Non-cluster cases
Case 1. A 28-year old man (S) visited Primary Health Centre (PHC) Sukakarya on 3 January, 2014 with fever, chill, nausea, vomiting, and headache for 2 weeks after he arrived in Sabang from Bireun District, Aceh, which is not known to be endemic for malaria [
7]. He arrived Sabang during the third week of December 2013, where he worked at a construction site in Kuta Timur village, Sabang. Diagnosis from the PHC and the Municipal Health Office (MHO) microscopist was
P. vivax with treatment by 3 days dihydroartemisinin piperaquine (DHP) + 14 days PQ. Follow-up diagnosis for days 3 and 7 were negative with no further follow-up as he returned to his hometown outside Sabang. One week prior to presentation at the PHC, PHC staff and a JML performed migration surveillance at his camp site, but he refused to be screened. Eighteen co-workers were screened but no positive malaria cases were detected. PHC and MHO staff classified S’s case as imported.
Case 2. NB, a 27-year old man, and boat crew member arrived Sabang from Aceh Besar district in northern Sumatra. He had consistently stayed overnight in Aceh Besar, but came back to Sabang when he came down with fever as his family lives in Sabang. He had a history of fever of 7 days when presented to PHC Sukajaya on 27 January, 2014. He was diagnosed with P. vivax and treated for 3 days with DHP + 14 days PQ. Follow-up was conducted on days 3, 7 and 14 with negative blood smear tests for every visit. RACD was performed for 8 neighbours with negative results. This case was likely imported.
Case 3. IY, a 27-year old man and driver with frequent travel between Sabang and the Aceh mainland (there is routine ferry service between the two). On 28 February, 2014, he sought treatment at PHC Sukakarya with symptoms of 7 days of fever, chills, vomiting, headache, nausea, unconsciousness with a Glasgow Coma Score of 12 and blackwater urine. The PHC, MHO Sabang and provincial microscopists all reported his blood smear test positive for Plasmodium malariae. He was treated with DHP + PQ, with DOT conducted by a nurse. Follow-up was done on days 3, 14, 21, and 28 with no parasites found on his blood smear. He had stayed overnight at his workplace campsite at Batee Shok Village in Sabang for 1 month prior to emergence of symptoms. MHO Sabang classified his case as indigenous. PHC staff performed RACD at the workplace campsite, with 27 people screened by microscopy; all were found negative for malaria infection.
Case 4. FP, a 21-year old business man and farmer had a week of fever and was screened by a JML on 3 July 2014 via ACD. According to thick and thin blood smears sent to PHC Sukajaya by JML, the result was P. malariae, which was subsequently confirmed by the district microscopist. The case was treated with DHP + PQ, with treatment observed by the JML. Follow-up screening was complete with results all negative. Although he had travelled outside Sabang to a non-endemic district before diagnosis, CI revealed that he had been febrile before travel and during his travel. He frequently visited his farm at forest fringe. RACD was conducted near his residence on 20 people, with all negative.
Case 5. On 1 July, 2014, PHC Jaboi reported one P. falciparum microscopy-diagnosed case found through ACD. R, a 17-year old student, had 13 days of fever, chill and nausea but had not sought treatment from any health provider until he was interviewed by a JML. Both the MHO and provincial microscopist diagnosed him with P. malariae infection. The case was treated by DHP + PQ, DOT was performed by JML, and blood smear tests on days 7, 14, 21, 28, and 90 were negative. He had no travel history outside Sabang. His house was located within 500 m of the forest and 500 m from a stream. Twenty-one neighbours were screened via RACD, with negative results.
Case 6. A 30-year old farmer, ES, had visited PHC Sukajaya complaining of nausea, a week of fever, and headache. He was diagnosed by PHC Sukajaya with P. vivax on 1 September, 2014; MHO and provincial microscopist concluded that he was infected with P. malariae. He received DHP + PQ with DOT performed by a JML. He recovered, with blood smears negative from days 3 to 90. No travel history outside Sabang was reported, but his house was located near the forest and he frequently visited his farm near the forest. Twenty of his family members and neighbours were screened and no other secondary cases were detected.
Case 18. At 28 December, 2014, RN, a 12-year old female student from Batee Shok village visited PHC Pria Laot with 5 days of fever, which a general practitioner had diagnosed as common cold, thus no malaria test was done. Because of lack of improvement, RN visited the district hospital with headache and haemoglobinuria on 1 January, 2015 where the microscopist diagnosed her as infected with P. falciparum. On the same day, MHO Sabang investigated the case and family, and cross-checked RN’s blood smear. The MHO microscopist decided the case was P. malariae, but suspected that it might be P. knowlesi. The case was treated with DHP + PQ with complete follow-up on day 3, 7, 14, 21, and 28. All follow-up smears were negative. In addition, 30 family members and neighbours were screened with negative results. On 2 January, 2015, the MHO Sabang responded with house spraying within a radius of 1 km from the index case, with LLINs also distributed to RN’s family members. RN’s house was located in the forest fringe, where macaques were observed.
Cluster 1 at Iboih Village
Case 7. TF, a 70-year old man and hostel owner presented with fever at PHC Iboih on 25 October, 2014, but his blood smear was read as negative. On 27 October 2014, still suffering from fever, chills and nausea, TF sought treatment at the district hospital; his blood smear was negative. The patient returned to PHC Iboih on 28 October, 2014, complaining of 7 days of fever, chills, nausea, no appetite, muscle weakness, unconsciousness, and feet oedema. His blood pressure was 90/70 mmHg, pulse rate 90/min, respiration rate 24/min, axilla temperature 37.2 °C. Another thick and thin blood smear was taken and read as positive for P. falciparum. PHC staff sent a case notification to MHO Sabang the same day. The blood smear was cross-checked by 4 certified microscopists at the MHO on 30 October, 2014, but interpretation varied as to whether the parasite was P. vivax, P. malariae, or a mixed infection of P. vivax and P. malariae. Parasite density was 24,368/µl blood. The blood smear was then sent for examination at the Provincial Health Office by the certified microscopist, who interpreted the infection as a mixture of P. falciparum and P. vivax. The patient was treated with DHP for 3 days and PQ at 0.75 mg/body weight for day 1, and 0.25 mg/body weight for days 2–14. Follow-up blood smears were negative for days 3, 7, 14, 21, 28, and 90. In response to the positive diagnosis on 28 October, the PHC Iboih and MHO carried out CI and RACD on 29 and 30 October, 2014. The subject had no travel history to a malaria-endemic area; the case was classified as indigenous. Thirteen residents residing within a radius of 500 m from the TF’s house were screened and found negative. TF lives in a hilly, forested area and Anopheles larvae were found near his house. On 1 November, 2014, MHO Sabang distributed LLINs and sprayed his house and his 7 nearest neighbours’ houses.
Case 8. On 1 November, 2016, AK, a -ear old man and a shop owner visited PHC Iboih complaining of a week of fever and a severe headache. He had sought treatment from a private nurse 1 week previously. AK was screened on 30 October, 2014 during the RACD of TF, but his blood smear was negative. Nonetheless, because of his complaints of severe headache and fever, venous blood was taken and sent to the MHO Sabang. Microscopists there found low density P. vivax with only 3 parasites detected from all fields. The diagnosis was cross-checked by a provincial microscopist who determined that the parasite was P. falciparum. The patient received treatment of 3 days DHP and 14 days PQ as per mixed infection protocol. The patient was hospitalized for 3 days, and follow-up blood smears on days 3, 7, 14, 21, 28, and 90 were all negative. Case investigation was carried out on 3 November, 2014. The investigation determined that the patient owned a tourist shop in the farthest western point of Sabang and frequently spent the night there. AK’s house was located about 500 m from TF, and less than 1 km from the forest. His shop is in the forest and near a road construction site. Because AK split his time between his residence and his work site, the MHO Sabang carried out RACD at both locations. On 3 November, his 5 family members and 7 neighbours were screened and found negative. Work site screening covered only individuals with fever or a history of fever; 49 construction workers were screened, constituting about 80% of those living in the area. This screening yielded 3 microscopy-positive male workers: D, 27-year old; AC, 26-year old, and IR, 18-year old. D and AC were diagnosed on 4 November, 2014, while IR was diagnosed on 5 November, 2014.
Case 9. D reported fever for 5 days, headache and chills. His blood pressure was 100/70 mmHg, and axilla temperature 38 °C. His initial blood smear could not be identified to species by the MHO microscopist; it was sent to the provincial laboratory where a diagnosis of P. vivax was made. The patient was hospitalized for 3 days in PHC Iboih and treated with 3 days’ DHP + 14 days of PQ as AK doses. Follow-up was incomplete as he returned to his home town outside of Sabang on day 4 after initial treatment; however, on day 4 his blood smear was negative.
Case 10. AC reported 5 days of fever, chills, headache, nausea, cough, and gastritis. His blood pressure was 160/70 mmHg, pulse rate 72/min, respiratory rate 28/min and axilla temperature 39 °C. His blood smear was positive for P. vivax, as determined by both the MHO and provincial microscopists. AC was admitted to PHC Iboih on 4 November, 2014 and treated with 3 days’ DHP + PQ for 14 days. DHP consumption was directly observed. Follow-up was done on day 3 upon discharge; his smear was negative but no additional follow-up was done as he returned to his home town outside of Sabang.
Case 11. IR was admitted to PHC Iboih on 5 November, 2014 with a history of 3 days of fever and chills. His blood pressure was 100/70 mmHg, pulse rate 68/min, respiratory rate 18/min and axilla temperature 38 °C. Both the MHO and provincial microscopists diagnosed him as suffering from infection with P. vivax. He was treated for 3 days with DHP + 14 days PQ for mixed infection doses. He was discharged after 1 day but follow-up smears were taken on days 3, 7, 14, and 21. All were negative.
The workers had been in residence at the construction site near the zero (0) kilometre monument (which marks the westernmost point of Indonesia at Fig.
1) for about 1 month prior to detection of the first infection. They slept under a temporary wood shelter with no mosquito net. The environment is forested and both long-tailed and pig-tailed macaques are common.
In response to the cases detected within a week in Iboih village, MHO Sabang expanded RACD to all individuals residing within 500 m of an index case house. In addition, all construction workers were screened. Mass screening and treatment (MST) was conducted at Iboih village aimed to prevent further transmission. However, all 450-people screened were negative. The MHO also distributed LLINs to all villagers and sprayed houses in the village as well as at the construction workers’ camp.
Cases 12 and 13. Concurrent with the MST, a construction worker (H, a 21-year old man, case 12) and a primary school student (MH, a 6-year old boy, case 13) sought treatment at PHC Iboih on 8 November, 2014. H complained of 7 days of fever, chills and nausea. His blood pressure was 120/80 mmHg, pulse rate 72/min, respiratory rate 20/min and axilla temperature 36.5 °C. Both the MHO and provincial microscopist diagnosed the case as P. vivax. He was treated according to mixed infection protocol for 3 days with DHP + 14 days of PQ. Follow-up on days 3, 7, 14, and 21 was negative. MH presented with 7 days of fever. On 8 November, the MHO microscopist diagnosed him as positive with P. vivax. Although he lived near AK, he was not screened during the RACD on 3–4 November because he was outside of Sabang (Bireun), a non-malaria endemic area, to visit his grandfather for 1 week. Other that this visit, he had no travel history except to the primary school near his house. He was treated for 3 days DHP, plus PQ for 14 days, with treatment observed by his mother. His smears were negative on days 3, 7 and 14, when he was lost to follow-up as his family travelled outside of Sabang. On 12 November, 18 people living near MH were screened, all were negative.
Case 14. On 21 November, 2014, SH, a 22-year old man and hostel receptionist, visited PHC Iboih with complaint of 5 days of fever, chills and headache. The PHC microscopist diagnosed the case as P. vivax, while the district microscopist diagnosed the smear as P. malariae. SH has lived in Sabang since 2010, but frequently travels to his home town in non-endemic Bireun District. He was treated with DHP and PQ with negative follow-up on days 3, 7, 14, 21, and 28. RACD was performed for his 12 closest neighbours, all negative.
Cluster 2 at Ie Meulee Village
Case 15. On 27 December, 2014, M, a 16-year old male student from Ie Meulee village visited Sabang Municipal Hospital with a 6-day history of fever and chills. The hospital microscopist diagnosed him with P. falciparum, while the MHO microscopist identified the species as P. malariae. RACD was conducted near M’s house with 18 people screened on 28 December, 2014. Two additional cases were found, both family members: SF (case 16), a 38 year old woman (M’s mother) and RV (case 17), a 12 year old student (M’s sister). Both additional cases were diagnosed as P. malariae with the appearance of parasites in the blood smear similar to M’s smear. Case investigation revealed that SF had history of intermittent fever in the last 10 days, while RV presented with intermittent fever 3 days after M. The 3 cases were treated by 3 days DHP and 14 day PQ. M and SF were hospitalized for 3 days at the Municipal Hospital. All blood smear test results during treatment follow-up on days 3, 7, 14, 21, 28, and 90 were negative. This family’s house is located fewer than 500 m from the forest fringe, and macaques were observed in the yard surrounding the house.
The MHO periodically followed up all cases in Sabang through December 2015. No complications or relapses were detected. Surveillance activities continued, including ACD by JML, migration surveillance, and RACD, with special attention paid to the zero kilometre monument and associated construction campsite. These activities detected three additional microscopy-diagnosed P. malariae cases: in July 2015 at Keunekei Village, in September 2015 at Iboih Village, and in September 2016 in Ie Meulee Village (but likely infected at Iboih Village). RACD following these three cases yielded no additional positive cases.