Prevalence of hepatitis b, c and hiv infections in children with sickle cell anaemia at Muhimbili national hospital, Dar es Salaam, Tanzania.

Abstract

Background: Hepatitis B virus (HBV) accounts for a large portion of the disease burden worldwide with 350 million chronic carriers ofthe disease. Africa, with 12% of the world's population, carries approximately 18% of the global burden ofHBV infection, with hepatocellular carcinoma and cirrhosis accounting for 2% of the continent's annual deaths. World Health Organization (WHO) estimates that about 170 million people, 3% of the world's population, are infected with hepatitis C virus (HCV) and are at risk of developing liver cirrhosis and/or liver cancer. Besides HBV, HCV infections, Sub-Saharan Africa is also affected by human immunodeficiency virus (HIV) infection. In 2007 the number of people living with HIV was estimated to be 1.4 million in Tanzania. The majority of children get infected with HIV perinatally. Acute severe anaemia necessitating blood transfusion is very frequent in Tanzania because of malaria and infections. Children with sickle cell anaemia (SCA) are at even a greater risk of frequent blood transfusions and consists mainly the use of packed RBCs. The viruses mentioned above can be transmitted from mother to child (intra- uterine, breast feeding), through horizontal transmission by contaminated blood. Part of the national blood transfusion services is to reduce transmission of infections. Donor blood is screened for Hepatitis B, HIV and syphilis. Data on the magnitude ofHBV, HCV and HIV infections in children with SCA are limited.

Objectives: To determine the prevalence and factors associated with HBV, HCV and HIV among children with SCA aged between 6 months and 10 years in a tertiary referral hospital. Materials and methods: This was a hospital based cross-sectional study that was carried out between November 2008 and March 2009 at Sickle Cell Disease (SCD) clinic at Muhimbili National Hospital in Dar es Salaam, Tanzania. All children with SCA aged between six months and ten years inclusive attending the SCD clinic who met the inclusion criteria during the study period were eligible to be enrolled in the study after getting informed consent. Data was collected using structured questionnaire which included patient history, physical examination and test results for HBV, HCV and HIV infection. The data were analyzed using EPI Info version 6.4 and the SPSS version 15.

Results: During the study period, 540 children with SCA were enrolled into the study. Of 540 children, 308 (57%) were males. Three hundred and seventy eight (70%) children were not vaccinated with hepatitis B vaccine. Seventy three point five percent of those vaccinated had protective anti-HBs levels 2:1 OmIU/mL.

Vll Of540 children, three (0.6%) had HBV infection, two were female, one being below five years of age and two being above. Both had no hepatomegally, splenomegally was present in one and jaundice was also present in one child. Five (0.9%) had HeV infection, 3 were male, 2 female and all were above 5 years of age. Three children had received blood transfusions. Hepatomegally was present in one child. Splenomegally was also present in one child while jaundice was present in 2 children. There were no statistically significant differences between HeV infected and uninfected children in relation to socio-demographic, anthropometric measurements and clinical characteristics. Twenty four (4.4%) children had HIV infections. Of these, 11 were males and 13 were female. Nineteen of24 children were above five years of age. Fourteen children had received blood transfusions. Hepatomegally was present in 4 children, splenomegally in 3 and jaundice in 18. There were no statistically significant differences between HIV infected and uninfected children in relation to socio-demographic, anthropometric measurements. Conclusions: The seroprevalence ofHBV, HeV and HIV were found to be 0.6%, 0.9% and 4.4%, respectively, in children with seA. Seventy percent of children with SeA were not immunized with Hepatitis B vaccine. In spite of having multiple blood transfusions, blood transfusion was not associated with HBV, HeV or HIV infections. Recommendations: It is recommended that screening of donated blood for HBV and HIV should be continued to prevent risk of transmitting these infections via blood transfusions. Screening of He V should be started. There is a need for vaccinating those who were not vaccinated especially those who show no evidence of prior infection. A booster dose should be given to those who did not mount a response to vaccination.