total sample of 180 medical records was collected, 60 corresponding to cases and 120 to controls following a 1:2 ratio. From the total sample, 88.33 % (159) of subjects were originally from Tumaco, 7.78 %, most of the patients of the study (104) were diagnosed and treated in 2013. Among the laboratory findings, the platelet count was found to have statistically significant differences between cases and controls; this was also true for total bilirubin value and transaminases. The most prevalent severity finding was clinical jaundice, followed by elevated bilirubin (25 %) and elevated transaminases (44.4 %). Thrombocytopenia was found in 11/44 cases (20 %) and only five of 60 patients (8.3 %) presented severe anaemia. The multivariate analysis showed that a platelet count <100,000 and clinical jaundice not associated with organ failure, were the two variables associated with severe malaria in the patients described.

Conclusions

Most of the cases studied, despite meeting criteria of severity, were shown not to be as morbid or severe as in other countries. Clinical jaundice and thrombocytopaenia are associated with severe malaria, and they can be used by general practitioners or primary care physicians to promptly identify patients who may have severe malaria.

A descriptive study of 16 severe Plasmodium vivax cases from three municipalities of Colombia between 2009 and 2013

BACKGROUND

Plasmodium vivax, the most geographically distributed cause of malaria, accounts for more than 70% of cases in the Americas. In Colombia, P. vivax was responsible for 67.3% of cases in the last five years. Despite vivax malaria impact worldwide, historically it has been neglected and considered to be a benign disease. In the last decade medical literature reports have emerged countering this benign outlook. This study pretends to describe the clinical and paraclinical profile of severe vivax malaria cases hospitalized in Tumaco, Cali, Buenaventura between 2009 and 2013, to contribute to the knowledge regarding the behaviour and clinical expression of this disease.

METHODS

This is a descriptive, retrospective case-series study of 16 severe malaria vivax cases, hospitalized between 2009 and 2013, in Colombian municipalities of Tumaco, Buenaventura and Cali. Severe malaria vivax cases were defined using criteria adapted from the national guidelines. Descriptive analyses of reason for consultation, signs and symptoms, diagnosis, treatment, paraclinical characteristics, complications, and time hospitalized, were conducted.

RESULTS

Sixteen cases of severe P. vivax were analysed. Fever, chills and headache were shown to be the main admission symptoms. Elevation of total bilirubin levels in 18.75%, and severe thrombocytopaenia in 25% of cases were the main complications presented during hospitalization. All cases responded to treatment, there were no deaths.

CONCLUSIONS

The following questions derived from this study could be the basis for future research: 1) Does the time to consultation have an impact on the number of days hospitalized and how cases progress during hospitalization, 2) Are the severity criteria in WHO guidelines sensitive enough to be used in clinical practice compared to national guidelines, and 3) How does malnutrition contribute to anaemia in malaria-endemic regions.

Potential contraceptive use of epididymal proteins: immunization of male rats with epididymal protein DE inhibits sperm fusion ability

Rat epididymal protein DE associates with the sperm surface during maturation and participates in sperm-egg fusion. Immunization of male rats with DE raised specific antibodies and produced a significant reduction in the animals' fertility. The present study focused on determining the in vivo mechanism involved in fertility inhibition. Wistar males were injected with DE, and antibody levels and animal fertility were evaluated. Results revealed an association between the two parameters, since animals with absorbance values lower than 0.5 in ELISA presented high fertility rates (66%, 100%) while those with absorbance values higher than 0.5 exhibited the lowest fertility rates (0%, 33%). Histological studies showed no evidence of orchitis, epididymitis, or vasitis in DE-immunized animals. ELISA results revealed the presence of anti-DE antibodies in epididymal and vas deferential fluids. Indirect immunofluorescence and ELISA experiments indicated that these antibodies would not interfere with the synthesis or secretion of DE or with its association with the sperm surface. Finally, while epididymal sperm recovered from DE-immunized animals presented no changes in motility, viability, or ability to undergo capacitation and acrosome reaction, they exhibited a significant decrease in their ability to fuse with zona-free eggs, with no effect on their ability to bind to the oolemma. Together these results indicate that immunization of male rats with epididymal protein DE specifically interferes with the sperm fertilizing ability, supporting the use of epididymal proteins for contraceptive vaccine development.

Analysis of the effect of nitric oxide synthase inhibition on mouse sperm employing a modified staining method for assessment of the acrosome reaction

A commercially available staining kit (Spermac) was combined with swelling in a hypoosmotic medium (HOS) for simultaneous assessment of viability and acrosome reaction in mouse spermatozoa. We compared the results obtained with the combined technique (HOS-Spermac) with those obtained with currently used techniques: the chlortetracycline fluorescence assay and eosin exclusion. The results obtained with HOS-Spermac were the same as those obtained with the chlortetracycline fluorescence assay. Viability assessment with HOS-Spermac showed a good correlation with the percentage of spermatozoa showing eosin dye exclusion. Using this novel technique, we studied the effect of a nitric oxide synthase inhibitor (NG-nitro-L-arginine methyl ester, L-NAME) on the acrosome reaction. L-NAME produced a dose-dependent inhibition of spontaneous acrosome reaction and its inhibitory effect was specifically counteracted by L-arginine. We conclude that HOS-Spermac provides a simple and reliable tool for assessment of the acrosome reaction and that nitric oxide synthase participates in this important function of the spermatozoon.