The research was conducted between 2006 and 2011 in Kyela District, Mbeya Region by scientists from the University of Munich in Germany in collaboration with the National Institute for Medical Research (NIMR) Mbeya Centre.
The findings challenged local health authorities to double their efforts in fighting the elephantiasis disease caused by a filarial parasite called wuchereria bancrofti and spread by mosquitoes.
Speaking to The Guardian yesterday, NIMR director general Dr Mwele Malecela said according to a 2004 survey, the whole country is endemic to the disease but prevalence is higher along the coastline mainly due to plenty of conducive breeding sites for mosquitoes.
According to Dr Malecela, varying levels of endemicity were seen throughout the country with particularly high-level areas being the Kilombero River Valley and the Lake Nyasa shoreline.
“In rural Tanzania, the anopheles mosquito that spreads malaria also spreads lymphatic filariasis (elephantiasis),” she said, naming the other highly-endemic countries in Africa’s top four as Nigeria, Ghana, and the Democratic Republic of Congo.
She however pointed out that in the case of elephantiasis, a person needs several thousand mosquito bites to get the infection, whereas with malaria just one infective mosquito bite can cause the disease.
The manifestations of the disease are scrotal swelling (hydroceles) and swelling of the limbs (elephantiasis), she further explained, stating:
“There is no cure because none of the drugs kill the adult worms. But through mass drug administration, transmission can be interrupted and the disease can be eliminated.”
“People who have hydroceles need a surgical intervention, whereas patients with elephantiasis are counseled by health care workers on how to take care of their affected limbs.”
She said elephantiasis as a disease is targeted for elimination by the year 2020 through preventive chemotherapy, where all people in endemic areas take a drug to interrupt transmission.
According to Dr Malecela, Tanzania is among countries which have made great strides in its efforts to interrupt transmission. She cited an example of one individual achievement in Tandahimba District, Mtwara Region.
The World Health Organisation (WHO) has reported that by the year 2000, some 120 million people were infected by the elephantiasis parasite worldwide.
The mosquito-borne worm can live in the human lymphatic system for years without showing any symptoms, according to the Kyela research findings.
"The long duration of the wuchereria bancrofti parasite - around 10 years - creates an ongoing immune response," which could make people more susceptible to HIV infection, said Dr Inge Kroidl, a tropical medicine specialist at the University of Munich.
In the study, researchers analysed 2,699 people whereby participants were examined annually over a five-year period and blood, urine, stool and sputum samples were collected to test for HIV and wuchereria bancrofti infection.
Interviews determined if sexual activity could have heightened their risk of contracting HIV. The researchers found that people carrying the parasite were twice as likely to have the HIV virus. The impact was highest among adolescents and young adults.