Isaiah Onwunaumba
Study on cultural diagnosis of Salmonella typhi has revealed the unreliability of widal agglutination test., which is basically the diagnostic procedure used in many suspected cases of typhoid fever in Nigeria and Sub-Saharan Africa.
According to a Report released today, despite the fact that malaria and typhoid are endemic in Nigeria, the result of this study has indicated that malaria is far more likely to caused fever than typhoid fever. “Cultural diagnosis of Salmonella typhi has revealed the unreliability of widal agglutination test., which is basically the diagnostic procedure used in many suspected cases of typhoid fever in Sokoto and Other parts of Nigeria.”
For an accurate and reliable diagnosis of typhoid fever, the use of Blood cultural method should highly be taken into consideration. This could be followed by stool and bone marrow. It should be noted that bone marrow aspirate is highly difficult to obtain and culture from stool has the tendency of increasing the prevalence rate by 10-15%. This leaves the blood as an alternative and reliable method in the diagnosis of salmonella typhi infection.
“In this research study, of the 300 blood samples,78 of them were positive for widal agglutination test, but the result of cultural isolation indicate that it was only 4 patients that had actually typhoid fever., Others may have malaria, brucellosis and other cross- reacting antigen.
Widal test positivity has been associated with non-typhoidal fevers resulting from anamnestic reactions, subclinical typhoid infection in a typhoid fever endemic area, cross-reacting antibodies produced by non-typhoidal salmonellae, Malaria.
This study have shown that the prevalence of typhoid fever and malaria parasite (P.falciparum) co-infection was 1.33% using culture method and 10.33% using widal agglutination test.
“It is pertinent to state that two malaria diagnostic approaches currently used most often, do not allow a satisfactory diagnosis of malaria. Clinical diagnosis, the most widely used approach, is unreliable because the symptoms of malaria are non-specific. Microscopic diagnosis, the established method for laboratory confirmation of malaria, presents technical and personnel requirements that often cannot be met, particularly in facilities at the periphery of the health care system. In addition, delays in the provision of the microscopy results to the clinician mean that decisions on treatment may be taken without the benefit of the results.”
In view of this significant difference and in order to rule out any case of malaria with mimicking symptoms the practical use of blood culture for the diagnosis of typhoid fever is strongly recommended. This will help improve patient’s management by cutting down cost of treatment and eliminate other risks associated with misuse of antibiotics. In conclusion the prevalence of malaria and typhoid fever co-infection in endemic areas will be greatly reduced if diagnosis of typhoid fever will be based on culture method.
