Understanding the drastic drop in hepatitis B prevalence figures

In a record 13 years, Uganda has brought down the hepatitis B virus from a 10% prevalence to the current 4.3%. This is in sharp contrast with the time it took the country to bring down an equally aggressive virus; HIV to the current 6.7%.  From Uganda AIDS Commission data, HIV/AIDS was at 6.4% in 2004/5 and is currently at a 6.7%.

 It is also worth noting that areas high with hepatitis B tend to have a lower HIV/AIDS prevalence, for two viral conditions that are spread almost the same way.

In 2016, the Health Ministry released the preliminary results of the 2016 Uganda Population HIV Impact Assessment(UPHIA) that indicated that the hepatitis B national prevalence was at 4.3% among adults(15-64years). The study according to the report covered a total of 16,670 women and 12,354 men in the districts in the country.

In terms of regional distribution, the study shows that hepatitis B prevalence was highest in the northern region, a region divided into Mid North (4.6%), followed by North East (4.4%) and West Nile (3.8%). The lower burden areas are South West (0.8%) and East central (2.7%). 

The Uganda HIV/AIDS Sero-behavioral survey 2004-2005 showed that 1 in 10 adults (10%) in Uganda was infected with hepatitis B at the time. Just like the UPHIA study, the Northeast, North Central, and West Nile regions had considerably higher levels of infection than other respondents (24, 21, and 18%, respectively). Residents in Southwest region had the lowest infection rate of 4%, Kampala (5.5%), East Central (5.5%), Central (5.8%) and Eastern (6.7%). This covered a total of 6000 respondents aged 15-59.

The argument raging on is how the interventions that have only been prominent in the last five years been able to suppress the virus to current rates as portrayed by the UPHIA findings, a study that was endorsed by the health ministry in collaboration with ICAP-Columbia University and funded by US. President's Emergency Plan for AIDS Relief (PEPFAR) and technical assistance from the US's Centre for Disease Control and Prevention(CDC).

Dr Sam Biraro, the ICAP's country representative in Uganda and coordinator of UPHIA in defense of their findings explained that, "our research design was evaluated for scientific rigors by different review boards both in Uganda and the US. It was thus passed to be able to estimate reasonably and accurately both the national and regional levels of the different conditions that were under investigation." 

Possibility of suppression

According to the 2014 National Population Census data, children aged between 0-14 years constitute 47.9% of the total population. The ministry of health indicates that since 2002, children have been receiving the hepatitis B vaccine under the regular Uganda National Expanded Programme for Immunisation. This would therefore imply that children below 16 years, who constitute almost a half of the population have been protected in case they went through the recommended immunization schedule.

The other argument fronted is the fact that with over 85% of adults able to fight off the infection because of good immunity, chances are that many have since developed a natural immunity against the virus. 

Dr Biraro also argues that though it took the country almost two decades to bring down the HIV/AIDS infections, the same yardstick may not necessarily apply to the hepatitis B. "Different infections or viruses respond differently to interventions. That too can explain why the numbers have drastically come down," he says.

Dr. Jacinto Amandua, the retired commissioner of clinical services in the health ministry, who spearheaded hepatitis B interventions in the country called it the effect of ‘dilution'. 

"This shows that the interventions we put up in the communities are bearing impact and with almost one million people being added onto our population every year, the virus cannot be as aggressive as it was previously," he argues.

Banson Barugahare, a virologist and immunologist argues that since hepatitis B virus is said to predate HIV/AIDS, chances are that the virus could have undergone mutation processes as a way of adapting to the changing environments. It can therefore not be as high as 10% presently.

 "There is no way the double digit prevalence with some areas like West Nile posting over 18% prevalence can now be at less than 5% What magic have we done in the last 10 years that have suppressed the virus to that extent?" argues one of the hepatitis B advocates who preferred anonymity adding that the disease has since been politicized at the expense of the plight of many Ugandans. 

Dr Patrick Anguzu, the district health officer for Arua in West Nile (one of the regions that had the highest prevalence), though expresses surprise on the drastic decline, he does note that a number of factor could have played into this.  Just like Biraro, he also cites the fact that if almost half of the population is vaccinated, chances are that the virus has indeed been suppressed.

"We however need to look at the dynamics that led to the earlier prevalence and whether the factors then are no longer at play," he says.

He argues that currently, the district would not be able to clearly assess the impact of the interventions that barely started four years ago. This includes understanding how the different interventions such as mass vaccination and health education have interrupted the spread of the virus and impact on behavior.

In Nakapiripirit, Dr John Anguzu, the district health officer says they are currently battling with stigma that has since pushed people away from testing centres. "When we first called out people for mass testing and vaccination, they came in droves. However, overtime, they are withdrawing because of the stigma those found positive have been experiencing," says Dr Anguzu.   

Current interventions 

According to the Director, Clinical and Community Services at the Ministry of Health, Dr. Charles Olaro, explains that after a "successful universal screening and vaccination" in 39 districts in Karamoja, Lango, West Nile and Teso, they have now embarked on another 26 districts in Busoga and Bugisu. The programme will eventually be rolled out nationwide. 

Fact file

• Hepatitis B is a viral infection that attacks the liver and can cause both acute and chronic disease.

• The virus is transmitted through contact with the blood or other body fluids of an infected person and can survive outside the body for atleast 7 days.

• An estimated 290 million people (Men. Women and Children) are living with hepatitis B virus infection (defined as hepatitis B surface antigen positive). 9 out of 10 people living with viral hepatitis are unaware and every 50 seconds one person dies from the complications of this vaccine preventable disease.

• Hepatitis B is an important occupational hazard for health workers.

• However, it can be prevented by currently available safe and effective vaccine.